Catalyst and White Smoke!!!

[Paul Richards.]

I have a 1.8k supersport and decided to bandage exhaust manifold in preparation for a hot Le Mans trip and in an effort to keep engine bay temperatures down.

When I came to give it a test run on the motorway piles of white smoke came from exhaust and engine lost power. At first I thought it was the head gasket blown, but after slowing down it picked up and carried on as normal.

When I got home I investigated further and exhaust appears to be very hot (I put a rag over the end and it caught fire!!!). I am assuming that the bandage has caused the heat to move straight down the pipe to the catalyst and caused it to over heat. I will naturally be returning to normal and take the bandage off at first opportunity.

My questions are:-

1. Am I correct in my assumption?

2. Will there be any permanent damage to the cat?

3. If the cat is damaged will it merely be the emmissions that are a problem?

4. Will it be OK to carry on running the car with a damaged cat?

Early replies appreciated as I am preparing to go to Le Mans and have little time.

 

Paul R.

C7PPR

[F355GTS]

Paul

 

Assuming the Catalyst has not disintegrated and blocked the pipe you should not have a problem with running the car although as you suspect the emissions may be a bit of a problem.

 

If the cat is of the honeycombe ceramic type and it has broken up it is possible for it to block or partially block the exhaust causing massive back pressure ( look for a light grey or white powder at the tailpipe... if it's there it's a sure sign the cat is breaking up), other symptoms are that the car will feel like it's got square wheels and tries to shake itself to death at higher res which it will do in short order if you don't stop, it's also sometimes possible to hear a rattling from the exhaust as the internals of the cat are loose.

 

 

 

 

Mark

[Paul Richards.]

Mark

Thanks for your advice/information. There certainly seems to be no blockage in the exhaust as gases appear to be passing through OK.

I would have thought that someone else has probably had a similar problem.

Look forward to more responses.

 

Paul R.

C7PPR

[Fred]

paul when you fit the exhaust bandage you have to run the car for 20 min to allow for burn of from the fibres. this smokes for about 15 min if you drove the car before this was done this is where you get the white smoke. the heat is transferd down the pipe but your cat will handle it your cat is just like a block of sand stone with lots of holes in it. and your exhaust will be hotter. is this just a standard exhaust you have and a standard manifold if so i cannot make coment all the ones i have done are 4--1 and all are fine the heat reduction under the bonnet is very good i think you just got a fright with all the smoke.eek.gif you may want to revert back just for peace of mindidea.gifenjoy Le Mans trip

 

fredid=blue> eek.gif

[Paul Richards.]

Fred

Thanks for your comments. I was aware of the need to 'burn off' all the oils etc that are in the bandage and indeed I let it warm up and saw all the smoke produced. The exhaust is the standard 4 into 1. The white smoke was definitely from the exhaust and not as a result of the bandage and there was also a definite drop in power.

I am planning to remove the bandage as soon as work finishes today and then take the car on another test. I am surpised that the bandage could be the cause and wonder if I have disturbed anything else in the course of my activities. I am not sure of the function of the lambda sensor. Could this be the problem if it has been disturbed?

 

Paul R.

C7PPR

[Fred]

Paul

When the engine is operating at normal running temperature a Lambda sensor or Exhaust Oxygen Sensor, situated in the exhaust close to the engine, is used to control fuelling. This sensor for 95% of the engine operation is in total control of the fuel mixture settings.

 

fredid=blue> eek.gif

[Paul Richards.]

Bandages removed and patient appears to be back to normal. Took a test drive last night in a complete circle round the M60 before LADS meet at Belmont. Must try it again on a dry road as it's difficult to give it a good trial (and spot any white smoke)when it's lashing down and there's standing water.

Le Mans trip seems dogged with problems already. I'm currently waiting for the man from Auto Windscreens to call and try to repair the stone chip I picked up on the way home!!!

 

Paul R.

C7PPR