1999 E300 Rough Cold Start - PeachParts Mercedes-Benz Forum

nate300d · #1 11-23-2007, 11:31 AM

Well, my 1999 E300 has 90583 miles on it. It is parked in a garage, but lately when you start the engine when it is cold it runs rough for a few seconds and blows some smoke out the back in the process. After a few seconds it is fine and starting it when the engine is warm is no problem. I have no check engine light or glow plug light, but I wonder if there is a weak glow plug. On on had I hope that it something as simple as that, but on the other hand I changed the glow plugs less than three years ago at about 52000 miles. Could this be anything else?

JimSmith · #2 11-23-2007, 11:33 AM

I have never had a glow plug fail without any other electronic reminders on the dash. However, your symptoms are exactly those of one or two bad plugs. I would pull the plug at the relay and check the resistance of each glow plug to ground. Jim

Skid Row Joe · #3 11-23-2007, 01:28 PM

Glow plugs.......replace them. A $700.00 job @ your friendly MB dealer.

nhdoc · #4 11-23-2007, 02:01 PM

Glow plugs HAVE been known to go bad without giving the user any indication other than rough cold starts...it's 99% sure to be one or two bad ones causing your problem since your rough starts are accompanied by smoke.

If you DIY it I'd say test them with an ohm meter, determine which plug(s) is(are) bad and replace only those and not risk breaking one off that is still good.

Hatterasguy · #5 11-23-2007, 02:01 PM

Could be the clear plastic fuel lines leaking. If air is building up in the system overnight it could start poorly.

nate300d · #6 11-23-2007, 04:44 PM

Quote:

Originally Posted by Hatterasguy

Could be the clear plastic fuel lines leaking. If air is building up in the system overnight it could start poorly.

I have had that happen so I also checked for it, but not sign of any air in the fuel lines. Also to perhaps clarify is that the engine starts right up, but it is rough for 10-20 seconds.

I have changed the glow plugs before. What would torque me off is that these glow plugs are less than three years old.

nhdoc · #7 11-23-2007, 06:58 PM

Quote:

Originally Posted by nate300d

I have had that happen so I also checked for it, but not sign of any air in the fuel lines. Also to perhaps clarify is that the engine starts right up, but it is rough for 10-20 seconds.

I have changed the glow plugs before. What would torque me off is that these glow plugs are less than three years old.

Age is not what "wears them out" but the frequency of use. Your car is very low miles so I would assume you don't use it too much so I would think you got a bad one from the factory. Did you use OE plugs or aftermarket when you did yours? Test them with an ohm meter...I'd bet you'll find one is out. If you are lucky it is the front one which you can get to without pulling the IM off.

barry123400 · #8 11-23-2007, 07:33 PM

Look at the bright side. Even if you locate a bad plug they were all out three years ago so hopefully it will spin out now. At least make sure to put anti seize compound on the threads of the replacement.
.Age or milage alone does not define the life of a glow plug. Just like light bulbs one can fail earlier than the average.

nate300d · #9 11-24-2007, 10:02 AM

Quote:

Originally Posted by nhdoc

Age is not what "wears them out" but the frequency of use. Your car is very low miles so I would assume you don't use it too much so I would think you got a bad one from the factory. Did you use OE plugs or aftermarket when you did yours? Test them with an ohm meter...I'd bet you'll find one is out. If you are lucky it is the front one which you can get to without pulling the IM off.

I do not know the OE from aftermarket glow plugs. I installed Bosch glow plugs. I see that there is another supplier named Beru. I do not know if one is 'better' than the other.

pimpernell · #10 11-30-2007, 12:58 PM

just did the glow plugs on my 96 e300d, and the mercedes shop manual makes no mention of using anti -seize on the glow plugs. I did some further checking, and came up with a couple of sites indicating that the use of the wrong anti seize compound could cause problems. This was just one of them. Just wondering about opinions regarding this matter. Thanks.....

http://mbca.cartama.net/archive/index.php/t-2066.html

aklim · #11 11-30-2007, 04:13 PM

Quote:

Originally Posted by pimpernell

just did the glow plugs on my 96 e300d, and the mercedes shop manual makes no mention of using anti -seize on the glow plugs. I did some further checking, and came up with a couple of sites indicating that the use of the wrong anti seize compound could cause problems. This was just one of them. Just wondering about opinions regarding this matter. Thanks.....

http://mbca.cartama.net/archive/index.php/t-2066.html

I would. After 2 years my plugs came out nice and easy with anti-seize. Before that, they were tight. 3 were stuck. 2 of them came out eventually and one broke off. Yes, we had to take the head off. Machine shop found the prechambers were pretty clean and not carboned up

crmont · #12 11-30-2007, 09:17 PM

Just a thought; I recently lost my voltage regulator. The initial symtom was hard/rough starting. Simply a weakening battery will cause the GP's not to reach the proper temperatures. The GP sequence seems to terminate on time not temperature. Air in the fuel lines will also cause the exact same hard/rough starting. The colder ambient temperature causes my o-rings to shrink and suck air. I have replaced the o-rings in the past but it appears I must replace them again. (or i missed one...)

nate300d · #13 12-02-2007, 08:39 PM

First, thank you for all of the support. GP #3 was bad and I only replaced that GP. All of the other GP's test at 0.9 resistance. I have removed the intake so many times on this 606 that I almost can do it blind folded (GP replacement, o-ring replacement, fuel line replacement, muffler grease pack replacement

). The longest time of the procedure was dropping the 5mm wrench to unmount the intake from the tube from the intercooler. I drove to a store to buy a another 5mm wrench because I could not find the one I dropped in the engine. But as life is when I got back I found the #$%@ wrench. Four hours total. If I did not drop the !$#%! wrench it would have been under three hours. By comparison I can replace GP's on a 617 in 35 minutes.

The 606 in my 210 is fun to show off to others what a diesel can do, but I love my 617's

sokoloff · #14 12-03-2007, 10:23 AM

Quote:

Originally Posted by nate300d

First, thank you for all of the support. GP #3 was bad and I only replaced that GP. All of the other GP's test at 0.9 resistance.

Nate - I'm curious. When I had one bad glow plug, my '99 threw a check engine light and glow plug light. You say yours did not. What was the reading on that bad glow plug? I'm wondering why mine did and yours didn't?

aklim · #15 12-02-2007, 09:06 PM

As a rule, I would replace only one if I had a few miles. For instance, if one burnt out 10K after I installed a new batch, I would replace that one. Otherwise, if it is long enough, I replace them all. If I elect not to do it, I would certainly R&R the plug and dab some anti-seize on the threads so it doesn't freeze up. After all, I paid admission when I bought that intake manifold crush gasket.