Hydraulic lifter replacement.... 119.97

[Mercedes Mechanix]

Subject: 1994, Mercedes S420 119.9712.

Problem: Nosey ticking, rattle and becomes much worse with acceleration. The idle is smooth and consistent. Engine has not coded and further inspection has revealed lubricant has baked with both cylinder head, valve train/ cam lubricant areas. This was qualified during further explanation by the owner/driver with the history profile provided.

1. Have positioned the crank at 45 degrees before Top Dead Center (45 deg BTDC).

2. Pulled both head covers (valve assy. covers)

3. Removed TIMING CHAIN TENSIONER

4. To remove all four cams and inspect lifters. WIP on Passenger side presently.

4a. After removal of passenger intake and exhaust cams and noted hydraulic lifters (16 presently) collapsed (+2mm) from norm.. ordered and received 32 OEM Mercedes hydraulic lifters. Images of removed lifters below, new OEM lifters also included for comparison... side by side helps with viewing difference.... cams were not under much valve spring pressure at all! Reinstallation will show a dramatic difference in pressure and engine performance! A huge difference!

4b. The cams must be removed with EXTREME CAUTION! These are extremely expensive and fracture and crack easily. I always start with the center Cam Bearing Tower and alternate from left to right moving toward each end of the cam. This may take a few extra moments to relieve the valve spring tension on the cam evenly, but this is extremely important to ensure undue stress is NOT placed on any of the bearing journal machined edging! The installation is also tedious and involves the same alternation fastener installation process! Again, this to ensure undue stress
is not placed on your expensive cam. Take your time!

We will follow-up with further images as time allows!

Oh yes, Timing Chain looks very good, we scoped via the upper cover and viewed all guides as in serviceable condition. Also did an inspection of the cylinder walls via spark-plug orifice and no scoring is noted, other than expected for 167k miles. The T-chain (chain only) was replaced 15k ago, was R/R by the owner.... qwner referred to this as normal maintenance per her decision.... we give Major kudo's and great work... to this owner after she personally inspected the original T-chain. There were a couple of worn links evident. She pulled the passenger Head Cover and checked while manually rotating the crank clock-wise. Great follow up by this concerned Owner, well, we only assisted with some verbal advice! We do wonder if she is a member of Benz-World yet? She has alldatadiy.com and uses it!

She asked for this assist.. only due to other obligations at this time.

Dietrich

The original lifters (16)removed as of this date, have been checked and have collapsed by just over 2mm. All are totally gummed up with crystal hydro-carbon.... WIP on the remainder 16 lifters on the drivers side...

FYI, per this Owner, this engine had been inspected by a local Dealership's Service Department and no problem was found.

The Owner stated that she was advised by the Dealer Service Writer...
"allow their Service department to give the engine a thorough "Engine Flush" with their "special product" and that annoying ticking will be corrected!

[bobs]

Dietrich, is it just me or do those last couple of pictures show an awful amount of sludge build-up in there? Would you consider this to be normal? My 1997 model (119.981) with 94,000 miles on it is much cleaner.

Also, would you recommend replacing cam bearing & oil tubes while you're in there that far?

[mwhalen]

Nice work Dietrich.

I was thinking the same thing as Bob on the sludge buildup. When recently replacing my oil guides, my surfaces were much cleaner 97 S500 - 80K.

I think the owner should take the faulty lifters back to the stealership and ask for a refund on whatever they charged for the estimate.

[JamesBahn]

Dietrich,

Your posts never cease to amaze me. Great details and insight.

My 97 119 w/ 118k also look much cleaner.

[Mercedes Mechanix]

Will try this again, we did go through and check all the areas for tolerance. Seems the owner forgot to mention about driving the vehicle almost 100 miles after the water pump failed. OUCH.... can u believe it...we could/ would not either until the owner further explained and we saw the odometer..... the owner reported to have reset when the Temp lamp illuminated and was concerned about stopping in the area the "temp alert" occurred. The Owner was very clear about not pulling over, and listening to the engine get louder after approx. 60 miles.... WHAT.... yes, is as explained to us... I helped Dietrich up off the floor from laughing and then began asking the owner if he was F____ Nuts? I reminded him of the ethics thing, etc.... but even I was laughing and thing this guy is really out there somewhere in space. But the facts are, this machine has been through a huge amount of heat and survived. Also, Dietrich also set a garage SPEED record dropping those pans and pulling a few journal caps. Very lucky! Very, very lucky?

Darn engine did sound like a barrel of steel balls were loose within the engine when at idle and when a little acceleration... well, has anyone heard a 50 cal. automatic weapon or an old rotary, water cooled machine gun? But darn thing idled as smooth as silk... well a very smooth silk bag... full of LOUD as hell steel balls!

The rapping and tapping was huge. And Dietrichs eye's were even larger when he pulled both pans and the journal caps.... all tolerances were OK.... Also...he dropped the number four piston to check rings and cylinder.... all appears ok. What a TANK..... Somebody was definite on this Owners side that day. The only damage is the lifters....ALL 32 are totally frozen and burned lubricant solid within..... Appears that lil circulation pump did somewhat of a job moving the coolant.... and all three fans were working their heart out.

The water pumps bearing cap was burned through... from the race heat. But to survive this with only lifter failure..... Well enuff said.

Back to putting back new lifters.... the black glisten noted within both valve areas is actually old original black paint and burnt in hydrocarbon that even Dietrich's stainless tooth brush will not remove. Amazing.... but true.

We are running our scope into all cylinder chambers and imaging to ensure NO Surprises. Will follow up with further images from the Drivers valve/ lifter areas if anyone is interested?

Robert

[CaliE320]

Great write-up as usual,

I'm facing this dilemma right now sticky lifter ticking speeds up with acceleration.
I've put in some oil detergent and has eradicated the ticking somewhat but from time to time it'll reappear,is it safe to drive with a sticky lifter? For a job like this what are the costs involved? I've taken to my car to my Indy MB mechanic and he says it's safe to drive and
he wouldn't recommend fixing this problem now what are your thoughts?
Thanks,
~Cali

[miloking]

Originally Posted by CaliE320

Great write-up as usual,

I'm facing this dilemma right now sticky lifter ticking speeds up with acceleration.
I've put in some oil detergent and has eradicated the ticking somewhat but from time to time it'll reappear,is it safe to drive with a sticky lifter? For a job like this what are the costs involved? I've taken to my car to my Indy MB mechanic and he says it's safe to drive and
he wouldn't recommend fixing this problem now what are your thoughts?
Thanks,
~Cali

I have similar questions but would also like to do the Valve stem seals at the same time since the cams,lifters will be out. Anybody know how hard is it to do valve stem seals and is any special tools required (apart from those long nose pliers)....

[symbolic95]

the tool is expensive ,Snap-on has one for $400 ,but considering the price your indy or stealer charges i would say its affordable when it's time to change the seals.its an arm that "bolts" to the head with push rod.
seals are deep inside so you need L shape rod to push the seal onto the valve guide.

[miloking]

Originally Posted by symbolic95

the tool is expensive ,Snap-on has one for $400 ,but considering the price your indy or stealer charges i would say its affordable when it's time to change the seals.its an arm that "bolts" to the head with push rod.
seals are deep inside so you need L shape rod to push the seal onto the valve guide.

The reason i am thinking valve seals is because at accelerating around 5000 rpm iam getting bit of grey smoke, normal driving/idle etc. or even cold starts no smoke at all.... i should probably do a compression test first to be sure its not worn piston rings but i doubt it will be. Most likely Valve seals.... (not that piston rings would be any easier to deal with)

[gold benz]

At what mileage interval does the timing chain need to be replaced?