So my repair guy quoted me $800+ bucks to adjust the clearance on one valve. I decide I would save the money and try to do the job myself.

Does anyone know where I can find a DIY, preferably with pictures, showing how to adjust valve clearance on a M103 engine? Been searching and searching but can't seem find someone who has done the job and documented the procedure.

Thanks.

That engine has hydraulic lifters, no adjustment. If there is a noise it indicative of another problem.

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90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

I wonder what he was gonna do for $800!?

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http://i193.photobucket.com/albums/z...-RESIZED-1.jpg
1991 300E - 212K and rising fast...

Funny thing duxthe1 should mention hydraulic lifters, because that's exactly what the mechanic said he would replace. I think he was going to do them all for $800.

But I know only one of the lifters is making noise. Ignoring my little goof up about valve clearance, the next obvious question is how do I change the lifters? I've tackled several different jobs on this engine but I don't want to get in over my head. Any special tools needed?

Thanks

Anyone?

The lifters have sufficient allowance to compensate for normal valve/valve seat erosion, but if the valves have been ground, sinking the valves without taking a little off the stem tips they could "bottom out". New lifters will not help unless they have more travel, which I doubt. I'm sure there is information in the service manual about this.

So what's the history of the engine? Is the above a possiblity.

It's possible that the lifters are just dirty. Are you using CJ-4 oil???

A high detergent supplement might help clean them out if that is the issue.

There is no sense spending one dime on new lifters unless some good diagnostic work clearly indicates this is necessary, but if they have bottomed out, the head will have to come off and be disassembled so the valve stems can be ground a bit shorter IAW service manual procedures.

Most "mechanics" are too quick to change parts without understanding the real underlying cause of the problem.

Duke

@ Duke2.6 - Thanks for taking the time to post a helpful reply. I've had this car since 07 and have always noticed that one lifter sticks, or whatever it is that it's doing. I don't use C-J4 oil, I have no idea what that is. Perhaps you can tell me? I've been told that most modern oils like are okay to use.

I changed about everything that's fuel and vacuum related on this car since I owned it and still notice hesitation that comes and goes, so I am almost certain it's the lifter.

Now, I've been told that lifter springs can loose compression, and a stuck lifter will retard engine performance due to the fact that it will cause the valves to stay open or shut longer than is needed by the engine. From your experience, is there any truth to this?

Thanks!