How does oil end up in coolant and/or vice versa?

what color is it?(the motor not the leaking fluid)

 

Have seen on a cat engine (C11) the water pump let go but the weep hole was plugged so the coolant went into the engine. Luckily it was caught before bearings were taken out.

Knowing what type of engine will help people with possible ideas.

 

I had a trans cooler go out on my 2000 Pete/Cat that caused oil in my coolant. Spent 2 days at Peterbilt of Knoxville. They claimed that they psi checked the trans and oil cooler and that they needed to dig into the engine for more diagnosis. I told them I would drive it home to my mechanic to be fixed. He correctly diagnosed it in 15 min by pulling the plug on trans and seeing the milky oil.Cost about $350. Sued Peterbilt for the $1100 service bill and for my 2 nights in hotel and won.

On my N14 the oil cooler went out and was putting oil in coolant. Including psi checking from Cummins and a used cooler cost less than $200.

Always check the cheap(er) stuff before assuming liner or hg.

 

Anti freeze does not kill an engine. Why would you drive a truck away from the shop when you knew it had a problem, did you think it would get better after he swore at it?
If you had any chance at warranty you lost it, and a simple fix will only get more expensive.

 

Oil pressure is higher than coolant pressure, so if the oil cooler goes it usually transfers oil to the cooling system. The oil when mixed with coolant will tend to plug the rad over time, you might notice the problem with the engine warming very quickly when climbing grades or working hard. If your coolant seems brownish or there is an oil film on it, get er fixed fast so you don't have to pull the rad too.

 

That would make it a Cat

 

Really? Antifreeze won't wipe out a set of bearings? When did they change that?

 

You're joking....aren't you? You don't even know what kind of motor is in the truck you drive? You believe it's yellow? Wow

 

1.2 million miles the bearings are not exactly new already. It is time for a full overhaul but that is talking real money. the downside is not doing a major and taking the engine all apart again at 1.3 million miles