Compression in 200s sell or keep, 87 300d

[Geezer]

Title says it all. I just bought a 1987 300D with 298k miles. Interior is great, all electrics work, east cost car so some rust around wheel wells. After getting it home I thought I'd run a compression check before really throwing any money at it.
Cold it comes back
#1 240
#2 260
#3 220
#4 260
#5 240
#6 280
For fun I put a little oil in #1 and re-checked and it and it shot up to 380.
Car runs OK, smokes a little till it warms up, but then it stops.
What would you do? Would you cut your loses and sell, or keep it and start fixing it up?
Samson

[t walgamuth]

Depends on what your goal is. If the car runs fine why not keep it and enjoy it. It is in the minimum for cold compression to start regularly.

Perhaps changing the oil to some good diesel rated will raise the numbers.

In a few years you may find the need to go through the motor.

[shadetreemechan]

x2 on the oil change. It sounds like you know neither its viscosity or age.

[SwampYankee]

Ditto on the oil change and just drive it if you didn't pay much for it.

[Geezer]

right now I have about a $1k into it. Going to be changing the coolant, heat shields, injector overflow hoses, and trying to fine the source of a few oil leaks(where are the common places on these?). I'm sure the oil is old, but I don't thank an oil change is going to change the compression. I just feel like i could probably find a better example(with better compression) for not too much more. I've seen a few go lately for around $2k

[Jeremy5848]

At least keep it until you have changed the oil and have determined how much oil it burns (and leaks) per thousand miles. If it's only a quart or so and if the engine otherwise continues to run well, ignore the low compression and continue fixing up the car. For easier winter starts in your part of the world, you might consider investing in a cord for the block heater (the OM603 engine came with one from the factory).

Jeremy

[ah-kay]

Originally Posted by Geezer

right now I have about a $1k into it. Going to be changing the coolant, heat shields, injector overflow hoses, and trying to fine the source of a few oil leaks(where are the common places on these?). I'm sure the oil is old, but I don't thank an oil change is going to change the compression. I just feel like i could probably find a better example(with better compression) for not too much more. I've seen a few go lately for around $2k

Not sure your $1k is your purchase price or in addition to it. If it is the former then it is a good price and I would just change the oil and drive it. I do not throw seriously money at any car unless I want to keep the car for a while. I am sure you can resell it at the same price a year or so down the road after some cosmetic fixes.

[Geezer]

$1k is including the purchase price, so yea, I feel pretty good about being able to get my money back, but by the same token, if the compression gets worse, I'm going to have a much harder time.
According to the previous owner it didn't use any oil between changes, we'll see about that. And it has vurtually no blow-by, which makes no sence concidering it must be the rings that are worn(140 psi boost when oil is added to cylinder)

[ah-kay]

Originally Posted by Geezer

$1k is including the purchase price, so yea, I feel pretty good about being able to get my money back, but by the same token, if the compression gets worse, I'm going to have a much harder time.
According to the previous owner it didn't use any oil between changes, we'll see about that. And it has vurtually no blow-by, which makes no sence concidering it must be the rings that are worn(140 psi boost when oil is added to cylinder)

No one has a crystal ball. The engine may crap out tomorrow, same for the tranmission. $1K is only 2 or 3 months car payments. MBZ diesel is built tough and if you enjoy the car, maintain it well, I am sure you will come out ahead.

[Billybob]

Originally Posted by Geezer

Cold it comes back

A proper compression test is conducted with the engine at operating temps 80-90C! So the test you performed and the numbers you'e posted are meaningless with regard to any specifications! But the range of specification meaningless numbers do point to a fact that there is relatively not that much deviation between the cylinders, and one can therefore assume that there is not likely a significant difference in the cumulative wear factors such as ring, piston wall condition and things like valve and valve seat wear.

As you obviously already posess the required equiptment you would be doing yourself a favor to conduct another survey of the compression under the correct conditions and then compare those results to the published specifications. That way you would actually know where this issue stands.

[babymog]

If you're not that worried about cosmetics, put the parts in it and drive it.

If you're worried about cosmetics, you've already got a rust issue, dump it and get a better example.