lj0403

Hi, I have a 2014 E350 4Matic 126K miles with cold start up rattle plus code P034600 and P002177. After doing some research on internet, I decided to replace the chain tensioner and oil check valve. It turned out the chain tensioner is normal (length > 74.5 mm) so chain tensioner is not the problem. While I was rotating the engine, I accidentally found the camshaft adjuster oil control valve (#2760500278) of the left intake slips. From internet it seems that I need to need to replace the adjuster for sure but do I need to replace the oil control valve as well? Advice is greatly appreciated!! Thanks in advance.

S-Prihadi

Best if you replace the cam phasor/adjuster ( VVT ) and the oil control valve, both.
If you enjoy the experience and hassle for learning sake, you can start with cam phasor/adjuster first.

My friend's M271, have a very strong knocking sound. 70,000KM, no DTC yet just that irritating metallic knock.
In line 4 cylinder. So only 2 cam adjusters and 2 oil control valves. Change the tensioner too. These 5 items replaced.
Chain and plastic guides OK, so no change.
He doesn't want any headache later. Now so nice and quiet.

By mechanical work, the cam adjuster does more mechanical works. Lock-unlock and balancing oil pressure...sort of. More mechanical wear and tear.
Oil control valve is precision work, not really hard mechanical work...but precision work is also very important. Its cheap this oil control valve.

lj0403

Thanks a lot. I’ll replace adjuster at first and see if that fixes the problem. If not, I’ll replace the control valve later. Will post back my finding when that’s down.

S-Prihadi

If you do not yet own one : make sure you have the camshaft lock tool/bar.
The big torx to loosen the oil control valve I am sure you have.
Don't use the timing chain as camshaft lock .

M276 / M278 / M157 timing tool, china stuff is good enough. I have one but not Autool. I forgot the brand.

S-Prihadi

You went thru this verification already .... yes ? : https://static.nhtsa.gov/odi/tsbs/20...62561-2280.pdf

I don' have my EPC/WIS with me now as I am not at home.
Which data sheet or WIS stated 74.5mm chain tensioner is an acceptable figure for M276 engine...being a 2014 your engine is M276 correct ?

I recalled when assisting my friend M271 there is a special tool this one : https://media.carooline.com/media/01...LU40125_GB.PDF
to verify chain "stretch". The workshop does not have it though.
Are you using similar tool but for M276 to get that 74.5mm measurement ?

thanks

lj0403

Thanks friend for the response. I get 74.5 mm from WIS and I just measure it.


For the left intake camshaft adjuster I plan to remove the vacuum pump in the back and see if I can counter hold it with a T60 to remove the control valve. If I get a surprise, like there is nothing for the T60 bit to hold on, then I’ll remove the valve cover and use the hold down tool and a vice grip to hold the camshaft when I loose the control valve. After all it needs 130 Nm.

up_too_late

I came across a video of someone doing this job, may not be the right way but maybe of some help.