300CE Fuel smell and knocking at rear axle. - PeachParts Mercedes-Benz Forum

MARINE_V · #1 12-27-2010, 08:04 PM

Hi guys, back again for more DYS or helpful info.
I have a 1991 300CE Benz
Lately I have began smelling a strong gas odder coming from the hood.... The car seems to be running fine but this smell of fuel is becoming over welling.. I am unable to find where the smelling is coming from. I have checked fuel lines and all but I just can not locate the problem.
The second issue is that I have began hearing a knocking sound coming from the rear wheels. Only when Stopped at a stop and then I accelerate. The knocking stops once I get to second gear. Also it only seems to make that sound when turning right. Any ideas? I have lifted the car and was unable to find any thing hanging on the under body. Lastly, does any one know if a 300CE (91) have rear brake sensors? I just had my brakes pads and rotter's replaced in the rear and they said my car did not take rear senors even though Benz told me I needed them. Thanks so much for your wisdom and help.

alienman · #2 12-27-2010, 08:53 PM

I had an intermittent clunking with similar symptoms as you described. It turned out to be a worn half-shaft.

mlozzi200478 · #3 12-28-2010, 01:37 AM

if i was you i would be very concerned with a cracked E.H.A valve on the back of the fuel distributor,they crack from heat and age and they are under extreme pressure they begin squirting fuel down the rear of the engine and may cause fire,the part will cost you approx $280.00 brand new,you should loosen up the fuel regulator nut on fuel distributor as to release any built up fuel pressure in lines using a rag to soak up and that squirts out,then you will need to disconnect the 2 pin black connector end from it,then there is 2 stainless machine screws holding the valve to the back of the fuel distributor,once its out inspect all around the part for any cracks,this is generally the most common reason they are replaced,you may find a newer used one on e-bay for about $70.00. as far as the rear axles go,i would check to make sure the cv axxles in rear are not worn out,but most likley your issue is defectively worn out flex joins on the prop shaft,there is 2 of them 1 is located up front and other in the rear,they use these instead of universal joints,you can find some nice german ones for about $80.00 for the pair.that should solve the banging or clanging isue,check to see if there is a chattering while releasing the accelorator while slowing down then it may go away when reaplying it,goodluck.

mbzman · #4 12-28-2010, 01:47 AM

For the fuel leak I too would take a close look at the EHA valve. Very common for them to leak fuel as they get older and crack. Try smelling around the air cleaner area and see if the smell gets stronger.

mlozzi200478 · #5 12-28-2010, 02:48 AM

you def got to check it man.

MARINE_V · #6 01-04-2011, 06:31 PM

Thanks guys will do ASAP. thanks

wagonman124 · #7 01-09-2011, 01:14 AM

I had a similar issue.... it was the fuel line that drops down to the fuel pump. It tooks months for the pin hole to finally open up. If you have ramps get someone to start the car while you manipulate the fuel lines you may be surprised what you find.

big dog 2 · #8 01-09-2011, 08:52 PM

Several posters had that particular hose leak, including me! An easy and inexpensive fix! Change the fuel filter while you are down there! Hope it is not an EHA issue!

MARINE_V · #9 01-11-2011, 03:06 PM

Hi guys, can anyone post where the EHA valve is on this car? I cant seem to locate it.. 91 300CE thanks so much

MARINE_V · #10 01-11-2011, 03:07 PM

Quote:

Originally Posted by wagonman124

I had a similar issue.... it was the fuel line that drops down to the fuel pump. It tooks months for the pin hole to finally open up. If you have ramps get someone to start the car while you manipulate the fuel lines you may be surprised what you find.

I have not been able to locate the smell... which is driving me crazy!!! I am going to go get a set of ramps..

rick's autowerk · #11 01-11-2011, 04:44 PM

EHA is under the air cleaner. It's black plastic in a sea of aluminum & some steel lines with a 2 pole plug attached.

conski · #12 01-11-2011, 10:29 PM

the clunking sound you hear in the back when going around corners could be your wheel bearing, my sister's '89 300e had the same problem only happened when she was turning left though. It's a cheap part, just need the right tools to get it done.

Ferdman · #13 01-12-2011, 05:36 AM

MARINE_V, start the engine cold after removing the air cleaner housing and inspect the EHA valve for weeping gas. The outside of the EHA valve will get wet when the engine is cold. Underhood temperature evaporates the weeping gas so things will look normal when the engine is hot. Chances are a hairline crack has developed in the black plastic EHA valve body and it needs to be replaced ... a fairly expensive part. Be sure to replace the 2 green O-rings also. I had this happen to the EHA valve on our 1991 300CE years ago.

timmyr · #14 01-12-2011, 02:40 PM

if the above mentioned tips dont help, another possibility could be the charcoal canister which is hidden in the driver's side fender.

good luck

my83300cd · #15 01-12-2011, 06:15 PM

Had a nice gas odor in the 89 190e.
Removed air filter housing and saw gas spewing from the joint between the EHA and the 'sea of aluminum'. Took off the EHA and all it took was a new set of green O rings replacing the squashed flat black whatever they were things once called O rings. No more gas smell.

Look at the prop shaft and check the level in the rear differential- I've got a clunk whenver I shift; with 280k miles on it and a weeping seal at the prop shaft/differential I'm figuring the diff is a bit worn.