E320CDI Engine "Pinging" - Page 3 - PeachParts Mercedes-Benz Forum

aklim · #31 12-12-2008, 01:59 PM

Quote:

Originally Posted by JimSmith

I spend very little time looking for smoke that normally doesn't exit from my 1998 E300 TurboDiesel,

I was never able to see smoke until I chipped the car.

Oracle12345 · #32 12-12-2008, 02:03 PM

engine pinging can be caused by many things besides fuel. Is the car running good? Is the engine running hot?

DieselAddict · #33 12-12-2008, 02:07 PM

Quote:

Originally Posted by Oracle12345

engine pinging can be caused by many things besides fuel. Is the car running good? Is the engine running hot?

Of course. But it makes sense to start with cheap/easy fixes. That's why we recommended a cetane booster or different fuel source. If that doesn't fix it, the owner can proceed from there.

Jerzeeshor · #34 12-12-2008, 02:20 PM

The absolute best additive I've found to combat the loss of lubricity from the ULSD fuels in my '96 E300 is STANADYNE.

lkchris · #35 12-12-2008, 02:21 PM

Lots of guessing here. I especially like guys that think new filters are the cure for everything.

Ours recently exhibited a significant "knock" at idle and some nailing coming off idle.

The dealership tech immediately suspected fuel injector and there is an electronic test (with printout) for fuel injector performance.

We got a new #2 injector ($750) and all is now well.

Understand that the injector test indicates a range of diagnositics and an injector could be approaching but not at the cutoff point where replacement is required--that is, covered by warranty.

Injectors on these engines are not the simple calibrated holes of earlier days, but rather are sophisticated, complicated electronic devices not necessarily going to last forever. Our #2 made it 38K miles.

Oracle12345 · #36 12-12-2008, 02:40 PM

Quote:

Originally Posted by lkchris

Lots of guessing here. I especially like guys that think new filters are the cure for everything.

Ours recently exhibited a significant "knock" at idle and some nailing coming off idle.

The dealership tech immediately suspected fuel injector and there is an electronic test (with printout) for fuel injector performance.

We got a new #2 injector ($750) and all is now well.

Understand that the injector test indicates a range of diagnositics and an injector could be approaching but not at the cutoff point where replacement is required--that is, covered by warranty.

Injectors on these engines are not the simple calibrated holes of earlier days, but rather are sophisticated, complicated electronic devices not necessarily going to last forever. Our #2 made it 38K miles.

Yeah its a injector balance test. You measure the fuel pressure with key on engine off then you hook a fuel injector tester to see how much the fuel pressure drops when activated. the one that drops the most is the faulty injector.
you can also see the injector spray pattern. A good injector sprays a conical pattern and a bad just sprays straight and dribbles. A injector could be good electrically but could be bad otherwise.

a bad injector will cause an improper an A/F mixture and cause the engine to ping

DieselAddict · #37 12-12-2008, 03:01 PM

Quote:

Originally Posted by Jerzeeshor

The absolute best additive I've found to combat the loss of lubricity from the ULSD fuels in my '96 E300 is STANADYNE.

How do you measure lubricity? You can evaluate engine noise, but I don't see how you can measure lubricity, unless you're taking out some fuel system component and measuring the wear scars.

aklim · #38 12-12-2008, 03:11 PM

Quote:

Originally Posted by DieselAddict

How do you measure lubricity? You can evaluate engine noise, but I don't see how you can measure lubricity, unless you're taking out some fuel system component and measuring the wear scars.

http://www.johnfjensen.com/Diesel_fuel_additive_test.pdf

Problem was they were simply measuring a wear scar. If they had hooked up a bunch of engines and run some on and some off and given us some indication of what is what, I wouldn't be so dismissive of their "report". All we have is "More is better.".

DieselAddict · #39 12-12-2008, 03:12 PM

Quote:

Originally Posted by aklim

http://www.johnfjensen.com/Diesel_fuel_additive_test.pdf

That was my point. I doubt the poster is doing that at home, unless he meant he picked that additive based on a 3rd party report like this one. In that case, biodiesel is the best "additive".

aklim · #40 12-12-2008, 03:18 PM

Quote:

Originally Posted by DieselAddict

That was my point. I doubt the poster is doing that at home, unless he meant he picked that additive based on a 3rd party report like this one. In that case, biodiesel is the best "additive".

My point is that he doesn't tell us very much. Like I said, to everything, there is a point of diminishing returns. He doesn't tell us what it is. How do you make calculations from there? If he can say that by going from 460 to 520, your engine is going to last X miles longer, it is easier to compute. If all the difference it makes is that you get 1000 miles more, is it cost effective when you compute cost per mile? Without that, it raises many questions. What is affected and at what point? Should I spend $1000 on paint to make my front door last for 500 years if the rest of the house collapses in 200? Will the cost of the additive make sense financially? None of it is really answered in his study which is why I call it rubbish.

Someone mentioned curing the lubricity problem. That is why I brought this up.

OTOH, supposedly bio has a higher cetane value. Maybe that will trigger some sort of change and give us a clue where to look.

DieselAddict · #41 12-12-2008, 03:22 PM

Quote:

Originally Posted by aklim

My point is that he doesn't tell us very much. Like I said, to everything, there is a point of diminishing returns. He doesn't tell us what it is. How do you make calculations from there? If he can say that by going from 460 to 520, your engine is going to last X miles longer, it is easier to compute. If all the difference it makes is that you get 1000 miles more, is it cost effective when you compute cost per mile? Without that, it raises many questions. What is affected and at what point? Should I spend $1000 on paint to make my front door last for 500 years if the rest of the house collapses in 200? Will the cost of the additive make sense financially? None of it is really answered in his study which is why I call it rubbish.

I wouldn't call it rubbish, just incomplete, and certainly not useless. Bosch, the maker of our fuel system and who should know the best, called for a 460 micron wear scar, right? Sure, it doesn't answer all questions, but I don't think it's meaningless info. Again, use this info as you see fit. You seem to be demanding me and others to "make the case" for various things to convince your mind. I'm not interested.

aklim · #42 12-12-2008, 03:32 PM

Quote:

Originally Posted by DieselAddict

I wouldn't call it rubbish, just incomplete, and certainly not useless. Bosch, the maker of our fuel system and who should know the best, called for a 460 micron wear scar, right? Sure, it doesn't answer all questions, but I don't think it's meaningless info.

Again, use this info as you see fit. You seem to be demanding me and others to "make the case" for various things to convince your mind. I'm not interested.

Well, maybe Bosch should show us data as to why then. Like I asked before, is it in both my interests and Bosch or just Bosch? Is Bosch trying to squeak out a few more miles AT MY EXPENSE to benefit their warranty department or is there mutual real benefit.

Hey Ernst. Use this gun as you see fit. Sorry but if someone wants to peddle something, why should we be expected to take it on faith? Are you saying we shouldn't demand proof as to whether something works just because someone says so?

DieselAddict · #43 12-12-2008, 03:52 PM

Quote:

Originally Posted by aklim

Hey Ernst. Use this gun as you see fit. Sorry but if someone wants to peddle something, why should we be expected to take it on faith? Are you saying we shouldn't demand proof as to whether something works just because someone says so?

Absolutely not. I'm just not willing to do the research for you while you sit back and wait for the answer.

aklim · #44 12-12-2008, 04:52 PM

Quote:

Originally Posted by DieselAddict

Absolutely not. I'm just not willing to do the research for you while you sit back and wait for the answer.

I'm simply asking for the peddlers of the snake oil to step forward and show us their research. Is that too much? If I want to sell you something, who has the onus to bring forth supporting documents?

Scott98 · #45 12-12-2008, 08:47 PM

Quote:

Originally Posted by lkchris

Lots of guessing here. I especially like guys that think new filters are the cure for everything.

Ours recently exhibited a significant "knock" at idle and some nailing coming off idle.

The dealership tech immediately suspected fuel injector and there is an electronic test (with printout) for fuel injector performance.

We got a new #2 injector ($750) and all is now well.

Understand that the injector test indicates a range of diagnositics and an injector could be approaching but not at the cutoff point where replacement is required--that is, covered by warranty.

Injectors on these engines are not the simple calibrated holes of earlier days, but rather are sophisticated, complicated electronic devices not necessarily going to last forever. Our #2 made it 38K miles.

Glad you got your car fixed. You might want to consider Jim's Fine Car Service as an alternative to the dealer. Mickey owns the place, is a Mercedes factory trained tech, has all of the tool / computers required for your CDI and charges only $82 per hour. I've bought parts from him many, many times.

Scott