Cat 980c

[junkyarddog]

I have a 1987 cat 980c motor was rebuilt has been threw multiple oil changes but when you pull the dipstick it still looks milky no oil in the coolant with that being said we also discovered that the pre cleaner was melted replaced it and it melted the new one in less than a couple days if anybody could point me in the right direction it would be very appreciated

 

[Nige]

If the precleaner is melting you need to be looking at the dust ejector assembly in the exhaust system. It has probably corroded away and instead of sucking from the precleaner will be blowing hot air into it from the exhaust.

Post a Serial Number I can put up an illustration of what it ought to look like.

 

[junkyarddog]

63x07820y

 

[junkyarddog]

That’s what I got from the vin tag it’s pretty much wore out

 

[Nige]

Serial Number is good.
See below. Remove the tube from the arrowed connection on the muffler and start the engine. Is the connection on the muffler blowing or sucking.? It should be sucking.
If it is blowing remove the exhaust stack and examine the circled tube. It's probably rotted away.

 

[Nige]

Regarding coolant getting into the oil but not vice versa it's not likely to be the cooler.

1987 cat 980c motor was rebuilt

What exactly did the rebuild consist of.?

 

[junkyarddog]

The tire the motor out new pistons and gaskets

 

[junkyarddog]

I pulled that piece it’s full of flaky soot

 

[kshansen]

Just off top of my head water in oil but not the other way around first thing I think of is liner seals. Couple other thoughts would be water pump seals/plugged weep hole, nozzle adapter orings in head?

Could possibly pull valve cover and inspect around injectors while putting some pressure on radiator. Same if you can remove oil pan with engine in frame, been years since I looked at a 980C up close!

 

[Nige]

I pulled that piece it’s full of flaky soot

New muffler called for in that case............

 

[Nige]

The tire the motor out new pistons and gaskets

No new cylinder liners fitted, or even new liner seals on the old liners.?

EDIT: That's not a rebuild BTW, unless I am misunderstanding what you wrote. it's a Band-Aid.

 

[junkyarddog]

Just off top of my head water in oil but not the other way around first thing I think of is liner seals. Couple other thoughts would be water pump seals/plugged weep hole, nozzle adapter orings in head?

Could possibly pull valve cover and inspect around injectors while putting some pressure on radiator. Same if you can remove oil pan with engine in frame, been years since I looked at a 980C up close!

So should I do I pressure test on the rad and see if it holds pressure

 

[Dave Neubert]

You need to pull the oil pan and see where it is coming from but check the weep hole on the water pump first

 

[kshansen]

So should I do I pressure test on the rad and see if it holds pressure

That would be one place to start.

I think if I was doing it I would check both with a cold engine and also with a warm engine. Also maybe drain the oil first and put a bucket under the drain to see if you see coolant coming out while pressure testing.

Actually I would probably pull the breather off the Valve Cover and see what is in that.

Don't know who changes your oil or how the oil is stored but there is always a chance the milkyness is from water in the oil and not a coolant leak of the engine.

There is a fast and easy way to determine if is say rain water or coolant in the oil. Actually two, one is by smelling the fumes coming out of the engine breather. Second is the taste test of the moisture dripping out of breather! Now I'm not suggesting drinking a coffee mug full of that stuff but just touch it with your finger and then touch the tip of your tongue. If using good old ethynyl glycol coolant it will be disgustingly sweet. Then wash out your mouth with your favorite beverage twice before swallowing any of that beverage!