190D - Should They Fire Right Up in the Cold - Page 2 - PeachParts Mercedes-Benz Forum

Amphicar770 · #16 01-30-2007, 08:55 PM

Found the following via Google which confirms that glow plug light does not come on if a GP is bad. That is actually good news in my book. Replacing the GP's is no big deal and car is obviously starting up even with one or more bad ones.

Peter, The glow plug light SHOULD come on as soon as the key is turned to
position #2. If it doesn't, the system is telling you that one or more glow
plugs are bad. The illumination of the light following engine startup
confirms this (and that it's NOT just the dash light being burned out). The
plugs can be tested with an ohmmeter at the large plug at the glow plug
relay on the drivers side (US left hand drive) inner fender. Unplug the
large plug and read the resistance from each pin to ground. The resistance
of good, cold (engine not run for hours) plugs should be 0.6 ohms.

Marshall
--
August M. Booth, Jr. Ph.D.
Univ of Pittsburgh School of Medicine
"der Dieseling Doktor" mboo...@pitt.edu
'87 300TD 140Kmi,'87 190D 2.5 189Kmi, '84 190D 2.2 234Kmi TERMINAL,
'84 190D 2.2 215Kmi, '85 190D 2.0 145Kmi, '87 190D 2.5 turbo 200+kmi
MBCA, GWSection

kerry · #17 01-30-2007, 09:04 PM

I hope it's not this style engine that has the reputation for glow plugs getting stuck in the head. Can anyone with more experience on newer engines comment on this? It might explain why the bad glow plug(s) have not been replaced.

DslBnz · #18 01-30-2007, 10:16 PM

Quote:

Originally Posted by kerry edwards

I hope it's not this style engine that has the reputation for glow plugs getting stuck in the head. Can anyone with more experience on newer engines comment on this? It might explain why the bad glow plug(s) have not been replaced.

No, that would be the OM606 of the mid to late 90s.

If the glow-plug light is not working, suspect the glow-plugs/GP relay. Usually when the engine is running, the glow-plug indicator will stay lit to inform the driver a glow-plug requires replacement.

The glow-plugs still take a good amount of time to get to. Removing the intake manifold and replacing the gasket to get at what lies beneath.
Or you can pray you don't damage the original when you try to reuse it.

Or you can just work with the IM in place and risk bloody knuckles.

justinperkins · #19 01-30-2007, 10:52 PM

Quote:

Originally Posted by Amphicar770

Just called the seller. Not sure if I am feeling better or worse.

The guy is not a dealer, just someone who buys a lot of cars he finds interesting, keeps em for a while, then sells. I have done the same thing myself. This car allegedly had one owner who he knows and bought it from.

I am not certain if he knows much about diesels (or is just BSing me) as he was telling me that this one "does not have glow plugs" which is the only reason it sometimes takes a 2nd or 3rd try. I said, "huh, how can it not have glow plugs". He replied that he does not see a glow plug light like on other diesels when he turns it on so he figured it does not have glow plugs.

OK, so we now know that the glow plug light is not working. What would be the likely cause of this? If something simple it could be a good sign in that he is just not waiting for them to cycle. On the other hand could it be inidicative of a bigger problem. Thoughts?

The 190 seems more similar to the W124 than the 617, so here's what I know:

If the #1 cylinder GP is broke, the GP light on the dash will not illuminate. If more than one of the GPs in cylinders #2-#6 are broken (that means more than one), then the GP light will not illuminate. However, if one and only one of the GPs in cylinders #2-#6 are broke, the GP light will still illuminate as expected.

My GP light was not operating, replaced GP #1 and light now works as normal. I still have rough starts when cold, which tells me that one of the other GPs is bad.

Amphicar770 · #20 02-01-2007, 02:43 PM

Hi all,

Well, the good news turns out to be that the seller was indeed a bit clueless when it comes to diesels. He did not realize that the GP light is the GP light and was not waiting for it as he thought that the 190 does not have glow plugs.

Anyway, per my other post, I took delivery of car. Glow plugs work as they should and car starts right up on first try.

Thanks.

#21 02-01-2007, 04:44 PM

The way this thread started is a text book case of why you should fill in your location. If you don't want the city for fear of someone stealing your car, then at LEAST fill in your state or country.

See my sticky thread on troubleshooting suggestions.