1.9 TDi sluggish
Discussion
Hi I'm hoping someone on here can give me some pointers for a problem I'm having with my '03 Seat Toledo 1.9TDi.
Bit of background first - before Christmas when we had all that lovely white stuff, car got stuck one day and the diesel engine management light started flashing after a few minutes of engine revving. This seemed to clear itself the next day after driving for a few miles. Had my local VW independent check it out but they couldn't find any fault.
Since then I seem to have had an intermittent problem where the car accelerates fine to about 2k revs, then becomes very unresponsive and takes a long time to accelerate any more. It happened again today, accelerating to join the motorway, up to 60 mph fine (this is apporx 2k on the rev counter in 5th) then it just doesn't seem to want to accelerate any more and took some time to get it up to 70 mph.
Today is only the 3rd or 4th time it's happened since that day I got stuck in the snow, and in the previous 2 years I've owned the car it's never happened. Does anyone have any ideas what may be wrong, what may be worth checking?
Thanks all.
Bit of background first - before Christmas when we had all that lovely white stuff, car got stuck one day and the diesel engine management light started flashing after a few minutes of engine revving. This seemed to clear itself the next day after driving for a few miles. Had my local VW independent check it out but they couldn't find any fault.
Since then I seem to have had an intermittent problem where the car accelerates fine to about 2k revs, then becomes very unresponsive and takes a long time to accelerate any more. It happened again today, accelerating to join the motorway, up to 60 mph fine (this is apporx 2k on the rev counter in 5th) then it just doesn't seem to want to accelerate any more and took some time to get it up to 70 mph.
Today is only the 3rd or 4th time it's happened since that day I got stuck in the snow, and in the previous 2 years I've owned the car it's never happened. Does anyone have any ideas what may be wrong, what may be worth checking?
Thanks all.
I would get it read for fault codes first and foremost but it does sound awfully like the ECU has gone into limp home mode. ie its will not let the car rev to protect itself from (or what it thinks is) damage.
Loats of possible candidates, MAF is the usual suspect but sounds like the turbo isnt spooling at all? cam speed sensor, or boost problems. Tame Tech is the man to answer this methinks.
Loats of possible candidates, MAF is the usual suspect but sounds like the turbo isnt spooling at all? cam speed sensor, or boost problems. Tame Tech is the man to answer this methinks.
Edited by istoo on Tuesday 9th February 10:34
If its not login any faults codes, (presumably it isnt if the indy couldnt find anything) Then the likely candidates are MAF or Boost pressure sensors. As when they play up 90% of the time they dont log a code.
To diagnose properly, need to road test and monitor various MVB's while the fault is occuring, have a look at what the ECU is seeing by way of Air Mas and Boost pressure.
To diagnose properly, need to road test and monitor various MVB's while the fault is occuring, have a look at what the ECU is seeing by way of Air Mas and Boost pressure.
Thanks for the replies.
When I took the car in last time, I mentioned about the diesel engine management warning light flashing even though it seemed to have cleared itself the next day, and the independant couldn't find any fault codes at that time.
Car was fine this morning, but on the way home last night it was ok until a couple of miles from home when I accelerated uphill onto a dual carriageway, it seemed to 'jerk' once, just as I got to 70mph, and then same problem of not wanting to go over 2k revs.
Reading another forum, someone else with similar sounding problem had to replace one of the hoses that feeds into the engine. But I'm not convinced one of my hoses may be leaking as I would have expected the problem to be every time I drove and not intermittent.
Anyway I'm off for a couple of days next week, so will try to get it into the indy again for a proper check.
When I took the car in last time, I mentioned about the diesel engine management warning light flashing even though it seemed to have cleared itself the next day, and the independant couldn't find any fault codes at that time.
Car was fine this morning, but on the way home last night it was ok until a couple of miles from home when I accelerated uphill onto a dual carriageway, it seemed to 'jerk' once, just as I got to 70mph, and then same problem of not wanting to go over 2k revs.
Reading another forum, someone else with similar sounding problem had to replace one of the hoses that feeds into the engine. But I'm not convinced one of my hoses may be leaking as I would have expected the problem to be every time I drove and not intermittent.
Anyway I'm off for a couple of days next week, so will try to get it into the indy again for a proper check.
If its overboosting, it will log a code.
I had Ruled it out as indy didnt come up with any faults.
Maybe the indy couldnt check the fault memory.
Next time it wont go over 2000rpm, pull over turn ignition off then on again, then see if its better. From your description it didnt sound like limp home, but maybe it is. This will show us.
If you suspect overboosting the way to test is pull from very low rpm, say 1200 in 3rd gear, then hold it on full throtle until say 4500rpm. If posible do this a few times. If its boost related will go into limp home before the 3rd attemp.
If it goes into limp home, you need to find a more gifted indy. Find our weather its overboosting (turbo)or underboosting (N75 or vac fault) or a mis reading sensor (usually boost pressure sensor)
I had Ruled it out as indy didnt come up with any faults.
Maybe the indy couldnt check the fault memory.
Next time it wont go over 2000rpm, pull over turn ignition off then on again, then see if its better. From your description it didnt sound like limp home, but maybe it is. This will show us.
If you suspect overboosting the way to test is pull from very low rpm, say 1200 in 3rd gear, then hold it on full throtle until say 4500rpm. If posible do this a few times. If its boost related will go into limp home before the 3rd attemp.
If it goes into limp home, you need to find a more gifted indy. Find our weather its overboosting (turbo)or underboosting (N75 or vac fault) or a mis reading sensor (usually boost pressure sensor)
Tame Technician said:
If its overboosting, it will log a code.
I had Ruled it out as indy didnt come up with any faults.
Maybe the indy couldnt check the fault memory.
Next time it wont go over 2000rpm, pull over turn ignition off then on again, then see if its better. From your description it didnt sound like limp home, but maybe it is. This will show us.
If you suspect overboosting the way to test is pull from very low rpm, say 1200 in 3rd gear, then hold it on full throtle until say 4500rpm. If posible do this a few times. If its boost related will go into limp home before the 3rd attemp.
If it goes into limp home, you need to find a more gifted indy. Find our weather its overboosting (turbo)or underboosting (N75 or vac fault) or a mis reading sensor (usually boost pressure sensor)
TT, I did this today actually, I'd noticed it's happening when I was in third and accelerating to about 3,500 rpm then changing to 4th it becomes sluggish. I then stopped at the shops and after re-starting the car it was fine.I had Ruled it out as indy didnt come up with any faults.
Maybe the indy couldnt check the fault memory.
Next time it wont go over 2000rpm, pull over turn ignition off then on again, then see if its better. From your description it didnt sound like limp home, but maybe it is. This will show us.
If you suspect overboosting the way to test is pull from very low rpm, say 1200 in 3rd gear, then hold it on full throtle until say 4500rpm. If posible do this a few times. If its boost related will go into limp home before the 3rd attemp.
If it goes into limp home, you need to find a more gifted indy. Find our weather its overboosting (turbo)or underboosting (N75 or vac fault) or a mis reading sensor (usually boost pressure sensor)
Normally I don't accelerate very 'hard' and usually change up about 2,000 - 2,500, but occasionally I do need to accelerate more and go up to around 3,000 - this is when it's happening!
Will get it back to the indy for another check - They're setup for VW, Audi, Seat and Skoda and been going for years, I've never had problems with them before so will explain what's happening so they have all the info!
Thanks again.
Sounds like text book overboosting. Sorry but 99%, needs a turbo.
What happens is......................
When you use lots of throtle at low rpm, the varriable vains inside the turbo, move into a position that allows the turbo to spool up quicker at the lower rpm, as the car continues to accelerate above 2500-3500 rpm, if they are supposed to move back to the normal position. Its done like this to reduce lag and control boost pressure. Not enough boost pressure and car is slow, to much boost pressure engine blows up, so the ECU monitors the boost pressure and moves the varriable vains (with a vacuum diaphram) to control keep it in the best place or best performance.
The trouble is, customer x will use full throtle from low rpm all the time, but change up very early, all the time, the turbo is basically always running with the vains in the low rpm position, add to this the large ammounts of soot in the exhaust +100,000 miles and the vains get stuck. First time customer A goes over 2500-3500rpm the vains are stuck the turbo makes far too much boost pressure and so to save a blow up the ECU put the thing in limp home mode, customer notices lost of power until ignition cycle.
Variable vain turbo
http://www.youtube.com/watch?v=Gc2awh0O0Bc
http://www.youtube.com/watch?v=cLa4qwA3x7s&fea...
Just to be clear, This is not an Audi thing, all turbo diesel cars can have this, and faults are pretty common.
What happens is......................
When you use lots of throtle at low rpm, the varriable vains inside the turbo, move into a position that allows the turbo to spool up quicker at the lower rpm, as the car continues to accelerate above 2500-3500 rpm, if they are supposed to move back to the normal position. Its done like this to reduce lag and control boost pressure. Not enough boost pressure and car is slow, to much boost pressure engine blows up, so the ECU monitors the boost pressure and moves the varriable vains (with a vacuum diaphram) to control keep it in the best place or best performance.
The trouble is, customer x will use full throtle from low rpm all the time, but change up very early, all the time, the turbo is basically always running with the vains in the low rpm position, add to this the large ammounts of soot in the exhaust +100,000 miles and the vains get stuck. First time customer A goes over 2500-3500rpm the vains are stuck the turbo makes far too much boost pressure and so to save a blow up the ECU put the thing in limp home mode, customer notices lost of power until ignition cycle.
Variable vain turbo
http://www.youtube.com/watch?v=Gc2awh0O0Bc
http://www.youtube.com/watch?v=cLa4qwA3x7s&fea...
Just to be clear, This is not an Audi thing, all turbo diesel cars can have this, and faults are pretty common.
Edited by Tame Technician on Friday 12th February 18:59
TDI Road test diagnosis.
You can ckeck for all the common 2.0TDI engine faults in one simple maneuver on the road test. (mostly applys to 1.9 too)
Once the engine is warm find a nice long clear stretch, (you will be doing 70 odd by the end)
Accelerate in 3rd or 4th gear from very low revs say 1200rpm but at absolutely full throttle.(in 2nd it happens to quick, so doesn't show up any faults). Make sure you start ar 1200, slow down and it will take a while to pick up)
It should slowly gather speed and take off at around 1500-1800 rpm, it should then accelerate smoothly and well upto about 3800 then slightly drop off, but keep on full throttle until around 4400. DO this 2 or 3 times, and Dont be alarmed if it smokes alot the first time you do it, means the current driver doesnt rev it high very often.
If it doesnt take off until 2200-2500 there is a vacuum issue or a fault with the N75.
If you get a smooth loss of performance over 3000rpm, the MAF is knackered.
If you get a sudden major loss of power on the second or third attemp (limp mode) the turbo is knackered.
If you get any misfiring (loss of performance that isnt smooth, propper juddering) above say 3000 then there is a loss of fuel pressure, either tandem pump or injector seals leaking.
You can ckeck for all the common 2.0TDI engine faults in one simple maneuver on the road test. (mostly applys to 1.9 too)
Once the engine is warm find a nice long clear stretch, (you will be doing 70 odd by the end)
Accelerate in 3rd or 4th gear from very low revs say 1200rpm but at absolutely full throttle.(in 2nd it happens to quick, so doesn't show up any faults). Make sure you start ar 1200, slow down and it will take a while to pick up)
It should slowly gather speed and take off at around 1500-1800 rpm, it should then accelerate smoothly and well upto about 3800 then slightly drop off, but keep on full throttle until around 4400. DO this 2 or 3 times, and Dont be alarmed if it smokes alot the first time you do it, means the current driver doesnt rev it high very often.
If it doesnt take off until 2200-2500 there is a vacuum issue or a fault with the N75.
If you get a smooth loss of performance over 3000rpm, the MAF is knackered.
If you get a sudden major loss of power on the second or third attemp (limp mode) the turbo is knackered.
If you get any misfiring (loss of performance that isnt smooth, propper juddering) above say 3000 then there is a loss of fuel pressure, either tandem pump or injector seals leaking.
Took car in yesterday and got it back today. Two fault codes reported:
449B Intake manifold pressure sensor short to B+
462D Boost pressure control above control limit
Garage lifted car and freed off the turbo wastegate and added diesel treatment. Road tested and again reported fault 462D, checked boost pressure sensor and found one wire not connected properly, so they have re-connected this. Road tested again and now not reporting any faults. They said as far as they can see, the actuator on the turbo is moving freely.
I've driven it this afternoon and it now seems fine, but have been told to regularly use the car through the rev range - rather than the way I usually drive of changing up before 2,500 rpm.
One other problem they found was when they lifted the car and took off the lower cover, they found the air conditioning clutch, which for some reason had come off. The garage said this was a common problem on these cars.
449B Intake manifold pressure sensor short to B+
462D Boost pressure control above control limit
Garage lifted car and freed off the turbo wastegate and added diesel treatment. Road tested and again reported fault 462D, checked boost pressure sensor and found one wire not connected properly, so they have re-connected this. Road tested again and now not reporting any faults. They said as far as they can see, the actuator on the turbo is moving freely.
I've driven it this afternoon and it now seems fine, but have been told to regularly use the car through the rev range - rather than the way I usually drive of changing up before 2,500 rpm.
One other problem they found was when they lifted the car and took off the lower cover, they found the air conditioning clutch, which for some reason had come off. The garage said this was a common problem on these cars.
Hi all,
Recently bought a 1.9tdi Octavia with an AGR engine and a near complete service history. First time I'd driven a turbo, and a LONG time since I'd driven a diesel. Anyway, once I got more comfortable with it, I started to drive it properly and noticed what, after reading this thread and others several times, is a constant case of limp mode. It's fine in first and second throughout the rev range, but once I hit 3500 in either third or fourth, bye bye turbo. It doesn't come back until you restart the engine, and it happens every time you go above that threshold, even if i change from 2nd to 4th and bypass 3rd. I did disconnect the MAF and drive it, with the result that the performance is just generally worse, so I'm guessing that's not it.
My question then is, not understanding much about vains and turbos in gerneral, does it sound like the whole unit is shot, or is a strip down and clean out in order? I wanted to get the benefit of your combined experience before I start paying technicians for tests (I live in Sweden where they don't come cheap and in my experience creative thinking to work through the possible solutions is not so common!)
Many thanks for your comments,
Jim.
Recently bought a 1.9tdi Octavia with an AGR engine and a near complete service history. First time I'd driven a turbo, and a LONG time since I'd driven a diesel. Anyway, once I got more comfortable with it, I started to drive it properly and noticed what, after reading this thread and others several times, is a constant case of limp mode. It's fine in first and second throughout the rev range, but once I hit 3500 in either third or fourth, bye bye turbo. It doesn't come back until you restart the engine, and it happens every time you go above that threshold, even if i change from 2nd to 4th and bypass 3rd. I did disconnect the MAF and drive it, with the result that the performance is just generally worse, so I'm guessing that's not it.
My question then is, not understanding much about vains and turbos in gerneral, does it sound like the whole unit is shot, or is a strip down and clean out in order? I wanted to get the benefit of your combined experience before I start paying technicians for tests (I live in Sweden where they don't come cheap and in my experience creative thinking to work through the possible solutions is not so common!)
Many thanks for your comments,
Jim.
Is most probably turbo failure, siezed varriable vains causing overboost. But you need to have the fault memory read and the car tested to be sure.
A boost leak would cause the same symptom for the oposite reason, underboost.
Some people do take the turbos apart and clean them, this does usually work but is generally a tempory fix.
At the Audi main dealer we replace turbos for this fault.
A boost leak would cause the same symptom for the oposite reason, underboost.
Some people do take the turbos apart and clean them, this does usually work but is generally a tempory fix.
At the Audi main dealer we replace turbos for this fault.
I had a similar problem with my a6 last year, ended up being related to a split hose on a vacuum line which wouldn't allow the car to rev normally (i'd have been overtaken by a milkfloat is was so poor). I'd read about the variable vane setup causing problems so i removed the exhaust downpipe from the turbo to rule it out and it was so coked up I was staggered. used a fair amount o cleaner and some pretty vigerous wiggling on the actuator mechanism and its been fine ever since but yes definately need to alternate the quality of fuel used (not all supermarket gasole) with something better and to ensure you give it some beans every once in a while.
Was convinced it was the MAF to the point of buying another and also the N75 but no....
Was convinced it was the MAF to the point of buying another and also the N75 but no....
Back from the garage after timing belt change today. They read the codes, and came up with 17958, which translates as charge pressure deviation. The codes were reset, but on the drive home I had the same problem - though arguably occuring a little later in the rev cycle in third than previously. This turbo is the GT1544 Garrett, is the vanes still an issue if it isn't VNT? Rumour here points to the N75 solenoid being the problem. What do you all think?! Thanks...
Normally the fault says weather its to much or too lilte boost. Just saying there is a boost deviation (i.e its out of spec) isnt really much help.
If the boost is too low, it could be the vacuum fault, including the N75. To little boost could also be cause by a leaking pressure hose or intercooler, but you would have noise and exhaust smoke if it was that.
Too much boost is normally the turbo.
In would drive the car monitoring the boost pressure with the MVB (think its 11) and see if it above or bellow the specified figures.
You can test the N75 and the turbo with a hand held vacuum pump, but its a bit involved.
I should add, I have No idea if the turbo fitted to the Skoda is the same as the Audi ones, but I would think it is. If it is different the comments above might be wrong, but what I have said is true for all vacuum operated Variable vain turbos.
If the boost is too low, it could be the vacuum fault, including the N75. To little boost could also be cause by a leaking pressure hose or intercooler, but you would have noise and exhaust smoke if it was that.
Too much boost is normally the turbo.
In would drive the car monitoring the boost pressure with the MVB (think its 11) and see if it above or bellow the specified figures.
You can test the N75 and the turbo with a hand held vacuum pump, but its a bit involved.
I should add, I have No idea if the turbo fitted to the Skoda is the same as the Audi ones, but I would think it is. If it is different the comments above might be wrong, but what I have said is true for all vacuum operated Variable vain turbos.
Funnily enough, the other error codes in the VAG-COM list either side of this one are indeed more specific; 4 different ones relating specifically to load pressure control on the N75, and two different ones for the load pressure control border - either exceeded or fell below. So, I guess I'll have to book in another time for further checks, but sounding ominously like the turbo itself. The hoses look to be in good shape, though I'm sure many leaks are not actually visible.
Thanks again for your help. Update to follow in due course...
Thanks again for your help. Update to follow in due course...
Well well. Since I last reported here I've had a crcked hose changed and a temperature gauge replaced, and still the same problem. So we went for it and today replaced the turbo; as the used ones have already clocked up a high mileage, I got a new one from Germany at a very good price. Guess what? SAME PROBLEM! When all this began I tried disconnecting the MAF, and that seemed to make performance poor from the beginning; at least with it connected I would get turbo use up tp about 60mph and 3K revs... So, any views from the wise, before I reach the end of my tether?! Many thanks... (At least the turbo and the work was paid for by the dealer, so it's not all bad!)
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