w124 - dealer says coolant leaking from cylinder bolt

[richard28]

My son's 1988 300ce is at the dealer after major coolant loss while driving. He needed a loaner, so car towed to Dealer in Los Angeles. The initial report is coolant leaking from an engine/cylinder bolt, and they are still looking at it. [I hoped it was just the hose from engine to heating core, but no such luck.] My son reported there was no oil in the coolant or reservoir, or water in the oil. Could this be a blown headgasket? If so, my inclination is to dispose of the car, the repair cost just is not justifiable on such an old car.

Thoughts?

Richard

[JamesDean]

As I understood it there is a defect in the M103/M104 headgaskets. That effected ALL engines and it was more a matter of WHEN rather an IF an m103/104 was going to need a new gasket.

When my 2.6's went it started to seep oil out near the #6 cylinder. My shop quoted me about $1200 for the whole job. My friend had his M104 done for about the same.

Cost justification is a matter of personal opinion. I opted to have a 3.0L m103 dropped in, it too will need a headgasket in probably 50-75k. I'll probably just have it done at that point. or swap an m104 in

[JohnM.]

I don't think coolant can leak from a cylinder bolt, but I could be wrong.

It is very rare for the M103 headgasket to fail in such a fashion, just coolant loss with no oil in coolant or vice versa.

I really want to say its a rubber hose that failed and the dealer is being daft. Did they check the hose at the lower drivers side of the block? I wouldn't throw in the towel until I see a compression/leakdown check.

[richard28]

JohnM,
On my 1987 300e I had the coolant leak from the hose you mentioned, and replacing it fixed the issue. Based on your note I emailed the dealer's service advisor to have the shop check that hose too.

[richard28]

Well, the LA dealer said it's the freeze-out plug under the exhaust manifold, needing 6 hours labor and $300 parts (incl gaskets & antifreeze) to replace. I called my indie, Willy in Great Neck,NY is brilliant, who originally got the diagnosis 100% correct; & he said it should cost about $300 to replace.

[JohnM.]

Better than a headgasket.

[ah-kay]

Freeze plugs are to plug the holes when the engine is casted. Most, if not all, engines have freeze plugs. 99% of the time freeze plugs leak due to rust and neglected coolant change. The rust inhibitor in the coolant prevents them from rusting and hence leak.

Some cars have freeze plug between the engine and tranny. Go figure how much it costs to fix in labor. Part is only $1 or less. If one freeze plug leaks then the chance the other will leak is pretty high.

Good luck.

http://www.automedia.com/Replacing_a_Freeze_Plug/ccr20070401fp/1

[ps2cho]

I had to replace the freeze plug on my 300TE.

The above is correct about not using the correct Zerex G-05 coolant. That or MB coolant is the ONLY coolant you should be using -- along with distilled water.

6hrs labor? Gotta be kiddin.... You can access it, albeit a little tricky without removing anything. Its probably leaking at the same one in my pic (left one).

Here's where it is. You can see I replaced it. Ignore the arrow

[richard28]

To finish the thread, yes, it was the freeze plug and Enrique replaced it, the thermostat & radiator cap for less than $250 in labor. I'm very satisfied. Thanks to all.

Richard

[190E 2.3 rur rur rur]

that sure is a strange looking freeze plug in that pic. why does it have a nut shape in the center??? for turning???? hmmm u can ask the dealer to send a pic of the leak in action. the more you understand them , the more confident you can be that you have a fix for your money. if it is along the engine below the head , they could take the pic from below. casting, soft, or (freeze) plugs can be replaced individually. there is a plug offered by dorman that may simplify things. its metal, and you use two wrenches to start it. then you tighten the brass capnut. access is the key to success in these repairs because you have to tap in one side of the old one to spin it perpendicular before grabbing it and yanking it out. that is if its a standard core plug . there is also ,in some cases, the possibility of putting an engine heating plug in place of the one you remove.a block heater, then start your benz in freezing temps. i have been asked to stay late and get freeze plugs changed, at the expense of putting me on the hiway after dark in the snow. you can bet we had some expansion type plugs used in those instances to do us all a favor. huge time saver and debateably more reliable. NOW, if its a bolt, you might remove it, measure it, and add teflon sealer to it before installing and retorquing. stretch bolts need only be replaced when they are too long!!!! malpractice believers always sell new

[optimusprime]

Yes these are bolt in frezze plugs. Just for others looking in on this old post .You can get them just like a large wall plug Like runbber with a bolt going through it you lock it up and it expands .