507OverBiturbo

Hey guys, I'm sure there's a thread on this somewhere, I remember seeing one long ago, but I didn't find it when running a search, apologies in advance -- operator error.

I have a 2014 c63 507, engine light came on, took it to the shop I regularly take it to, they say the code is for the intake manifold.
But they also say the only way they can tell if it is actually an intake man issue is to remove it from the car, and then I'll probably need a new one, and they said that's like $5K (!)

I remember seeing suggestions a long time ago that it's probably gaskets, not a cracked manifold, and that if replacement is needed you can get one from Weistec or similar -- but I can't find that thread now....

Anyway, any help appreciated -- I don't want to have to take the car to the rip off dealer, but I do need to know how to get the problem diagnosed (I don't work on the car myself, don't have that knowledge), and then if I do need a new intake manifold, are there places like Weistec that usually have them, for a 2014?

Thanks much --

Solo wing

- It would be helpful if they gave you the actual codes, or even better buy a cheap scanner (iCarsoft OR Foxwell NT530) and read the codes your self.
- M156 intake manifold issues can be caused by a faulty PCV, gaskets, loose bolts, bottom plate corrosion, TB plate corrosion, and many other vacuum leaks.
- After knowing the codes, I suggest they do a smoke test to reveal the leaks, instead of guessing and throwing $5k + down the drain.
- The intake manifold in our engines does have its issues but I still believe it is still very solid. I took the 15yrs-old manifold off my car and its still spotless with no corrosion or leaks whatsoever.

Good luck and get a second opinion 👍🏻

507OverBiturbo

Very helpful, thanks for the quick, helpful reply

Dogtag114

I had an intake manifold replaced under warranty early (in 2011 on a 2009) on so I didn't care. In the last several years of ownership, I've had the code again, simply cleared it and it never came back.
Regardless, you need to have a scanner to use on all your cars, often a simple code read and a google search will save you tons of money over the long run with all your cars.

hachiroku

as mileage goes up on these engines, you're most likely to see air leaks in area's which are not intake manifold gaskets. the gaskets will leak right away or seal right away, they don't get worse unless your fastener has lost tension.

throttle body mounting plates leak over time. other area's that can leak are vacuum lines, brake booster lines, or PCV.

if your PCV is 50k or more miles, i would replace this before doing anything with the actual intake manifold. if all else fails you'll need to complete a smoke test to determine a leak.

507OverBiturbo

Thanks - Here are the codes:
0745: mixture, cyl bank 1 is too lean
2091: mixture, Cyl bank 1 is too lean
0749: mixture, cyl bank 2 is too lean
2095: mixture, cyl bank 2 is too lean

Took it first to BenzbyBlair in Houston, as they said they would need to dissamble the manifold to diagnore it, took it to deal (Merc Benz of Sugar Land). Waiting on their diagnosis.

Any thoughts on these codes?

AMGSPY

It seems to me an intake manifold problem would be more likely to show up on a single cylinder bank. I'm going with hachiroku and solo wing on this. The dreaded PCV, vacuum / booster lines, smoke test. Let us know what you find. I have the same year 507.