shlounek

iTrader: (1)

Hello,

This is the second SC3 5 speed purchased after the death of my old SC3 in an accident. The new car has 193,000 miles, but runs good, actually better than my older one. The car does not leak oil, but the problem is as follows:

1. On idle the engine sound seems to fluntuate not a constant hum.
2. RPM needle stays the same. So even though engine seems to fluntuate it has nothing to do with the engine
3. From the back of my exhaust one of the exhaust shoots out more fumes than the other exhaust.
4. There is exhaust noise, it doesn't seem to be normal liek my older car.
5. Also the car wiggles due to engine bay moving from side to side on idle (you can feel it).
6. If i rev the car above 2500 RPM flunctuation goes away.
7. this happens when the car warms up only, otherwise its normal
8. car pulls hard, no probs with engine, compression seems to be fine.

I am thinking the problem is with a sensor (but no engine light is on), another idea is that my cats are burnt. (but why would it do create this flunctuatuion. In other words the back of teh exhaust tell me something is constricted.

Can someone please help me in this matter, your advice would be grateful. I also all the parts form my old SC3 so i can switch up any parts.

Ali

Buttercup

When the engine vibrates during cold idle, but then after about 15 seconds, does the rpms jump back up? I had some coolant leaking into the combustion chamber and it increased the compression enough to cause the engine to start bogging for the first 15 seconds.

The exhaust noise is probably from the two exit pipes creating sounds that interfere with each other. You can try this by taking two pre-1982 pennies and flick them both up in the air at the same time.

BTW, the new Pontiac GTO is a v8 with a true dual exhaust- the exhaust pipes don't connect. So basically there are two 4 cylinders running. The engineers tuned the pipe lengths so that when the sound exits both exhausts, they interefere with each other to produce a deeper sound.

shlounek

iTrader: (1)

Hi,

I will check if any coolant is leaking into the combustion chamber, unfortunetely i doubt thats the problem, It seems only when the car is warm that i feel this bogging. I might take down my Cats, and all the pipes leading to the exhaust, to see if teh car still boggs.

It feels like something is constriction the exhaust flow. Also I didnt understand what you do with teh pennies, explain??

Also do you know why one exhaust is shooting out more smoke then the other (not a small difference but a big one), my old car never did it.

Thanks for the reply,

Ali