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  #16  
Old 12-30-2015, 04:16 AM
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Oops. You sorta answered my question as I was asking it.
Again, thanks.

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  #17  
Old 12-30-2015, 05:22 AM
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You're welcome. Since they get tight, you can see why valve adjustments are VERY important to the well being of the valves and the performance of the engine. A loose valve makes noise, but a tight valves gets flame cut and leaks compression. 15k miles.
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  #18  
Old 12-30-2015, 09:44 AM
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A few things:

Why was the car parked 7 years ago?

Most everything looks good in fuzzy pictures, are you in an area where salt is used?

Pull carpets up , look in trunk , look under the car at the body for rust. It may have nice paint but the part you can't see might be rusted away.

With any older non running car with unknown history , it is pretty much worth scrap value plus maybe a few $100 if y really want it. Locally cars are paying $ 2 per 100 lb.

Multi plunger diesel pumps are controlled by moving a rack ( like rack and pinion ) that rotates plunger barrels. This opens fuel passages to add more fuel. This rack can stick and cause 2 different problems. If stuck in the minimum / stop position, you won't get any fuel flow. If stuck in the full speed position, then engine will run away and you won't be able to shut it off.

Don't even bother with the fuel in the tank, use a lawn tractor or other tank as a temp fuel source. At first manually pump fuel and place the return in a waste can until what is coming out looks clean. Also be sure to have a way to shut off the fuel / block intake air with a plate should then engine run away.

Quote:
A cold compression test is pretty useless on these engines.
Given most engines start cold, good cold compression on a diesel is absolutely vital.
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  #19  
Old 12-30-2015, 12:53 PM
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Well, that's a good question. I'll ask him. It supposedly came from down south.
It's not far from where I live but I'm still on vacation and won't get back till tomorrow. The suspense is palpable. His pictures are nice and clear but they don't show under the floormats or the trunk. They show nice upholstery and a dash with no cracks.
Do these cars rot at the B pillars like the 123s do? I've read about door bottoms being an issue, too. Any other areas specific to the 115s? I've had enough rusty cars to know to be suspicious and to walk away when it gets bad.
I've brought several out of long term storage. I really enjoy carefully waking up an old car and all the little systems and features but I've never done it with a diesel.
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  #20  
Old 12-30-2015, 04:19 PM
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The floors are very vulnerable on the 115 along with pretty much everything else not protected by oil leaks.
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  #21  
Old 12-31-2015, 02:29 AM
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Chrysler slant six engines (60-77) have a similar solid valve train (thus need regular adjustment) and do tend to get looser as they wear. One would expect this from wear of the camshaft lobes and lifter base. The exception is if the exhaust valve seats recede, which is a concern w/ unleaded gas. I haven't heard of similar concerns in diesel engines, but some here have found valves too tight. Might be due to incorrect adjustments by prior owners.
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  #22  
Old 12-31-2015, 06:54 AM
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Overhead cam

The OM617 is an overhead cam engine hence wear in the cam and valve relationship results in clearance tightening. A quiet OM617 is one that needs an adjustment. You should hear the soft clatter of good German machinery doing it's job.
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  #23  
Old 12-31-2015, 09:02 AM
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Quote:
Originally Posted by rocky raccoon View Post
The OM617 is an overhead cam engine hence wear in the cam and valve relationship results in clearance tightening. A quiet OM617 is one that needs an adjustment. You should hear the soft clatter of good German machinery doing it's job.
um... there is no amount of wear of a cam that would result in tightening of the clearance.

the only thing that could wear that would tighten the clearance would be the spring loaded surfaces... I.E. the valve face/seat relationship. and it would not matter if it was a pushrod or a overhead cam engine.

the reason clearance increased in the older push rod motors was the lifters would dome out and the cam lobe would wear out. also, the huge amount of items under tension increased the amount of things that would wear... cam lobe, lifter face, pushrod cup, push rod ends, rocker arm push rod cup, rocker arm pivot fulcrum surface, and rocker arm tip... overhead cam just has cam, follower, and valve tip.
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  #24  
Old 12-31-2015, 10:18 AM
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Quote:
Originally Posted by whunter View Post
A cold compression test is pretty useless on these engines.
I'm going to disagree with you on this one, Roy. To determine the actual condition of the engine you need to check it cold.

Now if you are saying for the initial start up of an engine which has sat idle for a long time (months or years) then I'll agree with you but for a regularly used vehicle, then you check it "cold".
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  #25  
Old 12-31-2015, 10:24 AM
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My old chiltons from 1970 says a mb diesel needs 220 psi cold for reliable starts. I've never figured out how to move fast enough to get hot starts seeing as how its not the easiest thing to remove glow plugs and install a compression gauge.
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  #26  
Old 12-31-2015, 12:35 PM
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Thanks

Vs. A fine clear explanation.
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  #27  
Old 01-02-2016, 02:54 AM
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Ok, saw the car with my own eyes. It's a little rustier than it was in my fantasies but I still like it. My one suspicion is this,
What goes on under the rugs? I pulled them back and all I could see was the fat sound insulation that's glued to the floors. I looked under the car and the floors look fine, great in fact. But I wonder, do those rubber of foam mats trap moisture and hide rust or do they protect the metal from moisture?
I talked to the Dad this time. He knows cars pretty well but doesn't internet. I've been talking to his son who internets but doesn't really know the car.
It was in a garage for about 8 years after the owner died. The wife finally sold it to this guy who had it in his driveway for the last two years.
There's some evidence of moisture on the front driver's side floor mat but it was a good floor mat and the carpet was basically dry.
Does that come from a bad windshield seal or the cowl vent?
He said he did a compression check and got high 200s across the board. He thought the rings were stuck from sitting. But you say low 200s is good enough. Hmm.
I'm gonna sleep on it.
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  #28  
Old 01-02-2016, 04:47 AM
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200 is the MINIMUM for cold starting. Perfect compression is around 400 I believe. Most have around 350 or so. At 200, glow plugs are very critical and a block heater/extreme measures become necessary below 40-50* F.

Doing a valve adjustment and an MMO soak for a week has the potential to raise compression into the very good range, but only if the rings are stuck or gummy and not worn out legitimately.
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  #29  
Old 01-02-2016, 09:02 AM
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Being able to do a compression test on a diesel is a step above a gas motor since the tools are less common. ( Though with the internet more accessible these days. )

This guy may know more about it then he leads on.

In any event, buy the car for what it is and not what others say it is. The underseal on these cars does a good job of protecting from rust, . . .until there is a break in it then it does a good job of holding rust together in the shape of a car. Are you in an area where road salt is used?

Even with 200 PSI the engine should start on a warm day.
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  #30  
Old 01-02-2016, 05:06 PM
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It'll probably start on a warm day, but the process will be similar to those with high compression starting in the cold. Low compression starting in the cold is like starting a high compression engine in the Arctic circle...

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