Hello 83MB240D
If the fuel filters have been in for 40K miles; there is little doubt that they need to be replaced.
What calendar time frame does 40K miles translate to?
The valve adjustment can not hurt.
Have them check the O rings on the fuel supply line to the fuel filter housing as a precaution, there is a small possibility that you may be sucking air into the injection pump.
Have you been treating your fuel tank for algae every year?

Averaged 28 mpg; sounds a little low to me for your region.
A fouled fuel tank could be the real issue.
The mechanic can blow backwards through the fuel line, with the filler cap off the tank, and listen for bubbles, if it is plugged up, this may clear enough algae glop to start the car.
Have a great day.

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1985 300SD
1983 300D
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If the car runs all day at 80 MPH, there is nothing wrong with the fuel filters and replacing them would be a waste of money and time. Filters do not clog proportional to time but to the contaminates in the fuel. If there were no contaminates in the fuel, the filters would last forever.

The theory that filters have to be clean to work is a lot of bunk. They work perfectly up to the time they will not pass enough fuel for full power operation of the engine.

P E H

What is the going rate for a valve adjustment? I'm in SE Mass and would like to get it done. AFAIK, mine has gone 6+ years without one...

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1983 240D
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Hello PEH
I would agree; in a perfect world.
Reality has slapped me enough times that poor fuel quality or contaminated fuel is an every day thing.
Changing filters; like oil change limit, is a personal choice, which I will not argue.
All I can do is suggest possible solutions; based on professional experience in the field.

Whunter,

If you get badly contaminated fuel like I did in Colorado once, it will plug up a new filter almost as fast as a used filter. Either way, I had to change the filters, but I didn't have to replace a new filter with a new filter. As usual, I had spare filters in the trunk, so I was not stranded in the Rocky Mountains.

The primary filter has been on my '79 SD for 60,000 miles and I'm not about to replace it, Just got back from a 4000 mile trip and it ran perfect all the way. The secondary filter would probably have been on the car as long but it sprung a leak in the side of the can. That ended its life quickly and prematurely. Unfortunately it was a "white label brand", put on by previous owner, so I couldn't return it and demand a new one.

P E H

The valves are adjustable,so they get out
of adjustment after some time.(they won't
open when needed or stay closed when
they need to be open).

Mb123,

Say what?

The valves will work as usual except when adjusted too tight there will be a hairline gap between the valve and the seat. This gap will leak air and cause a lower compression pressure in the cylinder. This exacerbates cold starting because of the lower temperature in the cylinders due to the lower compression pressure.

P E H

Sorry P.E.

I had the right idea,just didn't know
how to bring it into words.

Louis.

Did the Valve adj help? What were the results of the compression check?

__________________
'83 240D (W123) 321K miles
250KM Mileage Award
500KM Mileage Award

'84 300TD (W123) 215k miles
250K mileage award pending

Well, this is like the sine vs. dino oil posts. I must disagree. The new 240D would run at 80 MPH all day. But at speed when pressing on the accelerator to accelerate more, I know not much more accelerating left in a 240D, the engine would "miss". I cleaned all the filters. Fuel tank screen almost completely blocked. Inline and main filter had sludge in it, algae. After changing the filters and installing new fuel the car ran perfect.

I do feel his problem is multifacited. Fuel, glowplugs, valves, injectors may be dirty. Compression may be a factor, but if the other items are sound I don't see the car not starting all of a sudden over a 4 week period.

It will be intersting to see what the cause is!!!

Dave

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1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

All,

I just received an update from the shop regarding my vehicle. First off, let me say that I want to thank all of you for the very useful information and suggestions. You are all not only very knowledgeable MB owners, but very nice people as well.

In any case, the update is not a very good one. They did a valve adjustment followed by a compression test, and they told me the engine is gone. The compression test revealed only 50 psi per cylinder on all 4 cylinders compared to a normal 350 psi. They said the engine needs a $3600 rebuild to get back up running again. Upon hearing this, I was not only upset, but very surprised that the engine was this tired. As I mentioned before, the car ran great. I've been using it to commute 90 miles a day to work for the past couple of years. It always started great, ran 70 mph on the highway with no problems, and I could take it up to 80mph without flooring it. I can't believe that an engine this bad (50 psi on all cylinders) could not show any early signs of fatigue or wear. The ONLY problem that I had was that 4 weeks ago the car had problems starting when the engine was cold. Once the engine was warm, I could turn it off and turn it back on within the next couple of hours with no problems. In fact, I feel that if I just made it a habit of turning the car on every 4 hours (even when parked) and leave it running for a couple of minutes, it wouldn't have a problem starting and could still be on the road!

Any way, I guess I'm just rambling because of my disbelief that the engine was in such bad shape. Now, I have to think about whether to put an old engine in, or just donate it to charity and write it off. I hate to see her go after 21+ years of ownership.

Thanks to all again.

Regards,
Cal

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83 240D (256K miles)

I personally find it hard to believe that the compression in all four holes has dropped equally to around 50psi over the life fo the car...
That being said I am not there and cannot verify this with my own compression test but sheesh, that seems really odd.
it almost sounds like their gauge or hookup to the tester was bad and thereby measured a consistant 50psi as that is all the bad connection could hold.

Maybe someone can comment but I wouldn't think that it would have even come close to starting at 50psi or let's say 75 psi as it was on it's way down... I don't think it could have created enough pressure to fire off the fuel mixture.

Anyone ever done the math on this to figure out the compression/heat ratio and burning point of diesel at ambient temps?

I hate to think of a fine car like this finding it's way to the wrecking yard but I also understand that a motor is not cheap.

Before you donate or junk it check around here as there are a few of us that like a challenge...

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'85 300SD Silver - Sold
'78 Ski Nautique

That does not sound right at all. I'd be looking for a second opinion.

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Rick Miley
2014 Tesla Model S
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Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
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I second what Rick says. Get a second opinion.

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Never a dull moment at Berry Hill Farm.

Third that opinion. Something odd here. 50psi is very low and the fact that it is uniform across all cylinders makes it suspect. One would expect significant variation in numbers on different cylinders. Is it possible that the timing chain jumped a tooth and is causing the problem? Have you had any issues with low oil pressure recently?
It sounds like a very big leap from running well to totally shot. Possible, but not likely.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Not sure about the 240D, but my 300D glow plug system continues to heat for about ONE minute. I believe the glow light going out at the 5 second interval is only a "suggestion" as to when to try to start the car.

Try keeping the ignition switch in the "glow" position for 30 seconds and see if that helps.

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84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)