OM 603....oil consumption.....blue smoke on startup - PeachParts Mercedes-Benz Forum

brandlj · #1 11-20-2006, 04:41 PM

Within the last week at cold startup in the AM my car starts to miss and stutter. Temps have been about 30-40 degrees. While it is idling, I get a loud knocking noise, louder than lifter tap. At the same time clouds of blue smoke come out the exhaust. Oil pressure is pegged at 3. As it warms up and I drive away, sounds become more normal as it warms up. As I put about 10 miles on the car it is as quiet as it always has been. This car has never used oil and now I have used one quart in800 miles. I use Mobil 1 Synthetic 10w-40.
Car has 90,800 miles on it. No coolant loss. Upon inspection in AM when cold, upper radiator hose is nice and spongy. Looking in the oil filler cap, all is well there too, no coolant in the oil, no oil in the coolant.
Did I get some bad fuel? Have I blown a head gasket? Fuel mileage is still consistent at 25mpg.
Thanks
John

rrgrassi · #2 11-20-2006, 04:45 PM

Is that 10-40 diesel rated? It is very harmful to a diesel engine to run oils for gasser engines. I personally have not come across a diesel rated 10-40.

Jadavis · #3 11-20-2006, 04:50 PM

Are your glow plugs working as they should? The sounds my 87 300D (same engine as yours) made just after starting with 5 of 6 glow plugs bad were horrible! I replaced all 6 and now it starts easily and sounds/runs smooth. I had a loud clicking/ticking sound that has been cured simply by replacing the glow plugs.

-Jim

brandlj · #4 11-20-2006, 05:14 PM

Yes the Mobil one is a Truck/SUV synthetic 10W40. It is sold at O'Reilly's and I have been using it for the last 12000 miles or so.

Perhaps I have a bad glow plug. It starts immediately after the light goes out. Maybe tomorrow I will do a double glow situation and see if it changes anything.

rrgrassi · #5 11-20-2006, 05:28 PM

They make oil for truck/suv in gasoline form as well. That is pretty much a marketing gimmick. Just because is says truck/suv does not mean it's rated for a diesel engine. That blue smoke is oil smoke.

The oil label should also say something about soot control, if it does not mention diesel engines. There is also a "C" classification, but I do not remember what is is right off hand. There is usually an outline of an 18 wheeler on the label.

Rotella T is for diesels. So is the Synthetic Rotella T. Diesels exert more pressure on the moving parts in an engine, that is called oil sheer. Gasoline engine oil will not stand up to the pressures found in a diesel. Quickest way to kill a diesel is to use gasser oil in them.

pawoSD · #6 11-20-2006, 05:30 PM

Just because its truck/suv oil doesn't mean its intended for diesel engines. Most trucks/suv's in the US are gassers...and 10w40 is a gasser weight oil...I've never seen it for diesels. The diesel mobil 1 oil is either 5w40 synthetic, or 0w40 synthetic, and 15w50 is available too. I'd double check the bottle of that oil and make sure it explicitly says for use in diesel engines and has the certification mark for it.

A glowplug thats out should only affect the engine for the first 30 seconds to a minute or so. All a dead glow plug will do is make a specific cylinder colder upon startup, so it will idle rougher until that cylinder generates enough heat to combust the fuel like the others.

Brian Carlton · #7 11-20-2006, 05:31 PM

Quote:

Originally Posted by brandlj

Yes the Mobil one is a Truck/SUV synthetic 10W40. It is sold at O'Reilly's and I have been using it for the last 12000 miles or so.

Perhaps I have a bad glow plug. It starts immediately after the light goes out. Maybe tomorrow I will do a double glow situation and see if it changes anything.

You can forget about the glow plugs. The oil consumption is telling this tale.

One quart in 800 miles with blue smoke is telling you that oil is definitely getting into one or more than one cylinder. Since it clears up as the engine warms, I'm not likely to be convinced that it's the turbo seals.

One other item that would tend to convince me that it's a head gasket is the fact that the engine smokes badly upon initial startup at idle. When the turbo seals go bad, the engine won't smoke on startup. The oil pools in the outlet of the turbo and it's just waiting for you to open the rack and send a dollop of air to the cylinders. Then the oil will immediately be seen in the exhaust.

I'll be interested to hear other's opinions...........

Jadavis · #8 11-20-2006, 05:35 PM

Having just been through the entire glow plug system let me pass on what I have learned from the forum and verified on my now working system.

The glow plugs will continue to run for up to 30 seconds as long as you do not try to start the car. The light goes off after 5-10 seconds, but the plugs continue to heat. To verify this get in and turn off the climate control unit and radio so that you can hear the relay click.
Turn on the dome light.
Turn the key to where the glow plugs come on, the dome light should dim.
The dash light will go off after 5 seconds or so but the dome light will stay dim.
After 30 seconds or so (36 on my car) the dome light will brighten back up and you will hear the relay click as it deenergizes.
If the glow plugs are working correctly it should start right up with no problems.

If not then you will need a multi-meter.

http://www.dieselgiant.com/glowplugrepair.htm

At least do the resistance checks. It is easy and will give you a good idea what you are looking at, even if you pay someone else to do the work. On the 603 engine you might as well replace all of them if you are taking the time to go in and replace a couple. They are a pain to work on. I pulled the intake manifold to get to mine. The SDL has more room in the engine compartment and may allow you to do it as is.

-Jim

brandlj · #9 11-20-2006, 05:35 PM

I will check the oil bottle when I get home. I really thought it says Truck/SUV diesel on the bottle.
Thanks for the input.
John

brandlj · #10 11-20-2006, 05:48 PM

OK I have been using the Mobil 1 Truck/SUV diesel synthetic 5W-40 oil. I had a bottle in the trunk and it is specifically for diesel motors.
The oil smoke really concerns me and the stumbling idle when cold ( it stutters ) led me to think fuel problem. I looked at my pre filter and it is a little cloudy? It usually looks like golden honey. No chunks of anything in the pre filter.

If this turns out to be a headgasket, how difficult on a 603 to replace?
I have no dealer here in Monroe LA. The car has only 90,800 miles on it and has been mechanically maintained by myself and the original owner. He bought it new in 86 and I bought it in 2005 with 79,000 miles.
The body has no rust but has issues on the passenger front and rear doors from parking problems by the 82 year old first owner.

What I am driving at is if it is the head gasket, by the way the head is a 14,
maybe I should warm it up and trade it in, because when warm it is the smoothest, quietest diesel I have ever owned.

Advice?

pawoSD · #11 11-20-2006, 05:55 PM

With that few miles on the car it'd be hard to believe that the head cracked...unless it was overheated at some point, which also seems unlikey, too few miles. I'd have it checked out by a shop that works on MB's....

Jadavis · #12 11-20-2006, 05:57 PM

The blue smoke concerns me, but I still think you should give the glow plugs a look. Mine smoked like crazy on startup until I fixed my glow issues.

Its the BLUE part of the smoke that concerns me...

-Jim

brandlj · #13 11-20-2006, 05:57 PM

Wow, I just read the glow plug article from diesel giant. It was great. I need to test my plugs. If I have a couple of bad plugs, those cylinders would not be at the same temperature when the car starts? So the blue smoke could be unburned diesel fuel? This is what I am hoping.

As another test, should I plug in my engine heater one night and see what happens when I start it with warm coolant. After driving 20 miles on a 60 degree day and I turn the car off for 10 minutes, when I start it I do not let it glow and it starts immediately and sounds perfectly normal.

pawoSD · #14 11-20-2006, 06:13 PM

Test the plugs and try overnight with the engine heater, if it starts up fine then I would have to say that its glowplug related. Cylinders with dead glow plugs will still be dead cold on startup, only the compression heat will be present.

A general question....when an engine burns oil, does synthetic oil burning (if it does even burn?) burn blue like dino oil? I always figured it'd either not burn well or at all, or that it'd be a different color if it did. Anyone?

My dad forgot to glow his '83 SD a week ago when it was cold out, and cranked it to life....took about 6-7 rotations to catch (it was only 29F!!!), when it did it ran rough/unhappy and blasted out some blue and white for 20-25 seconds, he rev'd it to about 1500 for a few seconds, and then it was happy/fine. The engine has mobil 1 0w40 synthetic in it, and uses Zero oil between changes, essentially nothing at all, even after 4k on the oil. I was guessing the blue was partially or unburnt diesel....from the cranking.

babymog · #15 11-20-2006, 06:27 PM

Jadavis: Doesn't the '87 have afterglow on the plugs?

Synthetic does burn like regular oil, just not as easily, blue.

Cranking without starting will fuel the cylinders and start blue also, partially from the fuel partially from the oil it washes from the cylinder walls.

- Jeff
'87 190Dt
'87 300Dt