I've been a diesel engine lover for a while, and had previously owned large diesel engines such as cummins and detroits in old schoolbusses. I'd been dreaming of a little diesel car for so long, and a few weeks ago I found my dream car-A 1980 300sd turbodiesel.

I bought it in north carolina, and went to drive home to vermont.

It cranked right up, sounded pretty damn good for a 30 year old engine, and ran great. I was using quite a bit of oil, but was obsesivly checking my oil every 50-100 miles.

Abotu 100 miles from home, I started losing power going up steep hills, but I figured I was almost home, and would figure it out when I got there-she was still running great for the most part.

When I got about 50 miles from home, the leak seemed to be getting worse. The last time I stopped to check the oil, it took almost a halfgallon, after having checked it only 80 miles before.

12 miles after I added the last halfgallon I was driving, and with no warning at all the engine cut off, and I pulled to the side and saw that my baby had puked a gallon or two of oil onto the road. I opened the hood, and there was oil eeeverywhere. It seemed like it must have come from near the top-perhaps the valve cover gasket, or the blowback valve-both of which had been at least partial sources of the leak before.

Deleriouse from driving 900 miles pretty much straight thru, and almost home, I called AAA and got towed the last 30 miles home.

When I got home, I put oil in, and was startled to see that she cranked right up, and didn't sound much rougher then she did before.

I tested the compression, and found it very low (150-200) in all cylinders.

Unfortunatly, I had to canabalize an injector to get the tester to screw on, so now I at least need to find a new injector before I can drive her again.

Soooo....any thoughts? What's wrong with my baby? What happened? Is it a lost cause?

I'm certainly not a mechanic, but I've been living with (and therefor fixing...) janky diesel engines for a little while, and I'm not intimidated by getting my hands dirty. Do I need to find someone more qualified, or are there more diagnostic things I should try?

Thanks!

Welcome to the forum unfortunately it sounds like your oil cooler line dumped the oil and your continued driving took the motor out.
Also, on this forum, thread titles need to be descriptive of the problem.
Keep us posted on the progress!

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My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Uh, 150-200 sounds rather low for these diesels. I believe 360 is good/normal?

Sounds like either you didnt perform the compression test correctly or you've got major compression issues.

Thats quite a bit of oil to go through for such a trip! I would check the oil cooler lines to make sure they are intact!

EDIT: I agree with what Vstech said.

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82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

not a good moment,but....Welcome




.

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

Were you loosing all of that oil along the way or were you getting incorrect dipstick readings and just overfilling the engine?

Can you explain what you mean by "cannibalize an injector"? You will need new crush washers (seals) for the injectors, after having removed them for the compression test, but doing a comp test shouldn't involve disabling an injector.

You need to address the leak, and get the injectors back in and let it run for a while, then try driving it. That car weighs over two tons. If the compression IS that low, the car won't be able to get out of its own way (I've driven one about that bad).

The fact it started up again and ran pretty much okay is not what I would have expected.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

Do you mean it was cranking as it normally does or it actually started? You need a really warm day to start a 617 with 150-200 psi across the board.

Sixto
87 300D

You called AAA way too late.

It reminds me of anther thread I read where the Guy bought a Mercedes and was determined to drive it home despite the fact that it started to over heat mid way on the Trip. The things He did; did not in the end save the Engine that He continued to drive with.

Lack of Oil is even worse because it ruins the precisions surfaces inside of the Engine.

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84 300D, 82 Volvo 244Gl Diesel

If you disassembled an injector and are some how using it to test compression I have to wonder if that impacts your low readings.

As Zacharias asked, explain what you mean by "cannibalize an injector".

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First off I pray that your compression measurements are off. I suspect that using an injector as an adapter may be leaking compression. If you managed to get it running after the event then most likely you have more than 150# as the others said.

Check your oil cooler hoses they are a weak point and will cause the symptoms you describe.

These engines are tough but not bullet proof. Hopefully the lack of lubrication did not do irreparable harm to the engine. Fortunately the PNP yards are full of 617 engines so as long as you have a good car body (i.e. rust free) it's worth saving.

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Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

About a month after we got my '82 300SD on the road, it went through about 4 quarts in 100 miles one day. Turns out it was an o-ring in one of the oil lines going to or from the turbo. Can't remember exactly but the turbo oil system is another place you can lose a surprising amount. Worth checking.

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~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL

I suspect you have somehow increased the volume being measured for the compression test. Thats by using the adapted injector base. Any increased air space before the check valve will seriously lower compression readings. If so the readings will be low.

Find the oil leak seal it up and see what you really have.

Here is what I would do/suggest. Clean all the oil off the motor with a pressure washer, or get it as clean as you possibly can. Next, drain all the oil out of it. Fix replace the bad injector. Refill car with the proper 8 quarts of oil and check level on dipstick.

Take a deep breath and start it up, noticing if it starts easy after glowing or not. Then, look at the oil pressure gauge on the instrument panel and see what it reads. Lastly, listen for any bad sounds or any really rough running.

If all checks good, let it run for a bit, watching the temp, and look for your oil leak. Post results here and we will help in what ways we can.

Bottom line, scrap the motor only as a last resort.

Oh yeah, get a proper compression tester, or get it done by a shop.

Good luck,

Glenn

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)