Starting my diesel in the cold

When I try to start my car on a cold morning, the engine will start to turn over, but then cuts off leaving a spinning sound. I let the glow plugs warm up, and try to plug it in. I didn’t plug it in for about two months. In those two months, the spinning has slowly taken over the starting experience. The spinning sounds like it is coming from the starter. Have I ruined the starter? I can replace that with much ease. The car starts up right away when the engine is warm.

Don’t know how old your vehicle is, but it sounds that the starter does have a porblem. Whether it was you that ruined or not, that is depending on the age and use of the vehicle

It sounds like the starter pinion is slipping out of engagement with the ring gear on the flywheel. The best diagnositic method is take the starter out; examine the pinion; and the solenoid engagement mechanism. With the starter out, look at the teeth of the ring gear to make sure none are hogged out or missing. You will have to turn the engine one revolution to inspect all the teeth.

it does sound like the starter is dying.

typically the starter grinds a little bit of the metal tooth on the ring gear each time you start it.

over time the “dust” from the worn metal cakes around the bendix spring and gear, making them not retract like they should.

this in turn makes more “metal dust” which makes it jamb up even more.

the solution is to get a new (rebuilt) starter and throw it in the car.

hopefully the ring gear isn’t torn up too much. don’t wait too long (or at all) or the ring gear WILL become an EXPENSIVE casualty.

If there is no grinding in your “spinning noise”, you should be able to get by with a starter solenoid replacement. This will likely involve the removal of the starter, but is much cheaper than replacing the whole starter.

What kind of car/truck are we talking about?

I have to agree, sounds like the starter. Don’t mess with trying to replace the solonoid. Too much hastle for a car starter. Plus you would be delaying the inevitable of replacing the whole starter. Wear and tear on a starter is more extreme on a diesel because of the higher compression ratio of the engine.

Take a look at tripper’s profile and you might change your mind. Mercedes parts aint cheap. A few bucks for a solenoid or a bucnch of bucks for a starter. Over 90% of the machines I service are diesel and I rarely need to change a whole starter. It takes a LOT of starts to wear out a starter.

I’m not sure of the year from the photo, but the starter for that W126 is only about $2-300. I’t not worth just replacing the solenoid if you are going to go to the trouble of removing the starter (it’s probably due anyway if it’s original). Also, I don’t know if the solenoid are available separately. Mine did that once (in -5F temperatures) and I just replaced the entire starter, it never gave me trouble again.

The car in the picture is well over 20 years old and may have several 100k miles, so starter wear is not totally out of the question. A good quality reman won’t break the bank and should last a good long time.
The problem is the labor. This is a swine of a DIY job. You need about 30" of extensions to get the top bolts, and some special grinding on a old open end wrench on the bottom side.
Farm the job out to a good Indy and save the headaches. By the way, book time for labor on a 617 starter in a 126 chassis is 2.5 hours.


Is that a 617 W126 or a later one, I wasn’t sure from the photo?

My original 617 starter lasted about 300K miles until the solenoid stuck once in very cold weather. It is a PITA to remove, even on a W123.

Well, I took it as a short w.b. 300SD… And yes, the job in a 123 is no walk in the park either. The good news is they last a very long time.


Yup, I think you are correct, so it’s a 81-85 with a 617 (based on the wheels too). Either way, I would never put an old starter back in after going to all the trouble of removing it.

So it’s about $200 for the starter plus labor, that’s about $400 total for the replacement.