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How To: Oil Cooler Delete (Level: Easy)

42029 Views 136 Replies 46 Participants Last post by  cdoublejj
How to delete (remove) your oil cooler. (Skill Level: Easy Mod)
If you can change your oil on your own, you can probably do this. Maybe.

Test vehicle:
1997 GMC Safari SLE
RWD V6 4.3L Automatic
Note: This mod should not take any additional tools for the AWD models, but the space will be tighter to work in. Procedures should all be exactly the same.

-Most 4.3 V6s and even some other GM models.

There are a few reasons you may or may not want to do this mod. Most people are looking to do this mod because they are tired of the factory oil cooler lines leaking all the time, and they don't have a real need for the added cooling. There are other vehicles with this same engine that do not have this cooler from the factory- hence why everything is already setup on the engine to not use the cooler.

-Fewer parts dealing with moving oil through the motor and especially considering these are external lines means increased reliability against losing oil and critically damaging the engine.

-If you have factory lines on your cooler or even upgraded lines, and something goes out you can do this mod in a pinch on the side of the road to fix your leak and get you home. Carry the list of tools in your tool bag with you! You will find the list further down.

-This solves an issue where the oil cooler portion of the radiator gets clogged and creates backpressure, giving repeated leaks even with newly replaced OEM lines. (This is most likely why so many people have this repeated issue, to begin with, it may not be the fault of the fitting design like many suspect and in fact, maybe a fail safe for this situation- I would rather a leak there than something else blow out. :2:)

-No More leaky lines to worry about or waste money on. 👋

-If your lines were leaky like mine were, you will see improved oil pressure.

-No extra parts are needed, just do the mod on your next oil change and it's free.

-If you carry full loads or tow often removing the oil cooler may cause too much heat build up in the oil and break down which causes added engine wear.

-Some have noted that removing the oil cooler reduces miles per gallon. I have not noted enough of a difference personally (read: if any at all, still testing) to warrant the price of regular hose replacements along with extra oil purchased due to leaks.

-If you have a working non-leaky oil cooler and do this mod, you may see a slight decrease in oil pressure. I can't personally confirm this.

-GM put it on all the vans for a reason...

Our best conclusion for why it was put on is the fact that the motor is stuffed deep inside a dog house, and the vans were sold worldwide in every climate imaginable and needed to be able to manage the heat differences. For the pacific northwest where we spend 90% of our time, I found it to be over-engineered, hurts reliability, and doesn't add any real-world performance gain (Engine temp, MPG, or otherwise). You should consider all the factors and decide for yourself what route you would like to go. Again I can't stress enough to carry this kit of tools and supplies with you if you do plan to keep the oil cooler. It may very well save you someday!

Let's Begin!

First, we'll go over the list of tools and supplies you will need for this job:
-10mm Allen Wrench or Socket [Oil filter threaded tube]
-13mm Wrench or Socket [Hose attachment to the side of the block]
-15mm Wrench or Socket [Oil drain plug]
-40mm Torx Bit or Socket [Adapter internal mounting bolts]
-Socket/Bit Drivers and Extensions
-Oil Filter Removal Tool (or hands of steel and sandpaper, one of the two. :rockon: )
-Knife to cut tubes (easier removal, I'll get the size of the hose fittings soon)
-5 qts of oil (Recommend full synthetic for better heat protection)
-Oil Filter (Recommend an extended size for easier installation/removal and protection)
-Oil Catch Pan (Not needed for rescue kit, it's already on the pavement.)

Step 1:
Prepare the vehicle securely on jack stands or a lift. You could do this job on your back if needed though. Put the oil catch pan under the location of the oil drain plug on the oil pan. Remove the oil filler cap under the hood to allow the oil to move more quickly through the system. Then after you are ready to get messy unbolt the drain plug and let the oil run out. Replace the drain plug after this so you can use the catch pan in the next step.

Step 2:
Place the catch pan under the oil filter and proceed to remove the old filter. If the filter is stubborn and your hands of steel and sandpaper are just no match for that greasy old filter, break out the oil filter tool and get er' done. An old-school trick in a pinch is to jab a screwdriver into the filter and turn it. Yes, it makes a mess but you are probably past that point by now anyways. Tip the old filter into the catch pan to drain it all while you continue to catch the remaining oil coming out of the filter attachment area. Once most of it has stopped proceed to the next step. Don't remove the catch pan from this location yet.

Step 3:
Remove the bolt towards the front of the motor that holds the lines to the oil cooler attachment block. It is the 13mm one.
When you pull the lines off dip them down into your catch pan to drain the remaining oil left in them.
Once that is complete you can use the 10mm Allen wrench to remove the oil attachment tube in the center of the oil cooler attachment block. The Allen key just slides right into the middle of the threaded post. Counter-clockwise to remove and it may be tight!

Ensure both of the bolts in this step are removed before continuing on to the next step, otherwise, it will be much more difficult to get them off.

Step 4:
Remove the two 40mm Torx bolts that hold the oil cooler attachment block onto the engine block. The picture below is for reference, the cooler lines should be off at this point too as noted in Step 3.
Once these are removed, a quick jiggle should get the block to come free from the engine.

Step 5:
Thread the oil filter tube directly into the engine block by hand, short fat end in. Look to see if the paper gasket is inside first, remove it.
Tighten well with 10mm Allen key.
Clean off any gunk or debris from the block's oil filter mating surface. Then just lube the new oil filter seal and screw it on like normal!

Step 6:
Now that your filter is on you shouldn't have any drips coming from the hoses or your engine block/filter and can move on to removing the old cooler hoses. I just chose to cut mine at the rubber area because it was getting late. I will go back and remove the rest of the lines from the radiator later and add that to this How To. Don't forget to place your catch pan under where you cut the hoses! They will definitely leak some more out of them for a little bit.

Step 7:
This is very important! Fill your engine with new oil, preferably full synthetic to help with heat breakdown in the oil. It's a decent way to regain a little lost heat protection if you weren't running synthetic before. 5 quarts with the XL filter seemed to be just about perfect. It's easy to forget this step being so excited about fixing your leaky hose issue and jumping in to start her up. Well, you certainly wouldn't have any more leaks! (You also wouldn't have a very happy motor lol).

Alright, that's it! It's pretty easy to do and requires minimal tools and mechanical ability or understanding. Hopefully, this rests any questions you all may have about the process, or the pros and cons and real-world results.

Pictures are coming, they just need to be edited and uploaded.
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I don’t have much besides a jig saw and a drill honestly
Well, if you bolt it back up, and have the right size allen wrench, you can add some leverage to it. It also would not hurt to tap around it with a hammer. In rare cases, heat is needed.
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You can also use a pipe for leverage, on a breaker bar or ratchet.
I don't recall any trouble whatsoever removing mine.
Removed it with standard ratchet after pulling the adapter
(don't recall if I put it in a vise to hold it)
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Certainly you could "temporarily place it" back on the engine to hold it (if you don't have a vise)
There are also ALWAYS ways to add leverage to tools if need be (MechBob shows example above)
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Was at this one bolt for about 8 hours. Broke a lot of my tools working it, never budged once. Afraid this one’s a wash.

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I even went and bought an impact driver. This thing won’t budge.
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I never ran across one, but heard some were epoxied in.
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I pretty much gave up on trying to extract that fitting and I just have to wait here til the new one comes in. Something strange was that I couldn’t even find a replacement adapter if I wanted to. The part number on the adapter is GM10179211, I don’t know if it’s the same as everyone else’s.
The part # on the adapter means nothing, unless you have a casting interchange source.
The number is-GM 12562827, but is obsolete. But still some in junk yards, and one on the bay right now, if you want to pick it up, it is cheap--
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GM sells just the fitting I have one if you really want it.
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I bought one on Amazon, just waiting for it to get here. Thanks though
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I got a replacement fitting on Amazon here:

I noticed that my oil pressure gauge now swings a little wider than it used to. When stopped with a foot on the brake the pressure will sometimes drop below 40, while rolling it will sit at 40, and with a foot on the gas it goes above 40. I haven’t noticed any other issues.
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Less "buffering" since the lines/hoses were removed from the system, perhaps.
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Got mine done today. I shattered my H/F T40 3/8 drive bit in the process, but managed to get it off with a regular 1/4 bit. I thought the center fitting was a T50 and was getting nowhere. It turned out to be a 10mm Allen. It came right out as soon as we figured that out.

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I just bought a new adapter, only $14 bucks on flea bay.
I keep meaning to do this but never get to changing the oil early enough the day, but next one I will and I'll be ready. Not entirely sure how much mine are leaking, but it's an oily mess under the front along them.

GM-OEM-Oil-Cooler-Coupling-14081300 B23 | eBay

Edit: Is there not a better replacement for these lines? Like maybe some better quality hose and hose clamps? Better routing?
Oil bypass that eliminates the oil cooler. If the engine is to cold or the oil cooler has a blockage.
ah-ha! so a blockage shouldn't be an issue. i'm going to run aftermarket radiator. so i suspect being cooler, less chance of the oil cooking in there and making blockage. though a leak could be an issue i guess.

After only 60k on AC Delco oil cooler lines I had a leak (at the crimp, like everyone else gets)... so I did the Oil cooler delete today.

Delilah is a 97, but I had no problem with the oil filter fitting being too short.
This what i wanna know, just how often they leak, AFTER NEW hoses. i see people seeing the headache deleting them. but, how often after new aftermarket hoses?

That's what I did with mine.. mainly because I cut the lines up when I removed them.
I ensured there was ZERO chance I'd ever put this mess back in!
Eventually I replaced that radiator with performance aftermarket.. no longer an issue.

I suspect you could possibly unscrew (I think it may be an adapter) and replace with NPT plug if you really wanted to. But really, I don't think any of this is worth all the trouble. You could also just plug the cooler holes with some kind of soft rubber putty .. any number of creative possibilities.
so my after market all aluminum rad won't have the provision? if so glad i didn't buy new lines yet

so not much oil lost. I used an oil filter wrench, and I suspect that because the filter is so incredibly close to t
so with out a longer filter, filter changes are harder?

i still like the idea of cooling the valve train in death valley but, if the rad is that much better than a stock rad would it matter? i think an oil cooler might help in death valley.

also you get half to a quart of extra oil in the engine with helps with extra mileage before a change. i wonder if cooling the oil slows down the breakdown?

but, also think i might like the oil pressure bump in the engine! ...wonder if you could higher pressure pump to bump pressure with the lines on! though if you deleted them later you might have too much pressure. also rubber does go bad thats part of why i'm planning dropping the entire sub frame to save my knuckles
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My engine bay is absolutely covered in grime, which is one of the main reasons I did this mod. When everything is covered in 1/4" of grime, it not only makes the work harder, it also can help hide issues.
yeah in the rust belt it also makes sure you have a vehicle to work on at all as the oil keeps the metal form oxidizing and disintegrating in to orange dust.
When I had my 1981 Jimmy/Blazer with small block Chevy V8, it came with oil cooler line option like the van does.
When the old cooling lines rusted out I removed the cooling line adapter.
Inside the cooling line adapter the pressure relief valve part like shown above was screwed in.
I removed the oil pressure adapter from line part and screwed back into block and the center treaded oil filter nipple.
I looked into the GM Shop manual and there is no mention of an oil pressure relief valve inside the van block.
Looking at the pictures above, it looks like the oil pressure relief valve is built in the oil cooling line adapter.
Can someone who has removed the cooling line adapter look into the housing and see if it is in there.?
yeah 6 pages in, this is still not confirmed.

Unless you are running some old oil from the 1970s, you really don’t need an oil cooler.
good point

In my honest opinion, An oil cooler is a wise personal choice unless you live in cooler areas. We live in the blistering desert and CHOOSE to be smart enough to use one regaurdless of what oil you use. BTW We run synthetic oil in all our vehicles. ;)
I live in the blazing fires of hell and frigid temperatures of the friend zone or the church. In North West Missouri it's -5 to-20f one day and 80f - 105f the next day.

It’s an opinion that makes sense until you realize that most of the 4.3s fit into other trucks and vans did not have them. Full size trucks with higher towing ratings…

When the Astro was drawn, the engineers were concerned about the more compact front end… The SAE standard for oils had changed a long time before, but the engineers were concerned about coking…

Was never a problem…. Even less likely with todays oil.

What absolutely IS a problem is losing oil pressure because the oil cooler lines part. Even the ACDelco lines can and do fail.
Yeah that sounds pretty damn plausible, i've always said vans hold too much heat. usually the bean counters lock the engineers in a closet to they agree to screw the consumer with cheaper materials or reduced part count somewhere. shout out to the peeps who know who Sandy Munro is.
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