New user/Mercedes noob needing help with a huge resto job
 

First off I would like to say hello all.

I'm a Mercedes virgin and am in need of guidance.
I think I might have bit off a bit much for my first MB but I am an experienced mechanic with close to 20 years under my belt this far so I'm confidant I can do it lol.
So enough about me on to my project thus far.

I have all ways wanted a mob and finally purchased a cheapy (never good lol) these are the details; 1987 190e 2.6L with 217xxx miles on the clock.

The body and interior don't show the age as much as the engine does, I got the car for 900$ With a blown water pump and ruff "cold" idle is what the add said, "cold" turns out to be all ways.

I went ahead a purchased it and drove it straight to my friends house where I could repair the water pump.
I never let the temp gauge get above 3/4 on the 2.5 mile drive.

The drive was made at night so I wasn't able to see if it smoked or anything else.
The person following me reported only a slight smoking right before I would pull over to let it cool down.

It started every time on that drive.
I replaced the water pump and after the repair it wouldn't start, it turned out the coil was bad. Replaced said coil and now it starts good.

When diagnosing the no start I performed a compression check and found 5/6 cylinders were at 14 +/- 4 psi and #5 cylinder was at 0 :(. The compression test was performed after the vehicle say for about 4 days.

Once I got the coil replaced and I got her started I found that she makes severely and runs rougher than running on 5/6 cylinders would explain.
So I performed another compression test and found that the 5 cylinder were now down to 100 psi even at about the first mark on the temp gauge.

This is really freaking me out because I don't have a lot of cash to dump into this project I bought hoping for something for safe for my girl friend to drive the kids to school in.
So I have to watch every penny I spend really carefully and so I really don't want to have to pay a 150) tow bill because I don't have a way of towing it so my first question is more of an opinion poll.

My shop is 19 miles from where the car is at, at my shop I have everything I would need to repair anything on it besides machining.
So I want to drive the car to my shop but I don't want to screw it up anymore then it is, so is there anything I can do to make sure I don't or to make the drive even lol.

I have a bunch more questions but figure I'll ask them with new info considered.
Please let me know if u need anymore info, I am writing this on my phone so I can't guarantee I didn't leave anything out lol.

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Personally I would bite the bullet and have it towed to your shop. Its likely that you have head gasket issues as well.

I, OTOH, would make the drive. Just take it easy, go in daylight when it's not too cold. If it conks out, you can call a tow then. Since you're going to have to pull the head for the compression issue anyway, I don't see the huge risk.

tow it, you don't want to ruin a head that could possibly be salvaged, I found out the hard way that the most expensive car you can own is a cheap Mercedes, check out my build thread http://www.peachparts.com/shopforum/tech-help/344125-1985-w201-build.html

Ya thats what I am worried about is that in the long run its not a good deal, but hey I figured id give it a shot :).

I haven't been able to get the car to the shop yet since Ive been busy plowing the last 2 days.
I do have another question tho, the compression was a lot better before I had the no start after water pump install issue.

Do you guys think that the loss of compression was due to fuel washing the cylinder walls and breaking the hydrostatic seal of the piston rings?
If thats the case wouldn't driving it the 20 miles to the shop help? I'm drawing on my experience from other types of automotive and aircraft engines, so if I'm being retarded just let me know :)?

One other question for the moment is the oil pressure on the car is maxed out as soon as I start it and it drops to about 2 bar when at 80c at idle, is there anything to explain that the oil pressure is extremely high?
Besides bad sending unit lol.

When I drove the car to my friends house when I first bought it oil pressure and everything else was completely normal, meaning mid point on the gauge when cold at idle and then fluctuating correctly with temp and RPM.

I also wanted to tell everybody thank you for all of your known and unknown help, lol Ive been searching the forums for a couple hours a night every night since I bought the car :).

Thats how I was able to get the car started and diagnosed as far as I have.
What kicked my butt the most was the fact that the coil bench tested just fine but under operation it would fail.

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Is this near you? Found on car-part.com this is a USA wide online salvage yard inventory search. It might be a more direct route to replace engine.

1987 Engine Mercedes 190 -201 2.6L RAN OK 122K 160-170-122K 122,000 A C129 $550 Blake's Small Car Salvage, Inc. USA-CO(Erie) E-mail 1-800-665-4326

SWEET! Thank you VERY much 97 SL320 :)! Thats right down the hwy from me, I'm just about 30 miles away in loveland :). Im going to have to check that out in the morning

Anything anybody would recomend during an engine swap in one of these? Any tricks, special must have tools...? Any advice would be greatly appreciated

If You Want To Tow It
 

For what it's worth...

I just towed one of my Benzes.
Uhaul rents a full size trailer for $50.

Surely you have a friend with a pickup truck like I did.
Flipped the Uhaul yard guy $5 & he made sure I had it hitched properly.

Had the job done in a few hours & returned the trailer & got the Uhaul manager to knock $10 off my rental charge because he could rent the trailer out again that afternoon.

Not for everyone, but worked in my situation.

Good luck.

P. S. Why not trailer your car & pick up the engine & put it on the trailer too, if you decide to buy the engine.
Just another thought

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thats actually what im trying to get set up right now, Im the fleet mechanic for a couple landscaping companies and we have about 30 trailers just collecting dust during the winter so Im trying to talk the owner into letting me use one for the weekend so I can move the Benz. Typically Its no prob for me to move cars cause I have a 98 dodge 2500 set up to tow and plow but it ate a valve and I haven't had time to tackle it yet lol.

Have a look at 190rev.com for motor removal info ( and be sure to keep posting info here.)

It _might_ be better to pull engine and trans as a unit, I'm not sure. The upper rad support unbolts allowing for the motor to come forward during removal. Also Mercedes hoods stand straight up if you push / pull a lever on the hood hinge so no need to unbolt the hood.

If your a professional wrench; just approach it as if it were just another car. Because that's all it is. The older model Mercedes are easy to maintain and repair. That being said, there is a bit of a learning curve involved.

Start by checking for a head gasket issue: a four gas in the surge tank, or use a "block tester". Then go for your compression test hot, do a wet test on the funky cylinder, leakdown if needed. You have any top end noise? Could have a cam lobe going south. The bottom end of these engines are bulletproof given reasonable maintenance.

I paid $300 for an 89 300te. Used parts from 3 engines to build one. I've done a lot to her in the last year but still only have about 1500 total in her. Also put almost 20k on her since the engine went in a little over a year ago. I love my cheap Benz! I drive it a lot more than I do my 560SEC. Use your skills, not your dough!!

p7fan, ya thats exactly as im approaching it (oh joy yet another engine swap lol) but since my goal is a smooth running totally custom benz i wanna make sure i do it right :). I did both a cold and a hot compression test and before I changed the water pump and had the no start issue 5/6 cylinders were at 140 +/- 5 PSI, so definitely within spec as far as differences across the board but the #5 cylinder is flat lined, I tried the oil down the hole trick to test for rings and it made maybe a 10 psi difference, I dont have the car near shop air yet to do a differential compression/leak down test to pin point the issue. If it is say valve guides, can those be done with the head installed on one of these engines? What worries me is the fact that the compression dropped so much after I got the no start issue taken care of, it went from 140ish across the board to 100ish across the board. Im keeping my fingers crossed that its just due to fuel washing the cylinder walls and will improve with mileage.

Question for everybody, has anyone had an issue where the engine was producing to much oil pressure? Like a stuck pressure blow off valve or something? When I start the car it pegs the oil gauge at max and only drops down to about the upper 3/4-7/8's of the gauge when it warms up to normal operating temp. But when I picked the car up and drove it to my friends the oil pressure was completely normal so im leaning away from it just being an indication issue. And Im pretty sure if I could figure out the oil pressure thing that would cut down drastically on how much the car smokes.

Im talking to the junkyard that 97 SL320 sent me the add about but im really hoping I can just repair this engine due to the desperate need of a car to get the kids to school lol. And Im going to try to get the benz to my shop before the blizzard rolls in tonight and hopefully have it on the road by monday :).

Sorry for the long posts lol. But I wanted to add one more thing: A thank you to everybody on here for all their input, everybody has helped me SO much all ready :)! Let me know if theres anything at all I can do for anybody. I feel like a wet behind the ears fresh outta training mechanic instead of an experienced fleet and aircraft mechanic when it comes to this car lol

Are you sure your gauge is working properly? It isn't common to instantly lose compression on an engine that has not been run.



Doing a wet compression is a waste of time and if too much oil is added, compression will rise due to an artificially induced compression ratio increase.( decreased chamber volume not "sealing the rings" and, if the rings are very worn they will be leaving lots of oil on the walls already. )


Do a quick compression test ( be sure disable fuel / ignition and prop the throttle wide open, you need air to do a proper test. ) then follow up with a leak down test. This will let you know where the problem is.

Some leakdown in the crankcase is normal, some out the exhaust on high mile engines, some from the intake on very high miles engines, any from the rad cap is a sign of headgasket / head combustion to coolant leak.


Valve guides won't cause low compression unless they are very very worn out to the point the valve won't seat.

Guides are not changeable with the head on the motor, they are pressed in ,sometimes resized and the valve seat needs reground.

If you are thinking of valve guide seals, these are changeable on most engines with head on but bad seals will only cause oil smoke not compression loss.

What do you call "normal"? Form some engines top of the gauge when cold is normal.

High oil pressure won't cause smoke from the exhaust.

I got in the habbit of doing 1/4 oz of oil down the spark plug hole when I was in aviation, (I know completely different worl lol). I tested the compresion gauge on several trucks in my fleet and it measured accuaretly on each one, thats whats throwing me for a loop because if the gauge is right then something weird is going on cause I totally agree with you and have never seen it either when an engine instantly loses 40+ psi compression just by not starting. The main reason I was asking bout the oil is I have seen a couple engines that the only pressure was way high and it caused or was part of the cause of the engine burning a lot of oil. The reason I say that is that on those couple of occasions I replaced the oil pressure relief valve/oil pump and it cleared the smoking up. I use the term "normal" pretty lossely lol. Im going to get the car to the shop this weekend and will get a gauge on the engine itself to test the oil pressure and do a leak down and everything, and then Ill be able to tell exactly whats going on. Ill let you guys know when I get those numbers and find out exactly what happens.

Sorry for being such a noob on this car, I dont know whats wrong with me cause I shouldnt have an issue getting this thing fixed up, Ive done it to countless cars before lol. I trully have been doing this stuff for about 20 years on things that stay on the ground and about 10 years on things in the air lol, (but all ways in a fleet type setting) Im just having a "mentally handicapped" moment :)