Vacuum leak

[MuRCieLaGo]

Originally Posted by Dynomite

I think you can pick up a good used Oil Cooler that will not break the bank. ZRXMAX may have one or know where to get one.....just in case.

I don't want to be that cheap guy but I'm pretty sure I won't need to change my whole oil cooler only because of stripped threads.

Plan A: Try to put a conventional drain plug there (with a washer).
Plan B: Tap bigger threads with a bigger drain plug.
Plan C: If it is cracked, I'll have a plate welded under the oil cooler.
Plan D: If the oil cooler really is broken, alright I'll look for a used one.

But thanks Dynomite I really appreciate your help!

[Dynomite]

Originally Posted by MuRCieLaGo

I don't want to be that cheap guy but I'm pretty sure I won't need to change my whole oil cooler only because of stripped threads.

Plan A: Try to put a conventional drain plug there (with a washer).
Plan B: Tap bigger threads with a bigger drain plug.
Plan C: If it is cracked, I'll have a plate welded under the oil cooler.
Plan D: If the oil cooler really is broken, alright I'll look for a used one.

But thanks Dynomite I really appreciate your help!

I like your Plan A.
If it is originally an NPT or Pipe thread it would be relatively easy to find a slightly larger straight thread for which you can drill and tap and then use a bonded washer like for the Oil Pan Drain Plug. You would then have a Real and somewhat Unique Oil Cooler Drain Plug

Others would then consider that conversion for Draining/Changing Oil Cooler Oil

[WVZR-1]

Originally Posted by MuRCieLaGo

I don't want to be that cheap guy but I'm pretty sure I won't need to change my whole oil cooler only because of stripped threads.

Plan A: Try to put a conventional drain plug there (with a washer).
Plan B: Tap bigger threads with a bigger drain plug.
Plan C: If it is cracked, I'll have a plate welded under the oil cooler.
Plan D: If the oil cooler really is broken, alright I'll look for a used one.

But thanks Dynomite I really appreciate your help!

I don't think A, B or C rational or practical. I believe you remove the plug and with a "correct device/thread pitch gage" determine what it is that's there and make no "rush to judgment" in repair. I don't believe I'd go to the aggravation of removal until it was determined that I needed to.

Is it magnetic? If it can be determined that it is an NPT product maybe just changing the material used and an appropriate sealer is a more desired repair. Is it maybe NPS? Is it maybe an ISO 7-1 pipe? Is it maybe Metric? It's a "once and done" thing. Identifying the removed plug I'd think critical - no guessing - use thread pitch gage and appropriate measuring devices.

[Dynomite]

Originally Posted by WVZR-1

I don't think A, B or C rational or practical. I believe you remove the plug and with a "correct device/thread pitch gage" determine what it is that's there and make no "rush to judgment" in repair. I don't believe I'd go to the aggravation of removal until it was determined that I needed to.

Is it magnetic? If it can be determined that it is an NPT product maybe just changing the material used and an appropriate sealer is a more desired repair. Is it maybe NPS? Is it maybe an ISO 7-1 pipe? Is it maybe Metric? It's a "once and done" thing. Identifying the removed plug I'd think critical - no guessing - use thread pitch gage and appropriate measuring devices.

On second thought......I completely concur with WVZR-1.....he is DAMAN. I am not sure if there is enough material or thickness to start drilling/threading for one thing never having even removed said plug. And concur on the removal of the Oil Cooler also. It is pretty easy to try all sorts of sealers for sure depending on the situation.

But if you DO remove the radiator....time to inspect and clean the trash from both the radiator and Oil Cooler...AND....AC Condenser.

[Billy Mild]

I would be worried if you threaded the drain plug all the way in that it will get circulated through the motor and cause a clog somewhere else. Which could cause oil starvation.

Take the cooler out and see if you can get the drain plug to come out of the cooler altogether. Plus with it out, you can make a better repair to it.

Vacuum leaks suck. It seems like everytime I fix mine they come back during the winter time. Not sure what causes that to happen. If you become a member you can actually get the Heart of the Beast magazine. There was a good article about vacuum leaks by Marc Haibeck.

[MuRCieLaGo]

Originally Posted by WVZR-1

I don't think A, B or C rational or practical. I believe you remove the plug and with a "correct device/thread pitch gage" determine what it is that's there and make no "rush to judgment" in repair. I don't believe I'd go to the aggravation of removal until it was determined that I needed to.

Is it magnetic? If it can be determined that it is an NPT product maybe just changing the material used and an appropriate sealer is a more desired repair. Is it maybe NPS? Is it maybe an ISO 7-1 pipe? Is it maybe Metric? It's a "once and done" thing. Identifying the removed plug I'd think critical - no guessing - use thread pitch gage and appropriate measuring devices.

I had to remove the cooler because the drain plug was stuck inside. I sent it to a local shop to have it welded, I don't see any purpose on that plug, especially because it has NOT an easy access (a beam is in the way).

Originally Posted by Dynomite

On second thought......I completely concur with WVZR-1.....he is DAMAN. I am not sure if there is enough material or thickness to start drilling/threading for one thing never having even removed said plug. And concur on the removal of the Oil Cooler also. It is pretty easy to try all sorts of sealers for sure depending on the situation.

But if you DO remove the radiator....time to inspect and clean the trash from both the radiator and Oil Cooler...AND....AC Condenser.

I removed everything but the AC Condenser. It was really dirty there, so I cleaned everything.

Originally Posted by Billy Mild

I would be worried if you threaded the drain plug all the way in that it will get circulated through the motor and cause a clog somewhere else. Which could cause oil starvation.

Take the cooler out and see if you can get the drain plug to come out of the cooler altogether. Plus with it out, you can make a better repair to it.

Vacuum leaks suck. It seems like everytime I fix mine they come back during the winter time. Not sure what causes that to happen. If you become a member you can actually get the Heart of the Beast magazine. There was a good article about vacuum leaks by Marc Haibeck.

That's exactly why I removed the oil cooler, I wanted to remove that plug from there ASAP.

Kinda sucks to break something while trying to fix a vacuum leak... That's part of the game I guess!

Thanks everyone!

[MuRCieLaGo]

Oil cooler is in place now, started the car this morning. Everything is fine now. The most expensive in that story was the coolant flush. Wasn't ready to pay 94$ for some Prestone.

That vacuum leak will wait now. Enough love given to the car at the moment, time to go back on the RX-7. Much easier.

[weldbead]

hi guys...
havent posted here in months..logged on a few times recently..i got my 94 back in march of '14 ..as the snows melted i realized it had the dreaded constantrunning vacuum pump peterout at 5000 rpm symptoms of leaky vacuum/failing secondaries..immediate solution was buy myself a harley in june of 14 for my wife's birthday..sorry for rambling.. point being here's what i finally did after 11,000 miles on the harley and maybe a thousand on the vette...and the advent of cold weather here in poughkeepsie..i called my local chevy dealer , healey chevrolet..told the service manager i needed an oil change( i had the 3 gallons of amsoil and the wix filter laying around and they agreed to use it),told him about the vacuum leak.. he said they had two techs who had been on vetts for ever..i breathed deep, gave them the car, they fixed it for $600, the vacuum pump runs for 1/2 second and it pulls like hades..
just saying theres that option..enjoy. and good luck..very good luck on tigwelding and tapping the oily threads on the aluminum pan..you could try lampwick on the plug..

[Dynomite]

Plugging the Oil Cooler Drain Plug Permanently (90'-92'-93').

Originally Posted by MuRCieLaGo

Oil cooler is in place now, started the car this morning. Everything is fine now. The most expensive in that story was the coolant flush. Wasn't ready to pay 94$ for some Prestone. That vacuum leak will wait now. Enough love given to the car at the moment, time to go back on the RX-7. Much easier.

So....just to be clear.....you removed your Oil Cooler and had a local welding shop weld/plug the hole where the Oil Plug Was Located? Or they just welded in the Old Oil Plug? I assume all that or any of that is ALUMINUM Welding?

Originally Posted by MuRCieLaGo

I had to remove the cooler because the drain plug was stuck inside. I sent it to a local shop to have it welded, I don't see any purpose on that plug, especially because it has NOT an easy access (a beam is in the way).

Anyway.......you did use the Original Green Coolant?

Originally Posted by Marc Haibeck

The question often comes up about what is the best coolant for the LT5 engine. I recommend the OE style conventional green coolant. I have found that Dex-Cool causes swelling of the OE LT5 head gasket.

Since it is possible that organic corrosion inhibiter softens the head gasket material, coolant containing organic corrosion protection should not be used in the LT5 engine. The possible values of using organic corrosion protection are small. Dex-Cool claims extended service interval and possible longer water pump seal life. It is not worth taking even a small risk for those benefits since the consequences of head gasket damage are huge.

Use coolant that has the following characteristics:
- Labeled, “For older vehicles.”
- Coolant that is colored green
- Texaco UPC number 76568 12016
- Chevron UPC number 23968 10000
- GM specification 1825M coolant. The current pn is 12378560.
- AutoZone part number 540722. The UPC number is 52948 59081.
- Blue Mountain UPC number 74804 01858

The green coolant might not be available in a brand that you like. However the correct formulation is more important than the brand. Avoid “Universal” coolant. There is no need to compromise when the green coolant is available. Retailers like universal products because they reduce inventory costs, universal coolant is not the best for your LT5, the conventional green coolant is.

For detailed information about my observations of LT5 head gasket swelling see:
http://www.zr1specialist.com/HAT%20W...d%20gasket.htm

Good For You on the Repairs....appreciate the Feedback

[MuRCieLaGo]

The shop welded the old drain plug in the hole with silver, $40 later.

I used the conventional pre-mixed green Prestone coolant.