hookah

Guys my car is in the shop. Last week I took it for check engine light and car was showing a lean code. They pinpointed a leak in one of the intake manifold gaskets. Replaced both gaskets and bolts for both side. Also did spark plugs while in there. A few days after picking up CEL came back on and now the tech is saying they are finding a leak potentially in the middle portion of the manifold. RPMs started idling high and somewhat sporadic after the initial work as well. He is saying Mercedes does not sell a middle gasket and I would potentially need a new manifold for $3k. Please help with any options or even if you know a good tech in the Bay Area that has expertise in this. Thanks

BLKROKT

That “middle gasket” is just a rubber oring. When I took mine apart to clean it, I found that mine had a pinch in it from the factory (never noticed any issues, was prob not leaking). I sealed it back up with some RTV on the mating surfaces as well as on the outside, and it’s sealed just fine. I think you should take it apart and spend some time cleaning the surfaces and checking the oring, then sealing with a good amount of RTV. Or ask your shop to do that. Or take it somewhere else. You shouldn’t be replacing the IM unless the metal is rotted away which is about the only thing that can’t be fixed.

hookah

Thanks, I was hoping to hear something like that. My tech suggested the same thing. I think I will go that route first and if all checks out when he opens i then just re seal and be set. Hoping thats all it is. Do you know if they sell that O ring seperately? my shop says Mercedes only lists you having to buy a entire IM. I would do this myself but with my current work load I have no time to do bigger jobs on the car.

Crya

iTrader: (1)

I personally haven’t used them yet but it’s the shop I’ll use for engine mounts. A guy with a highly modified coupe recommended German Auto tech in Walnut Creek. They did his tune, headers, a bunch of stuff. They may be able to help you out.

BLKROKT

They don’t sell the oring separately. MB considers the IM “non-serviceable”. There aren’t even torque values for the clam bolts in WIS.

hookah

So my shop split the manifold and re sealed the IM. Unfortunately the tested it after with carb cleaner and there is still a slight leak as the idle fluctuates when carb cleaner is sprayed. I picked it up yesterday and he said the CEL would likely come back. Sure enough it popped back on last night. So seems I will need a new IM. Can anyone help on where to source one? I do not want to pay $3k to buy one from Mercedes. Any help would be appreciated.

BLKROKT

That’s weird. Can they not pinpoint exactly where the leak is coming from? It shouldn’t be hard to figure out what’s going on, the idle will jump where they are spraying and that’s where the problem area will be. Is the o ring compromised, did they check it carefully. Only if the metal is rotted or there’s a crack I’d replace it. Otherwise practically anything else can be fixed. I don’t even see how it’s possible for that to get warped, but you have to track down exactly what is leaking and where before you can figure out if it’s a $5 fix or $3k.

I’ve even seen these Al/Mg manifolds get welded before. The R63 guy did it and it was tricky but turned out fine. Don’t give up so easily.

hookah

My tech said they cleaned and inspected and could not find any issue with the casing or gasket. I located a company through CARID named RMT that will completely refurbish the IM for about $530. They said I send it out to them and I would have it back by next Friday. Considering this route. They do not have any refurbished ones on hand until June for some reason. I would prefer sending mine out anyway so I keep my original part and plaque.

manuelsm

DO NOT USE rmt company i purchased the middle plate where the throttles go and the gasket from them melted and had to do everything again and buy a used plate from ebay

hookah

Jeez! Thanks for the heads up. Do you know any company that would be better?

manuelsm

Do you only need the gasket ?

p31c63amg

vacuum hoses, sounds like either mileage and heat or maybe pulled on a vacuum hose to hard playing with you air filters.

skratch77

Need to make sure the vacume hose under the pcv valve has no leaks anywhere it goes to.

That line goes directly under the throttle body flaps and will let air in past the blades.

p31c63amg

It’s most likely where your air intake mounts to the throttle body. You will find a vacuum hose and a some what rigid vacuum tube. Sometimes when you take off your intake or play with removing the air filter housing one could damage one of the two vacuum hoses. I had this happen it caused a CEL light and a lean bank code. Have your local MB AMG tech check for this leak. The techs have all the toys to figure out these types of leaks. It took my tech a few day of replacing intake gaskets among other things to find the less than $100 part to fix it. Hope this helps.