No change in oil pressure prior yo failure. Filter is a good possability, as its due for the oil change.

Heres what we are doing. Putting on compression fittings rated at 3000PSI and using hydrlic hoses, so I should be all good to go there. This will also make for a nice easy install as well. Parts should be in tomorrow. All said and done it will cost about $60-$70 not counting the oil and filter.

Yes I'm going to check everything over real good while I'm under there.

 

My oil filter lines failed at about 50k. First they leak around the fittings. You may not notice it, because the fittings are behind the plastic "rock shield", along with the rubber hoses connecting the oil filter to the engine block. I did see it, so I had the dealer replace them. If you don't see the leak, then the oil permeates the rubber hoses, and they leak worse. Soon you will get a failure. This failure is a well-known Blazer weakness, like so many others. I don't see any reason to think there was any kind of other failure in the engine that would have caused this, because sooner or later all Blazers suffer this failure. All you need to do is replace the oil cooler lines, then mark your calendar for the next time they fail, or when you plan to sell your Blazer so you don't have this problem again.

 

It never hurts anything to double check all other aspects of the system. The reason why I asked what kind of filter is installed and when it was last changed is due to the failure of a certain brand of filter (FRAM) that could cause a buildup of pressure in the oiling system. Fram filters are known for their flimsy bypass valve design that sometimes will bypass prematurely and others will close completely off and could cause a buildup of pressure. I stay away from fram filters like they have the plague.

The engine oil cooler is located in the driver's side radiator tank and is designed much the same way as the transmission cooler, but with larger passages. I do agree that you probably should run an oil flush through the system to clean up the cooler. It is possible that it has started to gunk up and has restricted the flow. And I am also unsure if you would have seen an increase in oil pressure if the filter or cooler were to restrict the flow. IIRC, the oil pressure test port is delivered oil from the cam bearing galley which would be post filter/cooler, but I could be wrong...

I do not know if the cooler is pre-filter or post-filter. If the engine output line was the one that ruptured, it could be the filter or the cooler. IIRC, the lines running from the remote filter to the cooler and back again are all hard lines and the only 2 flexible sections are in the input and output from the motor. If the return from the motor blew, then something else is wrong, but I'm betting it was the pressurized oil feed from the engine to the oil filter that actually blew.

*EDIT* - yeah, I do agree on the availability of -AN fittings (or lack there of). We just happen to have some on hand and threw them on. We also had flare connections that we could have used, but elected to braze them because, again, we had everything on hand and didn't want to deal with flaring the lines. My experience has been iffy at best when flaring old lines. We just didn't want to take the chance.

 

Yup its a "FRAM" filter. Never had a problem with one yet. Till now (maybe).
I will take your advice and stay away from FRAM filters from now on though.

The line that blew was the one closest to the engine block.

 

Well she's all fixed up.. What a pain in the a$$ job. Parts only cost me $69.00, plus $20.00 for the oil and filter.

Now I only got 2 more Blazers to do. lol.

 

Sounds good Jman. They make nothing easy for us.

 

Glad you got it back together!