Mercedes SLK World banner

1 - 20 of 38 Posts

·
Registered
Joined
·
172 Posts
Discussion Starter #1
hi, when i fill 70 percent fuel tank sometimes i smell fuel vapor in cabin ,,and when i open the fuel tank cap i hear absorbing or breath air fuel vapor,,
i change the o ring fuel filter pump i test all lines with canister and electric purge valve with dc voltage its open and close ,also the two way valve down the tank ,,,

so pls advice if i must make more specific test or someone passed in this problem and discover something special i didn’t remark it? and i must change the fuel tank cap even there is no air vapor leaking due i hear air breathing when i open it ? or its not a sign relate if its an good cap?
sorry for my questions but before i spent money for cap or other parts for no reason ,


thx for reading
all my best


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
4,452 Posts
Double-check your rubber seal.


If you hear air rushing into the tank when you open your cap that is an indication that the cap is working. There is no pressure relief valve on the R171 cap.

I would inspect your fuel lines - underneath the car and in the engine compartment - while the fuel lines are pressurized. And I would not park the car indoors until you find the source of the leak.
 

·
Registered
Joined
·
152 Posts
Once you get it on a ramp, check the rubber fuel lines coming from the tank to the metal one going to the engine. As stated a loose clamp or bad rubber line. On mine the rubber line is like 6 inches long. Replace since you in there anyway.
 

·
Registered
Joined
·
172 Posts
Discussion Starter #5
thx and i appreciate yr advice so much but i was wonder if you see picture down my car ,there is no clamp in some rubber goes to two way valve and canister and the rubber are little hard but with little force can remove it and turn left right !! i don’t know if normal !!!
thx again
regards



Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
1,618 Posts
Is that flex hose in pic 2 original? Shouldn’t there be clamps at either end?
TonyS
I agree, screw on hose clamps are not original so someone has been tinkering under there.

Fuel hose should most definately have clamps on, yes
 

·
Registered
Joined
·
172 Posts
Discussion Starter #9
hi
i will check the serial number for canister and ask my mec friend ,
about clamp not original : i add it from about 9 or 10 month when i was testing my fuel line for another issue and it was long ignition and change the fuel motor pump and since i have no ignition problem ,,,, but all around i didn’t touch since i buy the car ,,
i will test and change rubber and add clamp and try and see the smell
thx so much for yr help
all my best




Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
172 Posts
Discussion Starter #10
my car came from germany maybe mercedes have two canister type , really i dont know but these are pic and part number and fit for slk55 amg,



Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
172 Posts
Discussion Starter #11
sir
as i see several pic for my car in google for down rubbers and canister also its not clamp it ,,
maybe they use high glue and get steam after 14 years and cause evaporate fuel smell !!
as i told i shall remove all rubbers and test and change and add clamp for all ,,,
hope to get result due all my fuel line are in good condition after all been tested ,,

all my best for yr kind reply


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
172 Posts
Discussion Starter #12
special morning here from burny and tooty play together



Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
172 Posts
Discussion Starter #14
Did you check the fuel hose nut and washer going into the ramp, engine bay?


yes sure and i changed from about 1 year , but also as i remark the smell come in front around the throttle and i test valve purge and lines and all is perfect ,,,
however i shall check again and i think to pressurized with air gauge all line if smell is still,,,
all my best


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
172 Posts
Discussion Starter #16
Start the car and try to find out the source.


i lift the car with (car lmp) and start the car for 30 minutes and test all lines from tank to engine with no sign for fuel leak at all,,,,
but about the valve purge vapor beside the engine when i put my finger i feel an fast click inside that mean working and bypass the vapor , but in weekend when i test it was not clicking as i remember,,
my questions if that purge valve have always dc voltage when engine on ? or take electric order from ecu and sensor when is hot weather ?

regards




Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
4,452 Posts
I have experienced many purge valve failures over the years, MB, Volvo, and VW; never once was there any fuel odor. That doesn't mean it's not possible, this is just my experience.

Usually when my car fails, the first question I ask myself is: "is this related to the last repair I made", and if yes, I revisit that repair. In your case, the rubber seal on the fuel filter is definitely related, especially since your issue only occurs at 70% fuel capacity.
 

·
Premium Member
Joined
·
4,452 Posts
Regarding the lines with no clamps - these lines are not pressurized, so don't require strong clamps. They must seal tightly under vacuum though. In US cars at least, a leak under vacuum will trigger a CEL and code.
 
1 - 20 of 38 Posts
Top