Since I am new at posting a question, and I find everyones" postings so intelligent, I have a problem hoping someone can help me with. My 1987 SD has been making the typical diesel rattling sound for some time. Compared to my other cars, more current, the Benz is driving me crazy. WHAT SHOULD I DO OR HAVE THE MECHANIC DO TO TAME DOWN THE DIESEL NOISE? MY VALVES ARE OKAY, ALL IS WELL MAINTAINED. Please help me. Tnx, Cindy :?:

Hello Cindy Ann:

Welcome to the Benz Forum. The first question that comes to mind is what are you comparing the sound of you 300SD too? It seems very likely that there is nothing wrong with your SD based on the limited information you have supplied.

-Scott

Hello, Scott,
Thank you for the response. My 300SD's engine sound, i.e. the typical rattling noise when first started, seems to have gotten louder over the years. The mechanic wants to add some sort of additive, but he's not sure it would work. Since I don't like guessing and I am naive about mechanics I don't feel comfortable if the service man is charging me for things that might not work. Perhaps, I'm comparing the current diesel cars and their relative quiet to my 1987. If you or anyone else can suggest more, it would be much appreciated. Otherwise, I may have to live with it.

Cindy

Cindy Ann:

The newer diesels are a quieter ride than the older/larger ones. My '91 was a quantum leap from my 190D and 300SD. The diesels which will be introduced in 2004 are another quantum leap in noise level improvement from the last family of diesels.

Regarding your concerns over the quality of service work, go to the "Dealerships and Shops Experiences" discussion at http://www.benzforum.com/forum/viewforum.php?f=13 and post a request for information on good shops in your area. That may help.

If your SDL is actually getting louder, that may represent a problem. "Louder" will probably be somewhat subjective though without taking dosimeter readings. If there is a new noise, or different noise, that should be investigated promptly.

Regarding additives, Diesel Purge is highly recommended in MB diesel circles. This is a fuel additive you can aquire at many car parts stores and administer yourself. It helps to clean the fuel delivery system. Our Forum Sponsor may also offer it.

The only other thing I can think of with the current information is driving habits. If you use the SDL primarily for short trips and local driving, an "Italian Tuneup" in conjunction with the Diesel Purge would be recommended. That is simply running the car hard for a couple hours (70-75MPH on the interstate).

If all that still does not meet your expectations, sell me your car! :D The SDL is a great vehicle!

I hope this helps.
-Scott

Thanks much, Scott, for the constructive and eloquent advice. You sound like a medical doctor. I'll follow up on the info. given.

Also, thank you for suggesting, light hearted as it might be, in taking over the vehicle. However, it was my stepfather's before he passed, so there's a real attachment to it.

I drive like one of the darn female drivers who don't drive fast enough, don't run it hard, take short trips to the country once a month with my two dogs. So, the car doesn't get a lot of wear and tear. (over 200K miles)

You might be right that the whole thing is subjective about the "loud" diesel sound. Last night, I went out for dinner and after awhile the "sound" wasn't so annoying.

Nonetheless, I will act on all you've suggested, doctor. This is not, and I hope will never be, a "do not rescusitate" case.

Best regards,


Cindy

Regarding sentimental attachment to MB Diesels, have you run across Pindelski's web page? In addition to some good information regarding the cars, he posted this really moving story in February. Enjoy:

http://www.pindelski.com/cars/W126/SD/300SD_comes_home.html

You are welcome! Happy motoring.

:roll: Hi I had a simmilar problem with my 190 2.5 D there is a small shock absorber that is on the tentioner on the fan belt that causes the noise.
I even had the timing chain changed to stop the noise and no luck. Just by error i noticed that the shocker bearing was loose and worn it was replaced and the noise was gone.
hope this works.

Hi Cindy Ann,
Welcome to Benzforum. I also have an 87 300SDL, and both Rivermaster and Jurek have posted some very good advice. I think the Diesel Purge is an excellent product an I have used it on several occassions. If you have just started noticing this noise, you may also want to check your hood pad to insure it has not been removed or deteriorated, as this does help to reduce motor noise. Also, if the plastic panel underneath the engine has been removed, the engine noise may be more noticable. Try the suggestions above and let us know the results.

Ken

This is how I handle this. 1 quart of automatic transmission fluid, once a month for a short while will quite the" diesel rattle" in the way of clean injectors and other critical parts of the fuel delivery system. A good clean injector will spray a fine mist, where slightly dirty or clogged injectors will not. Also, be aware that your injection pump needs to be in good tune - this will cause an inadequate amount or improper timing of fuel being injected into cylinders to be combusted.

Diesel Medic is as effective, however, more costly.

Good Luck! :D

This is how I handle this. 1 quart of automatic transmission fluid, once a month for a short while will quite the" diesel rattle" in the way of clean injectors and other critical parts of the fuel delivery system. A good clean injector will spray a fine mist, where slightly dirty or clogged injectors will not. Also, be aware that your injection pump needs to be in good tune - this will cause an inadequate amount or improper timing of fuel being injected into cylinders to be combusted.

Diesel Medic is as effective, however, more costly.

Good Luck! :D

droland52:

What are you doing with the ATF? Mixing it with a fuel tank of diesel?

-Scott

Cindy,

I don't know if you're still strugling with your noise problem, but it sounds to me like you need new motor mounts. Based on the age and mileage of your Merc, you're probably overdue on changing these out. If your mounts are the source of the noise problem, you will notice a "dramatic" reduction in diesel noise after you have this maintenance done.

Brian

Could it be something has damaged or degraded the sound-proofing in the passenger compartment?

I'm having simliar problems with my car.
My Mechanic, although he is a family member (and I don't want to sound biased), has been working on mercedes benz for almost 55 years now, and he knows more about cars, (and especially the beauties from Stuttgart) than anyone i've ever met.
My '93 300D 2.5 Turbo has been idling hard and loudly, more noisy than usual. Also, when coming up off the gas and moving to the brake a HARSH vibration is felt from the undercarriage up through the seats and into the cabin. My gas mileage has been dwindeling as well.
He said that it is the muffler/exhaust system which needs to be replaced.
It also could be the engine mounts, but you probably already knew that.
If you have been having some of these symptoms, hopefully this helps.
Don't know if it does, but that is something I would look into.


Sam.