Archived Compression test and crankcase pressure

[jeff95]

My 95 Ram has recurring oil leaks. For about a year, I had four or five different oil leaks fixed. Each time one was fixed, a new one was created. I have just let it leak for the past year or so. I do know that when I tow at highway speed, my tailgate and trailer are covered in oil. I want to find the cause of the leaks. I though a compression test and or a manometer test (I think it measures the crank case pressure) would point me in the right direction. I don't want to spend $5000 on new rings or a rebuild and I don't want to keep fixing oil leaks if there is a problem that is going to just lead to more oil leaks.

I took my truck into the dealer. We don't have any diesel mechanics in the area. After waiting for three days for them to look at it, they say they can't do any tests until they fix the current leaks. All they have done is clean the motor and installed a dye so they can find the leaks. They haven't found any yet after running the truck for two hours, according to them.

I don't want to spend hundreds or thousands of dollars fixing oil leaks for them to later tell me that there is some larger problem that isn't worth fixing. I can't see spending $5,000 or $6,000 to rebuild a motor in a 95 truck that I use to dump garbage with.



Is the dealer right that they can't do any tests until they fix the leaks?



By the way, they also told me that I needed new brakes and my steering was loose. It's amazing that it took three days to do nothing on the issue I brought it in for but had time to identify problems any shop can repair.



Thanks for your advice,

Jeff

 

[Partyat33]

OK, oil leaks in diesels are pretty common. An oil leak as you describe it does not seem to me to be a bad cylinder. Are there no spots on your driveway ? If not, maybe it is a cylinder. Dealers tend to be somewhat stupid sometimes. So if you are leaking on the driveway, and the truck does not visable smoke on the highway, its not the rings.



Dennis

 

[jeff95]

The truck is modified. It does have a haze at idle. Step on the throttle and you can't see behind you until the boost comes up. It does leave stains on the driveway. Big stains. I would say it goes through 5-10 quarts every 3,000 miles

 

[Signal73]

Has your KDP been fixed or maybe did it let loose. Also Maybe your Vaccum pump is pressurizing your crankcase because of a bad seal? couple ideas to throw around... . Can you clean your engine real good to find the source of the leaks any better?

 

[jeff95]

The engine has been cleaned and I am looking for leaks. The vacum pump is a new one for me. How can I test to find out if that is pressurizing the crankcase?

 

[Signal73]

You would have excessive blowby coming out of your tube on the pass. side of the engine, or your dipstick would blow out a little causing oil leaks.

 

[K5IP]

The crankcase is open to atmosphere through the crank case vent tube. (On a 95)Check to see that it is not plugged. There should be no crankcase pressure.

I once developed leaks when a drip can I placed on the end of my vent tube sealed the vent. This seemed to make everything leak and simply removing the can fixed things.



Also, you can get a good idea of the pressure balance between individual cylinders by disconnecting the fuel solonoid connector so the engine will not start. Then crank the engine over with the starter and listen for an even cranking speed as each cylinder is being compressed. A bad one is usually observable by a noticable change in speed as one of the pistons tops out.

Rog