Exhaust fumes through heater

[Dave W 0]

Hi folks, when I turn fan heater on in car I get a strong smell of exhaust fumes through vents. Car runs spot on. 1.8 16v. Am I being over worried thinking head gasket. Any ideas ??.

[lesarcsneil 0]

Check your exhaust manifold for cracks. My old manifold had cracked which meant that it was leaking exhaust fumes into the engine bay (and blown into the cabin) when cold.

 

Neil

 

94 Flash Red 16v

[Dave W 0]

This is worse when hot. Doesn't seem to be any blow from manifold area. Weird.

[1xshaunx1 27]

There must be Dave, manifold or down pipe thing, there's got to be something wrong with the front/start of the exhaust system. The next point of entry is a drain hole in the boot under the spare wheel.

[SR_Neale 10]

It's gonna be the manifold or down pipe. Defo not head gasket as engine wouldn't run right. If the smell is worse when engine is hot is because the manifold is expanding from the heat so hole is getting bigger.

[Supercharged 2]

Sure it's not also a petrol leak??

[phil34.parsons 10]

Hi I had a 16v in my corrado.had same smell from heater..

It was a small oil leak in back of cam cover that leaked onto exhaust.

The heater gets it air supply from under bonnet. So picks up all smells under

Bonnet...hope this helps..

[Dave W 0]

Thanks for the replies. Cam cover was leaking oil previously but has been cured. Only part of exhaust I haven't renewed is down pipe so could be culprit. I have a spare so may change and do manifold gasket as well. Hope this cures it.

[dythama 10]

Hi mate, have you resolved the smell of exhaust fumes on your Corrado? I have exactly the same issue. I've had a Mercedes tech who is a friend and also my VW retailer tell me my exhaust is ok. We removed and refitted the manifold with new gaskets and still no good. We also sealed the exhaust at the tailpipe and still could not detect any leaks. Short of dropping the subframe the Downpipe cannot be removed. My retailer is now suggesting renewing the crankcase breather hoses despite them not being perished or cracked. I'm stumped but don't have oil leaking from the top of the engine or near the exhaust. Let me know how you're getting on! Cheers, Andrew

[davidwort 0]

Hi mate, have you resolved the smell of exhaust fumes on your Corrado? I have exactly the same issue. I've had a Mercedes tech who is a friend and also my VW retailer tell me my exhaust is ok. We removed and refitted the manifold with new gaskets and still no good. We also sealed the exhaust at the tailpipe and still could not detect any leaks. Short of dropping the subframe the Downpipe cannot be removed. My retailer is now suggesting renewing the crankcase breather hoses despite them not being perished or cracked. I'm stumped but don't have oil leaking from the top of the engine or near the exhaust. Let me know how you're getting on! Cheers, Andrew

 

 

what are you driving behind :)

 

knowing the 16v fairly well, I'd say a small leak from the cam cover can occur at any time, and on a new gasket too, unlikely anything from the rear of the car is causing the problem, air escapes from the cabin there not enters, unless you leave the tailgate up :)

one tiny drop of oil can make a lot of smoke, as the others have said it's that or a manifold/downpipe leak unless a breather is totally split.

[dythama 10]

Hi David, thanks for coming back to me. The breather system looks like new, no split hoses and no leaks since I cleaned up the out let hose and tightened the clip. It's all dry now. I've still got it in my head that it's the Downpipe or flexi joint, but there just isn't any noise or blowing from it. I actually put a rag in a plastic bag and blocked up the tailpipe the other weekend, forcing my knee against it to try and increase the exhaust pressure to show up any leaks, but it didn't! I am completely stumped. I'd jump for the Downpipe, if I was convinced but it's a hell of a job, dropping the sub frame etc if it doesn't fix it. I could do with seeing a specialist with lots of knowledge of these old engines. I can get a new gen Downpipe but for strong money, so I need to be convinced before I take the plunge! Have you any ideas to proving its the Downpipe? Rocker cover and head gasket by the way are free of oil leaks.

[Wullie 1]

Get some Redex, start the car and get someone to hold a rag over the end of the exhaust and get some of the Redex into the induction. This will produce loads of white smoke that will show up any leaks in the exhaust. Last time I did it I undid a vacuum hose and allowed that to suck the Redex in. Be warned though, it does produce a lot of smoke. It won't harm the engine as it is an old fashioned cleaner/lubricant.

[dythama 10]

Wullie, that's a fantastic idea! I'll get some refer and do as you suggest....ill report back! It really is a mystery everyone is insistent the exhaust is not leaking and I'd like to believe them but it's only my wife and I that have smelt what's coming into the car; everyone else thinks it's fine, but I feel the tingling in my nose and get a bit of a bad head after more than 15 mins in the car. To us it stinks!!!!