Email on the way, Steve...

http://www.w124performance.com/image...olt_driver.jpg

:euro:

Although I didn't get any history when I bought my 603, my mechanic looked at it and said, "The head's been replaced." I suspect a PO overheated and cracked the original. The replacement head is unfortunately another #14 but so far it is OK except that the valve guides/seals leak such that the car smokes a little and I have to add some oil occasionally. Given the cost of a replacement head, I've decided to put up with the smoke and just drive the car.

-22 head cracked
 

Dave, I thought that I had told you about this. The -22 head that came with the crate engine cracked. My indy discovered a problem on a coolant system leakdown test. The engine hydro-locked after the test and would do so repeatedly after any pressure was applied to the coolant system. The crack was on the rearmost cylinder and was from the valve to prechamber area. The head was replaced by the dealer through which the crate engine was sourced. At the time, it was the only 603.960 crate engine available in the US and came from a warehouse in Baltimore. It had a 4 year, 50K warranty and I was very close to the upper time limit-but not miles. My only complaint is that they did not install all of the clips on the fuel hardlines to the injectors and rubbing caused a leak which they would not cover. I seem to recall that you had asked for pictures but I could not get them from the dealer. The only other thing of note was on the front two cylinders there were impact marks on the head/top of piston where some hard foriegn object had bounced around. Not major damage, however.

Jeremy, the 60x valve guides almost never need replacement. If you're getting some blue smoke and oil consumption, and you're fairly sure it's the valves (not turbo, head gasket, etc) then it's most likely the valve stem seals. These can be replaced without pulling the head but it's still a fairly big job, as you need to pull the cam, carefuly rotate the engine 120° at a time from TDC (0°, 120°, and 240°) to get a pair of pistons at TDC, then use a valve spring compressor to remove the springs and access the seals. Don't forget (like I did) to then rotate the engine another 360° to bring the IP back into sync with the cam, and then check IP timing after the cam is re-installed.

Parts (new valve stem seals) are cheap but it's a lot of labor, and some special tools are required. If the head gasket is at all suspect, or leaking elsewhere, I'd just pull the head and replace the head gasket at the same time. Same deal with the head gasket replacement - parts are cheap, but it's a big job!


:stuart:

http://www.w124performance.com/image.../valve_job.jpg

You may have told me before... my memory ain't what it used to be, d'oh. This is starting to sound vaguely familiar now that you describe the details. I would have been really upset with the dealer that screwed up, both the fuel line fiasco, and then leaving some hard part in the intake tract to dent up your new pistons!

Was there any overheating prior to the indy pressure test / hydrolock? Any idea what may have caused the crack?


:boat:

Dealer SM got very quiet when I asked about cause
 

There had been some slight heating issues-going up to the 100 mark in winter-certainly not up to the red zone. The main issue that caused the indy to do the pressure test after many other tests was very rough running engine. When he found the hydrolock he was convinced that was the cause of the engine roughness. The hard object in the cylinder was apparently not the dealers fault since the head had not been off after the new engine was installed 3.5 years earlier. In fact it was the dealer that found the marks and brought it to my attention. There had been no work done on glow plugs or injectors prior to the dealer removing the head. Suspect that it came that way from Berlin.

Incidentally, I think I now am a believer in your "change the radiator every 5 years" policy. And I am due.

Bump
 

for customer with a cracked cylinder head.

New head
 

I see I never replied to this, so for the record:

The problem indeed turned out to be the valve stem seals. Whoever had last worked on the head had installed the cheapest aftermarket seals and they did not seal very well. The exhaust seals seemed to leak more than the intakes and, in addition to the smoking, was the cause of the external oil leak because the exhaust manifold was not properly torqued. Oil would leak through the exhaust valve stem seals into the exhaust ports and then seep between the head and the manifold and coat the right rear side of the block with a layer of oil.

The head gasket was in good condition and the head itself was OK except for some dings in the head and piston crown of the #2 cylinder -- sounds very much like what theref described in his #22 cracked head. I can't imagine what might have caused such damage.

In the end, I decided to upgrade to a later casting and picked up a #20 head with most of its bits and pieces from Sixto, who had had it on his '92 300SD that got rear-ended. I had a "light" valve job done and installed factory valve stem seals and a bunch of new gaskets. Made a $10 valve spring compressor from scrap metal and screws by modifying a design for a VW tool that was mentioned in a forum post several years ago.

The new head works great and the engine has stopped smoking and leaking. For what it's worth, by the time I got the head serviced (Paul's Empire Head, Santa Rosa, Calif.) and installed (including $140 in special tools) and replaced all of the missing/broken/damaged parts hidden under the turbocharger, I had spent $2,000. :eek: OTOH, the car is a lot more fun to drive since I can romp on the throttle without leaving behind a cloud of smoke. :D

Jeremy

Cheers just got this 300 sdl in June in the attached photo do I have the new trap oxidizer on the eng. ? ty 350,000 km on eng, runs fine when the turbo is engaged. ty in advance,, I would hate to loss the head.

No you don't have a trap ox.