Hi !

I have a '99 E 300 Diesel. In the display near the steering wheel, the glow plug light still remains on even when the engine is on.

Do you know what could be the problem.

 

It means you have a burned out glow plug. You probably notice that the car runs ruff when you first start it. The wonderful news is these are sometimes very difficult or next to impossible to replace because they get stuck in place with carbon.
Make sure the engine is hot when you try to remove it. Better luck that way.

 

I have the same issue with my '96... a seized glow plug. I had a mechanic trying to get it out without sending it to the machine shop and he eventually gave up. He got the threaded part outbut could not get to the rest of it. I've read that water injection can clean out carbon. I'm going to try it and see if it can loosen the remains and let the pressure pop it out. Hopefully I will save myself that $2K trip to the machine shop. The theory is therelatively coldwater causes the hot carbon to cool rapidly and bits of it to shatter and flake off. And it adds power, the lack of which has always been my biggest peeve with this car.

 

empi123: Cold water on a hot engine is NEVER a good idea. With cast iron blocks, you run the HIGH risk of cracking the block. With the case of some engines that are fully aluminum, or cast blocks with aluminum heads, you run the risk of warping the aluminum, which is just as bad as a cracked block.

The BEST way to remove a glow plug, is with the engine totally cooled, remove the wiring and set it well aside. Get yourself a small propane torch, and heat the metal AROUND the glow plug nice and slow, and evenly. Then with a wrench, and the aide of a cheater pipe if necessary, turn the glow plug out. Do not heat the glow plug at all if you can.

The reason for heating the metal around the glow plug, is that the metal you're heating will expand, helping break loose the carbon that is in the threads and such, while the glow plug itself does not expand. I've done this many many times.

 

Hi, I too have the same issue with my 98E-300 Diesel. I have my glow plug light on telling me one or more of my plugs are bad. Its pretty obvious when I try to start it cold and its sputters then warms up.

Does any one have directions or pictures to remove the intake manifold to get to the glow plugs in a 96-99 E class? I can see all the torx bolts and I think I can see two nuts that hold the manifold to the down pipe but curious if there is anything else I need to know about??

I have the new plugs and gasket in hand just dont want to tear it apart and have to stop because of a hidden bolt or tool I need to finish.


thanks Chris

 

Tap the inside of the GP body and either pull it out with a slide hammer or fashion a puller from nuts, bolts and washers. You have nothing to lose.