Technical Loss of power when accelerating

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Technical Loss of power when accelerating

Joedxer

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Hello,
My 2003 fiat Punto 188 has started to lose power when accelerating, following this there is a quiet hissing sound at idle, and increased volume when accelerating. This has also flagged the engine light to come on, I can check this on Monday, and will update on this thread what it flags up. We did a compression test and it came back that it had 16 Bar in each of the cylinders, when removing the spark plugs one by one we found that in the second from left cylinders spark plug was covered in oil, and as we all know, that is not good, the other spark plugs are covered in black carbon buildup. Other problems with the car include a topped rev of about 4000 when in neutral, when before it would reach the limiter between 6 and 7 thousand. Driving the car also means that I can hardly reach above 40mph as a result of the lack of power. The exhaust also has hair-like material coming out of the tip, and dripping what I can only think is condensed fuel vapour, it doesn't smell like fuel, but it would've been burnt as it is dripping from the clamp between the cat and the silencer toward the back of the car.

If anyone has had this problem before, or knowledge on where to check for air leaks, as that what is sounds like.

I'll be happy to answer any more questions anyone has to ask

Regards
Joe
 
Have exact problem with a different car. I don't have any hissing sounds but now suspect a clogged exhaust. Hissing sound do point to a clogged exhaust though.
 
The "hair" is probably the baffle material coming out of the back silencer box. That happened on one of my old cars. Maybe it is causing a blockage and preventing exhaust gases from being removed properly.
 
Hi

it sounds like some of the exhaust wadding is coming loose inside the exhaust, this may be caused by other metal baffles moving inside too.

i would consider the exhaust blocking up as an easy to test option just by disconnecting the exhaust further forward under the car, this will let you know if its a blockage issue, the 1 plug being oily might just be the excessive back pressure not allowing the engine to burn properly hence all the other 3 plugs being dark.

do you seem to have a reasonable amount of air coming out of the exhaust at idle compared to other cars in your local area.

Tim
 
Thank you for your responses, today is a fairly dry looking day, a day for taking the exhaust manifold off I think, I will get back to you on whether we gain our power back again.

Joe
 
I also done some vacuum test which point at exhaust blockage. Disconnect the exhaust from the CAT and started the engine. The sound was too quite even under power so CAT collapsed or blocked. I tapped the CAT with the hammer with engine idling and then some small bit of the CAT came out and also the low frequency noise of a blowing exhaust came up. Under load is still sounds dim and high pitch so the CAT is still quite blocked. The CAT is got a shape that the exit pipe has 90 degree bent so is not easy to remove CAT internals. I'll be driving around with exhaust disconnected and see if the internal remove themselves in time. Also unlike the punto I cannot remove the CAT myself so this is not an option for me to try to remove CAT internals.
 
Hair like thing at the back is the sign you need to replace your exhaust muffler. It's basicly a silencer and it's filled with this hair-like material. If it comes loose, than the muffler is eaten by rust. Buy a new one.
 
I have since replaced the whole exhaust system at the cost of about £160, the problem has gone and sounds alot cleaner
 
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