R320 fuel leak and dead bettery
Thread Starter
Junior Member
Joined: Oct 2010
Posts: 55
Likes: 1
From: Colorado Springs, CO
2008 R320 4MATIC
R320 fuel leak and dead bettery
So I have noticed an odor of diesel fuel at night in the garage. The car runs fine otherwise. Been meaning to get around to it I have just been busy. I removed the engine cover and can see fuel on top of a small canister on top of the engine.
Recently standing in the garage I noticed a high pitched sound like the fuel pump running, an hour after I turned it off. My wife even said she heard it at 10 o'clock at night, I'm home by 530 or 6.
I just replaced the battery a few months ago and now it seems to be dead again.
So my question:
Does the R320 fuel pump try to maintain fuel pressure even when the car is off?
Thanks
Recently standing in the garage I noticed a high pitched sound like the fuel pump running, an hour after I turned it off. My wife even said she heard it at 10 o'clock at night, I'm home by 530 or 6.
I just replaced the battery a few months ago and now it seems to be dead again.
So my question:
Does the R320 fuel pump try to maintain fuel pressure even when the car is off?
Thanks
MBWorld Fanatic!
Joined: Jun 2006
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From: Nova Scotia, Canada
2023 GLK250, 1987 560SL
It shouldn't. I noticed an odour also, and observed black residue around injector 1 indicating a seal failure, which I am currently working on. I'll report back.
Thread Starter
Junior Member
Joined: Oct 2010
Posts: 55
Likes: 1
From: Colorado Springs, CO
2008 R320 4MATIC
Yours may be leaking slower than mine. I can see a good bit of fuel on tip of the little round cannister on top of my motor.
Thread Starter
Junior Member
Joined: Oct 2010
Posts: 55
Likes: 1
From: Colorado Springs, CO
2008 R320 4MATIC
Shop says it's a leaky fitting on the fuel filter housing.
My dead/fried battery is due to a faulty rear SAM module which is trying to power up various components while the car is off. This explains the apparent fuel pump cycling while it's off.
Just so happens that it contributes to the damn fuel leak that makes the air in my garage toxic!
My dead/fried battery is due to a faulty rear SAM module which is trying to power up various components while the car is off. This explains the apparent fuel pump cycling while it's off.
Just so happens that it contributes to the damn fuel leak that makes the air in my garage toxic!
Thread Starter
Junior Member
Joined: Oct 2010
Posts: 55
Likes: 1
From: Colorado Springs, CO
2008 R320 4MATIC
So I got all these things in the last post fixed shortly after afterward. Now it's got another fuel leak. The aforementioned repaired fuel filter housing is dry. I can smell fuel again in the garage at night. Here's the new slightly disturbing symptom; I can see a very fine mist of fuel at night passing through the headlights. I got close and the mist definitely smells like diesel. I wonder if it could be coming out around an injector or from the high pressure pump somewhere?
