Extremely Loud Engine Noise - PeachParts Mercedes-Benz Forum

aznlegend · #1 01-03-2008, 08:10 PM

Hello all,

I have a question about my 98 E300TD and was hoping someone would know what the problem could be with my car.

I live in Northern VA and the temp is about 20-30 degrees right now and I always warm up the car for about 10 -15 minutes in the morning before driving it. I've notice that my engine is really loud. It has a really deep humming noise when I give it gas. it is also very loud when I am just cruising at about 50-60MPH. If I stop, shut the car off, and start it right back up, the engine is a lot quieter. I don't think it's the engine mounts because i just had them replaced about 20k miles ago.

Does anyone know what this could be or why it is doing this?

Thanks

whunter · #2 01-03-2008, 08:30 PM

First question:
Check your V-belts for age, glaze, and tension.

babymog · #3 01-03-2008, 09:08 PM

And a comment, it will warm up when driving, drive it easy instead of idling and you won't foul your rings as much.

notfarnow · #4 01-03-2008, 09:51 PM

Quote:

Originally Posted by whunter

Third question:
Have you used vegetable oil as fuel?

I'd be curious to hear your theory behind this. As an indirect injection engine, I've heard the 606 engine runs beautifully on vegetbale oil, if properly converted (ie, two tanks, sufficient heat, clean oil)

whunter · #5 01-03-2008, 10:04 PM

Quote:

Originally Posted by notfarnow

I'd be curious to hear your theory behind this. As an indirect injection engine, I've heard the 606 engine runs beautifully on vegetbale oil, if properly converted (ie, two tanks, sufficient heat, clean oil)

Vegetable oil turns to jello below 40F and cokes at low temperature.

Quote:

Northern VA and the temp is about 20-30 degrees right now.

notfarnow · #6 01-03-2008, 10:13 PM

Quote:

Originally Posted by whunter

Vegetable oil turns to jello below 40F and cokes at low temperature.

Gotcha, thanks. So it's not that running vegetable oil in a 606 is particularly bad, running cold vegetable oil is.

sorry for the hijack

Skid Row Joe · #7 01-03-2008, 10:54 PM

Quote:

Originally Posted by babymog

And a comment, it will warm up when driving, drive it easy instead of idling and you won't foul your rings as much.

How do "rings foul?" What happens when they foul?

TMAllison · #8 01-03-2008, 11:09 PM

You shouldn't need to warm it up so long. On days where it is below 40 I get heat within a few blocks of home and am at full op temp within 2 miles with no warm up.

Try popping the hood and listening with a mech's stethoscope or metal rod or even a broom handle to different parts of the engine AND the exhaust while you are letting it warm up. From your description it should be very easy to find where the sound is coming from, then we can help.

NFN - The only 606.962's I know of running on veggie burn 5 gal jugs of SVO in a single tank Elsbett system. I'm dubious about that system for the long term personally. I know no one burning WVO in a 606 turbo. The 606 does burn B99 just fine. You will need to change some o-rings eventually but that is not too difficult. I get 10% less mpg's burning commercially prepared B99 (which costs more than D2 currently) so is not to be done if you are cost conscious.

TMAllison · #9 01-03-2008, 11:16 PM

Quote:

Originally Posted by Skid Row Joe

How do "rings foul?" What happens when they foul?

They get stuck/gummed up. That and bad/fouled inj spray patterns result in "sudden death syndrome" from burning unheated oils not intended to be used as fuel. Loss of compression or burning a hole in tops of piston is common cause.

aznlegend · #10 01-04-2008, 05:17 PM

Thanks for all the replies.

To answer WHUNTER's questions,

The both filters were changed about 15K miles ago.

I don't run on biodiesel or vegetable oil.

I have not added any biocide to the fuel tank.

I not sure what winter diesel is, I just fill it up at the gas station.

TMAllison,

I will try what you suggested to see if I can find where the noise is coming from.

Thanks

whunter · #11 01-04-2008, 05:58 PM

Quote:

Originally Posted by aznlegend

Thanks for all the replies.

To answer WHUNTER's questions,

The both filters were changed about 15K miles ago.

I don't run on biodiesel or vegetable oil.

I have not added any biocide to the fuel tank.

I not sure what winter diesel is, I just fill it up at the gas station.

TMAllison,

I will try what you suggested to see if I can find where the noise is coming from.

Thanks

First question:
Check your V-belts for age, glaze, and tension.

Drive Belts: Drive Belts