In my other post (considering a 84 300SD) you can read more about this car. I posted about this there as well. I just looked at the car and it is in excellent condition appearance wise, with no rust, excellent interior and shiny original paint.

The possible problem that has me concerned is the severe shake the engine has at idle. It will actually shake the entire car. Just the slightest acceleration- the engine will smooth out as smooth as silk. Its only at idle when it does it. It has 330K and the seller stopped driving it last summer because the A/C went out. It has been in the garage for a few months. He said it was not doing it before and it may need a "tune-up". I know nothing about Mercedes. Could this be something as simple as a tune-up, or is it something major? My dad said it sounded like an injector is going bad. I really like this car, as it is in excellent condition and if it is nothing major- I will probably buy it. I am supposed to go back tomorrow in the daylight and drive it. I wanted to check here first to check on this engine problem before I bought it. BTW- he is asking $2399 for the car, but I think I can get it for less than that. ANY advice/information greatly appreciated.

Thanks. That may be part of it- but out the tailpipe- it has a "put put put" sound, like it has a miss. Slightest increase of RPMs it smooths out like silk.
I just want to be sure it is not a major problem.

Thanks again.

I suspect water contaminated fuel and/or clogged fuel injector. Because of the contamination, the pump isn't pumping enough of good fuel at idle to keep the engine running smooth. When you add throttle, you increase the amount of fuel going through the injectors, thereby making the engine run smoother. This might be cured if you drive the car to near empty and then refuel with at least one bottle of water-dispersing/injector-cleaning additive such as RedLine. It might also help to change the fuel filters.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Thanks.... So can I safely assume that it is nothing major- like a bad engine causing this? If it is nothing major- I will definetely buy it- if the car checks out OK on the test drive.
It is in excellent condition otherwise. He has owned the car since 1989 and it has been garage kept.
If I do buy it (if not a major problem)- would it be OK to drive this car home (about 15 miles) until I get it repaired, or drive it to the repair shop?
Thanks again.

Also- if it makes any difference- it does it when hot and cold.
I searched "rack dampening bolt" and found several topics. I seen one where "Virginia Dude" and "Sixto" replied to a topic about a shaking 300TD. I seen replies from bad compression, bad mounts, bad rack dampener, water in fuel, bad injector, etc.

I just talked to my uncle- who used to sell these cars new back in the early to mid 1980s and then owned an auto repair shop and car lot. He said I should have a compression test completed on it before I buy it. He said it could be as simple as an injector, or as major as a fuel distributor pump- which he thinks is about $700.

I guess I will see if I can take it tomorrow and let the mechanic do a compression check on it.

Any additional information appreciated.

You posted before I finished. My uncle said the exact same thing. He said if the compression checks out OK- it should be something minor- unless it is the fuel distributor pump. It was not spraying oil. Oil pressure showed to be very good on the guage- even when it warmed up. ** Also- if it is bad compression- about how much $$ will that cost to repair? I can offer him that much less for the car, if it is not a $2400 repair.

Thanks. Hopefully the compression will be OK.
My uncle said if the owner objects to me taking the car to have a compression check (checked by the mechanics) then I should walk away from this car.

I just posted on my main topic- I guess I will have to pass on the car. I realized that the license plates and state inspection was expired on the car and I am sure the seller has cancelled the insurance, so I obviously cannot drive it anywhere. I guess I will have to search for another.
Thanks again for all of the replies.

Worn or bad rack dampner bolt will produce exactly the symptoms seen on the 617 engine -- shakes like crazy at idle, but runs prefectly at any higher speed.

What happens is that there is a harmonic vibration in the injection pump that exactly matches the harmonic of the spring on the fuel delivery control rack in the IP, with the result that at idle it ocsillates back and forth in harmony with the engine vibration. When the spring gets weak or the dampner bolt gets worn, it gets bad enough to cut the fuel off to some cylinders, causing the shake to get much worse.

Usually can be fixed by adjusting the dampner bolt in some, but eventually it can no longer be compensated for, and the pump will have to be disassembled and repaired. I'd not do that until something else needed fixed!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks... So you do not think it is bad compression? That is the only thing that worries me. As mentioned- it smooths out when I press the accelerator. When it idles- it rocks side to side and moves the whole car vigorously.
If I do buy it and it turns out to be bad compression- would it be worth $1700.? They are asking $2399, but what should I safely offer not knowing the problem? As mentioned- the body and interior are excellent. No rust or dents. A/C does not work. Also- when it does that side to side rocking- it has a "put put put" sound from the tailpipe- like a miss. I also forgot to mention that the diesel smell from the tailpipe is a strong smell- but that may be normal for all I know. Thanks again.

Nobody here can say for certain that it isn't bad compression. That requires a hands on test.

Check with the DMV about getting a temporary tag for demonstration or test drive purposes. They should have a provision for that, I know Florida does.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

True- I would love to have that test done, but since the plates and sticker have expired, there is no way to drive it to repair shop in town. I guess I will offer much less and take a chance on it and hope if it is something major- I can at least get my money back out of it- or just forget it all together. Thanks for all of the replies.

DITTO!!!!! on the motor mounts and shocks.9 times out of 10 after changing the mounts.shaking will cease....

The state of Tennessee offers a Temporary Operation Permit. Call 1-888-871-3171 for more information.

__________________
Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

Thanks for that information, but here is what I found out about the car: (This is the same reply I put on "considering a 84 300SD)

Well, I just got back from looking at the car again and driving it. I noticed sometimes- that shake would go away- even at idle. Needless to say- it has less power than the other 300SD w/224K I drove a while back. It had a quick 2-3 shift and the shifts were firm. I remembered it took a while to get used to the shifts on these cars. However, the other 300SD I drove shifted firm, but it did not require releasing the accelerator pedal for a shift. This one would go to 4K before if shifted, unless I let off of it. I did not drive it far- it was low on fuel. Engine did not warm up that much either. I did notice GREEN anti-freeze leaking from under the right front area. He said the car had been serviced regulary. I did not think you was supposed to use green anti-freeze in these cars? I think that could be a high $$ repair. Coming back up the driveway- which is a fairly steep grade- the car had very low power. I did not hear the turbo going up the grade, but heard it going down the driveway and on the other parts of the test drive. I was going like 4 mph up the drive, with the pedal to the floor. It finally started gaining speed. There was a memo book from 1986- that showed everytime the oil, transmission fluid and fuel filters were changed and it went all the way up to 2003. There was also a LOT of service records, but it looks like it was more or repairing of problems, than regular maintainence. Mostly from 1989-90- when he first bought it- it was receipts from the Mercedes dealer- which is still in business. I seen one where it said the illumination dash lights had stopped working and was repaired, rear window was off of the track in 1989, several about coolant leaks- repaired over the years, valave cover gaskets replaced, valves adjusted, etc. etc. There was all of the receipts for tires, tune-ups, etc. I seen one where it said owner was complaining of rough idle receipt showed that mounts and/or engine shocks replaced. There was other receipts that stated "engine was running hot". He also said that sometimes the "oil temperature"? light was coming on sometimes, but he said the mechanic said it was just a sensor, as the car was running cool. The A/C has been switched over to the new R-134a, but compressor is bad. He said everything worked, except for the cassette deck. No leaks from the sunroof, but the rear windshield did leak, but as soon as he noticed- he resealed it. Again- it is 100% rust free- trunk pan, floors and rockers are 100% rust free - which is typical around here. So, possibly there is more wrong with this car than I thought. It has been a good car obviously- it has 336K miles- something that most cars cannot do. He came down to $2100 on the price. My dad said it was probably worth that- but I have no idea about all of these problems.
I think I may go down this weekend and check out the gold 300SD- the one that the other "considering a 300SD" topic was originally about - that is supposed to be in perfect working order for $2500. It also has less miles. Or- I may get a newer Camry and wait for another good Mercedes diesel to come along in the future.
Thanks again to everyone for their advice and information.