1987 300D Turbo won't start - PeachParts Mercedes-Benz Forum

Marcb · #1 01-05-2003, 02:29 AM

Please help me! I have a 1987 300D Turbo which I recently installed a "good" used OM603 motor into. The original motor seized up due to a failed oil pump. The engine swap went fairly well and the car fired right up after everything was connected! I was so elated... the 6-cylinder diesel sounded so good and would idle at approx 600 RPM. You could hear the turbo whirring and everything seemed fine. I decided to take the car for a test drive. I immediately noticed that the car was quickly loosing power and I couldn't get above 30mph. I began noticing some whitish smoke behind the car and I thought I had better head home. I went to back off of the throttle and it died. I cranked and cranked and it finally restarted but had almost no power. I finally made it back home and the car would idle very well but would die if I tried to rev it above idle speed. It would restart (for a few trys) if I cranked and cranked on it. Finally it decided it wasn't going to restart at all. I have checked the compression and it is in the 400 range and all 6 glow plugs are glowing red-hot. The injectors look pretty good and are MB reman units. What could be causing this no-start? It turns over and over and appears like I am getting fuel at the injectors but it will not fire. Also, I have noticed that after cranking for a few times, the cooling system seems to have pressure in it. I have cracked open the radiator cap a few times and it sure seemed to be pressurized. When the engine was running, it came up to operating temp just fine (approx 80 deg C) and all seemed well. Please help me...

Thanks.

Kennyandco · #2 01-05-2003, 07:20 AM

Have you checked the injection pump timing?

Marcb · #3 01-05-2003, 11:57 AM

No, I have not checked the injection pump timing. I am not sure how to do this on the OM603.... Would the pump timing have changed so quickly since it was running so well? Also, what might cause it to possibly change?

P.E.Haiges · #4 01-05-2003, 12:15 PM

Marcb,

Since you just changed the engine, make sure all the fuel line connections are tight.

It unlikely that the injection timing would change so rapicly unless the timing chain jumped. You might pull the valve cover and check the cam timing. If the chain jumped, the reading on the balancer on the crankshaft will be way off the TDC mark when cam timing marks are aligned .

This is one time that I would tell you to check the fuel filters. Too bad the 603 engine (NOT MOTOR) doesn't have a manual fuel pump because this pump makes checking the filters much easier.
Take off the fuel line from the secondary fuel pump to the injection pump, crank the engine with the starter and see if any furl comes out. If no fuel comes out, its filters, fuel pump, or a hole or loose connection in the fuel line that is letting in air. There is also a fuel strainer in the fuel tank thet could be plugged.

P E H

Marcb · #5 01-05-2003, 12:50 PM

P E H,

I went out and performed your test and I am getting a small stream of fuel when the engine is cranked. Also, I cracked each injector line at the injectors and I can see a small drip of fuel coming out of each one. It appears that the primary filter is full of nice clean fuel and the secondary is also full of powerservice. Any more ideas... I really appreciate the help.

Marc

Marcb · #6 01-05-2003, 05:08 PM

One more thought guys.... I noticed that the cooling system seemed pressurized after cranking on the engine for a few minutes. It had not fired during any of this cranking... Why would the system be pressurized?

engatwork · #7 01-05-2003, 05:20 PM

It would be pressurized because of a head or head gasket issue - pistons compressing air into the cooling system.

Marcb · #8 01-05-2003, 05:27 PM

Engatwork,

Would the head or head gasket issue cause a no-start situation? I wonder if this is why I saw some white looking smoke behind me as I was driving the car back after I completed the swap. Are there any other tests I can conduct to prove this issue? If so, I need to pursue them so I can figure out how to get some money back from the company that sold me the engine.

Thanks,
Marcb

engatwork · #9 01-05-2003, 05:31 PM

It can cause a no start if it is bad enough. It can leave white looking smoke trailing behind. Try to do a compression test and see what kind of numbers you get. On a healthy engine all six cylinders will be 400+ psi BUT they will start/run down to 200 psi, although they will be harder to start. If it is a head/head gasket issue you will see one or more cylinders significantly lower than the others which is not a good thing.

Marcb · #10 01-05-2003, 05:40 PM

Engatwork,

Thanks for the reply. I did have a brief compression test performed when I was replacing the injectors and every cylinder seemed to pump up to 400+ psi... One of them was a little slower to build than the rest of them but still made it over 400psi... Could it still be a head and/or head gasket problem..? I did see some white looking smoke as I was driving it home but the temp guage seemed normal... It did take a long time to build up any heat in the ACC system...

Thanks,
Marc

engatwork · #11 01-05-2003, 07:24 PM

I don't know - after re-reading this thread you could possibly have a fuel delivery issue. Did you do the comp test AFTER it got where it would not run? Unburned fuel can cause the white smoke too. This could be caused by a timing issue.

ricali · #12 01-05-2003, 08:39 PM

You probably have already tried but;
check for coolant in thr radiator, coolant in the oil, leave the radiator cap off and crank it over checking for air bubbles, check the tail pipe for coolant signs, double check for possible bad fuel filters,pull the injectors and check for any coolant drops and do another comp. test. Do all the easy things first and try not to panic, I,ve been there a hundred times.
Find out any history from where it came from.

Best of Luck

kerry · #13 01-05-2003, 10:27 PM

Did you leave a rag under the hood and suck it into the air filter?
In order to run you need compression, fuel and air at the correct time. The problem must lie in one of these three areas.

Sometimes, odd things can occur which hinder an engine (or motor) from running. Once my father and I were fishing at a very remote lake in Ontario. When we got back to the car it wouldn't start no matter what we did. We hiked miles to get out of there. Turns out that when we parked we backed up to a pile of dirt and buried the exhaust pipe in the dirt. No exhaust=no vacuum=no air to mix with the fuel. Lesson learned; make sure your engine is breathing.

Marcb · #14 01-05-2003, 11:02 PM

Hey guys,

The compression test was performed after the car stopped running and I had numbers all above 400 psi. I am not sure if a rag is blocking the air filter housing, but I believe everything is ok on the intake side... I am not sure how to check the exhaust for any restrictions... It seemed to smoke ok out of the tailpipe when it was running but I am not sure. Also, the coolant looks clean and the oil doesn't show any signs of coolant mixing in with it. The car never did heat up per the temp guage... Any more ideas? This is really starting to baffle me.

Thanks,
-Marc

kerry · #15 01-05-2003, 11:13 PM

Have you checked the turbo to see if it is freely turning now? Will a jammed turbo hinder the amount of air flowing into the cylinders enough to stop it from starting?