1991 Mercedes 300D

The #4 cylinder is has a low pinging or knocking at idle but the noise stops when I hit the accelerator. Anybody knows what the problem can be? Please advise.

Reply to
SandMAuto
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They're supposed to sound that was. #4 is good the others may need rebuild injectors. Quiet diesls need work, they're supposed to sound like a loud bucket of bolts at idle.

Reply to
Richard Sexton

So when my Mercedes guy tells me "your car has the smoothest-running pre-81 diesel I've ever heard," something's up that this guy doesn't know?

Here he was asking me about the veggie oil I'm running and what sort of blends I use...

-tom!

Reply to
Tom Plunket

Most people don't.

Reply to
Richard Sexton

(If that sounded snippy, I apologize; didn't mean it like that but I am truly curious. Alas, without posting sound samples to the group I guess we'll never know.)

...I was just excited about this part. ;)

As of today I'm running about 2/3 virgin soybean oil for fuel. Runs a treat, although it was a bit tough to get started this morning, and again this afternoon (although not as bad) after it'd been sitting for a few hours. I'll probably back off on the mix, but it's pretty cool to be getting something like 60 miles out of a gallon of petroleum as well as supporting American farmers with my driving.

I just gotta figure out what's stinking me out inside now; something's burning on the outside of the engine and making its way into the fresh air intake.

-tom!

Reply to
Tom Plunket

I just read an analyis of running on a mix of diesel and vegetable (soy) oil. Here is and exerpt:

"Your cold starts will begin to deteriorate, your filter will probably start plugging, your injectors will get coked up, setting the stage for ring sticking, glazing of the cylinder walls, increased lube oil consumption and eventual engine failure -- if you can continue to get the thing started in the morning. More than 20% or so veg-oil in the diesel is not a good plan for more than short term 'experiments'."

They say it works great - for a while - but destroys your engine.

Details here:

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Tom Plunket wrote:

Reply to
heav

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