Misfire and Bad Egg Smell from Exhaust

[Oily Rag]

Afternoon boys and girls. Well, the title reveals all, and your help and guidance would be greatly appreciated, so down to the nitty gritty. My beloved SL500 has developed a misfire, and there is an awful smell from the exhaust. checked the engine compartment for moisture and coolant leaks, none. Oil pressure ok at idle, temp also ok. Where next, MAF !!!, thanks in advance for your continued aid. Best Regards Lee

 

[Gollom]

Afternoon boys and girls. Well, the title reveals all, and your help and guidance would be greatly appreciated, so down to the nitty gritty. My beloved SL500 has developed a misfire, and there is an awful smell from the exhaust. checked the engine compartment for moisture and coolant leaks, none. Oil pressure ok at idle, temp also ok. Where next, MAF !!!, thanks in advance for your continued aid. Best Regards Lee

I was told that when buying a 2nd hand car to smell the exhaust and if "rotten eggs" it could mean the cat is on it's way out? Much more knowledgeable souls than I will be along real soon I'm sure

 

[Oily Rag]

Thanks Gollom, had the motor over a year and this is my first REAL problem.

 

[dog68]

Does sound like the cat, the misfire could be the lambda sensor.

 

[Tiff]

You guys are on the wong track, its the misfire thats causing the cat to smell.. this is caused by unburnt fuel hitting the hot cat.. I'd be checking plugs leads and coils first, before your cat gets ruined...

 

[Oily Rag]

Cheers guys, Tiff, will check and replace those leads tomorrow, need all energy for Northern Soul allnighter tonight :bannana:. Kind Regards for your assistance. Lee

 

[Stratman]

The smell is hydrogen sulphide (more poisonous than cyanide), and is a clasic symptom of an over rich mixture causing the cat to function inefficiently.

 

[Oily Rag]

Now a little Urgent

From the initial post, the thought process went thus, Misfire = Ignition = plugs, checked and cleaned anyhow, but exhibiting the signs of correct function, next leads, if plugs are fine then so are the leads. Next = Distributors & Rotor arms, Heres where it gets interesting, Nearside Dizzy and Rotor operating perfectly, Offside, Dizzy coated with dust, resembling white pepper, and the Rotor has serious burn marks and damage to the "Bakelite ???", anyhow, this was replaced and when the distributor was cleaned, it looked as new. Suffice to say, when the bits were nailed back into place and the engine cranked, it roared into life then after a couple of minutes was back to its fault state, missing and bad egg smell from exhaust. Coils next on the list, but your assistance and thoughts would be greatly appreciated.

 

[Oily Rag]

Found the Cause

Yes its the MAF, and now need to source one, a.s.a.p. Anyone got any thoughts as to where best to get one. Regards. 95 SL500 pre facelift.

 

[BlackC55]

I can get you a price if you wish

 

[Egbert Nobacon]

www.airmassmeters.com

Try these people. I have used them before.

Genuine Bosch etc parts, were the cheapest I could find at the time and next day delivery.

You will need the part number from your existing MAF (normally on the side of the casing)