Exhaust pipe glowing red hot (blockage)
Discussion
It all started about a month ago when temp of Hong Kong start to go above 32C in the day (don't know if the temp is the main cause of this). My Chim 500 has been running beautifully. Having caught up behind heavy traffic, it started to vibrate and idleing at around 500 to 600 rev. I am sure it is not firing on all cylinders. I need to put my foot down and beyond 3000rev. It is then like hitting the turbo and it took off all the way to max rev. as normal. Once I drop back down to below 3000rev. It sputters again and vibrate madly. This continues from time to time but does not happens continuosly. It won't happens when just leaving the engine running (even for a long time till it is very hot). It really only happens (but not always) after being caught up behind heavy traffic (inching ahead) for a period of time. Push it past 3000rev, turbo effect comes in and cures it for a bit.
Took it in the shop, clean the plugs etc. Ok for a day. back to the shop again and it happens to vibrate very badly. Then discover the left hand side of the huge exhaust in the front (exactly where the sensor is) is glowing red hot. Immediately shut the engine down.
Has the idleing/stepper motor replaced, new plug and repaired/replaced the ignition cable of the HTCs (we think it was grounding). They also found a wire connected to the cpu has melted thus replaced.
Having ran beautifully for another 2 weeks (traffic jams as well as even hotter weather). It suddenly (no traffic this time but only doing around 2000rev. on A road for about 15minutes) vibrates again idle at 600rev and not firing on all cylinder plus massive drop of power. Stopped on the side of the road and floored the accerator. It is like clearing a blockage, it was back normal. Opened the hoop and the exhaust (same place as last time) was again glowing red hot. however, I can see it is cooling this time as the car was idleing properly.
Is it possible to have a blockage in the exhaust or even at the catalytic converter. Has anyone any idea as to what is wrong. Help is very much need here (Hong Kong) as not many people has heard of TVRs let alone know how to repair it!
Took it in the shop, clean the plugs etc. Ok for a day. back to the shop again and it happens to vibrate very badly. Then discover the left hand side of the huge exhaust in the front (exactly where the sensor is) is glowing red hot. Immediately shut the engine down.
Has the idleing/stepper motor replaced, new plug and repaired/replaced the ignition cable of the HTCs (we think it was grounding). They also found a wire connected to the cpu has melted thus replaced.
Having ran beautifully for another 2 weeks (traffic jams as well as even hotter weather). It suddenly (no traffic this time but only doing around 2000rev. on A road for about 15minutes) vibrates again idle at 600rev and not firing on all cylinder plus massive drop of power. Stopped on the side of the road and floored the accerator. It is like clearing a blockage, it was back normal. Opened the hoop and the exhaust (same place as last time) was again glowing red hot. however, I can see it is cooling this time as the car was idleing properly.
Is it possible to have a blockage in the exhaust or even at the catalytic converter. Has anyone any idea as to what is wrong. Help is very much need here (Hong Kong) as not many people has heard of TVRs let alone know how to repair it!
I had a similar issue with my exhausts glowing, mine was also kicking out huge ammounts of soot from the exhaust on start up, it turned out to be the catalitic converters, they had degraded and were blocking the exhaust, had them removed, main cat and pre cats, and I've not had the same issue since, and you get a bit more noise which is nice. 
No idea how you'd check for this before opening the exhaust up, especially in HK, can you get an emissions test from a 'MOT' place?
No idea how you'd check for this before opening the exhaust up, especially in HK, can you get an emissions test from a 'MOT' place?
It sounds like one of your pre-cat has broken free and is sometimes obstructing the exhaust flow. Best you take the manifold off and have a look. A fiddly job but still DIY if you are patient.
In the UK people sometimes remove the pre-cats for more noise. Apparentlty they only affect the emissions during warm up.
In the UK people sometimes remove the pre-cats for more noise. Apparentlty they only affect the emissions during warm up.
Thanks for your quick reply Raceboy,
Once you had your problem with the catalytic convertor, was it itermittance or continuous? My was not coninuous, it was all OK today. Running normally even after heavy traffic. There are also no soot coming out of my exhaust. I thought once the Cat is gone, it is gone and won't be intermittance like this?
Once you had your problem with the catalytic convertor, was it itermittance or continuous? My was not coninuous, it was all OK today. Running normally even after heavy traffic. There are also no soot coming out of my exhaust. I thought once the Cat is gone, it is gone and won't be intermittance like this?
The glowing cats suggest you have a misfire on that bank. This will eventually damage the cat, but if it goes away when you put your foot down you can be pretty sure it isn't the cat which is causing it. I would suspect you have a heat related fuel or ignition fault on that bank, perhaps a knackered HT lead or a duff lambda sensor. The symptoms could get confusing because the misfire will eventually damage the lambda sensor too. However, the fact that it seems to get better over 3000 rpm does point to a problem in the closed loop system and a lambda sensor problem would be the most likely candidate. I suggest you replace them both and see if that fixes it.
Don't know what happened but for the last 3 week, my 500 Chim has be running like a dream. The problem just disappear without anything being done to it. The weather was and still is very hot. I had it in heavy traffic, floored to over 200kmph. Fingers crossed, it will remain like this. I am having great fun with it at present.
Hi Andy,
First, did you have your car serviced by Andy Ng of Inter Auto Hong Kong? To my knowledge (from some of the original TVR's owners and Andy Ng), when TVRs were first sold in HK, they have a problem of overheating. So the thermostat were taken off. Later on, like mine and all the others now in HK, are fitted with a thermstat that is designed for Japanese cars (either a Toyota or Honda). My one kicks in at 70ish degrees.
How did you come by your car? Have you ever lived in HK and bought it here. Just curious how your car made it back home?
First, did you have your car serviced by Andy Ng of Inter Auto Hong Kong? To my knowledge (from some of the original TVR's owners and Andy Ng), when TVRs were first sold in HK, they have a problem of overheating. So the thermostat were taken off. Later on, like mine and all the others now in HK, are fitted with a thermstat that is designed for Japanese cars (either a Toyota or Honda). My one kicks in at 70ish degrees.
How did you come by your car? Have you ever lived in HK and bought it here. Just curious how your car made it back home?
Hi Winston, Is your car still running well? Sorry don’t want to tempt fate, but I’m having similar problems with my Griff 500 and wanted to know if you found the cause?
I had exactly same problem earlier in the year around March / April, and like you after giving car a good blast, problem disappeared...
Over the last 4-5 weeks car has been off the road (been replacing water pipes/hoses, treating chassis) and since got back on road has started to mis-behave again…
Like you noticed pre-cat on the right-bank (and the post-cat) were glowing red… and the engine sounds like is running on 4 cylinders (just the left bank)… and if blip the throttle to over 3k revs then it cures the problem for a while… (and get a few pops and bangs when petrol explodes in the exhaust)
The ignition leads, coil, and dizzy are not that old, (replaced around 2/3 years ago, along with recon ECU)… although due a 12k service in couple of months…
Interestingly I've found if re-start the engine it cures the problem for a while in same way as reving the engine…
Am wondering if there is a problem with Lamba sensors or one other sensors that feeds ECU, and if on start-up ECU runs in default mode for a few minutes??
Also like you that engine really does take off at around 3,300 rpm. Not sure if ECU is programmed to do something different at this point?
Anyway any info / pointers appreciated.. thanks (in mean time I'll just keep the rev's up!)
I had exactly same problem earlier in the year around March / April, and like you after giving car a good blast, problem disappeared...
Over the last 4-5 weeks car has been off the road (been replacing water pipes/hoses, treating chassis) and since got back on road has started to mis-behave again…
Like you noticed pre-cat on the right-bank (and the post-cat) were glowing red… and the engine sounds like is running on 4 cylinders (just the left bank)… and if blip the throttle to over 3k revs then it cures the problem for a while… (and get a few pops and bangs when petrol explodes in the exhaust)
The ignition leads, coil, and dizzy are not that old, (replaced around 2/3 years ago, along with recon ECU)… although due a 12k service in couple of months…
Interestingly I've found if re-start the engine it cures the problem for a while in same way as reving the engine…
Am wondering if there is a problem with Lamba sensors or one other sensors that feeds ECU, and if on start-up ECU runs in default mode for a few minutes??
Also like you that engine really does take off at around 3,300 rpm. Not sure if ECU is programmed to do something different at this point?
Anyway any info / pointers appreciated.. thanks (in mean time I'll just keep the rev's up!)
Hi I love to help but I just don't know what really cure the problem. It just disappeared. Fingers crossed. It is gone for good.
Most people said it is the lamda sensor because it opens up at 3000 rev. I have't change mine, so it was not that.
For mine, my best guess is with the ignition system. It got to be one or more cylinder not firing at low rev (don't ask me the cause) so unburn petrol were exhausted on the the cat and ignite there hence the glowing exhaust. A lot of guys were saying it was the cat. It has it days and blocked. However, if that is the case, there will be a lot of soot being kicked out at the exhaust, but my was clean. No problem with it now.
However something happened it may have something to do with it all along. I had all the leads, dissy cap, rotor arm clean and refit (mind you the leads were only 4 months old) for a second or third time. The car ran very well for a month. Then I could not start the car one morning, not firing. The coil was dead. Replaced with a new coil. Two weeks later the same thing happened. Another new coil. Three days later it happened again. Found out two wires going into the ECU were melted and shorted. Repair the wire and replace a new upgraded coil used in the latest Range Rover (you guys in the UK may already be using it. However I am the first one in Hong Kong tried it). Since then the car has been running a lot better that before.
In fact, it is returning better MPG as well as more low down power. Previously it was neck to neck with my friend's Porsche GT3. Now I am pulling away everytime with ease.
Don't think the above will help you much. Both I and my mechanic are totally bemused. we have not really done anything that we have not done before, the problem disappeared and sudden BHP (very noticeable)gained.
I am not complaining, keep my fingers crossed hope it continues.
Good luck with your Griff. I used to have a Griff when I was in Birmingham 12years ago. They are beautiful. Feel free to bounce off any idea with me if you need. If you do identify the problem, please let me know. It will definitely be useful
Thanks & best of luck
Winston
Most people said it is the lamda sensor because it opens up at 3000 rev. I have't change mine, so it was not that.
For mine, my best guess is with the ignition system. It got to be one or more cylinder not firing at low rev (don't ask me the cause) so unburn petrol were exhausted on the the cat and ignite there hence the glowing exhaust. A lot of guys were saying it was the cat. It has it days and blocked. However, if that is the case, there will be a lot of soot being kicked out at the exhaust, but my was clean. No problem with it now.
However something happened it may have something to do with it all along. I had all the leads, dissy cap, rotor arm clean and refit (mind you the leads were only 4 months old) for a second or third time. The car ran very well for a month. Then I could not start the car one morning, not firing. The coil was dead. Replaced with a new coil. Two weeks later the same thing happened. Another new coil. Three days later it happened again. Found out two wires going into the ECU were melted and shorted. Repair the wire and replace a new upgraded coil used in the latest Range Rover (you guys in the UK may already be using it. However I am the first one in Hong Kong tried it). Since then the car has been running a lot better that before.
In fact, it is returning better MPG as well as more low down power. Previously it was neck to neck with my friend's Porsche GT3. Now I am pulling away everytime with ease.
Don't think the above will help you much. Both I and my mechanic are totally bemused. we have not really done anything that we have not done before, the problem disappeared and sudden BHP (very noticeable)gained.
I am not complaining, keep my fingers crossed hope it continues.
Good luck with your Griff. I used to have a Griff when I was in Birmingham 12years ago. They are beautiful. Feel free to bounce off any idea with me if you need. If you do identify the problem, please let me know. It will definitely be useful
Thanks & best of luck
Winston
Thanks for the info guys,
Definitely sounds like related to Lamba sensors (especially as if just affecting the one bank and by the sound of it when it starts mis-firing it really does sound like the whole bank...)
I'll check the connectors and wiring to the ECU at the weekend, and if all looks ok, get my local dealer to investigate further and fix when book in for next service...
Thanks again, Stef.
Definitely sounds like related to Lamba sensors (especially as if just affecting the one bank and by the sound of it when it starts mis-firing it really does sound like the whole bank...)
I'll check the connectors and wiring to the ECU at the weekend, and if all looks ok, get my local dealer to investigate further and fix when book in for next service...
Thanks again, Stef.
redeye said:
ive had same problem on my chim,changed the lambda sensor ran good for a short time then runs like sxit.
turns out when i was giving it some welly the pre cats were moving up and around the lambdas removed the pre cats both were loose ,runs the best ever now
turns out when i was giving it some welly the pre cats were moving up and around the lambdas removed the pre cats both were loose ,runs the best ever now
I had the same issue as above so I whipped off the exhaust
- then the Y piece and you can actually see on the images below where the pre-cats have been moving whilst under heavy throttle and smashing into the lambda sensor. http://uk.pg.photos.yahoo.com/ph/symo
Begs the question how does it move back to its original position
answers on a postcard please.The difference is that my always seems to start after hitting traffic when the car stops and start at very low rev. while yours were shook loose by accelerating hard. In fact mine got better if I floored it. Honestly, I tried everything and could not identify the cause. Now it disappeared, I hope it stay that way forever.
Hi guys, well guess what, sods law, booked car in for 12k service at my local garage for next week yesterday... and thought would drive the car into town this morning to top up the fuel tank while in town (where the petrol is cheapest ), and was running fine, even though crawling through traffic in town which normally causes the problem to apear...!
On way home took it for a quick (controlled) blast (because had the Mrs with me
and to be fair roads were a bit wet... ) and is now running fine...
Obviously must have been the threat of having a prodding around at the garage!
Going to get them too look into it anyway and check the cats and Lamba sensors...?
I guess are a few things that could be causing it... Neve know might just be a bad connection somewhere I guess? Maybe the Mrs kicked the passenger foot well when getting into the car, and knocked the ECU foxing it?!
I'll let you know if the garage find if anything?!?
Stef
On way home took it for a quick (controlled) blast (because had the Mrs with me
and to be fair roads were a bit wet... ) and is now running fine... Obviously must have been the threat of having a prodding around at the garage!
Going to get them too look into it anyway and check the cats and Lamba sensors...?
I guess are a few things that could be causing it... Neve know might just be a bad connection somewhere I guess? Maybe the Mrs kicked the passenger foot well when getting into the car, and knocked the ECU foxing it?!
I'll let you know if the garage find if anything?!?
Stef
I removed the precats after a similar problem and all was well for a while
Then the problem returned!!
I replaced the lambda sensors on both banks and everything was fine for a while.
Then the problem returned!!!
I removed all the connectors that i could see on the engine and put a very small amount of silver grease (from mounting CPU's) on every terminal in the connectors and re-assembled.
Its never done it again
A friend had a black smoke problem on his Audi TDI and replaced a few parts,he then came to see me and I put the grease on again.
No more black smoke
I wish this stuff was readily available when i ran my MGB
Then the problem returned!!
I replaced the lambda sensors on both banks and everything was fine for a while.
Then the problem returned!!!
I removed all the connectors that i could see on the engine and put a very small amount of silver grease (from mounting CPU's) on every terminal in the connectors and re-assembled.
Its never done it again
A friend had a black smoke problem on his Audi TDI and replaced a few parts,he then came to see me and I put the grease on again.
No more black smoke
I wish this stuff was readily available when i ran my MGB
Hi old64er
Don't quite understand what you meant exactly regarding connectors. Did you mean the end of the ignition leads or the actual computer cable connecting the ECU. Please expand. This may confirm my previous posting that it may have something to do with some occasional shorting of the wires of the ECU.
Also Silver grease. What exactly is it and what brand are you using. Since I live in Hong Kong, I need to see if I can get them here.
Thanks and your help is much appreciated.
Don't quite understand what you meant exactly regarding connectors. Did you mean the end of the ignition leads or the actual computer cable connecting the ECU. Please expand. This may confirm my previous posting that it may have something to do with some occasional shorting of the wires of the ECU.
Also Silver grease. What exactly is it and what brand are you using. Since I live in Hong Kong, I need to see if I can get them here.
Thanks and your help is much appreciated.
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