petrol smell in header tank

[andy]

hi,
took the car out the weekend,for a round trip of about 50 miles,it was the first major run since water pump replacement,and overhaling the w.r.d,everything went smooth ,came back completely in love, checked for leaks,and all seemed correct.
so today i started the car up,drove a few feet out the garage,left it running while i started to clean ,then decided to check the water level at the header tank before the car got to hot,and that to was o.k., but what i did notice was  a petrol smell in the header tank.  car is  71 u.s.auto.

any ideas?
thanks,
andy
spain

[rwmastel]

quote:Originally posted by andy

....but what i did notice was  a petrol smell in the header tank.

Header tank?  Is this another term for "radiator overflow tank" or "engine coolant tank"?  Having a World wide forum exposes us to so many new terms.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[andy]

Rodd,
i really didnt know what to call it,i would have gone with radiator top up tank myself,but i had just finished reading that link to silverstarrestorations,and noticed it was to refered to as a header tank,so i presumed thats what you guys called it.
anyway,would also like to add,the car starts and runs great,the oil shows clean on the filler cap and dipstick,and havent noticed any change in m.p.g
if its bad news,lie to me instead.
thanks for taking it up,
andy
spain.

[George Davis]

Andy,

I've been sitting here trying to figure out how petrol could get into the cooling system by itself, and haven't come up with anything that isn't a real stretch.  I'd suspect a fuel leak nearby, or a filling station upwind, or the heady scent of antifreeze combined with uncatalyzed exhaust smelling like petrol, or simply a malfunctioning sniffer.

Make sure the CSV isn't leaking, then give 'er a gentle sniff when the engine isn't running.

George Davis
'69 280 SL Euro manual

[ja17]

Hello Andy,
Next time you cold start check the "cold start solenoid" on the intake manifold. These can leak fuel, it is close to the header tank.



Joe Alexander
Blacklick, Ohio

[andy]

thanks george,joe
tested the csv for leaks,no leak when i removed the small bolt and had the ignition on.there is no smell whatsoever around that area,only when i remove the top up tank cap and stick my nose close can i smell petrol.
this weekend i shall flush the system,i shall also look carefully at the water i drain off,when i refill i will use water only at first,and see if the problem happens again,
meanwhile any more thoughs would be helpfull.
andy
spain

[rwmastel]

quote:Originally posted by andy

tested the csv for leaks,no leak when i removed the small bolt and had the ignition on.

Doesn't the CSV Leak Test involve actually starting the car?  I wouldn't think the CSV would open while the ignition is on for 5 to 8 seconds while the injection is primed by the fuel pump.  Or does it?  I thought is just squirted fuel while the engine was cranking.  If it continues to squirt fuel, then it's a bad CSV.

Regardless, I don't know if you would smell a bad CSV unless it was leaking past a seal or gasket.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[andy]

Rodd,
got the information on how to test for a leaky c.s.v when i used the search forum,disscusion started by -lowleadman-19 04 2004.
however starting now isnt my problem,the smell of petrol in the header tank seems quite rare,maybe its as george says,uncatalyzed exhaust fumes smelling like petrol.
does any body else have the same smell from the header tank?
car is a 71 u.s.
thanks,
andy
spain.

[Ben]

Guys the CSV test is performed with the ignition on and NOT whilst cranking. Rodd is correct in tact it only squirts when cranking but this test is to see if it leaks past the valve seat at all other times. Whilst cranking it is supposed to go past the valve seat as the valve is open !

I'd say George is right about the smell so if you have checked around for fuel leaks and your water level is correct and your oil shows no signs of water then I wouldn't woryy too much !

Thing is I'm certain I've had the same experience with another car, I think my fathers C-Class, and I checked it through and found nothing wrong !  That was about 10,000 miles ago !

Regards,
Ben in Ireland.
'64 230SL 4sp.