Exhaust Fumes

[anthrope]

All,
    I have a problem with excess fumes from my exhaust system. A few months ago, the entire exhaust system with the exception of the front pipe had been replaced (with a brand new ANSA system). I was told by a mechanic last week that the front pipe had to be replaced and duly ordered a new ANSA front pipe with the appropriate seals. I spent the better part of this past weekend having it installed. Despite spending a lot of time ensuring that there were no leaks, I am disappointed to report that there is something wrong. The car is more full of exhaust fumes now than it was before, to the point where I have a serious headache after driving the car for a bit.

The front pipe has been welded to the resonator pipe, and I am sure that at the time we finished, there were no leaks there, or near the manifold where the pipe was screwed on. Any ideas as to what may have happened here?

    It's important to note that I do have a problem with the fuel tank, in that the expansion tank is busted. I do have that on order and will have it installed pronto. I expect that contributes to the general smell of gas in the car, but am inclined to believe that the smell of exhaust gas is from a faulty exhaust system.

Any ideas would be appreciated.

Thanks,
Prashanth

1967 250SL 4-speed California Coupe

[Cees Klumper]

I had a constant leak at the front pipes until I replaced my exhaust system front-to-back a few years ago. Sometimes I managed to get the downpipe connections tight for a few days, but never did I notice any exhaust fumes in the car with the leaky pipes. Seeing that you are pretty sure you have no leaks, I don't believe that can be the cause of your problem. The fuel lines in the trunk (expansion tank) sounds like a much more likely suspect.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[hands_aus]

what about the fuel sender seal?

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[al_lieffring]

It is not unusual for people to mistake crank case fumes or oil dripping on the exaust manifold from a leaky valve cover gasket as being exaust fumes.

Sometimes on these cars you will find the crankcase vent tube has been re-directed to down behind the injection pump instead of into the intake venturi, I guess people thought this would make the car go faster or something like that, Whatever the reason it will cause fumes that can smell like exaust to enter the passenger compartment.

Al Lieffring
66 230Sl
New blue top just arrived
new gas tank on order

[Benz Dr.]

There has to be a leak somewhere. The conection where the pipes go on the manifolds is a good place to start.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

[waqas]

I have to agree with Al, have you checked for any leaked oil getting burned on a hot engine surface?  Does it get worse as the engine temp goes up? I used to have an old honda with a leaky power steering hose that dripped onto the exhaust manifold; once the car reached temp, the 'pleasant' smell of the burning oil came wafting through the air vents...

Waqas ('Wa-kaas') in Austin, Texas