Hello,
I have spent days, weeks, months reading all the forums and have decided this is the site I should burden with issues about my w126. mainly because it is the most organized, clear and thoughtful site.

My above w126 engine is now running on Choc milk colored oil, due to my daughter being more worried about Gore's global warning (she is in college) than understanding that lights and gauges on the dash actually have uses and meanings. she overheated the beautiful MB.

I need to know if there is someone who has archived engine removal steps on a w126. I have looked and find bits and pieces. I also wonder if anyone (Calif I guess) has an engine for sale. I also think the e300 3.0 is the same engine and looking for one of those, as well

any help, opinions, would be appreciated

Thanks
Warren

Hi Warren,

Funny you should ask; I just did an engine swap on my 1989 300SEL last spring. I used a 1990 300E as a donor car and only had to change around a few of the engine sensors and accessory brackets to make it work. I am what I would call an aggressive do it yourselfer with a pretty good selection of tools. The whole ordeal took me and a buddy about 22 total hours. I suppose some of the more skilled out there may be shaking their head at this amount of time, but for a first timer I thought it was pretty good.

The biggest mistake I made trying to mate the engine to the transmission while still in the 300SEL. I would recommend pulling the engine and transmission as a unit (as I did with the donor car) and then putting them together out of the car and putting it back in as a unit. It was difficult to line things up properly in the car and it wasted some time.
It’s actually a pretty straight forward process. The fact that it’s a 6 cylinder in that big engine bay helps.

There’s a lot of things you need to do, and I’m not a very fast typer. Do you have a specific question I can try to help you with?

Before you dig in to such an enormous task, are you certain that it's been overheated so badly as to require a complete overhaul?

Granted, in-line 6 cylinder engines are not very tolerant of being overheated. That big long head likes to warp.

Do you think that chocolate milk oil is due to coolant in there, or was it just baked?

You might only need a head gasket and coolant leaking into the oil could have actually caused the overheat.

I really don't know enough specifics of your situation, but I think it might be worth the trouble to determine what exactly went wrong and if it really needs a complete rebuild.

Does the motor not run at all now? Have you compression tested the cylinders? A leakdown test would also be a good idea......


Just sayin'......


-tp

If there is coolant in the oil, then the rod bearings have been compromised...Even if just the head gasket failed, and he replaces it...there is a good chance that not too far down the road the engine will destroy a bearing or two, requiring a full rebuild. This happens ALL the time over on the Supra forums. The inline-6 engine used in the Supra loves to blow head gaskets, and requires very careful maintenance, and lots of attention to keep it alive.

__________________
Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

As a matter of fact I have entertained that thought several times...she drove it home it was overheating, when I open up the radiator overflow there was the oil water mixture. The dip stick looks like it is mixed but not as lite. My problem is that it happened a couple of months ago and I walked away from the car...I did not drain it or try to restart it. Pretty dumb for such a nice car but I was not happy at all. I took the valve cover off and front hoses as well. I just assumed the head gasket was blown....Next step??

If there was any moisture in the oil (like coolant) it has probably already started rusting things, and etched bearings, etc...

Here is a pic of what happens when oil and coolant mix and are left to sit in the engine for long periods of time. This was after about a month...surface rust on the cam lobes.

__________________
Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

Mine are clean!!!! theoil in the engine is almost clear and I took off the filter it had no residue..but it does drain out, being inverted...I am perplexed

Well, if moisture sat in there for any time (I didn't realize this was a month ago) then yeah, you're screwed. But, didn't you just say now that your oil is clean?

Like I said before, you should do some homework before committing to spending money or time.

Take an oil sample and send it off for analysis. Then you'll know......


-tp

I never looked under the valve cover till later and it was clean...not like the picture shows. i shall look into it more. Thanks
Warren

If it was me my daughter would be paying for the repairs....

But I'm kinda mean.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Wait, so when you say you saw chocolate milk colored oil, where exactly did you see it? I'm confused, because later you state that you didn't pull the valve cover until later and that you saw oil in the coolant reservoir.

Oil in the coolant (while still bad) is much more salvageable than coolant in the oil... For one thing, the oil in the coolant didn't necessarily come from the head gasket. You could just have a busted radiator and trans fluid is migrating into the coolant.

I still think sending your oil off for analysis is the best bet. They can tell you for sure if you have coolant in it, and other useful things as well.


-tp

TP
Thanks...I will send off sample I saw someone on here who knew of a place to send the sample. I appreciate your help and I am confusing the issue. I assumed it was head gasket. But the cams are clear

Definitely! Its the same song and dance with the Toyota Cressidas as well. I think they used the same engine. If not for that issue, these are amazing engines. I had a 1981 Toyota Cressida with the 2.8L I6 engine and it was an amazing engine until the headgasket went, but I drove that car another 25K miles like that, after I had put in some sort of "stop leak" junk. Mine never got coolant in the oil or oil in the coolant, but coolant would foul the spark plugs and it would steam out of the exhaust even in hot weather. Also these were bad for the valve seals/rings. If I would stop at a light and let it idle for a few seconds, it would smoke when I would accelerate. This was also an issue with the 1991-95 Acura Legends (which also are known for headgasket issues).

That "big" Toyota of 1981 was a good one. It still had 210K and not one squeak/rattle and the original tranny shifted like silk. I gave it to grandpa to fix, but he gave the car away. That was 7 years ago. I have not seen it since.

Whats ironic is that Toyotas first V8 (placed in the LS400 with its 1989 debut) rate excellent in this area. I have researched and I have heard there has never been a report of a blown headgasket on the 4.0L V8 Lexus engine. They need to use this type of gasket in the replacements for the I6 Toyotas and late 80s/mid 90s Toyota 4-Runners, because they were known for this problem as well.