Seat Leon Cupra R 225 boost leak.
Discussion
So, after having some problems with my LCR (cutting out at high revs in low gears and going into limp mode) I'm starting to suspect a boost leak. I've been over everything under the engine bay several times and cannot see anything obvious or hear a hissing while the engine is revved, I've looked at the dump valve, all hoses attached normally etc.
It's going to get the fault codes read on Saturday at a VAG specialist in Newcastle, describing the problems I was having over the phone their first guess was a boost leak, to which they suggested a smoke test to find any leaks in the engine. Apparently boost leaks are the bane of the 1.8T engine, so much so that they bought a smoke tester just for the purpose of fixing the turbo/intake systems on these engines!
Whatever it is, I'm hoping to identify it and eradicate the fault. I don't think the turbo fan is knacked, at least I hope not! It still seems to boost quite hard, just not as hard as it did and it seems to take a little longer to come on boost. Really got me a bit hacked off.
So much for VAG group reliability, has anyone else had trouble from a 1.820vt engine?
It's going to get the fault codes read on Saturday at a VAG specialist in Newcastle, describing the problems I was having over the phone their first guess was a boost leak, to which they suggested a smoke test to find any leaks in the engine. Apparently boost leaks are the bane of the 1.8T engine, so much so that they bought a smoke tester just for the purpose of fixing the turbo/intake systems on these engines!
Whatever it is, I'm hoping to identify it and eradicate the fault. I don't think the turbo fan is knacked, at least I hope not! It still seems to boost quite hard, just not as hard as it did and it seems to take a little longer to come on boost. Really got me a bit hacked off.
So much for VAG group reliability, has anyone else had trouble from a 1.820vt engine?
jjones said:
how bad is the leak? get your hand down the back of the engine (when its cold and turned off) and feel for the pipe coming off the top of the turbo. check that it is rock solidly secured they have a habbit of popping off.
It can't be that bad a leak, it still seems to boost normally, when I began suspecting a leak I thought it was feeling a bit sluggish and was not boosting as hard, but I think perhaps I was imagining that. It only cuts out when on full boost, at high revs (towards 6000rpm). I think it's probably a small split in a hose or a pipe that is not properly connected. I will try getting my hand down the back of the engine and feeling for that pipe.I'm getting the fault codes read tomorrow, could turn out to be something completely unrelated to the turbo system!
After getting the fault code read, the problem appears to have been illuminated. The problem was with the air intake temp sensor, was recording the air entering the engine as being very hot, which is probably what caused the limp mode activation.
After reading the fault codes they gave it a good rev to see if the turbo was boosting normally, which it was. Dear god it was loud, that Milltek exhaust sounds like the god of thunder
The sensor and the wires too it were looking a bit ratty, so it's getting replaced next weekend. One of the mechanics took my car out for a spin to see if he could reproduce the fault, and even though he was some distance away I could hear my car roaring through the gears, it's certainly louder than it seems when I'm driving it! When he got back he said that it had not cut out and seemed to be driving fine, and he was quite impressed with the performance too.
I did point out that the car has so far only cut out on hot afternoons, which is probably what was overloading the somewhat tired looking sensor. Hopefully after the work next weekend my Cupra R will be bulletproof again.
After reading the fault codes they gave it a good rev to see if the turbo was boosting normally, which it was. Dear god it was loud, that Milltek exhaust sounds like the god of thunder
The sensor and the wires too it were looking a bit ratty, so it's getting replaced next weekend. One of the mechanics took my car out for a spin to see if he could reproduce the fault, and even though he was some distance away I could hear my car roaring through the gears, it's certainly louder than it seems when I'm driving it! When he got back he said that it had not cut out and seemed to be driving fine, and he was quite impressed with the performance too.
I did point out that the car has so far only cut out on hot afternoons, which is probably what was overloading the somewhat tired looking sensor. Hopefully after the work next weekend my Cupra R will be bulletproof again.
Another infuriating update;
I took my car to a well known independent VAG specialist garage in Newcastle, who read the fault codes and it appeared to say the "Torque sensor" or something had caused the fault code. They had only seen this once before and could not remember what had caused it on the other car.
After some further investigation (revving the car hard while stationary) it seemed the turbo system was working normally, airflow into the engine was in the expected range and coolant and oil temps were normal. They did note that the air intake temp was high, and upon looking at the sensor decided that it was probably broken - it did look a bit ratty. As the car had previously gone into limp mode on hot afternoons, it was surmised that the hot afternoon air was overloading the knackered sensor.
Anyway, I had been driving like an old man for a week to prevent tripping the fault again, but last night I decided to give it a bit of leather, thinking that in the cool air at night it would be ok. The car seemed to do ok, pulling hard in 3rd and 4th gear up towards the red line, but it did not trip the fault this time.
I took the car back to the garage this morning to get the sensor fitted, they noted that no new fault codes had been recorded for the week and then I drove off, only to to find the damn fault reoccur immediately as soon as I put my foot down in third gear, once again leaving the car in limp mode as soon as I got to about 62mph. I phoned the garage immediately, who said I would have to leave the car with them so they could have a proper look at it. Unfortunately I cannot leave the car with them again until next Saturday, so that's another week of farting with a car that is still not right.
So, what could this torque sensor valve all about then? The car has a remap though I'm not sure which one, when the boost comes on it comes on very hard - could this be overloading the engine and causing it to go into limp mode to avoid damage? Has anyone ever heard of anything like this happening before? Looking back it does seem a little odd that a torque sensor fault could be related to an air temp sensor, but I'm not a mechanic so I trusted that these guy would know how to fix it.
Would it be a possibility that flashing the ECU with the original SEAT map for the car could prevent this kind of s
t happening again? I'd be happy to trade a bit of power for reliability and useability!
I took my car to a well known independent VAG specialist garage in Newcastle, who read the fault codes and it appeared to say the "Torque sensor" or something had caused the fault code. They had only seen this once before and could not remember what had caused it on the other car.
After some further investigation (revving the car hard while stationary) it seemed the turbo system was working normally, airflow into the engine was in the expected range and coolant and oil temps were normal. They did note that the air intake temp was high, and upon looking at the sensor decided that it was probably broken - it did look a bit ratty. As the car had previously gone into limp mode on hot afternoons, it was surmised that the hot afternoon air was overloading the knackered sensor.
Anyway, I had been driving like an old man for a week to prevent tripping the fault again, but last night I decided to give it a bit of leather, thinking that in the cool air at night it would be ok. The car seemed to do ok, pulling hard in 3rd and 4th gear up towards the red line, but it did not trip the fault this time.
I took the car back to the garage this morning to get the sensor fitted, they noted that no new fault codes had been recorded for the week and then I drove off, only to to find the damn fault reoccur immediately as soon as I put my foot down in third gear, once again leaving the car in limp mode as soon as I got to about 62mph. I phoned the garage immediately, who said I would have to leave the car with them so they could have a proper look at it. Unfortunately I cannot leave the car with them again until next Saturday, so that's another week of farting with a car that is still not right.
So, what could this torque sensor valve all about then? The car has a remap though I'm not sure which one, when the boost comes on it comes on very hard - could this be overloading the engine and causing it to go into limp mode to avoid damage? Has anyone ever heard of anything like this happening before? Looking back it does seem a little odd that a torque sensor fault could be related to an air temp sensor, but I'm not a mechanic so I trusted that these guy would know how to fix it.
Would it be a possibility that flashing the ECU with the original SEAT map for the car could prevent this kind of s
t happening again? I'd be happy to trade a bit of power for reliability and useability!The plot thickens...
When I dropped the car off this morning, the mechanic who was to work on it was on the phone trying to get the sensor delivered to the garage. He said it was nearby and that it would be brought over so it could be fitted. I thought nothing more of it, handed over my keys and jumped into my waiting taxi.
I picked it up about 1pm time and it didn't even pass the test of some hard revs in third gear before dying at 60mph.
After taking it for another (slow) drive, I decided to lift the bonnet up and have a look at the shiney new air intake sensor, and what did I find...
the exact same sensor as the car had on when I dropped it off this morning!
Here are some photos I just took about 20 minutes ago;
Here is the engine bay, the MAF is in the top red circle (though it was not suspected to be faulty) and the air intake temperature sensor is in the bottom red circle.
And here it a pic of the sensor where the air intake feeds into the block;
Let's take a closer look at that sensor...
The wires are hanging out (which the mechanic commented on last week), and it's filthy and tatty looking. Actually, it looks as though it's done 85,000 miles - just like the rest of the engine! Pretty damn dirty for a sensor that should only have come out of the box 4 hours ago. Has anyone else ever seen a new part aquire 85,000 miles of road dirt in 4 hours and 20 miles of driving? I certainly have not!
I was assured the new part was fitted and the car was functioning well on a diagnostic before it was handed back to me, and I paid my £70. Now, looking at it, part of, a very large part actually, suspects that the sensor never arrived, was never fitted and then I was billed and sent on my way in the hope that the fault would not reoccur and I would never notice.
Where to go from here?
When I dropped the car off this morning, the mechanic who was to work on it was on the phone trying to get the sensor delivered to the garage. He said it was nearby and that it would be brought over so it could be fitted. I thought nothing more of it, handed over my keys and jumped into my waiting taxi.
I picked it up about 1pm time and it didn't even pass the test of some hard revs in third gear before dying at 60mph.
After taking it for another (slow) drive, I decided to lift the bonnet up and have a look at the shiney new air intake sensor, and what did I find...
the exact same sensor as the car had on when I dropped it off this morning!
Here are some photos I just took about 20 minutes ago;
Here is the engine bay, the MAF is in the top red circle (though it was not suspected to be faulty) and the air intake temperature sensor is in the bottom red circle.
And here it a pic of the sensor where the air intake feeds into the block;
Let's take a closer look at that sensor...
The wires are hanging out (which the mechanic commented on last week), and it's filthy and tatty looking. Actually, it looks as though it's done 85,000 miles - just like the rest of the engine! Pretty damn dirty for a sensor that should only have come out of the box 4 hours ago. Has anyone else ever seen a new part aquire 85,000 miles of road dirt in 4 hours and 20 miles of driving? I certainly have not!
I was assured the new part was fitted and the car was functioning well on a diagnostic before it was handed back to me, and I paid my £70. Now, looking at it, part of, a very large part actually, suspects that the sensor never arrived, was never fitted and then I was billed and sent on my way in the hope that the fault would not reoccur and I would never notice.
Where to go from here?
Even the plastic plate part that sits on the metal intake body looks dirty though, and the big thumbprint on the connector housing is mine. I'm going to get some more opinions tonight on whether or not that sensor is brand new or 7 years old.
Some of the suggestions I've had from seatcupra.net as to why this fault is occuring include;
Collapsing turbo intake pipe starving air to the engine and engaging limp mode (would create a fault code in "intake manifold pressure" or something, not detected when read
Crap air filter failing to supply air to the engine
Possible faulty MAF (though no fault code for this was detected when read)
Possible dodgy map
tbh, the air filter is st, I had been thinking of changing that since I got the car, and the standard TIP is meant to be prone to leaks and collapsing, hence why a lot of owners upgrade to better ones.
Some of the suggestions I've had from seatcupra.net as to why this fault is occuring include;
Collapsing turbo intake pipe starving air to the engine and engaging limp mode (would create a fault code in "intake manifold pressure" or something, not detected when read
Crap air filter failing to supply air to the engine
Possible faulty MAF (though no fault code for this was detected when read)
Possible dodgy map
tbh, the air filter is s
t, I had been thinking of changing that since I got the car, and the standard TIP is meant to be prone to leaks and collapsing, hence why a lot of owners upgrade to better ones. Took it back to the garage today and had them show me the part they changed, so all is good, even though it did not solve the problem. It's going in again soon for a smoke test and a good days investigation to try and get to the bottom of the problem.
This afternoon I had the fault code read again after the fault had reoccured, same code, same mystery. There are a few things that need doing for the general health of the car, a new air filter and cold air feed to go on as the one on now is knackered and on the verge of disintegrating. I'm probably going to get a Jetex kit on there. A stronger spring might be needed in the dump valve as the weaker springs can blow open on full boost, venting the turbo intake and causing the engine to st a brick as it fuels at a high rate and the air flow suddenly disappears, they are only £18 so I might have a go and see if that helps at all.
The option is there to have the ECU reflashed with the default Seat map for the car, removing a potentially dodgy remap. I think I will probably put this on my "to do" list, as they will do it for about £40, and it will make life easier on the engine in the long run.
I looked at the TIP today and I'm pretty sure it's a Forge one that is already on there - it had a smudged white logo that I'm sure identified it as a Forge pipe, if so then thats good news.
Total ball ache but I hope to get to the bottom of it.
This afternoon I had the fault code read again after the fault had reoccured, same code, same mystery. There are a few things that need doing for the general health of the car, a new air filter and cold air feed to go on as the one on now is knackered and on the verge of disintegrating. I'm probably going to get a Jetex kit on there. A stronger spring might be needed in the dump valve as the weaker springs can blow open on full boost, venting the turbo intake and causing the engine to s
t a brick as it fuels at a high rate and the air flow suddenly disappears, they are only £18 so I might have a go and see if that helps at all.The option is there to have the ECU reflashed with the default Seat map for the car, removing a potentially dodgy remap. I think I will probably put this on my "to do" list, as they will do it for about £40, and it will make life easier on the engine in the long run.
I looked at the TIP today and I'm pretty sure it's a Forge one that is already on there - it had a smudged white logo that I'm sure identified it as a Forge pipe, if so then thats good news.
Total ball ache but I hope to get to the bottom of it.
My faith has been restored in the garage, had them unhook the sensor clip and show me the new bit underneath - to be fair, underneath that tired looking exterior there was a shiny brass ring of the new sensor.
I've ordered a Jetex red angled cone filter, rated for 250bhp, to replace the Green Cotton filter that is crumbling away.
While I suspect my engine may be generating somewhat more than 250bhp on full boost, with this fault it has been unable to drive on full boost anyway. I'll be fitting that filter at the weekend, then some time next week I'll be leaving my car at the garage again for a smoke test to root out any possible leaks in the turbo system and then a reflash of the ECU to restore the standard Seat map for the car. I know I will be sacrificing some power but 225bhp is enough for me, and it will reduce strain on the turbo and other systems too.
I decided not to go with the cold air feed kit from Jetex, it was about £95! There is a cold air feed in there already but it won't be connected up to the new filter, I think I will just pull the pipework out - it looks pretty ratty now anyway. If I'm running a standard map and not going for power I don't think I will get a great benefit from it anyway; I know heatsoak might be more of an issue on hot days when travelling at lower speeds but I think I should get on ok with just the cone filter.
Hopefully this new filter and a reflash should get the car back to regular health, and after the smoke test and any subsequent leaks that might appear have been fixed up, it should be awesome again.
I've ordered a Jetex red angled cone filter, rated for 250bhp, to replace the Green Cotton filter that is crumbling away.
While I suspect my engine may be generating somewhat more than 250bhp on full boost, with this fault it has been unable to drive on full boost anyway. I'll be fitting that filter at the weekend, then some time next week I'll be leaving my car at the garage again for a smoke test to root out any possible leaks in the turbo system and then a reflash of the ECU to restore the standard Seat map for the car. I know I will be sacrificing some power but 225bhp is enough for me, and it will reduce strain on the turbo and other systems too.
I decided not to go with the cold air feed kit from Jetex, it was about £95! There is a cold air feed in there already but it won't be connected up to the new filter, I think I will just pull the pipework out - it looks pretty ratty now anyway. If I'm running a standard map and not going for power I don't think I will get a great benefit from it anyway; I know heatsoak might be more of an issue on hot days when travelling at lower speeds but I think I should get on ok with just the cone filter.
Hopefully this new filter and a reflash should get the car back to regular health, and after the smoke test and any subsequent leaks that might appear have been fixed up, it should be awesome again.
rb5230 said:
Surely you want to be sure of what the problem is before sacrificing the remap and losing around 40horses.
I would have thought if the remap was the problem it would have been like that ever since it was done and therefore the previous owner would have taken it up with them?
I don't know what the map is, it doesn't feel like a Revo map, it's not smooth at all, it's very "1980s turbo", nothing......WHOOOSH! I would have thought if the remap was the problem it would have been like that ever since it was done and therefore the previous owner would have taken it up with them?
I will get them to do the smoke test before flashing it - if there is a boost leak and they can fix it then it might sort the car again, but they did note that even though the coolant and oil temps were in spec on the diagnostic, the engine bay of the car felt very hot and I had not even driven hard on the way there. A symptom perhaps of a poor map where boost limit and fuelling have been upped rather crudely to achieve big power?
I'd be quite happy to sacrifice a bit of power if it also meant that it could prolong the life of the turbo too - at full boost acceleration is quite savage!. At least I'd be back to a clean sheet, and if I ever wanted more power I could just get a Revo map on there.
As for the cold air feed, I might try and make it fit but tbh it looks shabby as and will probably fall to pieces when the current (s
te) air filter is removed. There is a circular heat shield around the intake pipe that sits just around the neck of the current air filter, I will try and leave that in place if possible.A new cold air feed kit from Jetex is £130 or so quid, I may put one on at some point in the future but I don't think performance will be dire without it in the meant time.
At the end of the day I'm just sick of the damn thing being broken, I would happily have a slightly more standard car, with less power if it meant I could use the power with less worrying!
Edited by Mastodon2 on Thursday 9th June 18:24
As an interesting note, I decided again tonight to test if the cut-to-limp-mode fault was 100% reproducible, it is not. Took it up to 6000rpm (above where the fault normally occurs) in 3rd and 4th gear (on a private track) and not even a stutter. Pulled like a freight train right up towards the red line. Air temp outside was 7.5 degrees, when I tried last week it was something like 13 degrees, neither time did it cut out.
So why does it only seem to happen in daylight hours? Now I am wondering what the other variables I have not considered may be - the last time it went into limp mode was about 5000rpm in third gear, outside air temp about 12.5 degrees. Perhaps the MAF has an intermittent fault - trouble dealing with the increased volume that warm air has over cold air maybe. Whatever it is, this one has stumped even the best VAG mechanics so far. The best they could suggest was a list of parts to replace, a smoke test and a reflash back to the standard map. I think I will get the reflash, if only to preserve the life of the turbo and other internals, but I'm damn near certain there are no boost leaks, the thing just feels so damn strong, and on a good day it feels so healthy. Perfect smooth idle, pulls incredibly hard on full boost etc. Drives like tonight's make me remember why I fell in love with this car in the first place!
The new air filter is going on tomorrow, so I will see if that makes a difference. I am slightly concerned about how small it looks compared to the one that is on there, I will report back with my preliminary findings after giving it a bit of a drive.
So why does it only seem to happen in daylight hours? Now I am wondering what the other variables I have not considered may be - the last time it went into limp mode was about 5000rpm in third gear, outside air temp about 12.5 degrees. Perhaps the MAF has an intermittent fault - trouble dealing with the increased volume that warm air has over cold air maybe. Whatever it is, this one has stumped even the best VAG mechanics so far. The best they could suggest was a list of parts to replace, a smoke test and a reflash back to the standard map. I think I will get the reflash, if only to preserve the life of the turbo and other internals, but I'm damn near certain there are no boost leaks, the thing just feels so damn strong, and on a good day it feels so healthy. Perfect smooth idle, pulls incredibly hard on full boost etc. Drives like tonight's make me remember why I fell in love with this car in the first place!
The new air filter is going on tomorrow, so I will see if that makes a difference. I am slightly concerned about how small it looks compared to the one that is on there, I will report back with my preliminary findings after giving it a bit of a drive.
Fitted the new Jetex red filter this morning, slipped on easily enough. Had to A-team a mount to hold it up though, a one of those screw-tightened rings you use to hold them onto the air intake mount, fitted around the thin end of the cone, linked to a cable tie through the old mount for the airbox. Not exactly pretty but it supports the weight of the air filter.
The old cold air feed pipe is in, but I did not attempt to connect it to the air filter, it's full of crap which I don't really want blowing straight onto the filter. It's position about 2" away from the end of the cone, so there will still be cold air coming up and into the cone to a degree.
Even though the new filter is only rated for 250bhp it seemed fine at sustained full boost in third gear, in all honesty it was probably flowing a lot better than that old st one that was on there anyway. It has a more hollow growl at idle now (from the front end, the Miltek is as bassy as ever) but the induction noise is just as good when driving.
Curiously, the car ran fine even when driven hard, I averaged about 24mpg although it was a short journey, just enough time to heat the coolant and oil, put it through it's paces and then cool it before returning home. Hopefully this new air filter will have solved the fault.
The filter that came off is now in the bin, I should have taken a photo of it really. It was a dark green cone filter with a circular metal collar around it's neck, almost like a small heat shield, and a bladed plastic vortex generator thing on the tip of it's cone (I thought it had an inverse cone like the one I just got, but apparently not), and it was bloody rotten - the outside was crumbling into dust!
I am still undecided on the remap, but after this mornings drive I don't think there are any leaks in the turbo system. It's a bloody funny fault this one. It was suggested that crap from the air filter could be getting sucked over the wire element in the MAF at high boost causing it to trip to limp mode, and after fitting the new air filter this morning it certainly felt strong and healthy.
I don't think ignition or coilpacks are faulty, it starts up first time, everytime, idles perfectly and does not misfire or grumble in any fashion at lower revs, the fault was only occuring in almost identical conditions, high up the rev range, almost like crossing an imaginary line that made it go into limp mode. And now, it seems the fault has disappeared, at least for the time being!
I think I have a standard TIP, but I know I have a Forge 007P dump valve, which is supposed to be one of the best you can get.
The old cold air feed pipe is in, but I did not attempt to connect it to the air filter, it's full of crap which I don't really want blowing straight onto the filter. It's position about 2" away from the end of the cone, so there will still be cold air coming up and into the cone to a degree.
Even though the new filter is only rated for 250bhp it seemed fine at sustained full boost in third gear, in all honesty it was probably flowing a lot better than that old s
t one that was on there anyway. It has a more hollow growl at idle now (from the front end, the Miltek is as bassy as ever) but the induction noise is just as good when driving.Curiously, the car ran fine even when driven hard, I averaged about 24mpg although it was a short journey, just enough time to heat the coolant and oil, put it through it's paces and then cool it before returning home. Hopefully this new air filter will have solved the fault.
The filter that came off is now in the bin, I should have taken a photo of it really. It was a dark green cone filter with a circular metal collar around it's neck, almost like a small heat shield, and a bladed plastic vortex generator thing on the tip of it's cone (I thought it had an inverse cone like the one I just got, but apparently not), and it was bloody rotten - the outside was crumbling into dust!
I am still undecided on the remap, but after this mornings drive I don't think there are any leaks in the turbo system. It's a bloody funny fault this one. It was suggested that crap from the air filter could be getting sucked over the wire element in the MAF at high boost causing it to trip to limp mode, and after fitting the new air filter this morning it certainly felt strong and healthy.
I don't think ignition or coilpacks are faulty, it starts up first time, everytime, idles perfectly and does not misfire or grumble in any fashion at lower revs, the fault was only occuring in almost identical conditions, high up the rev range, almost like crossing an imaginary line that made it go into limp mode. And now, it seems the fault has disappeared, at least for the time being!
I think I have a standard TIP, but I know I have a Forge 007P dump valve, which is supposed to be one of the best you can get.
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