sbainb

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maw1124

I don't have that car, and haven't researched this condition... from your description I would have thought MAF, but you seem to have ruled that out. My next two would be (1) fuel filter (insufficient fuel, but on one bank only?); (2) fuel pump (too expensive a guess); (3) spark plugs (perhaps a previous stab at this with improper plugs); or (4) coil packs (same logic as 3).

If it was my car, I'd tackle (1), (3) and (4), in that order -- all cheap and good to do in any event. If not that, then I'd suspect either the fuel pump or the ECU, both expensive fixes. By the way, how's your battery? Benz SClasses are notorious battery hogs -- faulty batteries don't adequately power the computers, leading to all sorts of crazy faults that make no sense. But the fact that it's heat dependent might say spark plugs.

Hope this helps. Good luck.

maw

benz_addict

change your intake manifold gaskets they have been updated to the sls ones

Rocman8

Very common for the crankcase vent valve on the back of the intake manifold to leak as well as the intake manifold gaskets leak or the bolts loosen up. Sometimes the purge valve sticks open as well.

sbainb

I seem to have read many times that the intake manifold gaskets and bolts are a weak link in the M156.

When you say they have been updated to SLS ones - should I look to purchase ones that are spec'd for the SLS specifically - and rule out any chance of being given the same flawed variety in the S63?

Thanks for you help.

sbainb

Wouldn't a crankcase vent valve leak or sticking purge valve cause both cylinders to run lean? Mine is consistently putting out only bank 1 codes. Just a thought.

I seem to have read that many people have complained about the intake manifold bolts on the M156. Are there replacement (steel or titanium) aftermarket units anyone can point me in the right direction to? Or is it just a better idea to remove them, add some Loctite and torque them down to spec again?

The one thing that I can't understand is why the car is more prone to stalling when hot than when cold. If it is the manifold gasket/bolts, perhaps its due to metal expansion - causing a greater gap and letting more un-metered air in?

Really appreciate the feedback.

Rocman8

Your right both banks will run lean however I've seen them many times where one bank is out over specs and the other bank if you look at adaptations is right on the border of the specs so if it's a smaller leak caught early enough then one bank will throw the code first. Just purchase the gaskets speced for the car they will be updated already and you have to replace the bolts as well. They are one time use aluminum bolts no loctite at all and the torque spec was also updated to add an additional thrird step of an additional 10 degrees after the 90 degrees. When the intake is off replace the vent valve in the back they always leak around 50k

Rocman8

Do you have some kind of a scanner that you can compare the left and right banks self adaptation values?

sbainb

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Rocman8

Ok let's see the left and right side adaptation values

sbainb

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Rocman8

Oh I missed those screen shots. Yeah I've never seen values like that before. It's an interesting way the scanner is displaying the information. The minimum / maximum values in the star computer is +- 5% so I don't understand the 650.86% thing that's just weird. Anyways it still looks like both banks failed and just haven't set the other code yet.

sbainb

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sbainb

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sbainb

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maw1124

Lots of good learning here, mostly on the perils of DIY if you ask me. I guess that's why I let trained guys do the work. I like to be educated (via this site and others) just to save them some time and me some money, but they'll be doing the work not me.

Now that your MAF is installed properly, I'll go back to my original statement. You shouldn't have any problem with K&N filters on this car. They don't let in so much air the computers can't adjust.

At the risk of pointing out the obvious, for all you know all the other people reporting these problems after installing K&N filters made the same mistake you did (improper MAF installation).

Although your experience moved me further to going back to factory filters where I have K&N filters. If the goal is clean, cool, compressed air passed by properly reading MAF sensors and into the engine, I'm failing to see how adding oil to "free flow" filters aids that process. Don't get me wrong, I'm not railing against K&N filters. But I think they may have a better home in old Detroit Muscle than in any modern MB AMG (or BMW M) car.

Enjoy!

maw

sbainb

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maw1124

Makes sense, Simon. Given your plans, I would skip the K&N filters and go straight to Weistec. It's just one less thing to lose grey matter over. And as you can see, it's easy to lose a lot of grey matter on these Internet boards and complex cars. I trust MB AMG over both K&N and these tuner companies, but that's just me. I can't put down all the power I have, much less use it on the streets, so why risk reliability on more of what I don't need. Conversely, given the cash and grey matter these things consume, I need all I can get.

I have K&Ns on my M3 and on my 500E, both courtesy of the prior owners. But I'm starting to think to go back to stock, at least on the M3.

maw

sbainb

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