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I am going to clean and then most likely replace my 2010, C300 purge valve. Is there anywhere I can find a complete set of instructions which match my car's model?
History for my decision to do this. I had my vehicle at the dealership in December. There was a slight whirring sound from my engine and the check engine light had came on about 2 to 3 weeks after I noticed the whirring sound. At the dealership they replaced the belt with part # 003-993-73-96 and they also replaced the charcoal canister shut off valve with assembly part # 203-470-06-59. When I got the vehicle back anytime the temperature would get very cold the check engine light will come on and disappear when it warms up outside. Last night I went to put gas in my car (I did not fill it all the way only 3/4 of tank was full) and after adding the gas it would not start. I had to hold the accelerator to the floor to get my car to start up. Once it started it has run fine. Check engine light still remains however. I made an appt. to take it back to the dealership but after researching on this board it seems likely the culprit is the purge valve and it seems like I could change that on my own..without the hassle of going to the dealership.
One other thing I might mention...2 years ago I had the same issue with the vehicle not starting after putting gas in. The service manager said to ONLY use premium and I put some in that very same day. Since I have only used premium gas and have never had another issue with it starting...until last night.
Certainly sounds like a possibility..the evap purge valve being stuck open, Sometimes just giving it a tap will fix the problem for a while. With the purge valve off, if you can blow through the outlets, it's stuck open.
Thank you gamma300C! I will definitely try that. How do you ensure the valve is off? which outlets would I blow through? the holes where the tubes would attach?
The valve is under the hood and very simple to replace, yes it should be normally closed, so when disconnected you should not be able to draw air through it. It's over by the left side headlight/washer tank area, there's a plastic hose running over to the engine intake manifold.
They tend to stick open at times, so it may be closed when you remove it, but if you cycled it 10-20 times, i'd bet you can get it to stick or not close fully. Doesn't take much to set the code or cause a vaporlock when refueling as you had happen.
Try to find out what the trouble code is, otherwise you are just swatting at windmills. Take it to an Autozone and they will read the code for free. Once you have the code, post again
Thank you gamma300C! I will definitely try that. How do you ensure the valve is off? which outlets would I blow through? the holes where the tubes would attach?
ItalianJoe's post answers your questions well. The code you see most often is a P2681 (lean at idle) when the purge valve is stuck open. Pretty inexpensive part and easy to replace..even though my purge didn't reset a CEL for quite a while after I gave it a "thunk, I replaced it just last week when I needed a "project".
I will double check the code at AutoZone this weekend. I will do some testing before I run out and just replace the part. I did locate it in my car last night. Looks easy enough but from what I read that band clip seems to give some people trouble, when they remove the part, so I will be careful about that. Thanks everyone!
Last edited by Jenncloud9; Jan 31, 2018 at 05:41 PM.
The fact that you had to hold the pedal down all the way to start, makes me think you have some drippy injectors. On most modern fuel injected cars the computer is programed to stop the fuel injection when the throttle is held all the way down during start up. This is like the old days to clear a flooded engine. Injectors do wear out, fortunately you do not have direct injection where the injectors are $300-$400 a pop. The injectors on your car are more like $30 each rebuilt. Don't know how many miles you have but I would definitely look at the injectors
Start with the easy things and start with the stored codes. That will point you in the right direction. A purge valve stuck in the open position can introduce a lot of "unmeasured" air into the combustion process which can cause hard starting and poor running.
Hey I was having a similar code pop up on my 2016 w205 c300 4matic .... P04F00 not sure If it's related. Was wondering if your diagnosis would help in my case?
Tried erasing the code. Keeps comming back. Need to know if it's the purge control valve or the Charcoal canister that need replacement? Or both?
WOT regen relies on the check valve being closed, so I'm not sure where it is exactly but that would be my first suspect. Your purge lines coming from the canister to the engine will have a valve somewhere so when you are at full throttle, with no manifold vacuum, you can't force the fuel vapors back out of the canister into the atmosphere. This valve is usually in the purge valve itself or in the line very near the engine intake manifold connection point, so I would check that first. Remove the valve or line that contains it, and lightly try to blow air through it, should only go to the engine side, should prevent any flow the opposite way.
WOT regen relies on the check valve being closed, so I'm not sure where it is exactly but that would be my first suspect. Your purge lines coming from the canister to the engine will have a valve somewhere so when you are at full throttle, with no manifold vacuum, you can't force the fuel vapors back out of the canister into the atmosphere. This valve is usually in the purge valve itself or in the line very near the engine intake manifold connection point, so I would check that first. Remove the valve or line that contains it, and lightly try to blow air through it, should only go to the engine side, should prevent any flow the opposite way.
Thank you, I'll definitely try that. Seems like it might be the purge control valve then. After clearing the code, I notice after roughly 35km/21miles it would Usually pop back up or once more throttle is given.
Which makes me believe there's a vacuum leak.. found a purge line that was broken on the clip but still secure. Could this possibly cause it? O ring seems to keep hose in place, but clip is broken
purge control valve seems to hold air flow. I'm alittle concerned about the way the lines are fitted, they might be crossed, is this a possibility?
Tried searching for a diagram but came up with nothing for my vehicle. Would it possible to have these crossed by accident? Does anyone know which hose connects to the evap canister and which connects to the intake?
If it's staying connected it shouldn't be a leak. The code you have doesn't line up with a vacuum leak, it is more for a valve stuck open or check valve failed if only at full throttle.
If it's staying connected it shouldn't be a leak. The code you have doesn't line up with a vacuum leak, it is more for a valve stuck open or check valve failed if only at full throttle.
It seems so. Just not sure what's causing the valve to stay stuck open.
any suggestions?
So far I've got faulty purge control valve or purge canister
They just fail, it's a part that is run with PWM so it cycles constantly. I'd replace it for that code, before you dig into the canister.
Got the new purge control valve installed.. super easy 5 min job. $139 after tax 👎
Spoke with the benz tech.
He advised me that this is a normal issue which happens to alot of people, Usually from topping up on gas.
the canister would get saturated then either ruin the valve on the canister or the control valve by sending clumps of the Charcoal through the valves.
Charcoal Canister at benz is $485+ tax
Shutoff valve on the canister is $242 + tax
Purge control valve is $123.63 + tax
canadian prices
Usually replacing the control valve solves the issue, also the cheapest way to start a diagnose repair, if you don't have an air pressure tool and 12 voltage battery to test the parts.
Was the Charcoal canister valve.
decided to replace the entire unit. Behind the tire wall.. passenger side rear Have spare hose clamps ready, just incase
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