I posted this initially as an E-class post but think it is probably diesel related so am re-posting it with the diesel section as those posts seem to generate more replies.

I have a 1997 E300 diesel, 160K miles, which has developed an intermittent problem which unfortunately is occurring more often - three times this week. Sometimes I cannot start the car. The engine will turn over but will not start. At that time the glow plug light is out and stays out. I have had it towed to my mechanic twice and each time he checks the diagnostics and says it is a security (key) issue. He has suggested we lock and unlock the car a couple of times and it should start. We have also tried using different keys. That certainly did not work this morning. The alternative would be to completely change the locking system. I just feel this may be glow plug related.

It was restarted by my mechanic earlier this week and the "check engine" light and all the other electronic "threats" did not go out after he started it. I thought that was just a problem of the computer rebooting itself and it would eventually work out. It never did before the car wouldn't start again. Any suggestions, please? Just checked again - the car is still stuck in my garage from yesterday and it won't start this morning. The battery is new.
Thank you for any suggestions.

 

It possibly could be the K-40 relay. I have read a number of posts on other forums where the same issues were described, and the K-40 relay turned out to be the culprit. As parts go, it is not that expensive, and can easily be replaced by most at home mechanics. Good luck

 

Pimpernell, I'd not heard of the K-40 relay and have now done some research on it. I appreciate the suggestion. It certainly fits my symptoms. Thanks!

 

Pimpernell,
Back in June you recommended we check out the K-40 relay as my car would crank and not start. I let my car sit through the summer as we were out of town and I didn't need the car, but I have now had it fixed. It was the K-40 relay. The main symptom for it was that the glow plug light would not turn on when I put the key in the ignition. If I were to crank the engine nothing happened. Thank you for the suggestion. I'm delighted to have my car working again!

 

My 1997 E 300D won't start. We cleaned the gas tank, changed glow plugs, changed the o rings in the fuel pump, changed the fuel filter but still it intermittently dies out.

This morning it won't start again. My mechanic came over and tested the computer and said that there is no electric current passing through. He suggested that I use the duplicate key. Viola! It started with one click.

Too bad. Such a nice car but too many issues that make it unreliable

 

Its a great ride, and I really enjoyed my 96 E300D, but last August, the passenger side spring perch failed, but luckily, it was parked in front of the house when it did. If I had been on the road, it could have caused a major accident. Just prior to that happening, the SRS light went on, and I was working on a fix for that problem. After pricing out having both spring perches repaired, and addressing the issue with the SRS system, I would have had to lay out about $3500. I could not justify putting that much money into a 16 year old car, and had to let it go. No telling what else was going to let go. Good luck with your vehicle.