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How To: Oil Cooler Delete (Level: Easy)

59K views 145 replies 48 participants last post by  sixsix 
#1 · (Edited by Moderator)
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.

Engines:
-Most 4.3 V6s and even some other GM models.

Pros/Cons:
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.

Pros:
-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. đź‘‹

-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.

Cons:
-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)
-Rags
-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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#2 ·
great explanation!! I am going to leave mine when I do the sub frame swap out but want to have an after market cooler and a solid aluminum radiator not a plastic thing. I'm also going with electric fan assy and remove the heavy clutch and fan. I do a lot of towing at times here in the south.
 
#3 ·
Old Barney said:
great explanation!! I am going to leave mine when I do the sub frame swap out but want to have an after market cooler and a solid aluminum radiator not a plastic thing. I'm also going with electric fan assy and remove the heavy clutch and fan. I do a lot of towing at times here in the south.
Thanks!

Yeah I highly suggest that if you guys do keep an oil cooler, run an aftermarket one outside of the radiator. I would be afraid that just fixing the leaky fittings/hoses would cause too much pressure in the radiator, blow a hole, and then you would run into cross contamination issues and need a new radiator. That's why I don't think just upgrading the lines to custom fittings is a good idea. Do the whole thing. Definitely keep the cooler down in the south, esp with towing. :thumbup:

I too want an electric fan setup. I think the fuel savings are nice but for cooling the stock fan can't be beat very easily.
 
#4 ·
Two things:
1) After a little bit of time, you can't go back into your post and edit it, so your initial post won't have pics. That's a problem for anyone coming to look for a DIY and if they don't see any pics they might not want to look further in the post.
2) That Astro profile sticker is ok, but only covers part of the vans. You need a 1st gen, both EXT & shorty versions.

It's great that you are doing how to threads, it encourages others to do the same as they find out what's involved and what to expect. Thumbs up.

-Andrew
 
#5 ·
icebrrg3rd said:
Two things:
1) After a little bit of time, you can't go back into your post and edit it, so your initial post won't have pics. That's a problem for anyone coming to look for a DIY and if they don't see any pics they might not want to look further in the post.
2) That Astro profile sticker is ok, but only covers part of the vans. You need a 1st gen, both EXT & shorty versions.

It's great that you are doing how to threads, it encourages others to do the same as they find out what's involved and what to expect. Thumbs up.

-Andrew
It was just a joke to copper as it's part of a sticker I'm making for him "Westfailia Towing"... You'll see soon enough.

The pics are coming guys, not to worry. :p
 
#6 ·
Lumpy said:
Particularly in a "How To" post, where there's lots of pics, clicking on a bunch of tiny thumbnails in order to see the pic is very tiring for me. I have to remember what you said about the stuff in the pic, then view the pic, then if I want to review your description, de-enlarge the pic etc.

The pic of your sticker profile, whatever that's all about, is, on the other hand, easy to see, doesn't require me to click, doesn't grey out the text etc.

Lump
Also, most of those complaints I can't do much about. The site admin should be adjusting the default values and setting for gallery picture posts. Other forums gave more posting options that this one does not... Or at least I haven't found them.
 
#7 ·
If you are doing it for the recognition, you might want to quit while you are ahead. If you are doing it for others to quietly reference when needed then you should be happy with your post(it's a good one). Most people that read your post won't even be members here and are unlikely to post a comment.
 
#8 ·
AstroWill said:
If you are doing it for the recognition, you might want to quit while you are ahead. If you are doing it for others to quietly reference when needed then you should be happy with your post(it's a good one). Most people that read your post won't even be members here and are unlikely to post a comment.
If people tell me it's good and want to discuss the content in the post then I'm happy and did my job. It's not for recognition its to help people and so far only one person actually indicated it was helpful... That's what it's all about.
 
#13 ·
There must be something inherently wrong about the design of our engines if all these oil coolers, OEM or aftermarket, are failing. Now the Durbango. What's the poop here? Do all oil coolers fail on all engines? We don't seem to hear about transmission oil coolers failing.

Maher, where did your engine wear through the hose? Is it at the cooler? At the sandwich? I wouldn't imagine that you did a poor job of routing the hoses in a bad spot. Or is that impossible to avoid?

Lump
 
#14 ·
Durango was abused and never taken care of before I got it. Used as a snow vehicle. I suspect judging from the brake lines. Which rotted and were seeping right through the metal. I got most replaced already.

The oil line where it goes from the hard line the fitting where it becomes rubber. I think that joint is what is leaking. I just need new lines.

Our vans leak at the radiator fitting with age. And in a few threads at the block under the oil filter. Rubber rotting. It is something you just got to stay on top of.

My van had a aftermarket oil cooler. It had rubber high pressure lines with no metal line involved. So it was a big floppy affair from the filter to the radiator. Well just vibrating against the frame eventually wore a hole in it. Judging by the dragon a rubber line of that type should not ever touch anything. They are suspended in mid air by the metal lines. Needed for flexibility but cannot touch.

And that was impossible to do with the aftermarket one. Had I known I would have made brackets to encase them with rubber inserts. Or bought lines with the metal sleeve around it used in racing for fuel and various things. But they said it would work and was fine in the instructions. I was a newby and bit hook line and sinker.
 
#15 ·
Seems to me an oil cooler would be a pretty important item. Maybe not for people in the arctic, but anywhere it gets hot, I'd think it is.

I think instead of just wholesale deleting them, we'd be much better served by installing or modifying them the RIGHT way to avoid whatever is making them fail. Cover them with loom. Braided steel lines. Brackets. Etc.

Adding one is somewhere on my list of things to do.

Lump
 
#17 ·
The only conclusion we could find for why the coolers blow lines is because of dirty oil clogging the cooler and creating high pressure on the fittings (the weakest link).

This would indicate why some will see leaky lines time after time only a month after replacing them.

When people replace the lines with upgraded ones that have better fittings, they seemed to come back reporting the radiator cross contaminated with the oil cooler from a hole forming between the two. (The new weakest link.)

If your in the North its not a big deal to remove it, everything has been really solid from MPG, oil pressure (even after long 1hr+ drives), engine temps.

If you are in the South do an aftermarket cooler so you can keep a better eye on it, and not end up replacing the whole radiator too!
 
#19 ·
Hi, you mentioned using a longer filter, I have a fram 3980. Do you have a stock number for the longer one? I have an old 2 qt monster from my mid 80's burb, too bad it wouldn't fit! Thanks for the post, finally found a shop who would listen and not consider me an alien when I asked them to take the adapter off! I also showed them this posting, and they were impressed.
 
#21 ·
I have read every post I can find on deleting the engine oil cooler. I have removed mine, but I am concerned that there appears to be two valves in the oil filter adapter which is removed in this process. no where is there a mention of these two valves nor their function.

Does anybody know about these?

Thanks,
 
#22 ·
WEHTTAM1 said:
I have read every post I can find on deleting the engine oil cooler. I have removed mine, but I am concerned that there appears to be two valves in the oil filter adapter which is removed in this process. no where is there a mention of these two valves nor their function.

Does anybody know about these?

Thanks,
Oil bypass that eliminates the oil cooler. If the engine is to cold or the oil cooler has a blockage.
 
#135 ·
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
 
#23 ·
I am considering doing the oil cooler delete also as my lines just started to leak. A drop or 2 every time I park the van. Just don't want all the mess on the driveway.

Before I start, I wanted to plug the lines/radiator in case I want to reuse the cooler in the future.

Is it a threaded connection at the radiator or some type of clipped connection. Does anyone know of a plug that can be used.

Alternatively, I could cut the rubber hose and put a bolt in the end with a hose clamp.

Thoughts?

D.
 
#24 ·
WEHTTAM1 said:
I have read every post I can find on deleting the engine oil cooler. I have removed mine, but I am concerned that there appears to be two valves in the oil filter adapter which is removed in this process. no where is there a mention of these two valves nor their function.

Does anybody know about these?

Thanks,
One of the valves is for the oil by pass for the cooler. The other is a by pass for the filter. When reassembling, the filter by pass should be reinstalled. That part is a shorter version of the unit in the "filter extension" found in the oil cooler adapter, and is attached using 2 small bolts.

Most of the when I see oil cooler lines leaking, it's usually at the aluminum crimp where the rubber meets the aluminum tube. Doesn't matter if it's on a full size GM truck, or an S-10 pickup, or even a 4X4 Blazer. They all seem to leak at that spot.

Most GM's I've seen use a screw together fitting that can be unscrewed from the radiator. I believe these are pipe threads on the radiator side, versus SAE threads for the line side.
Just something to think about if you ever want to plug the rad side.
 
#25 ·
I think the super secret reason there is an oil cooler is simply because, at all but the easiest of conditions, the radiator cannot adequately cool the van. Given that the oil removes much of the heat, this was a cheap half solution. However, in real world conditions, it does little to cool the head which gets incredibly hot. I have seen the van boil the coolant at 209 with a brand new 16lb cap. The true solution was an electric fan.

Them again, the Astro was and always will be a child of the 80s. Gm's desire was to keep it cheap and legal to title. It's incredible we waited until 03 to get disc brakes.

Anyhow, I will keep the oil cooler with my monster cooler. I feel better.
 
#26 ·
Meterpig said:
I think the super secret reason there is an oil cooler is simply because, at all but the easiest of conditions, the radiator cannot adequately cool the van. Given that the oil removes much of the heat, this was a cheap half solution. However, in real world conditions, it does little to cool the head which gets incredibly hot. I have seen the van boil the coolant at 209 with a brand new 16lb cap. The true solution was an electric fan.

Anyhow, I will keep the oil cooler with my monster cooler. I feel better.
I'd buy that, except I have an Astro and a Safari that both didn't come with an oil cooler. Same applies with the 92 S-15 V6 engine donor I have here.
Like you mentioned, the engine heat is in the heads. If you can keep them cool, the engine and it's oil will stay cooler. I've only had 1 GM truck that would even be considered to be "over cooled", and it had a huge 4 core copper and brass radiator for a big block in it, and the engine was a small block in the truck. That truck needed a piece of cardboard to get it to warm up on a -5*F morning.
 
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