Oil Cooler Leak - What Will Leak - Oil or Coolant?
#16
Rennlist Member
Thanks for the pics. I was trying to figure out the coolant flow. If you were running an external oil cooler could you just block off the coolant from flowing in to the housing and then you wouldn't have to worry about the two ever mixing if there was a leak?
#17
I suggest an all new rod and main bearings if you get severe water in the oil. I had motor back in 2003 that had really bad mixing. Could have been from oil cooler or head gasket. I did not because it came in parts car. Anyway even sitting for multiple years I was able to clean it and rebuilt the motor and it worked great. However it needed alot of cleaning.
my coolant still look like coolant and same with the oil so i guess it could have bin worse
#18
I'm not sure you can block off the flow through the cooler chamber. I need to undertsand the flow through the block, but if you did it would welding up (or otherwise filling) the ports in the block. Interestingly the turbo unit still has water flowing through this area and therefore suffers the same problems.
I'm working on a replacement cooler design which will improve the heat exchanger seals and convert the system to a external air / oil cooler, similar to the turbo unit but with improved seals since the turbo cooler suffers the same problems as the NA.
This project keeps getting delayed but the plan is to sell a complete kit billet adapter with inproved seal design with turbo oil thermostat and external oil cooler.
I'm working on a replacement cooler design which will improve the heat exchanger seals and convert the system to a external air / oil cooler, similar to the turbo unit but with improved seals since the turbo cooler suffers the same problems as the NA.
This project keeps getting delayed but the plan is to sell a complete kit billet adapter with inproved seal design with turbo oil thermostat and external oil cooler.
#19
Rennlist Member
I'm working on a replacement cooler design which will improve the heat exchanger seals and convert the system to a external air / oil cooler, similar to the turbo unit but with improved seals since the turbo cooler suffers the same problems as the NA.
This project keeps getting delayed but the plan is to sell a complete kit billet adapter with inproved seal design with turbo oil thermostat and external oil cooler.
This project keeps getting delayed but the plan is to sell a complete kit billet adapter with inproved seal design with turbo oil thermostat and external oil cooler.
#20
Track Day
I have a very wet passenger side engine bottom from oil leaks. One from the right front oil sump gasket corner, I can see oil drops forming the with the engine running. The other has oil leakage forming around the oil pressure sender but it is fairly new and tight with a new crush gasket. There are two other plugs in that same oil cooler area and I resealed and tightened them as well during a wp/belt change. Figured I would just drop the oil sump this winter. Got the car running and found the leak around the oil cooler got much worse! I was getting about 1000 miles/quart of oil the and after the "fix" I get 400/qt at best. i love my car!!
#21
Addict
Rennlist Member
Rennlist Member
Join Date: Apr 2002
Location: St. Louis
Posts: 1,176
Likes: 0
Received 0 Likes
on
0 Posts
I also had a bad oil leak coming from that area and did not believe this part could actually leak oil because of the fact the oil is within the coolant bath. But mine was leaking oil from the upper forward area of it ( found through cleaning and testing for it ). Changed out the gaskets and o-rings and it has not leaked a drop since. It could not have been from anywhere else because that is the only part I fixed that day and it went from making puddles of oil to zero leaking. Never had any oil/coolant mixing whatsoever.
#22
Yeah, resealing the oil cooler fixed a pretty big oil leak for me too (would only leak when running). I suspect the sections of the seal set that seal the OPRV or the oil pressure sender might have been to blame since it did not look like it was leaking though those threaded interfaces.
#23
Just finished this job this weekend... not terribly hard and I'm a novice.
Learned so much seeing in 3 dimensions.
Unless I'm way off, the coolant flows within the housing and enshrouds the oil cooler... Really allows us to run the car at high rpm's for hours with manageable oil temps. With the n/a engine having the housing right under the hot headers makes me wish I had the Turbo's external mounted cooler.
My oil leak was passenger side and drenched my sway bar bushings, control arm bushings and power steering boot. Driver side bushings are nice and dry.
Dripped oil from the oil cooler housing gasket right above the OPRV.
Verified same by degreasing & hosing the undercarriage; idling for 5 mins and looking for drip path. No milkshake but I was darn close by the looks of the seals. Another month and the oil nozzle o-ring would've failed thus introducing oil in to the cooling system. I'd assume the much higher oil pressures vs coolant pressures would result in far greater oil intrusion than vice versa.
Anyway, used Clark's and 944Foot2the floor... yes, terrific both.
1. We left ON the headers but removed the heat shield; removed PS pump and hose. Drained oil and coolant.
2. Bought the Pelican Oil Cooler seal kit for $36 and had everything needed.
3. Tested the oil cooler itself for cracks/leaks... tight. Installed a new Oil Pressure sender.
4. Thoroughly cleaned the 24-year old gasket gum/varnish off the block and the housing rim. Cleaned and tested the OPRV for 10 LBs actuation.
5. Changed the included gaskets and o-rings. Re-installed the Rubik's cube of the oil cooler & housing up onto the block. Slowly tourqued then inserted OPRV slowly. Re-installed heat shield. I have the '88 one-piece OPRV... and had to tap&die the threads due to a quarter century of heat cycling.
6. Loaded 2 gallons of distilled water and 4ounces of SHOUT to coolant system.
7. Loaded 5.9 quarts of 5W-30 to idle engine and prime oil pump. OC142.
8. Ran engine for 5 minutes with coolant bleeder open till fluid emerged.
9. Flushed oil and laundry fluid. Opened the coolant block nut to expel all fluid from block. Flushed another 2 gallons of distilled water to clear SHOUT and any oil from radiator system. Installed a 2nd OC142.
10. Reloaded with 15W-40 Rotella and 2 gallons of Zerex G-05 50%.
11. Enjoying no drips, nicenon-bouncing oil pressure and no milkshake fears.
Total net time: 6 hours... and yes we had a lift.
Thanks to Mark for his guidance and awesome set of tools.
Good luck!
Learned so much seeing in 3 dimensions.
Unless I'm way off, the coolant flows within the housing and enshrouds the oil cooler... Really allows us to run the car at high rpm's for hours with manageable oil temps. With the n/a engine having the housing right under the hot headers makes me wish I had the Turbo's external mounted cooler.
My oil leak was passenger side and drenched my sway bar bushings, control arm bushings and power steering boot. Driver side bushings are nice and dry.
Dripped oil from the oil cooler housing gasket right above the OPRV.
Verified same by degreasing & hosing the undercarriage; idling for 5 mins and looking for drip path. No milkshake but I was darn close by the looks of the seals. Another month and the oil nozzle o-ring would've failed thus introducing oil in to the cooling system. I'd assume the much higher oil pressures vs coolant pressures would result in far greater oil intrusion than vice versa.
Anyway, used Clark's and 944Foot2the floor... yes, terrific both.
1. We left ON the headers but removed the heat shield; removed PS pump and hose. Drained oil and coolant.
2. Bought the Pelican Oil Cooler seal kit for $36 and had everything needed.
3. Tested the oil cooler itself for cracks/leaks... tight. Installed a new Oil Pressure sender.
4. Thoroughly cleaned the 24-year old gasket gum/varnish off the block and the housing rim. Cleaned and tested the OPRV for 10 LBs actuation.
5. Changed the included gaskets and o-rings. Re-installed the Rubik's cube of the oil cooler & housing up onto the block. Slowly tourqued then inserted OPRV slowly. Re-installed heat shield. I have the '88 one-piece OPRV... and had to tap&die the threads due to a quarter century of heat cycling.
6. Loaded 2 gallons of distilled water and 4ounces of SHOUT to coolant system.
7. Loaded 5.9 quarts of 5W-30 to idle engine and prime oil pump. OC142.
8. Ran engine for 5 minutes with coolant bleeder open till fluid emerged.
9. Flushed oil and laundry fluid. Opened the coolant block nut to expel all fluid from block. Flushed another 2 gallons of distilled water to clear SHOUT and any oil from radiator system. Installed a 2nd OC142.
10. Reloaded with 15W-40 Rotella and 2 gallons of Zerex G-05 50%.
11. Enjoying no drips, nicenon-bouncing oil pressure and no milkshake fears.
Total net time: 6 hours... and yes we had a lift.
Thanks to Mark for his guidance and awesome set of tools.
Good luck!
#24
Three Wheelin'
Join Date: Oct 2021
Location: Southern WI - 89S2 Megasquirt PNP
Posts: 1,324
Received 289 Likes
on
252 Posts
11 year old thread, but I can comment that for me it took an afternoon. I work fairly slow and methodical (not as fast as if I were getting paid by hours in the book lol). 4 hours or so. I did not flush my system I was addressing an oil leak and not oil/water mixing. Figure another couple hours to do the flushing.
If you are paying a shop then I would expect it to be $500-$800 in labor ($100/hr assumption). All the more reason to do it yourself.
If you are paying a shop then I would expect it to be $500-$800 in labor ($100/hr assumption). All the more reason to do it yourself.
Last edited by walfreyydo; 04-06-2023 at 09:38 AM.
#25
11 year old thread, but I can comment that for me it took an afternoon. I work fairly slow and methodical (not as fast as if I were getting paid by hours in the book lol). 4 hours or so. I did not flush my system I was addressing an oil leak and not oil/water mixing. Figure another couple hours to do the flushing.
If you are paying a shop then I would expect it to be $500-$800 in labor ($100/hr assumption). All the more reason to do it yourself.
If you are paying a shop then I would expect it to be $500-$800 in labor ($100/hr assumption). All the more reason to do it yourself.
Thanks for the info.