black exhaust tailpipe
Discussion
Ever since i fitted the power tail pipes, the right tailpipe gets soot on it but the left one is always clean as a whistle. I just assumed that due to the pops n spits from the sports exhaust it was a bit of un burnt fuel landing on the pipe but then always wondered why only on the right tail pipe.
Can anyone advise please. Its ready for it's 6k service, i had the top end checked 5.5k ago and all was well no tappets needed adjusting either.
Would a bit too much oil in the engine cause the soot?
thanks
Can anyone advise please. Its ready for it's 6k service, i had the top end checked 5.5k ago and all was well no tappets needed adjusting either.
Would a bit too much oil in the engine cause the soot?
thanks
Edited by smithyl23 on Thursday 14th June 17:47
Isn't the SP6 effectively 2 banks of 3 cylinders controlled together by the ECU etc? One bank exhausts out of 1 side and the other, out of the other side. If one side is showing sooty deposits sooner than the other side then it might mean something is out of kilter with one of the cylinders for that particular bank or that the lambda sensor on that side is on its way out. Pretty much what has already been said really..
Don't help you much, I know, but I think that might explain the reason for the one-sided sooty stuff....
Andy
Don't help you much, I know, but I think that might explain the reason for the one-sided sooty stuff....
Andy
Not entirely relevant to your problem but....both of my tailpipes have always had black deposits on the inside right from new. For a while I had a sports exhaust and this was the same. Having the car tuned makes no difference and the TVR garage says the black exhaust is normal. Looking at all cars in their yard seemed to support this. Maybe these engines are designed to run slightly rich. (->mpg)
Edited by FOG on Thursday 14th June 15:09
If one is sooty and the other is not then the most likely answer is that one of the lambda sensors is not working properly. Alternative is poor alignment of throttle pots.
The front and back three cylinders are run from different O2 sensors. A slow sensor will lead to over fueling and therefore soot on the relevent exhaust. The ECU should overfuel by default to avoid engine damage from lean running and possible pinking/detonation BUT it is a TVR so....
In theory too much oil in a dry sump system should not be a problem unless it is way far too much. In my experience it is hard to over oil a SP6 unless you put oil in with the engine running, but why would anyone do that? In any case oil problems would be expected to effect both exhausts.
If the engine is used in town a lot (or you are a throttle wimp)* then throttle position is crucial. Position sensor inaccuracy has its largest effect when the throttle is closed. At full throttle 5 degrees is noise in the background unless you are running marginal mapping in a modified ECU. At closed throttle (idle) it will be a pig and hunt about especially when cold. It may be susceptible to stalling after start up.
Leftfeild problems (more expesive) could be a worn valve oil seal or cylinder rings or more likely but still not that common despite what you hear a worn cam/follower on a single cylinder. The latter would be immediatlely apparent at a valvle clearence check.
Many owners have spent thousands of pounds rebuilding an engine that uses oil when the simple solution is to check regularly and top it up. If it passes an MOT it is not broken, do not fix it, oil, even Mobil 1 is cheap.
If excessice oil consumption begins to kill the cat then you have to sort it out.
The front and back three cylinders are run from different O2 sensors. A slow sensor will lead to over fueling and therefore soot on the relevent exhaust. The ECU should overfuel by default to avoid engine damage from lean running and possible pinking/detonation BUT it is a TVR so....
In theory too much oil in a dry sump system should not be a problem unless it is way far too much. In my experience it is hard to over oil a SP6 unless you put oil in with the engine running, but why would anyone do that? In any case oil problems would be expected to effect both exhausts.
If the engine is used in town a lot (or you are a throttle wimp)* then throttle position is crucial. Position sensor inaccuracy has its largest effect when the throttle is closed. At full throttle 5 degrees is noise in the background unless you are running marginal mapping in a modified ECU. At closed throttle (idle) it will be a pig and hunt about especially when cold. It may be susceptible to stalling after start up.
Leftfeild problems (more expesive) could be a worn valve oil seal or cylinder rings or more likely but still not that common despite what you hear a worn cam/follower on a single cylinder. The latter would be immediatlely apparent at a valvle clearence check.
Many owners have spent thousands of pounds rebuilding an engine that uses oil when the simple solution is to check regularly and top it up. If it passes an MOT it is not broken, do not fix it, oil, even Mobil 1 is cheap.
If excessice oil consumption begins to kill the cat then you have to sort it out.
- many TVRs are run mainly on low throttle because only nutters drive a 350+HP car on full chat on the public highway suffieciently often to make a difference. I have measured my throttle position with a data logger and I rarely go over 30 degrees (pi throttle angle = 0.5) and I do not have a reputation for mechanical sympathy.
Edited by mcspreader on Friday 22 June 01:35
Edited by mcspreader on Friday 22 June 01:36
Edited by mcspreader on Friday 22 June 01:40
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