Lack of Power and Misfire

[ianfletcher]

There is a misfire coming from the front of my car when it has just been started and is running cold. It isnt misfiring through the exhaust and is clearly coming from the engine area. Also there is a metallic rattle which sounds like the exhaust. When warmed up to temp it still misfires but not as bad. Also have lack of performance. Could this be a fault with the catalytic converter? The mil light isnt on.

[Cymrudragon]

Originally Posted by ianfletcher

There is a misfire coming from the front of my car when it has just been started and is running cold. It isnt misfiring through the exhaust and is clearly coming from the engine area. Also there is a metallic rattle which sounds like the exhaust. When warmed up to temp it still misfires but not as bad. Also have lack of performance. Could this be a fault with the catalytic converter? The mil light isnt on.

Sounds like a hose leak from the breather hose (possable) check the following, throttle body.for a leak also the inlet manifold. Can you hear a hissing sound if so the breather connections may have split, remove sound proff of top of engine and check the connections they do become britle and leak/snap. Also where the hose enters (into the red clips )

What area is the Rattle?. Top or lower of the engine (possable inlet manifold butterfly valves.

[ianfletcher]

Originally Posted by Cymrudragon

Sounds like a hose leak from the breather hose (possable) check the following, throttle body.for a leak also the inlet manifold. Can you hear a hissing sound if so the breather connections may have split, remove sound proff of top of engine and check the connections they do become britle and leak/snap. Also where the hose enters (into the red clips )

What area is the Rattle?. Top or lower of the engine (possable inlet manifold butterfly valves.

All hoses to inlet, throttle etc are all secure and breather pipes are less than 6 months old and are still softish so not split.

I am 99% sure the rattle is the exhaust as can hear it vibrating through.

The engine is idleing rough and with the misfire coming from the engine area thats why i thought blocked cat maybe or beginning to block. Spark plugs have been changed to try to eliminate the problem but its still there.

[chrissyboy]

Originally Posted by ianfletcher

All hoses to inlet, throttle etc are all secure and breather pipes are less than 6 months old and are still softish so not split.

I am 99% sure the rattle is the exhaust as can hear it vibrating through.

The engine is idleing rough and with the misfire coming from the engine area thats why i thought blocked cat maybe or beginning to block. Spark plugs have been changed to try to eliminate the problem but its still there.

loose exhaust manifold ? duff ht lead

[ianfletcher]

Originally Posted by chrissyboy

loose exhaust manifold ? duff ht lead

Would a loose manifold cause a misfire? Ht leads have also been changed

[BigRuss]

Any smell of fuel at all?

Collapsed Cat can cause misfire and loss of power.

Symptoms can be perculiar as there's two cats on V6 the front one can disintegrate causing the front bank to choke itself leaving the back bank running normally.

I've known a case were occasionally it would clear after going over a bump only to return later when another bump distrubed the collapsed portion and again blocked the cat.

Russ

[ianfletcher]

Originally Posted by BigRuss

Any smell of fuel at all?

Collapsed Cat can cause misfire and loss of power.

Symptoms can be perculiar as there's two cats on V6 the front one can disintegrate causing the front bank to choke itself leaving the back bank running normally.

I've known a case were occasionally it would clear after going over a bump only to return later when another bump distrubed the collapsed portion and again blocked the cat.

Russ

Can't smell fuel from outside the car but can from inside as i have just changed the fuel fillter as anothe step to stop the misfire. I have just ordered a new fuel tank seal (esr3806) so will be replacing that just to see if it cures anything. Would a collapsed cat rattle when cold but stop rattleing once warmed up and would exhaust gases still come out of the tail?

[BigRuss]

Exhaust gasses would still come out of the tailpipe as the rear bank continues to run normally.
The bit that can collapse and partially block off the front bank is the "primary" cat, the bulge just above bolt 5 in this diagram:

http://www.rimmerbros.co.uk/ImagePop...x?i=GRID001949

It's possible that once it warms up due to expansion the rattle could disappear.

Not saying it's a definate cause but I have come across a case of one previously on a 190 that displayed symptoms very much like those you describe.


Russ

[ianfletcher]

Originally Posted by BigRuss

Exhaust gasses would still come out of the tailpipe as the rear bank continues to run normally.
The bit that can collapse and partially block off the front bank is the "primary" cat, the bulge just above bolt 5 in this diagram:

http://www.rimmerbros.co.uk/ImagePop...x?i=GRID001949

It's possible that once it warms up due to expansion the rattle could disappear.


Russ

Thanks Russ thats exactly what i was thinking. Just been looking on ebay for a cat and noticed that some auctions state the part is not a type approved product and from Y registration cars a type approved must be fitted. What does this mean?

[BigRuss]

Probaby only a small difference in the cat, but as they say the difference could cause the MIL to light and effect emissions.

Russ