L245dt compression

[TM9311]

In continuation of my other thread for removing the glow plugs, I decided to test the compression through the plugs. I used harbor freight cheapo kit and turned the end off in the lathe so it was short enough. front rear two read 300 and 350psi im reading the min is 350 psi. sooo im not really in the mood or position to do any sort of rebuild at this time. something I can check first? Such as valves??

 

[North Idaho Wolfman]

In continuation of my other thread for removing the glow plugs, I decided to test the compression through the plugs. I used harbor freight cheapo kit and turned the end off in the lathe so it was short enough. front rear two read 300 and 350psi im reading the min is 350 psi. sooo im not really in the mood or position to do any sort of rebuild at this time. something I can check first? Such as valves??

You could check valve adjustments, but 90% of the time it's just plain old cylinder wear.

 

[TM9311]

BOO!! it has about 1200 hrs. thought thatd be low. depends on history i suppose. I can try a wet test later when i get a chance.

 

[100 td]

BOO!! it has about 1200 hrs. thought thatd be low. depends on history i suppose. I can try a wet test later when i get a chance.

Is that 1200 "original" hours, that's about 35 hours per year? NIW knows these engines so his wear assumptions are probably correct, but one would hope for a few more depending on history/conditions.

 

[D2Cat]

From my experience I wouldn't bet the bank on a Harbor Freight compression tester. I have one that wouldn't work at holding pressure. Later returned it and got one that did hold pressure and readings seemed low, but I was like you not wanting to tear into the engine.

The engine starts easily, runs fine and I never think about those reading until I see a thread like this. I'd suggest use it until it won't start! Just assume the gauge in incorrect.

 

[100 td]

I'd suggest use it until it won't start! Just assume the gauge in incorrect.

Works for me, until the cost of topping the oil up gets to be excessive, or you can't breathe any more!

 

[D2Cat]

100 td, probably when it gets to that point it won't start!!

 

[100 td]

That may be the case, but for some old diesels they some seem to just keep on going spewing out smoke, especially old gensets!

 

[Dave_eng]

A few days of hard work plowing or similar may bring about improvement especially if the tractor is often operating at higher rpm's but light loads.

One post comes to mind. The owner was noticing lots of oil laden smoke from his low hours (1,000) tractor with FEL.

He could see the condition getting worse. Most of this tractor's use consisted of moving light material with the FEL.

Quite by chance, he loaned his tractor to a neighbor farmer who used it plowing heavy ground.

When the tractor owner got his machine back after days of hard work he could not believe the improvement that had occurred with his tractor.

I have belong to this Cat forum which deals with large stationary diesel gensets, often powering island communities, large ships electrical needs, hospital emergency power. With CAT actively involved, a lot of the information has high credibility in my mind.

Caterpillar - Home - Online Community

Below is a paragraph from their site:
.
Underloading Diesel Generator Sets


Generally speaking, standby- and prime-rated diesel generator sets are designed to operate between 50 and 85 percent load, while continuous-rated diesel generator sets optimize between 70 and 100 percent load. Operating diesel generator sets at loads less than 30 percent for extended periods can impact uptime and engine life.

The most prevalent consequence of underloading is exhaust manifold slobber, or wet stacking, which is the black oily liquid that can leak from the exhaust joints when the engine does not reach minimum temperatures and pressures. Visible engine slobber doesn’t necessarily indicate a problem, but it signals possible underloading concerns, low ambient temperatures or jacket water temperatures that are too low. Additionally, long periods of light loading can lead to deposit build-up behind the piston rings or inside the cylinders, which can cause power loss, poor performance, accelerated wear and in extreme cases, cylinder liner polishing.

Dave

 

[D2Cat]

Diesel slobber. A result of letting the engine idle for long spells and not letting it work under load.