How to know when Oil Cooler is bad

If it is leaking oil on the ground then more than likely the o-rings that are on the oil cooler going into the side of the block are bad. They will crack and get hard with age. The oil cooler itself is OK if that is what is happening, but it will have to come off the side of the block to fix.
The o-ring package runs about 35.00. 2 oil filters and oil to top off system. According to what kind of truck you have to determine labor but generally about 3-4 hours.

 

a couple years ago on my 60 series i had a seal go out on my oil cooler. it was a seep for quite a while that i never found kept thinking the filters were seeping then one day after starting the truck in real cold weather it started steadily running out. never had any oil in the coolant and never any coolant in my oil samples. re-sealed the oil cooler and never a drop sense

 

if your oil cooler is leaking it will be mixing oil will the coolant whiles truck is running the when the truck shuts off and the oil psi drops the coolant will mix with oil this happened to my truck this monday past. resulted in my oil presure dropping drastically and ended up pumping all the oil in the rad. had sludge coming from radiator cap overflow hose was a complete mess. Swapped out the bad cooler for a good one with a good flush and i am good to go as of yesterday.

 

I just got back my oil analysis and there are trace amounts of sodium. .16 I believe. In the explanation Blackstone said usually that means coolant in oil. There was no potassium which is the other signal that coolant is present. Recently my engine will get hotter quicker. I'm thinking my oil cooler core or cooler is going. I'm not loosing any coolant between services. Hope this doesn't sound dumb but are there such things as engine oil coolers? I know there are transmission oil coolers. When I Google that's what comes up.
What should I do to prevent catastrophe?

 

Run another sample after you put some hours on the oil. Could have been a bad sample. Follow up sample will confirm if its an issue or not.

Oil cooler is usually on the RH side of the engine. They are an oil to coolant type heat exchanger. If your coolant temperature is hotter than normal I'd look at the rad first since its what cools the coolant and the coolant in turn cools the oil.

 

Ok that's what Blackstone said as well. Run another in 10k and monitor it. The engine water is only slightly hotter. I know where it usually reads on certain hills and it's a hair hotter past 2 weeks. I will take that advice and update once tested again.

 

Oil samples can be so easily contaminated and therefore give false reports, you should always run two in a row to confirm. It is trace amount at this time, usually when they go bad it becomes a major event and it is obvious due to visual oil in the coolant.

 

oil samples are best with the engine at operating temperature taken from the dipstick tube.

that way there's no crap from the bottom of the pan. water will be near the top

you can get hand suction pumps for $20-25

 

I do retrieve sample at running temp from dip.stick tube with pump. I will monitor and see where it's at next sample. I am running sample every change now.

 

I thought water separates to bottom of pan.