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.
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!
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.)
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.
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.
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.
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.
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!
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.
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.