E300 Diesel noisy

[adrianbenz]

Hi, I recently purchased a 1996 Mercedes E300 Diesel with 140k miles this summer. I don't recall the engine making a knocking or what some people refer to as nailing noise when the engine is started cold. The engine starts up fine and idles smooth, but just sounds noisy until the engine warms up.

I wonder if the new ultra low sulfur diesel fuel is causing the knocking noise that I am hearing now. Is there any diesel fuel additives that you would recommend that will help improve the diesel fuel quality and not destroy the catalytic convertor since my car has one?

Interesting note, I did contact mercedes regarding a safe diesel fuel additive for my car, but they told me that there were none available and that I should find a better gas station to fill up? I fill up at a Shell station. Any help would be greatly appreciated.

After owning and driving, I can see why MB diesels are #1

[Parrot of Doom]

We've had ULSD in the UK for years, and no problems. It isn't that.

What oil do you have in there?

[TMAllison]

You dont provide your location.

If somewhere cold, you may be burning D1 now rather than D2 that was available in the summer months?

You can use any number of fuel additives. I like Red Line Diesel Catalyst 85 or as little as 1% of BioDiesel. Power Service also makes additives and Cetane Boosters.

Check around your clear plastic fuel lines and on top of the IP for any fuel leaks and that your EGR and Resonance flaps aren't sticking.

[pimpernell]

Originally Posted by adrianbenz

Hi, I recently purchased a 1996 Mercedes E300 Diesel with 140k miles this summer. I don't recall the engine making a knocking or what some people refer to as nailing noise when the engine is started cold. The engine starts up fine and idles smooth, but just sounds noisy until the engine warms up.

I wonder if the new ultra low sulfur diesel fuel is causing the knocking noise that I am hearing now. Is there any diesel fuel additives that you would recommend that will help improve the diesel fuel quality and not destroy the catalytic convertor since my car has one?

Interesting note, I did contact mercedes regarding a safe diesel fuel additive for my car, but they told me that there were none available and that I should find a better gas station to fill up? I fill up at a Shell station. Any help would be greatly appreciated.

After owning and driving, I can see why MB diesels are #1

I have the exact same year and model, and with temperatures at or below 35 degrees, my engine will have no clattering when first started. After a minute or two, I usually drive off at slow rate of speed, and it will clatter a little until the engine reaches about 85 F. operating temperature. After that, it is a smooth as silk all the way up to normal operating temperature. Good luck with your car.

[Hatterasguy]

Its an old diesel, its going to run a bit rough in the winter until it warms up. Or your GP's could be a bit weak.

[adrianbenz]

I actually think the knocking/nailing noise is only noticeable after driving off when cold, and not when starting up. I actually have a lead foot since I like to hold the rpms above 3k before letting the transmission shift, but since the engine is nailing so bad, I've actually backed off on the throttle till the engine warms up where the nailing is almost non existent.

The engine sounds like marbles when I'm accelerating hard when cold, just seems like it might cause damage to the engine. It is cold here in Washington, that might be the reason for nailing since I did not notice it during the summer months? I wonder if the poor quality of fuel might be a factor as well since it is nailing so bad in the cold weather. Thanks for all the help and advice!

[michakaveli]

Originally Posted by adrianbenz

I actually think the knocking/nailing noise is only noticeable after driving off when cold, and not when starting up. I actually have a lead foot since I like to hold the rpms above 3k before letting the transmission shift, but since the engine is nailing so bad, I've actually backed off on the throttle till the engine warms up where the nailing is almost non existent.

The engine sounds like marbles when I'm accelerating hard when cold, just seems like it might cause damage to the engine. It is cold here in Washington, that might be the reason for nailing since I did not notice it during the summer months? I wonder if the poor quality of fuel might be a factor as well since it is nailing so bad in the cold weather. Thanks for all the help and advice!

Mine behaves exactly the same. I just keep the lead foot off so that it nails a little. It clears up once she is warmed up.

I plan on servicing my injectors sometime in the future and I'm sure that will help it.

[oZ_E300]

95 e300d

i had this problem when bought the car, every morning when started it would make loud bang noises until it got warmed up. Didnt think it was normal & brought this in to a well known mb diesel mechanic within the same week. He diagnosed & also changed oil, gas filter all at the same time & told me it was some wiring problem to the glow plugs. Well anyway after that never had that loud noise.
Some other thing that was happening with the loud knocking noise, sometimes glow plug light would stay ON after the car was started for about 30-40 seconds, then go off. And if accelerated to +2500rpm that loud knocking noise would dissapear.

After the fix, glow plug does not stay ON after it starts, and idles without the loud knocking noise. This is how it should be & havent had any problems since.

[adrianbenz]

Well, I decided to e-mail Redline oil corporation to see which two of these Redline products are compatible for my E300 diesel and also asked them if they were safe to use in my car with the catalytic convertor.

1) Redline 85 Plus
2) Redline Diesel Fuel Catalyst

Redline response was:
Thank you for contacting Red Line Oil, both products would be
suitable for use in your diesel Mercedes, they will not harm your
trap oxidizer or catalyst, though they have not been specifically
submitted to Mercedes.

I thought only one Redline diesel additive was approved for cars with catalytic convertors? Am I missing something here or is redline wrong?
I would hate to use the wrong additive and destroy the convertor in the process. Does anyone out there know which one to use? Thanks!

[michakaveli]

I use the Redline Diesel Fuel Catalyst. It's my favorite additive other than Primrose. I can usually find the Redline at my local Advance Auto Parts.

I use the Primrose when I run mostly B20 and the Redline when I have a full tank of #2...

[WINGAS]

I wouldnt use Power Service, it has ethanol. I like Howes Meaner Cleaner for a nice lubricity additive for ULSD.

CHange the fuel filter and see if you still ahve the problem.

[nhdoc]

Originally Posted by WINGAS

I wouldnt use Power Service, it has ethanol.

No it does not...this is directly from their website:

3. Do Power Service diesel additives contain alcohol?

The only product manufactured by Power Service that contains the type of non-harmful alcohols recommended by engine manufacturers for removal of water is Power Service Diesel 911. Diesel 911, as its name implies, is used to solve the fuel emergencies diesel engine operators most commonly encounter. In winter, Diesel 911 reliquefies gelled fuel and de-ices frozen fuel-filters in a matter of minutes, eliminating the need for a tow truck. Diesel 911 also removes water from the fuel system to prevent icing problems and extend the life of fuel-filters, fuel injection pumps and fuel injectors.

No other Power Service product contains any alcohols of any kind, including Power Service Diesel Fuel Supplement +Cetane Boost and Diesel Kleen +Cetane Boost.

People keep saying that Power Service contains alcohol here but it is simply not true.