I have an 87 300TD, with the 6 cylinder turbo diesel engine, the 603.960. It has 168,000 miles on it. I am the second owner. The oringinal owner did frequent oils changes, etc, and there are no records indicating head work or timing chain work. I bought it with 148K. I recently discoverd the right rear corner of the head is beginning to leak oil. I have replaced the valve cover gasket, so I am positive of the location. Is this unusual?

I have the maintenace CD, and plan on replacing the head gasket soon. It looks very simple, with the hardest part probably undoing all the wire connections and plastic clips without cracking everything.

Here is my question, I plan on replacing the timing chain as well. Is there a need to replace the chain rails at the same time? I did a search and did not see much info on the diesels and non-V8's, which are notorious for failing and doing tremendous damage.

Are there any other things I should do while I am in there? I have all new hoses, belts, belt tensioner. Injectors are original, glow plugs unk. I will probably replace all six glow plugs since it will be easy, unless there is sticker shock when I price them.

Thanx in advance for any and all advice.

ANy comments?

How are you, Deezel? It is nice to hear from you again.

Replacing the vacuum shutoff requires removal of the cross over. You may want to change it too while the cross over is removed. It is cheap and don't forget to order the big rubber o-ring. 603 uses the same glow plugs as 617. There are very cheap too.


David

glad to see you're still kicking, kinda missed ya 'round here. Been a few flagrant safety violations spoken of, that could used some attention.

Sorry no help from this coast on your current situation. But hey, it's a comment .

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Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Nice to hear from you David and Mike! Yes, I have been derelict in my duties as safety czar. I have been extremely busy and not having much fun at all! If I can get this head gasket behind me and the new floor in the motor boat, I'll be in much better shape.

David, thanx for the tip on the valve and o-ring. I think I will pass on the valve at this time, since it is so easy to remove the cross over tube. I had the cross over tube out about a year ago to check for carbon and "adjust" the EGR valve. Bought a new o-ring at that time, and could not believe it was about $14!!! I saved the old one since it still looked like new.

Also, I think it is Jeff Sr that is really big on using Stainless Steel cap screws on exhaust manifolds. Looking at this job, my plan is to leave the exhaust manifold bolted to the head, and unbolt the "trap oxidizer" tube from the head, turbo, and egr valve. Since the trap was replaced about a year ago, these bolts should be relatively "unsiezed".

Concerning the timing chain & rails, the dealer says the chain AND RAILS are recommended at 120 to 150K miles. He also quoted $700 - $800 dollars and two maybe three days.

I am hoping some one will have the experience to advise if the rails are really required. It will add considerably to the project (time wise) and don't mind doing it if it is needed. Seems there would be a lot more info on this site if it was an issue.

I was also pleased to find out the new Snap-on triple square socket I bought for the rear axle is the same wrench needed for the head bolts!

Waiting patiently for advice before I start the project!

Hey guys, I'm talking to myself here! Surely someone has some relavent experience that can steer me in the technically correct direction! Many Thanx!

From what I have heard replacing the timing chain alone is easy, but to do the rails you have to pull off alot of front end parts on the engine. If you put in a new chain and the rails are bad, the chain probably will not last long. maybe there is some way you can peer down in there and visually inspect the rails, ask an expert what to look for. If it were me and i planned to drive the car for a long time, pull parts off the front end, do the rails and any other parts that could be replaced while it is disassebled, like the water pump, belts etc while you can save on the labor charges. Also replace any cheap parts while you are in there, glow plugs, injectors, etc

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1996 E320
2000 C230 Kompressor
1988 190e 2.3 - 225K miles, owned for 7 years. I cannot say enough good things about this car. Very well built, even at 225 it ran like new.

I changed my last two MB'S timing chains. A 300D and a 300SD. Cost me a chain with crimped on master link, valve cover gasket and tool rental fee for each car. Saw no reason to change side rails, weren't worn that much. I believe chain cost $80, valve cover gasket around $10 and tool rental fee $50 plus about one hour labor. I saw MD diesel were owner used a replaceable master link instead of the crimped on style. Big mistake, link came off. Two bent rods, two ruind pistons, damaged head and a camshaft broke in three pieces. This owner was doing 70 mph when chain let go. With a crimped on link finished results look like original eguipment.

Thanx for the tips on the timing chain, master links, and advice on glow plugs etc. I was hoping one of the experts, guys who look at these cars often, would be able to advise if the chain rails that look perfectly fine are prone to the catastrophic failure that the V8's are famous for. There is considerably more work to get to these, and I don't mind doing it for a good reason. It seems the five cylinder diesels do not need this type of regular work, other than the chain.

Steve Brotherton, Benzmac, Arron? Are you out there? I would love your opinion and value it greatly!

Many thanx!!

Do the chain tensioner and look at the rails. If they look ok I don't replace em. Take a good look at the tensioner rail , this one usually has the most wear and for goodness sakes DO NOT use the e-clip chain link. It's for installation purposes only. I personally have never seen a rail break on one these engines and worken on MBs for about twenty years. Brian

Thanx very much Shooter, your advice will be followed! I'm going out of town on a trip, so it will probably, be a while before I start. I will post results when I am done!