Is head gasket replacementa DIY job

[enenenk]

I have two diesels (OM602 & OM617) that have recently decided to begin leaking oil out of the head gaskets. Since I have two wengines to repair, I don't hve the funds to do the job. Thus, I am considering an attempt at a DIY on one. If I do one, why not do both (right?). Are there any online resources to help with this? Also, is this an entirely foolish attempt that will probably require my mechanic to rescue me from myself?

[rchase]

Headgasket not a DIY unless you have an engine lift and access to a machine shop. Valve Cover Gasket super easy and a definate DIY job.

Originally Posted by enenenk

probably require my mechanic to rescue me from myself?

As a paid mechanic myself, there is little I hate more in the world than a second hand/half finished job. If you like your paid mechanic and want him to give you good deals and help you out down the road, do not give him hell by doing this.

I have taken some half jobs in the past and there are customers I've sent doun the road because they made a total cluster-f**k of their "project".

The work is ok. It's finding all the little nuts and bolts that have been taken off and put who knows where. Nothing will get a mechanic red hot like being handed a bag of bolts and then told to put it back together, correctly.

/rant off.

Are you sure it's the head gasket? Where are the leaks on the engines(By the injection pump, back, front, manifolds)? Is it possible for you to post a picture? I'd hate for you to pull the head and later see it was the oil finter housing or something simple like that.

Like rchase said, it's not a DIY job unless you have a few years of serious stuff under your belt. If you drop the timing chain during the process, you will curse at yourself ten times over.

As for online resources, see the Online Mercedes-Benz Service Library link

[mplafleur]

That certainly can be a DIY job. Not the first I'd tackle though...

Just over a year ago, I replaced the cylinder head, oil pump chain, timing chain, and vacuum pump onan '85 300SD. I did it all in the winter, in my yard, and without a hoist.

No machine shop is needed.

If you are determined, you can do it. Make sure you get a service manual. Haynes, MB, or the CD (eBay).

An make make sure it really does need a head gasket. Are you sure the oil is not from somewhere else?

[Brian Carlton]

I, too, have replaced the cylinder head on the 617.

However, I would not recommend that you attempt this unless you are fairly knowledgeable with engines and especially familiar with the quirks of this engine. There are several critical steps along the way.......which if ignored.......or if screwed up.......will leave you with a pile of hardware that won't run.

It's also very critical to put all the small fasteners in suitable bags and label them as they come off the engine.......otherwise you have no hope of figuring out where they all go.

You need to have a lot of patience for this task. Every step must be planned to avoid costly mistakes.

The procurement of the FSM for the 617 is mandatory for such a task.

[rg2098]

I'm 16 years old and did the head gasket on my 250 before having to pull the head again and found a cracked block in which I did an engine swap and put my original head on the "new" engine. I've been working on Mercedes for 7 years so I do know a thing or to but the job is mainly just time consuming and risky if your inexperienced, although no special tools are really required.

The only special tool I needed was for pulling the timing rail on my OM617 which I fabricated out of $5 worth of washers and a bolt. Let me know if you go ahead with the job and I can give you detailed instructions on how to make the rail pin puller.

[barry123400]

Why not get the proceedural instructions, read them and see if you understand them well. Perhaps if you feel semi confident then try to enlist the help of a friend who perhaps has a little more experience if you feel it is required. Theretically just following the step by step proceedures will get you there. Everyone that has changed a head gasket had to do their first one at one time. Like most things in life the first time is the hardest. You express the motivation to do it. As others have mentioned you have to make absolutly sure it is leaking out between the head and block of course first. I would suggest doing the 617 first. If you go for it. Remember you will need to borrow or buy a good torque wrench for this procedure. One other possibility is to repeatedly clean the area of leakage if it is in a return passage area with laquer thinner. Then try an external seal with silicone. If you can suck all the oil out with the thinner from the area it might do. Providing it is in an accessable location. You will have to wash the area down several times at least. It only stands a chance if the oil is gone from the area. I have changed too many head gaskets on my vw diesels over the years for just the oil leakage problem myself and thought if I ever had to again I would try the external seal in that area first. The vw return passage area is located in a good working location though and if the siicone did not hold really does not compound a later head gasket change in any way. The last suggestion is also dependant on how much leakage is present as well of course. If it is pouring out forget it. Never set up a senario that could result in a loss of the engine. A moderate seep would not disturb me to try it on.

[Hatterasguy]

It depends on how skilled you are. If my 603 needed a head gasket I would do it, actually at least to me it doesn't look like to bad of a job. The exhuast manifold would probably be the worst part.

So I guess the queston is how much wrenching time do you have? Do you have the space and tools for such a job? Have you ever pulled a head gasket before on another car?

[ConnClark]

I would be hesitant about the OM603 gasket replacement. Aluminum heads are far less forgiving than cast iron ones and the OM603 head doesn't have the greatest track record. If I had to do both myself I would do the OM617 first.

Make sure you retorque the head bolts in the right order, then double check their torque after they are all installed

[Hatterasguy]

Originally Posted by ConnClark

I would be hesitant about the OM603 gasket replacement. Aluminum heads are far less forgiving than cast iron ones and the OM603 head doesn't have the greatest track record. If I had to do both myself I would do the OM617 first.

Make sure you retorque the head bolts in the right order, then double check their torque after they are all installed

So what? A head gasket job is a head gasket job. You should follow the torquing procedure on any internal engine work. You should also make sure your torque wrench is accurate.

[Brian Carlton]

Originally Posted by ConnClark

I would be hesitant about the OM603 gasket replacement. Aluminum heads are far less forgiving than cast iron ones and the OM603 head doesn't have the greatest track record. If I had to do both myself I would do the OM617 first.

.......he's got the OM602........no cracking issues AFAIK.

[vstech]

when they are removed warpage can cause sealing issues, so milling is usually required. whenever compression changes (ie. milling) are made to a diesel motor gasket thickness compesation may need to be made. factor this in before deciding to work on aluminum head vehicles.
John