thoughts on perspective purchase - PeachParts Mercedes-Benz Forum

wademunkey · #1 05-29-2009, 01:37 PM

One of my managers at work has a 83 300D turbo with 154,000 miles. The body is perfect, and the interior is close. When he lived in Florida, he drove it across town just fine, and as i understand it, the car was parked after that one drive. Since then he has moved to Ga, towing the car. He then began to work on the car and replace vacuum lines and the such. At first he said that the car had no power up hill, then he messed with it some and it went up hills good, but not down hills.
Currently he says that the car starts good giving off one good puff of smoke on startup and then going away. When the car is cold it runs good, getting around town just fine. but, when it warms up he says about 80C is where it tends to sit, it wont get above 20mph. He also says that the engine will occasionally stumble when warm for a matter of seconds, then it will go back to a perfect idle. similar to what i saw in diesel giants injector nozzle video.
He is not running a thermostat whatsoever in the engine, and the vacuum hoses have been absolutely molested. The power door locks work good, even after sitting all night. the car will not shut off by the key, which i believe is going to be the shut off valve on the IP.
Basically, i am not afraid of the mechanicals on this car at all, but i am just wanting to see what the consensus on the strength of the motor might be. I have not done any compression tests, but the fact that the car starts up and idles well until warm makes me think it is a problem in the control system.
I have gone through my lil miata front to back, so being dirty and nasty doesnt scare me, but i would like the fix to be more about tuning/ perfecting what is there, not buying large parts like a new engine.
Do you think that this is a car that needs some attention, or does it seem like it is on its last legs?
Thanks for any help folks, and this forum is great.
Andrew

sd300td · #2 05-29-2009, 02:45 PM

You don't say how much your willing to pay for this "perspective". Regardless, the car definitely needs work and be very suspect of the odo mileage.

winmutt · #3 05-29-2009, 02:52 PM

Running without a Tstat is stupid, so much so the manual points it out as being stupid. Rescue the car from him and fix it. Sounds like air in the fuel or filters or any number of easy things. Generally if these engines dont have a death knock of a rod they are just fine. As sd300td mentions, 154k is about where the odo's crap out.

Where are you located?

UriahT · #4 05-29-2009, 03:39 PM

Like winmutt said:
If it runs without a knock, the engine is probably totally salvageable with some minor work:
-Valve adjustment
-All fuel filters replaced or cleaned (tank screen)
-Check fuel delivery for air leakage (or a bad primer pump)
-Check/adjust IP timing, chain stretch
-Pop test spray pattern and pressure of injectors
-Adjust rack dampener bolt if necessary after these repairs

I'll bet dollars to donuts that if you do these things, that engine will purr like a kitten.
And there is absolutely no need to run without a thermostat. A diesel engine runs more efficiently when warm.
Get a vacuum schematic, and reroute everything (except the EGR). And check kickdown switch. There's been occurrences where these can get stuck and not upshift easily.

wademunkey · #5 05-29-2009, 11:33 PM

Thats exactly what i was thinking. THe car is going to end up costing me about 900$.
I am in statesboro georgia, and am going to check over the body and engine compartment good to make sure the mileage matches.
The car was owned by a pastor, then him, so i do not have any reason to doubt the mileage currently, will definitely give it a good looking over.
I am going to look at it tomorrow to seal the deal, then its probably going to sit for a little while longer until i get through some of my tests and such, then i can focus on getting it running right.
Does anybody have any idea what the running poorly when heated up could be?
Andrew

Bama1 · #6 05-30-2009, 07:30 AM

Number one suspect for the symptons you describe is inadequate fuel delivery. As someone suggested earlier, I would replace both of the fuel filters and if they are especially dirty consider cleaning/replacing the tank strainer.
Although that is not usually necessary unless the fuel is heavily contaminated with algae indicated by a noticeable green/black/yuckish coloration of the filters.

Look closely at the inline fuel filter on the driver's side of the block and let us know what the filter element condition looks like. Under normal circumstances it should be clear or at the worst, the yellowish brown color of very, very weak tea...

wademunkey · #7 05-30-2009, 05:21 PM

thanks alot folks, im going to take soem good pictures of it in a few, i will get some of the fuel filter, the over all car, and the interior.
Y'all rock
Andrew

wademunkey · #8 05-30-2009, 09:35 PM

alright, so i took a good look at it, it does have some blow by if i open up the oil fill cap while it is running, the body is not as perfect as i thought, it is solid, but showing its age, and to be perfect will require a donor car for various pieces.
We fired it up, smoked some, then got a bit of a rough idle with the engine shaking very lightly. after it warmed up some it was perfectly smooth on the engine itself, the airfilter was shaking some since it seems to be not mounted properly.
The car was making 2 Bar oil pressure at idle, going up to about 3 Bar before it shifted. The tach isnt working, so im not sure what rpm it was getting up to.
The transmission is not shifting properly, he had to let off the throttle to get it to shift, but when it did it was butter smooth.
There are some pieces in the vaccum system that are not hooked up. The solenoid that is to the left of the brake booster is not hooked up to anything, that the round valve about 8" from the brake booster is missing the nipple going towards the engine.
The air filter housing also has some oil built up in it.
He said that the engine took 10 Quarts of oil though, I thought is was closer to 8.5? That may explain some of the various problems.
The fuel filter, oil, air filter, are all fresh.
I am getting some pictures and a video of the car up right now just gotta convert the formats of some of them.
Andrew

wademunkey · #9 05-30-2009, 09:59 PM

here are the pics and video
http://www.youtube.com/watch?v=Ywkv6j-Mwhk&feature=channel_page

wademunkey · #10 05-30-2009, 10:30 PM

lol, just remembered, the fingers of the transmission control on top of the valve cover were both shot. That would probably explain the trans shifting.
Andrew

Skippy · #11 05-30-2009, 10:54 PM

Some blow by is normal. It sounds like your vacuum hoses are all messed up. Get yourself some diagrams and start putting them right.

In the video, it looks like your air cleaner mounting bracket or the little rubber mount things are broken. Fairly common on these cars and a relatively easy fix. You'll see what I mean when you get the air cleaner off.

The engine should take 8 quarts of oil. If there are 10 in it, that isn't good. I always do an oil change on a car when I buy it as one of the first things anyway.

After you get your vacuum hoses and linkages sorted out, the next thing to do would be a valve adjustment. You may also get smoother running and less smoke just from driving the car. They run better when they get driven a lot.

Edit: Statesboro-you don't go to Georgia Southern do you? I partied down that way once or twice.

toomany MBZ · #12 05-30-2009, 11:09 PM

That stuff on top of the cam cover can be removed, block all the vac lines, that is the egr system.
The air cleaner has been covered.
That round valve near the booster is a switchover valve, it guards against too much turbo boost, mine is bypassed.
Tach not working is a familiar tale, do a search on the subject, but you'll need a new amp eventually.
Shifting problems abound, another search is in order.
Do a proper oil change and a transmission service, making sure to drain the torque converter too.

wademunkey · #13 05-31-2009, 07:26 AM

thanks all
yeah, i do go to georgia southern, dont party too much, engineering degree tries to keep me busy.
Im getting really excited about this. I payed him part of the price, so he is going to hold it for me until i get moved into a house in a month. Then i am going to focus on getting the motor running right, then i will work on the trans, then i am going to drive this thing.
:-)
THanks again folks
Andrew

toomany MBZ · #14 05-31-2009, 11:34 AM

^^Cool, keep us posted.

wademunkey · #15 06-01-2009, 12:46 AM

does it seem right to yall that since the alda electronic valve is not connected to any vacum lines that the alda valve itself could be seeing no boost, so it wouldnt give more fuel, so wouldnt go fast? I do not remember if it had any lines on it whatsoever, but i will probably go take a look tomorrow.
It doesnt explain the temperature change, can somebody send me in the right direction on what happens when these hit operating temp? ( in a gas car it would go to closed loop mode, etc)