Factory service manual is posted online here.

Head bolt tool is shown below. The fatory tool is made by Hazet, and should only be about $20 or so at your dealership, or favorite source for dealer parts:

Jeff has told me this countless times and it hasn't sunk in yet

Be careful how you handle a head with the cam in place.

Sixto
87 300D

If you need to remove prechambers, do so BEFORE removing the head... it will be a lot more difficult without the head bolted to the engine.

Sorry to hijack, do you know the M-B part number for the timing-chain tool?

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Gone to the dark side

- Jeff

You mean the crimper, right? There is not a single number... you have to buy the pieces individually. Photos are here, the part numbers and descriptions are in this document. I vaguely recall there is a typo somewhere in there but I forget the details. You at least need the basic tool (photo 03) and diesel swage jaws (photo 10). For the OE link, the center plate is pressed in, and there are separate assembly jaws which press this into place (photos 07 & 08). The assembly links are recommended but not required (photo 09).

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Dave
Boise, ID
Check out my website photos, documents, and movies!

Thanks, I'll be pricing one as I don't like the master-link method.

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Gone to the dark side

- Jeff

Lojacking right back. I loaded my tools into another car and drove to where my diesel is parked (near the indy's shop) early this morning, planning to compression test the engine. Yesterday afternoon I went to Harbor Freight and got their diesel compression test kit $25, and their socket kit for fuel injectors (29mm and 27mm). I removed the front 3 fuel lines, the turbo-maniforld connector, and the flexible fuel return lines - zeroing in on the noisy #2. Unfortunately the 29mm socket was formed with a split (to accomodate an Oxygen sensor?) that caused it to spread and slip under the hight torque - 1/2" breaker bar and 2' cheater tube. (Harbor Freight said I could return them, even if used.) So I'm waiting for Sears to open at 11am.

Tomorrow I'll get the "triple sq." at the dealer. (Do I need the timing chain tools that Jeff is lookng for, to remove the head?

gsxr, thanks for the advice "to remove prechambers, do so BEFORE removing the head". I assume that means both the glowplugs and the injectors, right? Anyone know what both of these are torqued to? I was told by a local MB shop mechanic that he thought the injectors were about 125 lbs, and that the breaker/cheater sould work. I don't want to do harm to the alum head. And I assume they are LEFTY LOOSEY.

The master-link method is only approved by the factory for rolling a new chain into place (to connect the old chain to the new one, when turning the engine by hand). You're supposed to have a crimped link for final assembly. Make sure you check around at several dealers for pricing... note that Parts.com has the lowest price, but nail you with fixed 15% shipping. They might still be the cheapest overall though. Also try Caliber Motors.

And finally, make sure you're sitting down when you get the numbers... the basic tool + diesel swage jaws will set you back $375-$400. The assembly jaws (to press the center plate) will be $150, the case $45, temp master link set another $45, and retainer $30. Now you see why most folks don't buy the complete set, lol...

You don't need to break the chain to remove the head. You need some way to pull the pins holding the upper chain guide. Search eBay for 'Mercedes pin puller.' Or you can stack washers (old injector heat shields work well) on a 6mm bolt to extract the pins.

Injectors are torqued to 75 Nm/55 lbft or something close to that. You won't harm the head because the injectors screw into prechambers, not the aluminum head casting. When fitting a regular deep socket over an injector, make sure you don't damage or deform the return line nipples. That's the value of a proper injector socket (27mm). If you get a generic deep socket, pick one with as little internal shoulder as possible. In many deep sockets the hex goes only about halfway up. You can't lower the socket completely over the injector.

Sixto
87 300D

You want a 27mm deep socket, that is recessed internally to clear the return line nipples. The Craftsman socket may work ok. The OE/dealer socket is made by Hazet, works perfectly, but is a little pricey at $25 or so. Click here for a photo. It also works to turn the crankshaft bolt as well.



No, the timing chain can remain intact if you are only R&R'ing the head. You only need to "break" the chain and crimp a new master link if you are replacing the chain. I would measure the chain stretch prior to removal, though, so you can replace it if it's beyond spec.



If the head is only coming off for a simple head gasket replacement, you can leave the prechambers in place. If the head needs any serious work, the prechambers should be removed... special tool required to remove the lock ring, and then another one (with slide hammer) to pull the prechamber out of the head. The glow plugs must be removed BEFORE the prechamber is pulled out, or you'll destroy the plug, and possibly damage the head or prechamber. If you'll be having a machine shop do any "serious" head work anyway, you can leave the prechamber in there, the shop can remove them, since they should have the tools needed to do this on the bench.

Torque specs are in the factory manual. Injector spec is 60-70Nm (about 45-50 lb-ft), not 125 lb-ft, sheesh! The lock rings for the prechambers are 100Nm for vertical injection, 130Nm for angular injection. PLEASE read the factory manual procedures before tearing into any 60x engine. These do not respond well to "wrench first, ask questions later".

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Can the pre-chambers be removed with a plastic mallet from the piston side? Bad idea?

__________________

Gone to the dark side

- Jeff

Depends if they have been removed recently or not. On my original head with ~225kmi, it took a tremendous amount of beating with the slide hammer to remove them. After a full cleaning and installation in the new head, they required very little pressure to remove or insert. I'd be nervous about hammering on the tip of the prechamber, you wouldn't want to stress that area and have it fail later on, dropping into the cylinder...

Dave, thanks for the advice to hit the brakes, and hit the books. After reviewing the FSM, I'm heading back out to sears and the car to see if the Craftsman socket will work.

Can the type of valve stem seals (factory/aftermarket) be determined by inspection (pull the valve cover and look) or must the valve train be disassembled to see what is in there? I have a similar problem with lots of smoke after extended idling but had always assumed it was the low compression of cylinder #2 (keep reading!).

The car came to me in November 2007 with an indicated 134,000 miles and zero service history (yes, I shouldn't have bought it). Because the engine smoked a little on acceleration and because it used about 1 quart of oil per thousand, I had suspected leaking valve stem seals as one possibility. Local inquiries as to the easy availability of a valve spring compressor came up negative so I instead had the indy do a compression and leakdown test. The results were compression (cyls 1 --> 6) 400 - 300 - 460 - 410 - 420 - 380 and leakdown 20% on cyl #2 past the rings. This was at sea level on a warm engine.

From this I inferred that a PO had overheated the engine, cracked the head, and slightly melted the #2 piston, which got some aluminum in the ring lands, preventing the rings from completely sealing. The PO replaced the head with another #14 (probably locally rebuilt with aftermarket valve seals) but went no deeper into the engine (yes, I shouldn't have bought it).

Since the engine starts and runs well and gets 25-30 mpg, I chose to ignore the problem. The car now has 150,000 miles and continues to perform well except for the oil usage, which I can live with. Smoke upon acceleration has actually diminished (although it comes and goes) except after extended idling, which I rarely do.

Given gsxr's experience with aftermarket valve seals, I'm wondering whether it's worth the bother (and expense!) of having the seals replaced, given that it won't do anything to the #2 compression/leakdown problem (yes, I shouldn't have bought it). If the head does have leaky valve seals, replacement might reduce the oil usage (a feel-good sort of thing). So, how much work is required to tell the kind of seals?

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

You can't see the seals unless you remove the valve spring retainer, so the same work as replacing them.

__________________

Gone to the dark side

- Jeff