Oil Filter O-ring blew! Twice! Why?

I am working on a 6.9 diesel that I bought for $100 5 years ago. Last year I took it out and cleaned it up and got it running after a half a can of ether.

The oil filter blew out and oil was spewing everywhere. I didn't think anything of it and put a new filter on.

A year later, now, when I finally decided I wanted to put it in a bronco I started cleaning it up some more. Injectors, orings, filters, and making sure it still started. There was over a gallon of water in the pan but after cleaning it all up I got it running. A few days later I hooked up glow plugs and see if it would start on that. It did after a while but I had some dripping injectors.

Today I changed all the injectors making sure I had 8 good ones. It didn't want to start good but I got it running. After pushing the throttle it sounded like the motor was bogging and I saw something fly over my head and I saw oil come crapping out again. The oil filter oring blew out again.

Ive been working on this the past couple weeks and the motor is on the ground with a fuel line in the diesel can.

Any ideas why the oring keeps blowing? Hopefully tomorrow I'll get an oil pressure gauge to see where I'm at.

oil pressure regualtor is stuck. same thing that happened to goose.


find another oil cooler or tear yours down and hope you can free the valve.

Thanks Corey I'll check it out. Hope that's it.

By the way where is the regulator/valve at on the oil cooler? I have a few extra oil coolers and I just bought new orings and gaskets from rock auto. Cheap

Any chance an extra center sealing ring got left on the threaded mount making it to where you were stacking orings in the middle with it loose to the outer ring ? THis is such a common mistake, I've seen so many TSBs on it from various manufacturers it's not even funny.

To work on the oil pressure regulating valve you need to remove the oil cooler from the engine or at least remove the rear header. Then you will fing the regulating valve on the sealing surface to block area. Its staked in the aluminum housing and careful grinding with a very small burr will get it out. Remeber you need to have enough material for it to seal when it goes back together.. Or buy the one Uhal has for around $250.00. May as well replace the oil cooler o-rings while its out and easy to reach..

I had to do this to my dads 7.3 a little while ago. From now on I'm dismantling the oil coolers in the truck. Its so much easier than taking everything off to remove it and install it assembled.

thatnvalve does not like moisture

RLDSL said:

Any chance an extra center sealing ring got left on the threaded mount making it to where you were stacking orings in the middle with it loose to the outer ring ? THis is such a common mistake, I've seen so many TSBs on it from various manufacturers it's not even funny.

Click to expand...

I looked up there a few times, I didn't see any center sealing ring on the threads. I even checked my new oil filter I put on today and didnt see any seal for the center threads. I only saw the outter oring.

icanfixall said:

To work on the oil pressure regulating valve you need to remove the oil cooler from the engine or at least remove the rear header. Then you will fing the regulating valve on the sealing surface to block area. Its staked in the aluminum housing and careful grinding with a very small burr will get it out. Remeber you need to have enough material for it to seal when it goes back together.. Or buy the one Uhal has for around $250.00. May as well replace the oil cooler o-rings while its out and easy to reach..

Click to expand...

I had no idea what you were talking about until I took the oil cooler off. I had no idea how to remove the oil pressure valve but I see now what you meant. It turns out the oil pressure valve was the problem. I had an oil cooler assembly on the shelf and pushed the oil pressure regulating valve down with my finger, then I took this one (I just took it off the motor today) and it wouldnt budge. I smacked it with a hammer and it freed up. However I decided to try and get it out and I messed it up. Later I might actually try grinding it like you said. How would I reinstall the valve back into place?

Before I took the oil cooler off I started the motor up one more time, this time with a mechanical oil pressure gauge hooked up. The oil pressure shot up over 100 psi within a few seconds. I quickly shut it down but the o-ring already blew again (3rd time!). So thats why I took the oil cooler off.

After all of that I ended of installing my extra oil cooler I had on the shelf. I cleaned it up and put new orings on it. Hopefully Im gonna start it up again this week and if its has good oil pressure and starts good then its going right in the bronco.

Like posted above... They don't like moisture too much. Glad your finding the posting helpful too..

That was it!! But now its not running right!

Well now I'm 100% sure it was it. Fired up the motor today and the oil pressure went right to 60psi and stayed there.

It was running great the last times I started it but now it has a popping sound. Does anyone know what this is? I already checked all 8 injectors and made sure they were firing a few weeks ago but thats what it sounds like

You can hear it best in the 3rd video.

6.9 Start 1

6.9 Start 2

6.9 Start 3