Om603 smokes excessively - PeachParts Mercedes-Benz Forum

Mt2385 · #1 02-13-2018, 11:41 PM

Thanks in advance for your help. I recently found an om603 motor for cheap so I had to take it. I tried starting it outside of a car just on a pallet and once I got all the air out of the injection pump and wired up the glow plugs I got it to start. It does run but it idled very low and had an unbelievable amount of white smoke when revved but keep in mind there is no water in the motor as it is not in a car. My friend said it could be a bad turbo. The turbo spins but if u try to spin it with your finger it doesn't particulary keep spinning but does move freely. Any suggestions?

jake12tech · #2 02-14-2018, 01:25 AM

The turbo is fine. Don't listen to your friend. White smoke is most likely fuel. Depending on miles, it's worth checking injection timing. Retarded timing will cause a leaner hotter burn resulting in raw fuel. The timing retards as the chain stretches. The OM603 has an electronic idle control called the ELR. If it isn't hooked up, it will idle around 500 rpm.

What does the smoke smell like?

Father Of Giants · #3 02-14-2018, 07:04 AM

A video would help out (and would be cool to see as well). It could be a host of issues.
Here's a list of things to do go over to find the source of excessive smoking.

Check engine timing
Check injection pump timing
Crack injectors to see if there is a particular cylinder smoking, my OM603 has two cylinders that are smoking excessively.
Run two cans of diesel purge thru the fuel lines, preferably while the engine is at operating temperature.

Do a compression test to see if you have low or inconsistent compression numbers
If they are low or inconsistent, do a leak down test to determine where you are loosing compression from.

Doing all of this with the engine outside of the car will make these procedures 5x easier.

Maxbumpo · #4 02-14-2018, 09:53 AM

Quote:

Originally Posted by jake12tech

What does the smoke smell like?

This is key, does the smoke smell like diesel fuel or burning engine oil?

Maxbumpo · #5 02-14-2018, 10:02 AM

If the engine starts easily and sounds smooth, more than likely the smoke is a minor problem. However, you'll not know for sure until you've got it set up to run for longer than a short test with no cooling system hooked up. You'd need to start deeper diagnosis, so you'd need to decide if you want to do that with the engine mounted in a car or on a test stand.

Smoke can be from relatively cheap things like:
injectors
injection pump timing
excessive carbon that needs to be burned out
bad fuel
bad turbo feeding oil to intake
EGR failed in open position

On the more expensive end, a failed head gasket can feed oil into #1 cylinder, or broken rings / worn out cylinders can also cause oil smoke. Poor compression can also be an issue. Probably not the case here, but a cracked head can mix coolant into the oil and / or feed coolant into a cylinder.

Murkybenz · #6 02-14-2018, 10:12 AM

How long did it run , a few bad glow plugs will generate white smoke from the cylinders that have dead ones and this will also lead to it having a low idle speed. Once the engine warms up the smoke will clear as any cylinders with dead plugs get warm enough to fire and run normally.

ah-kay · #7 02-14-2018, 12:45 PM

Very Excessive white smoke can be burning oil from leaking turbo. I have experienced it myself on a 617 engine. It was like smoking machine blowing for 100' or more. You ran the engine dry so it is not from coolant. Glow plug has nothing to do with it. You can check the injectors but I doubt it.

Mt2385 · #8 02-14-2018, 02:53 PM

Thanks everyone for your responses.

The smoke definitely smelled like diesel and not burned oil and there was ALOT of it.

Maybe one day I can make a video of it but im really busy this month but when I get a chance I might just do that.

I will check all those things you guys mentioned. I was mainly concerned about the turbo being bad.

The motor did idle low so now I understand why but I will say that when I revved it, it did shake but that being said it was just sitting there and not fastened down to anything. I ran it for about 3-4 mins and it didn't seem to be getting any happier.

Once I get some time I will put it on a running stand I made and set up water to run through it and do some of those tests/checks you guys suggested.

I bought this motor for 200 bucks without knowing anything about it but it turns out its the 3.0 with the 22 head casting! So either way I would think the head and injection pump is worth more than that.

Thanks everyone for your input so far.

Maxbumpo · #9 02-14-2018, 03:59 PM

Sounds like the issue is probably a minor problem or no problem at all (the engine just needs to be run). For instance, hydraulic lifters not fully pumped up so low compression.

#22 head casting is a really nice score!

Once you get the test stand / rig set up, understand that you won't be able to test the turbo / measure the boost without a load for the engine to work against.

Mt2385 · #10 02-18-2018, 10:47 PM

Ya once I get some free time im going go put it on a running stand and run it with cooling hooked up. I'll try all the suggested tests and if I'm good on all those I'll have to suspect the problem is the turbo.

Mt2385 · #11 09-16-2018, 05:16 PM

https://www.youtube.com/watch?v=8SSB9Z3J8Fw

Mt2385 · #12 09-16-2018, 05:21 PM

ok so I finally got around to getting my om603 on the stand and running it. Above is the link to the video. During this video the motor has been running for about 5 minutes with the garden hose hooked up to it. An hour before I ran it for another 5 minutes as well so it wasnt cold by any means.

Definitly doesnt sound right. You can see the excessive smoke and how it just doesnt rev smoothly. I have not check IP timing. It was running on fresh fuel and I had to purge all the lines to get it to start. The smoke most certainly smells like diesel, not oil and is white-ish. Also it does have a good bit of blow by that the video doesnt show that well.

Around 0:35 in the video, you can hear a sound that resembles rod knock.. Maybe?

Thoughts?

Diseasel300 · #13 09-16-2018, 08:17 PM

That's a pretty unhappy 603. From the looks of the video, you've got a dead cylinder. The white smoke and chuggy exhaust is the unburnt fuel blowing out the tailpipe. The puffing blowby doesn't paint a pretty picture...

Mt2385 · #14 09-16-2018, 11:05 PM

Sounds like it's time to take her apart and sell what's is useable.

I want to keep the injection pump and I know the head is worth selling if it's in decent shape. ( I will send it out to get pressure tested).

What else is salvageable on an om603 in this condition?

Diseasel300 · #15 09-16-2018, 11:22 PM

Before getting too carried away, do a leakdown test and see if you can isolate the problem cylinder. The turbo is probably salvageable too if you wind up parting it out.