104 engine valvetrain questions - PeachParts Mercedes-Benz Forum

wbrian63 · #1 02-23-2007, 09:49 AM

My '92 300SE has about 113K on the clock. The engine recently had a new headgasket, oil pump and "some" new lifters. (Why someone would go to all the trouble to pull the head off and not replace all the lifters while the head was apart is a mystery to me).

Unknown as to whether the timing chain/tensioners, etc. saw any service during the headgasket job.

Occasionally, I hear a lifter ticking, and once heated up, the engine does seem to have an excessive amount of valvetrain noise.

HOWEVER, I'm new to these motors and what I'm experiencing may be normal.

Oil pressure at 90C-indicated engine temp at 650rmp is 1 to 1.1bar. Rises to 2 bar by 1000 rpm and is pegged by 1500-1750 rpm.

Engine runs smoothly.

I'm not opposed to doing some further work to ensure long-term reliablity, but I'm concerned that replacing the lifters is more work than I'd like to undertake on this DOHC motor.

Are there known issues with the upper valvetrain on these motors (tensioners that need to be replaced at XYZ miles, chains that stretch, etc.)

Also - how difficult is R&R of the lifters for an experienced DIY'er.

Thanks for your opinions and suggestions.

wbrian63 · #2 02-23-2007, 05:59 PM

Hoping David Poole or MBDOC will ring in on this - - - -

wbrian63 · #3 02-26-2007, 08:51 AM

Bump - again

Ali Al-Chalabi · #4 02-26-2007, 08:57 AM

I do not know of any consistent problems that have arisen with the valvetrain of the M104. It does not have the upper end oil consumption problems that the M103 has. As far as the timing chain goes, it is a short run double row chain with no complex turns, so it is about as durable as they can get. However, all chains can stretch and you can never know if it needs to be replaced until the stretch is measured.

david s poole · #5 02-26-2007, 09:55 AM

the 104 eng is one of the most reliable[except for the pesky head gasket failures]biodegradable wiring is an issue with those cars,it needs checking.usually the head comes off for gasket problems and it sounds as though someone was thorough about replacing what needed to be done.usual problems after head job involve the intake cam advance not being set properly but this evidences itself with a rolling miss that is hard to pinpoint.