Hi all,
When i first start my 1998 E300 TD (158k mileage) in the mornings (about 30 degrees F), the engine starts pretty rough and causes a good bit of shake. In addition I get a good bit of white smoke out the back. I recently had a CEL come on - the code was for the exhaust gas recirculation valve. That light went off a bit ago though and I haven't seen it since. Dont know if that is related. Anyway, after warming up for about 30 seconds the car runs great, no problems. Any starts with the engine warm causes no problems whatsoever. Bringing the car into the shop on monday but wanted to see if anyone has experienced similar. Thanks so much!

I have experienced this.
Here are the top three causes for your symptoms.

#1. Glow plugs
#2. Glow plugs
#3. Glow plugs

Glow plugs link thread All diesel models
Glow plugs link thread - PeachParts Mercedes ShopForum


Cold weather starting links
Cold weather starting links


.

__________________
ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

I figured it could certainly be a bad glowplug but I had read that if that is the case, the glowplug light will remain on after starting. Is that not always the case? Anyways thank you very much for your response

No, the light is not a reliable indicator.

More than 50% of the time there is no notable change in light function.

The symptoms are distinctive.

.

__________________
ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

The GP light ought to come on if one is bad. May be that one is going bad and hasn't passed the threshold needed to activate the cel, not unheard of for the bulb in the dash to be burned out either.

Checking resistance using a multi-meter at the GP relay on the drivers side firewall will tell you what's what.

In the mean time, try starting and then immediately backing out of the garage (or backing up 10' if parked elsewhere) and then going back into N or P while it warms up. When I had a GP out, for some reason doing the above caused the idle to smooth out right away. Strange but true....

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)