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  #1  
Old 09-03-2012, 02:41 PM
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Compression Test Results

Before throwing more money and time at my 82 300td with (maybe) 170,000 miles.

Compression, without updated valve lash and probably a bad injector

1. 240
2. 240
3. 230
4. 240
5. 240

The injection shop that tested it said that a valve adjustment and rebuilt/new injectors will help those numbers.

Is it worth it? The body is not in terrible shape, but the transmission isn't to happy with the world (vacuum issues, and probably needs new springs to).

To save or not to save this car?

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1982 300TD 300,??? miles, daily driver turned donor
1982 300TD, 184,000 miles, daily driver
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  #2  
Old 09-03-2012, 02:51 PM
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The numbers aren't bad and seeing them so even is a plus. A compression test isn't worth doing before adjusting the valves. Injectors have no influence on compression besides a physical leak past worn heat shields or prechamber lock rings (rare enough for one cylinder, very rare across the board). You either misunderstood the recommendation or they shop is some combination of incompetent and dishonest.

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87 300D
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  #3  
Old 09-03-2012, 02:52 PM
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I'm going with incompetent and dishonest. And since they're likely the original injectors, I'm thinking that those might not be in pristine shape.

Valve adjustment coming up soon, and pop testing my injectors.
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  #4  
Old 09-03-2012, 03:46 PM
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Quote:
Originally Posted by ubertino View Post
Before throwing more money and time at my 82 300td with (maybe) 170,000 miles.

Compression, without updated valve lash and probably a bad injector

1. 240
2. 240
3. 230
4. 240
5. 240

The injection shop that tested it said that a valve adjustment and rebuilt/new injectors will help those numbers.

Is it worth it? The body is not in terrible shape, but the transmission isn't to happy with the world (vacuum issues, and probably needs new springs to).

To save or not to save this car?
If that is psi you are on the low end of the compression scale and unless something happened to an Engine with 170,000 miles. In My opinion is that your compression should be higher for that milage.

A valve adjustment has been know to increase the Engine Compression.
New Injectors are not going to make you compression test better.
While the Valve Cover is off you coulc check your Camshaft timing by lining up the marks and looking at the degrees pointed to on the Crankshaft Damper.

It might be you have sticking Piston Rings. Soaking the Cylinders in Marvel Mystery Oil or some other stuff might help. People have said switching to Synthetic Motor Oil and driving 200-300 miles will also free up the Piston Rings.
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  #5  
Old 09-03-2012, 03:49 PM
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Sorry, I was off in my interpretation. 400 is excellent, 300 is passable, 200 is about the minimum to start the engine. I would think at 240 psi it would be impossible to start this engine for all but 3 months of the year in Michigan. Conversely, if the engine starts easily, something's wrong with the compression test, not the engine. A compression test is a diagnostic step, not preventive maintenance.

Valves should be adjusted, or more accurately, valve lash should be checked every 15K miles. No questions, don't wait for symptoms, just do it. Check timing chain elongation while the valve cover is off.

Sixto
87 300D
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  #6  
Old 09-03-2012, 03:50 PM
t walgamuth's Avatar
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The compression stated is the least possible. It might get better with a valve adjustment but IMHO probably not. It is on the bottom end of compression required to have reliable starting. I'd run it as is, keep the oil changed and save up some money to rebuild or replace the motor.

Report back in a few years.
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  #7  
Old 09-03-2012, 04:04 PM
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Good point on the rings, Tom. Has this engine run on vegetable oil or alternative fuel other than commercially available biodiesel?

Sixto
87 300D
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  #8  
Old 09-03-2012, 04:28 PM
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Call me

Quote:
Originally Posted by ubertino View Post
Before throwing more money and time at my 82 300td with (maybe) 170,000 miles.

Compression, without updated valve lash and probably a bad injector

1. 240
2. 240
3. 230
4. 240
5. 240

The injection shop that tested it said that a valve adjustment and rebuilt/new injectors will help those numbers.

Is it worth it? The body is not in terrible shape, but the transmission isn't to happy with the world (vacuum issues, and probably needs new springs to).

To save or not to save this car?
Call me tomorrow after 10:00 Am.

.
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  #9  
Old 09-03-2012, 05:07 PM
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Roy, you forgot the "take two aspirin..."

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  #10  
Old 09-04-2012, 04:49 PM
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ROFL

Quote:
Originally Posted by sixto View Post
Roy, you forgot the "take two aspirin..."

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Dan Ackroyd and Dr. Detroit! (and James Brown!) - YouTube

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  #11  
Old 11-19-2013, 08:59 PM
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Thread update, after a valve adjustment and winter oil (10w30 instead of 15w40) and the car starts on it's own in 6 degree weather. But, after spending money on the suspension and keeping it on the road, I discovered that the body is turning into tissue UNDER the paint. So, the car is now being parked where it will donate parts to a much better maintained diesel. Same year, same interior color, same model, so the parts gods should be appeased.
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1982 300TD 300,??? miles, daily driver turned donor
1982 300TD, 184,000 miles, daily driver
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  #12  
Old 11-20-2013, 10:59 AM
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trunk badge ???

So, you do have a wagon!!! Cool. What colors (interior & exterior) are your car? I will help find you a better shell.
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  #13  
Old 11-20-2013, 11:02 AM
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It is a wagon, with turbo.

I've already found another 300TD to replace it with, keeping the old one for parts.
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1982 300TD 300,??? miles, daily driver turned donor
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  #14  
Old 11-20-2013, 11:08 AM
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where did you find 10w30 oil with a C rating? Diesel rated oil is extremely rare in xw30 rating...
best bet for winter oil is 5w40 synthetic... not 10w30...
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  #15  
Old 11-20-2013, 11:22 AM
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@vstech I just checked, and you're right, it's 5w40, got it from the local diesel fleet place, it's Delvac 1.

That said, Chevron make Delo heavy duty 10w30, if you find a need for it.

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