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Howdy! A project I need to do on my ‘84 SE is fixing the oil cooler leak. A quick reminder of my car’s history is that it sat for over 13 years in my friend’s field then I brought it home last year and got it running. I’ve had a blast driving it around.
It now appears to be leaking more and more oil from the lower oil cooler hose. The hose itself is saturated with oil and pretty unsightly. So, I was looking at swapping out both cooler lines with the stainless braided lines from RB. While looking at their website I noticed the oil filter adapter that allows for oil temp and pressure gauge connections. Has anyone used this and is it fairly straightforward to install? My current water temp and oil pressure gauges don’t work. It’s hard to know where they’re faulty as my instrument gauges are spotty, as in my tach sometimes works and sometimes not. The dash lights sometimes are on and sometimes off. When the tach and voltage gauge are working the water temp and oil pressure gauges still don’t work. So, I thought I’d install new ones and mount them somewhere in the car. My current radio setup only uses one DIN so I could put them under the radio as I’ve seen some people do. Not sure where/how I’d put the water temp sensor, still thinking about that.
Anyway, I was just curious as to how difficult of a project this would all be and if anyone had any tips or suggestions?
The first thing to know is where the leak is coming from. Is it a bad oil cooler passage or a cracked oil cooler bung. They have a tendency to crack. If it's an oil cooler bung, one fix is to cut them off and have -10AN bungs TIG'ed on. Then make some -10AN nylon braded lines.
For the oil pressure/temp, get an oil pedestal that sits. I'm not sure if the "Mishimoto Oil Filter Sandwich Plate Adapter" will fit a GSL-SE.
For the water temp sensor, you have a few options.
1. Weld a bung onto the current t-stat neck.
2. Adapt a 2nd gen RX-7 aluminum water pump housing. This is the most work. I did this on my 1985. Search the first gen section. I have a write-up.
3. Add an upper rad hose adapter. This is the easiest.
If the lower FMOC hose is original, it's probably the hose is perforated. The stock didn't tend to last all that long, and aftermarket stainless braided hoses are made that way for a reason. Take a few minutes and read a few threads by me and GSLSEforME on how to secure an SE oil cooler fitting, as any amount of torque beyond what it takes to seal the connection will result in leaks.
As stated above, if you can find someone local to TIG weld the proper dash- fitting to your stock cooler, you'll never have to worry about it again. The last run of oil coolers from Mazda even had the fittings GLUED into place to try and prevent a known issue with leaks there. The aluminum of the cooler is just too soft for the threaded inserts to work and not cause hairline cracks in the bungs. Someone here turned the bungs down and welded on a sleeve, but that's a lot of work and some shops won't weld on oil coolers for fear of fires.
Howdy! A project I need to do on my ‘84 SE is fixing the oil cooler leak. A quick reminder of my car’s history is that it sat for over 13 years in my friend’s field then I brought it home last year and got it running. I’ve had a blast driving it around.
It now appears to be leaking more and more oil from the lower oil cooler hose. The hose itself is saturated with oil and pretty unsightly. So, I was looking at swapping out both cooler lines with the stainless braided lines from RB. While looking at their website I noticed the oil filter adapter that allows for oil temp and pressure gauge connections. Has anyone used this and is it fairly straightforward to install? My current water temp and oil pressure gauges don’t work. It’s hard to know where they’re faulty as my instrument gauges are spotty, as in my tach sometimes works and sometimes not. The dash lights sometimes are on and sometimes off. When the tach and voltage gauge are working the water temp and oil pressure gauges still don’t work. So, I thought I’d install new ones and mount them somewhere in the car. My current radio setup only uses one DIN so I could put them under the radio as I’ve seen some people do. Not sure where/how I’d put the water temp sensor, still thinking about that.
Anyway, I was just curious as to how difficult of a project this would all be and if anyone had any tips or suggestions?
I can't comment on your oil cooling as I have a GS that I put an eBay FC oil cooler on and am simply running AN lines for all that along with an aftermarket pedestal that has NPT holes, and I put my oil pressure sensor in that. For coolant I drilled and tapped my water pump neck for 1/8 NPT and put the sensor there. It's gotta be before the thermostat so that's really the only place you could put it.
Side note on the eBay FC oil cooler, it was supposed to accept AN fittings but it ended up having some oddball in-between thread that doesn't exist, I'm assuming it was a manufacturing error and I had to re thread it and use ORB fittings.
Holy gorgeous interior @KansasCityREPU ! Thank you for the replies, everyone.
I cleaned the lower hose and its associated fitting then took it for a spin to get it up to temp. When I checked afterwards I still couldn’t tell exactly where it’s leaking from. Looks like I’m going to need to remove the oil cooler and check the bung for any cracks.
Isn’t that how these projects go?! Haha. My problem is that I start thinking, well, since I’ll have to maybe remove the radiator to get the oil cooler out, should I look at putting an electric fan on the radiator instead of the motor mounted one that has a few cracked and chipped fan blades? If I’m gonna do that, should I look at removing the air pump since Idaho doesn’t have emissions… hmm, then I could maybe put an exhaust header on there since the exhaust has a small leak that creates an annoying noise at idle.
Surely I’m not the only one who gets sucked down these rabbit holes, right?
No you are not! Commonly referred to a "project-creep," when you start with one thing, and when all "is said, and done," your at a different place. However, what you "learn in the process is "priceless," good luck.
Are you sure it's even the cooler? Grab that lower hose with your hand and squeeze. If your entire hand comes back oily, the hose has perforations through the rubber and is a liability. If you get under the car, you should be able to see a spray pattern if it's a leak - as the lower hose is in the slipstream under the car and gets blown backward at speed like a giant arrowhead pointing to the source of the leak.
Honestly, I attribute my slow oil cooler bung leak to the oil saturation & preservation of my frame and undercarriage components. And I live in the Sonoran Desert! How's that saying go,... "When it STOPS leaking oil, that's when you know there's a problem"?
A car sitting for that long does it no good and parts like oil lines do deteriorate. An oil line replacement is easy but if it is the bung that has gone you need to consider if replacement with an OEM oil cooler is a better option.
As for your instrumentation and electrical gremlins, you might want to check all the wiring harness for signs of rodent damage. Sitting in a field for so long it surely had some uninvited guests.
@Rotnbrit I’m sure there’s some chewed or broken wire(s) somewhere. I’m surprised at how good the wiring looks, what wiring I’ve been able to inspect. At the very least I think I have a shady ground somewhere because the tachometer won’t work in the morning when it’s cool and the fuel gauge reads full. When I get out of work and it’s warmed up in the sun, the tachometer works fine as does the fuel gauge. I need a new dash for it and that would be a great time to take all that apart and look for loose or damaged wires. Just have to find a dash first.
