Good morning,

I've got a 2001 W210 Wagon (non-4MATIC) that will stall when cold after putting into gear. If I let the car warm up for ~5-10 minutes, it will not stall and starts/runs fine for the rest of the day. The vehicle is up to date on all service, including: new spark plugs, motor oil, transmission fluid, air filter, brand-new MAFS, new battery, etc.

I've had the vehicle into my mechanic and they are stumped. There are no codes when they hook up the computer. It doesn't even throw codes when they can get it to stall first thing in the morning. In all other respects, the car runs perfectly.

One thing I have noticed is that the dash lights (and headlights if they are on) dim a bit when I put the vehicle into gear and the RPMs dip. Could it be a failing alternator or some type of relay associated with it that is causing this issue?

Thank you for any suggestions.

have they checked the coolant temperature sensor?? It might be on its way out, if it fails it could be telling the computer that the car is operating temp and therefore leaning out the fuel mixture before it should.

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Dennis
2006 E320 CDI Black/Black Leather. Nav, HTD Seats HK stereo 32000 miles.
2000 VW Passat 1.8t 300,000 miles as of Dec 09, 2009 original owner
1997 E300d Silver 300,000 miles As of Jan 05, 2010
3rd owner SOLD

Is the temperature sensor easy to replace? I've spent a small fortune getting this car in tip-top shape. I'd hate to bring it in to the mechanic again.

CPS perhaps.

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1999 C280

Can anyone tell me where the coolant temperature sensor is located? It is my understanding that this is a fairly easy DIY job. A diagram or picture would be great.

2001 E320 Wagon

Two years ago I had a car here that did the same thing. It started and ran fine until the transmission was shifted into DRIVE, then the engine stalled. It turned out to be the torque converter.

I hope it isn't that. Did this happen just when the car was cold? This only happens to me when the car is cold after sitting overnight.

Find the temperature sensor and check it. Maybe connecting wire fell off. It sounds like the computer does not know that the engine is cold. It is assuming the engine is at normal operating temperature.

Can anyone tell him where the sensor is located?

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Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra

Yes, it only happened after the first start in the morning. I hope this isn't the problem with your car, though.

While the coolant temperature sensor theory sounds plausible, and is certainly worth checking, I can't imagine how it would stall the engine. If it were disconnected, a pre-determined default value would be used to allow the engine to run normally, more or less. The CEL would eventually light up as well.

Start your diagnosis with the simple stuff. On the car I worked on, I made sure the sensor connections were securely in place (air mass, CKP, etc), and checked for signs of corrosion. I left a fuel pressure gauge on the car overnight to make sure the fuel pressure came up quickly when the engine was first started. I had a volt-meter on the fuel pump to make sure I wasn't losing power. I used SDS to check the "Actual Values" being read in by the engine control module at the moment the engine was first cranked over.

I suspected the torque converter early on, but believe me, I didn't want to replace it only to find out later that the problem was a loose connector in the fuse box, or some other silly thing. I'm curious as to how this turns out. Keep us posted, and best of luck.

Thank you, ILUVMILS. The Coolant Temp Sensor is only an $11 part, so it is worth checking this first. I just need to know where the darn thing is.

Hi, I've got a 2000 e320 Wagon 4matic that has exactly the same problem, I've had it into the dealer and a bosch shop and both are stumped. The dealer says they think it might be the torque converter, but they aren't sure and wouldn't cover the cost if they replace it and are wrong.

I'm curious if you found out anything more on the problem?

Thanks, Pete