I have a friend with a 99 GMC Jimmy 4.3 2 wheel drive. The oil cooler lines are leaking between the oil filter at the back of the block and the radiator. She is on a very limited budget. It is not 4wd and she does no towing or heavy use. She only drives to work etc.
It seems to me that it would be ok to disconnect the oil cooler. I know some say since GM put it there do not disconnect it. But when you think about it the only place you see oil cooler lines is on heavy duty applications for trucks etc. There are millions of motors out there used for daily commuting and no oil cooler is necessary.
Does anyone know if the oil must be kept circulating througn the lines to feed the engine or if you can just install a block off plate at the oil filter?

 

Terry I made the same points with the guy who is helping up do the engine/transmission swap in our 1998.

The discussion was due to me trashing the 1/2 million mile engine just before the engine swap. When I back flushed the oil cooler a lot of bearing material came out so I got a new radiator. I have found after a trashed transmission or engine when each is cooled by the coolers added to the radiator it is good just to spend the $129 for a new radiator since there is no labor cost if one is doing an engine transplant at the same time as we are doing.

Actually the part is only $44 for the new hose set at O'Rielly's and may be less labor than plugging the lines but to do either is not easy do to space when the engine is installed so I bought a new set that got installed while it was on the engine stand.

Why keep the engine oil cooler? These 4.3L engines are good for up to a million miles in part in our trucks because they are over engineered compaired to cars. Cooling an engine from both the top and bottom is better but for your friend she may never see the difference.

Make sure the hoses are your main source of the leak because they all leak in many places.

The 1/2 million mile 4.3L was a big leaker but the power steering was part of the source. The 119K mile replacement engine was oily too so we tore it down to a long block just to get new gaskets on the bottom and top side.

Again I do think it would be OK (not ideal) to block off the engine oil cooler but getting a set of $44 new lines installed may be the cheaper option. Not sure how complex a job it is but I know Joe delayed the install by a day because New Years messed up parts supply just because he DID not want to install the oil cooler lines after installing the engine.

Hopefully we can fire her up tonight.

 

Thanks Gale. I agree an oil cooler is good to have even on a non heavy use vehicle but don't see why it would be necessary for a commuter vehicle. Since this is 2wd there is plenty of room to access the area at the filter. If a block off plate is available it would be easy to install.

I found this.

http://www.jagsthatrun.com/V6-instru...er-removal.pdf

 

DO NOT just block off the cooler or you will trash your engine, guaranteed. The reason is simple, the cooler is a flow through device. There are no bypasses built into the adapter currently on the block. If you want to get rid of it, you'll have to move the threaded adapter to the block or loop the lines.

 

Thanks for the reply. That is exactly what I was concerned about. Did you look at the link in my past post? That looks like an acceptable solution to me. What do you think?

 

OIL COOLER LINES REMOVED

 

Do Not Remove any Oil cooling lines!

 

I knew there had to be a clean safe way to delete the oil cooler lines since GM does not use oil coolers on a lot of cars. The fact that they sell the oil filter adapter without the oil line option is nice so the filter is not recessed even more unless they make a longer filter like for some other engines.

This week we just removed two in the process of swapping our out half million mile 1998 4.3 X for another 119K 1998 4.3 W VIN engine. We removed and replaced it on the 119K mile engine (required to remove the oil pan) and put in a new O-ring to be on the safe side when we installed the new pan gasket.

Since this S10 was purchased as project truck for shop lessons and to be the son's truck when he gets his licenese in a couple years he is removing the blown engine piece by piece.

It started out with a bent valve that after running it for 5 minutes with a gallon of diesel in the crankcase then rodded hard with only ATF in the crankcase for about 15 miles a rod broke on the hole with the bent valve. Being 20 miles from home we drained the ATF out and added 15W-40 Rotella and drove it home at about 50 MPH. About 100 foot from the driveway the rod came out leaving a hole in both the block and oil pan. I drove it on up the hill with it pumping out all of the oil. I was going to use the starter to get it upon to the dolly but it tried to start instead so I just drove it up onto the dolly. When we got it to my friend's shop we drove it into the lift bay on its own power. These 4.3's are tough engines and the details here was covered in another thread.

Tonight when we pulled the head where #5 was our initial error code misfire the piston was really marked by the bent valve. The one main we pulled had spun. I wanted to trash the engine to remove temptations to patch it up after we had the 119K mile engine setting in the back of the Nissan.

The funny part is the 5 minute diesel only flush then 25 minutes of hitting 4K-5K in 1st and second on some crooked back roads running pure Dex/Merc ATF did NOT clean the varnish build up of the push rods, wrist pins, ect. I will still flush with Sea Foam per directions on the can but NEVER put ATF or diesel in a running engine AGAIN.

After working New Years and every evening this week on installing another engine and transmission and tearing down the 1/2 million mile 4.3 part by part we have gained a better understanding of how they work and how tough they are.

We put new oil cooler lines on but because when we back flushed the oil cooler we flowed out a lot of bearing metal the discussion came up in the shop as how to delete the oil lines IF we had not purchased a new radiator. Since this was a class project we went overboard $$$ because the used engine and 5-speed transmission appear to be in good condition. Got the differential drained, cleaned and refilled with synthetic as well as synthetic in the engine and transmission. Got down to welding of the exhaust pipes before calling it a night. In the morning we will learn if we wasted a lot of money and time. Regardless there was a lot of learning going on.

Hope our new oil cooler lines do not leak.

 

On a vehicle used only for commuting what is the harm? These engines are used in other GM applications with no oil cooler. Help me understand the logic for your comment. Thanks.

 

I think you have enough detailed links to know it is OK . I like the idea of using the GM oil filter adapter that is without the oil line connections.

Found it interesting that the oil filter adapter has to be pulled in order to pull the oil pan bolt near it.