Rear engine leak, do I need to pull the head? - PeachParts Mercedes-Benz Forum

andrewjtx · #1 08-18-2011, 09:21 PM

617.952 from an '84 wagon with 185k.

I'm starting to plan my cooler months where I can actually bear to be out in the garage on the weekends.

I've been eying the nasty leak I found at the head/block line on the backside of the engine for a while now. After more recent examination, it looks like the head gasket has a leak in it and is the cause of the mess you see in the pic below.

I had originally thought, when this engine was in the '84 wagon, that the rear main seal had gone. However, all around the crank looks factory clean.

And if I'm going to take the head off (give a mouse a cookie) wouldn't it be prudent to go ahead and have it rebuilt? I've seen Metric's prices... not sure if I'm up for that kind of price tag...

greazzer · #2 08-18-2011, 09:42 PM

I have the same nasty leak but mine is on the passanger side of the engine, in the rear, with a nice flow of oil going down to the starter which creates nice hand-sized oil stains in the driveway. It will get progressivly worst or at least mine has. I have been dealing with it for about 9 months. If you do it yourself, you are looking at about $650-$700. That includes a donor head at under $50 from Pull-A-Part (I am assuming you can get a donor). Machine shop is $450.00 and it took about 2 weeks. Head gasket kit is about $50. Collars, seals, and guides were another $150 or so. I used a donor because this is my daily driver. Plan on an entire weekend, and try to get a cherry picker. The head is HEAVY ... hope this helps.

79Mercy · #3 08-18-2011, 09:49 PM

mine leaks in the exact same spot, leave a spot about the size of a quarter on the ground.

the motor runs great, would it be a bad idea to just pull the head and replace the headgasket and re-install the head without having a shop machine it?

a nice trick for re-installing the head is to take some old head bolts and cut the top of them off. Screw them into the block and then put the head on...that way you dont have to worry about your gasket and head being out of line.

greazzer · #4 08-18-2011, 09:53 PM

I forgot to add the costs of new bolts. I just did the machine shop because I do not want to fool with this for a while. I dont think it is necessary to do a machine shop, just a luxury I guess. If one goes the straight gasket route, then it is a pretty cheap job, except the FSM says replace the bolts. The bolts cost over $50 I recall.

Can you explain the bolt trick again ? That stumped me. Thanks .

andrewjtx · #5 08-18-2011, 10:00 PM

Hell, at the cost of a generic machine shop, I might as well send it to Metric. Their rebuild is approx $530.

andrewjtx · #6 08-18-2011, 10:01 PM

A finding a wagon head in a PNP around here would be almost impossible.

79Mercy · #7 08-18-2011, 10:57 PM

Quote:

Originally Posted by greazzer

I forgot to add the costs of new bolts. I just did the machine shop because I do not want to fool with this for a while. I dont think it is necessary to do a machine shop, just a luxury I guess. If one goes the straight gasket route, then it is a pretty cheap job, except the FSM says replace the bolts. The bolts cost over $50 I recall.

Can you explain the bolt trick again ? That stumped me. Thanks .

Take some old bolts and cut the tops off. Screw them into the block and then lower the head down onto the block. Your using the old bolts as guides so that you can lower the head down in the correct spot.

vstech · #8 08-18-2011, 11:30 PM

doesn't the block have guide sleeves around several of the bolt holes? head bolts would make it easier I suppose, but I don't think the gasket moves. I've had several blocks apart, but I'm not sure of the sleeves.