Hi I'm new here but I appreciate very much all your useful information. I have a problem with my tuscani 2.7 V6 year 2003 and I was hoping you could give me some advice if perhaps you had the same problem.
When I start the engine after a few seconds I start hearing some kind of "explosions" from the muffler or the exhaust tube. It goes on for some seconds then there's a final "explosion" louder than the others and the noise stops. When I turn off the engine after a while (the engine is warm) the noise starts again, with the engine off. It's not the ticking of the thermal expansions it's a sound like of uncombusted fuel that reaches hot surfaces and explodes. Have you ever had this problem and most of all what can it be? Thanks for your help

That might be exactly what it is--unburned fuel getting into the exhaust system and exploding there. Could be a problem with the injectors or valves, letting fuel leak when it shouldn't. Could also happen if you are running too rich of a fuel mixture, though that wouldn't explain it happening after shutting the car off.

I'd get it checked out soon though, because if fuel is getting into the exhaust it could cause problems with your catalytic converter overheating.

Thanks!
I'm having the car checked on the 4th of September but my fear is that the mechanic will tell me it's nothing and let me go.I want to get to the appointment prepared.
Do you think it could be the purge control solenoid valve that perhaps is not closing well?
I'm also having another problem lately: it seems to me the car is more nervous(as regards injection) meaning that when I press the accelerator and release it the car has a sort of nervous reaction. Also when I'm decelerating with the gear inserted after a few seconds I hear a sort of a tug with the car "jumping" forward. I don't know if it's a problem of injectors(it only happens decelarating) or if it's a problem of spark or wires.Any idea is appreciated, thanks again

Dear leon from Italy,

Every symtpom you are describing will cause a Check Engine Light (also called a Malfunction Indicator Light). This is the yellow silouhette of an engine block on the dashboard. Please get your Check Engine Light codes read at an automotive shop. This will tell you what is wrong...and the Tuscani computer will give you a code from just one misfire.

Byron

Hi Byron, thanks for the advice. I had once(few months ago when I already had the "combustion" problem) the check light switch to on and I took the car to the shop. They did their checks and eventually said it was one of the oxygen sensors that was not working properly. They changed it and the light went off but I still had the same noise/problem.
I'm going to force the mechanic fix this because I don't want to end up with major problems later.

If catalytic converter is polluted it can stops the air flow inside exhaust, so you can hear big bang when is released.
You can also hear rattling noise if catalytic converter got separated from the outer casing.
That can be one type of possible problems.

This post has been edited by Igor: Sep 25 2008, 07:02 PM