repeat oil cooler rupture?

Matt Saunoras · November 1, 2013

Well the worst oil cooler failure I've ever seen is back. Same crap as before, a degas full of oil but not nearly as bad as last time. WIth only 300 miles since the repair I would hope it couldn't recreate the same volume.

Now I spent the last half of the day trying to figure out which direction to go. Did I unknowingly let the truck go with oil still in the cooling system or does it actually need another cooler? I don't have any simple green on hand (picked more up tonight) so I pulled the bottle, cleaned it out, reinstalled and dumped some VC-9 in it.

Eventually I got the water in the cooling system running clear again after a few more bottle cleanings and what not. The initial stuff I drained out was disgusting but I can't imagine where it was hiding had I left it in there to begin with.

Now a few things left me wondering. First off I've decided it's getting an oil cooler, I can't deny the fact that I added 1 1/2 qts of oil to the crankcase to get back into the middle of the stick. It doesn't look like that much made it into the cooling system but where did it go? Nextly, the oil on the stick looks clean (like it was changed 300 miles ago) but the oil in my bottle looks exactly the same as it did the first time around.

I've changed a lot of oil coolers and none before this one have ever returned to me. I am just having a hard time believing this is totally coincidental.

Brad Clayton · November 1, 2013

I always replace all rubber hoses that come in contact with that sludgy mixture. It clings to the inside of the hoses like glue then drops out later and recirculates thru the system.

jimmy57 · November 1, 2013

Check base engine oil pressure cold. I have not seen 6.0 repeat oil coolers for this but I have repaired some plate n fin oil cooler fails for super high oil pressure on other makes.

Matt Saunoras · November 2, 2013

Well the second cooler is in, simple green is done and the second vc-9 is almost done. Really not a whole lot came out with the simple green flush. I still don't know what happened exactly but I will check oil pressure tomorrow. The cooler looked fine and all gaskets/o-rings were perfect.

Keith Browning · November 2, 2013

The last failed 6.0L oil cooler I did seemed to take an unusual amount of flushing to get the system clean. I don't think that the Heavy Duty Simple Green (purple formula) is all that it is cracked up to be. In all previous repairs I had used the regular Simple Green and they all cleaned up fairly well. Also, if you have a heater control valve you need to be sure that it is opening during your flushes by turning on the heat otherwise you will have a lot of thick goop trapped in the heater core which will eventually come out. Learned that lesson on the very first one I repaired.

Matt Saunoras · November 2, 2013

Yes this truck does have a heater control valve. I always keep the heat on high while flushing along with keeping an eye on ECT and EOT. The water in this truck is running crystal clear right now so I'm going to reinstall my t-stat, do my final fill and drive it around some more.

Bruce Amacker · November 2, 2013

The oil pressure regulator is very accessible, as you know. Maybe pop it out and inspect it, I might even rub it with some 400-600 paper if it has scoring (they usually do) or replace it.

Good Luck!

:grin:

Matt Saunoras · November 4, 2013

I was thinking about oil pressure and initially thought the cap would be the first to fail under high pressure but maybe not. I'm not sure the exact temp but I believe the filter is bypassed until the oil reaches a certain temp. I believe there is an oil cooler bypass also correct?

It'll take me 2 minutes to check the regulator, I'll do it first thing in the morning.

edit - it's not a temperature, it's a pressure differential. A 25 PSI difference will allow oil to bypass the cooler. A 20 PSI difference will allow oil to bypass the filter. Obviously when the oil is very thick it is not going to flow through the filter or the cooler very easily.