Tamora - Big revs... big fun ..... big noise....?
Discussion
), I get a strange crackling noise from the engine. Sounds a bit like heat expansion on the manifold. Would this be right?
Mark - I have exactly the same noise from my Tam. Asked London TVR to look at it when it was in for its big service and they reckoned it was the timing chain. However, I still have it at these revs! Either it wasn't fixed properly or it is something else. Must admit it is quite worrying hearing this.. almost sounds like gravel being sprayed up underneath - that kind of sound. Be interesting to hear what other people have to say...
hollowpockets said:
i used to get this in my car as low as 5k rpm, think its something to do with the petrol, other possible idea was the timing chain hitting off the underside of the cam cover, it just stopped happening though so im not 100% sure
Also had this happen a few days after picking it up, thought I'd killed it called up my local indy and he said more than likely timing chain bring it down, few hours later picked it up all good 
My 1st S6 engined car pinked quite badly at those sort of revs, however only did it when ambient temperature was high, even did it on super unleaded even with octane booster added
The noise was a "tinkling noise" sounds like it comes from under transmission tunnel and sounds abit like a spanner rattling inside the exhaust.
If it is pinking get it sorted pronto before it causes engine damage.
N
The noise was a "tinkling noise" sounds like it comes from under transmission tunnel and sounds abit like a spanner rattling inside the exhaust.
If it is pinking get it sorted pronto before it causes engine damage.
N
If it's like a handfull of marbles being dropped onto something metal or crackling like you say thens it's pinking or preingnition. I used to get it in my renault 5 turbo all the time when the intercooler got too hot. the fuel ignites on the compression stroke as it gets too hot so as the piston is coming up it ignites and tries to push it down again. very bad for the engine. I get it on mine with high ambient temps but mines a red rose with higher compression. The acid test is, does it do it at night when the ambient is around 10c mine never does it at this temp so i know it's pinking.
Pinking: (Someone correct me if i'm wrong)
As the fuel/air mixture is being compressed (piston moving upwards) instead of the fuel/air mixture being ignited by the spark plug it ignites on its own due to intense heat.(Note pinking can also be caused if your timing is out) So as the piston is on its way up before it reaches top dead centre the mixture ignites and tries to push it down. Putting big strain on your piston, conrod, bearing and grudgen pin etc. that it the metalic noise you hear.
Basically the momentum of you engine is compressing your fuel/air mixture and forcing your piston upwards the bang from the mixture tries to force it down.
Can anyone else explain it better? It's very bad for your car put it that way. In some cases it can burn holes in your piston.
Like i said before go out at night when the air temp is bout 10-13 and nail it and i bet you wont hear the noise.
It happened on my R5 turbo on a long hard blast when the intercooler couldn't cool the air enough and it got too hot.
As the fuel/air mixture is being compressed (piston moving upwards) instead of the fuel/air mixture being ignited by the spark plug it ignites on its own due to intense heat.(Note pinking can also be caused if your timing is out) So as the piston is on its way up before it reaches top dead centre the mixture ignites and tries to push it down. Putting big strain on your piston, conrod, bearing and grudgen pin etc. that it the metalic noise you hear.
Basically the momentum of you engine is compressing your fuel/air mixture and forcing your piston upwards the bang from the mixture tries to force it down.
Can anyone else explain it better? It's very bad for your car put it that way. In some cases it can burn holes in your piston.
Like i said before go out at night when the air temp is bout 10-13 and nail it and i bet you wont hear the noise.
It happened on my R5 turbo on a long hard blast when the intercooler couldn't cool the air enough and it got too hot.
Edited by smithyl23 on Tuesday 14th August 11:29
Mentioned it to the dealer this morning - they are going to take a look at it and I will let you know.
Don't want to worry anyone too much but explaination of pinking below.
Can someone explain why this happens more at higher ambient temperatures? Does a 10 degree difference in ambient temp really make a huge difference to the internal temp of the engine / temp of the air being compressed? Would it happen more if you are in town and the cooing fans have to keep kicking in i.e. oil and water temps are in the 90s?
Pinking - colloquially detonation—in internal combustion engines occurs when air/fuel mixture in the cylinder has been ignited by the spark plug and the smooth burning is interrupted by the unburned mixture in the combustion chamber exploding before the flame front can reach it. The engineered combusting process ceases, because of the explosion, before the optimum moment. The resulting shockwave reverberates in the combustion chamber, creating a characteristic metallic "pinging" sound, and pressures increase catastrophically. It can range from hardly noticeable to complete engine destruction.
Don't want to worry anyone too much but explaination of pinking below.
Can someone explain why this happens more at higher ambient temperatures? Does a 10 degree difference in ambient temp really make a huge difference to the internal temp of the engine / temp of the air being compressed? Would it happen more if you are in town and the cooing fans have to keep kicking in i.e. oil and water temps are in the 90s?
Pinking - colloquially detonation—in internal combustion engines occurs when air/fuel mixture in the cylinder has been ignited by the spark plug and the smooth burning is interrupted by the unburned mixture in the combustion chamber exploding before the flame front can reach it. The engineered combusting process ceases, because of the explosion, before the optimum moment. The resulting shockwave reverberates in the combustion chamber, creating a characteristic metallic "pinging" sound, and pressures increase catastrophically. It can range from hardly noticeable to complete engine destruction.
Edited by Markopolo on Tuesday 14th August 11:45
Well described smithyl23
Markopolo - ambient temperature will make all the difference.
Mine original S6 T350 only suffered pinking under load at high revs when ambient temp was say above 22-23 deg C with an oil temp readout in the high 80s.
If the outside temp was below 20 deg C it never seemed to happen, the timing is such that these cars seem to run on the edge of pre detonation when hot. A new chip retarded a couple of degrees seemed to sort things out.
No 6 cylinder is usually the culprit as this tends to run hotest.
Flagpole - always used optimax or BP super, plus added octane boost to try and stop pinking but on really hot days it didnt make a difference - so dont be mis lead in thinking that just cos you use super it wont pink.
If it is pinking get it sorted sharpish, dont use high revs, New chip is usually about £100
N
Markopolo - ambient temperature will make all the difference.
Mine original S6 T350 only suffered pinking under load at high revs when ambient temp was say above 22-23 deg C with an oil temp readout in the high 80s.
If the outside temp was below 20 deg C it never seemed to happen, the timing is such that these cars seem to run on the edge of pre detonation when hot. A new chip retarded a couple of degrees seemed to sort things out.
No 6 cylinder is usually the culprit as this tends to run hotest.
Flagpole - always used optimax or BP super, plus added octane boost to try and stop pinking but on really hot days it didnt make a difference - so dont be mis lead in thinking that just cos you use super it wont pink.
If it is pinking get it sorted sharpish, dont use high revs, New chip is usually about £100
N
Edited by Maxx-Waxx on Tuesday 14th August 13:28
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