Does anyone do a compression check as pre purchase inspection?

[EddieWalker]

It's pretty hard to remove the injectors to get test the compression of each cylinder. If I was selling and the potential buyer wanted to do that, I would not allow it for the basic reason that they could easily mess something up, or at the very least, create more work for me if it doesn't start up after they are done.

I guy I met awhile ago had a non running John Deere 710 backhoe for sale. He had the engine out and said that it was just rebuilt, but that he didn't have the ability to put it back together due to his health failing him. He said that he bought it at an auction and it started up right away and ran great, but after getting it home and putting it to work, realized that it didn't have any power. He pulled it apart and found out that a BB had been used to plug up the injector to hide the fact that the cylinder was dead. According to him, he said this was a common trick that was done when selling construction equipment, and he should have known better.

 

[abunchofidiots]

When I use to build rock crawlers for a hobby, I had a lot of vehicles go through my place. Anytime I was selling one off, I did a compression check and took a picture of it with the item I was selling. If someone wanted to do one besides that, I usually did no entertain it unless it was very easy to get to.

 

[CobyRupert]

Sure would add to the price of the tractor. Either to the seller of buyer. In a private sale anyway. Honestly don't know of anyone ever doing it..

Not sure. This issue surely makes one think (reminds one) what "the market" actually is. Is it the "general public" (some imaginary future person), or is it really just you and a potential buyer/seller?

That is, I mean: Say a person is selling a tractor that the market says is worth $10,000. Mr. **** Retentive comes looking to buy and gets a compression check, that shows a few cylinders are starting to get weak. Now what is the tractor worth?

The answer is a question: Worth to who? Mr. **** Retentive? ($7500) The seller? (Whatever he can get between $7500 and/or $10,000)* or to "the market" (Still worth $10,000)?

*: Now the seller has a moral and monetary dilemma on whether he should mention the test results to the next potential buyer.

 

[Coyote machine]

"*: Now the seller has a moral and monetary dilemma on whether he should mention the test results to the next potential buyer."

* ONLY if he's **** retentive.

To the OP: maybe next time specify what the heii you're asking about, and use a question mark to pose it as a question, duh!

 

[CalG]

"*:

To the OP: maybe next time specify what the heii you're asking about, and use a question mark to pose it as a question, duh!

I guess you missed the topic header.
That's OK, reading is hard.

 

[countrybumpkin]

He has that problem.

 

[Coyote machine]

I guess you missed the topic header.
That's OK, reading is hard.

No, wishful thinking on your part. It doesn't specify what you're asking about either. Diesel? Tractor, UTV, tugboat, freight-train?
You can go to get help with your reading, and come to think of it writing problems- don't be ashamed to ask for help.

 

[Coyote machine]

He has that problem.

What, wanting clarity?! Yeah, I guess its a lot to ask of a lot of those posting here these days. Being a 'bumpkin it should be a familiar issue.

 

[countrybumpkin]

Your to funny

 

[CalG]

No, wishful thinking on your part. It doesn't specify what you're asking about either. Diesel? Tractor, UTV, tugboat, freight-train?

It really doesn't matter, the question remains. Does anyone do a compression check as pre-purchase inspection?

It's a very simple question. Useful replies could add to the information on how to evaluate any engine's condition.

From the replies, I think not many have ever done a compression check, nor would know what values were meaningful if they did.

Myself, I like to put a vacuum gauge on any normally aspirated multi cylinder engine. Chain saws, I can tell all I need just by pulling the cord. ;-)

On a Compression ignition engine, it is often easiest to gain access by way of the pre heaters. No messing with the fuel system that way. Be sure to hold the fuel cut off closed when cranking for the compression reading!