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How To: Oil Cooler Delete (Level: Easy)

41783 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. 馃憢

-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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gman said:
I would also like to add that I had to drain a couple quarts of oil on the side of the road the other day because i added 5 quarts (these vans take 4.5), and after the cooler delete the oil level was like 3/8" of an inch above the hashmark.
Wiley said:
not sure why everyone seems so worked up these last few posts, no reason to act like dicks, gman is excited to be working on the van.
The "oil cooler delete" is great! Glad to see others do it themselves too.
Draining oil on the side of the road.. not so sure about that one.
No one was "worked up"... was mostly just curious about a few things.

[I retracted my comments from the permanent record.. :D ]

I'm glad to see gman's excitement and success too.
It's a good mod!
Rod's Trucks said:
It you want to make a plug, just keep junk out of that part of the radiator; consider crimping the end of the original line
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.
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Star Stuff said:
Help please! I just went through this process removing the lines during an oil change, and now the engine is running like crap
It's amazing how your story went from this (above)... to this... (below)

Star Stuff said:
* The only other thing I did was put in a new air filter just before the oil change
* another thing I did (yesterday): I took out the battery
* I had to un-clip the computer, and it had to be jostled around a bit
* I just vacuumed out some grit & debris that was in there (MAF sensor)
* Prior to all this, besides giving the entire engine compartment a thorough clean
* taking off the plastic cowlings below the wipers
* the only other thing I did the other day was remove the top of the fuse box and unbolt it from the firewall
WELL I'd say you did a LOT more than just an oil delete! :eek:

Clearly something you touched (or washed) is likely causing the problem!
Maybe the MAF got messed up when you "vacuumed" it?

I would look at EVERYTHING you've touched!
Maybe something damaged, maybe something unplugged.
But I'm pretty sure it's NOT from the oil cooler delete.
YEP! Same for me!
My "threaded insert" moved from the oil-cooler adapter directly into the block.
It was super easy.
But I know ALL this was posted already... (see first post on this
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Because we couldn't find the proper adapter my mechanic came up with this idea until we find the correct adapter.
  • The piece you need is still in the old adapter (see photo above)
  • Maybe your mechanic just missed it... (probably didn't know it un-threads)
  • See 1st post page 1 of this thread
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It was always my understanding that the 2nd number is the weight hot.
Since both are 30.. it seems both would be the same weight hot... 1st number less relevant in summer.

I'm in Florida.. I run 10w40 synthetic year round (older engine 260K).
I also deleted my oil cooler years ago, and my older van didn't come with one.
Neither did anything I've ever owned prior
No vise?
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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