Vacuum leak

[secondchance]

Sorry to hear of your predicament.

I didn't even know the oil cooler has a drain plug. Are the drain plugs on 90 - 92 model year coolers only? I had my oil cooler out and flushed it out with mineral spirit but didn't notice any plug.

Ebay has a used 90-92 oil cooler plus AC condenser for sale.
http://www.ebay.com/itm/90-91-92-COR...9SPMoP&vxp=mtr

Also, a new one but listed as for 93-95 ZR-1.
http://www.ebay.com/itm/94-95-C4-COR...UkygPw&vxp=mtr

Does anyone know what the difference is? If it's just bolt hole location, I would buy a new one for later years and modify as needed.

[Dynomite]

Originally Posted by secondchance

I didn't even know the oil cooler has a drain plug. Are the drain plugs on 90 - 92 model year coolers only? I had my oil cooler out and flushed it out with mineral spirit but didn't notice any plug.

I think that Oil Cooler Plug is only on the 90'-92'. And as WVZR-1 suggests it is likely an NPT (which is a tapered thread). And someone said (I forgot where) that it is the same as the Drain Plug provided by Corvette Central for the Differential.

Originally Posted by WVZR-1

I believe the "conventional wisdom" needs to prevail here because the plug the OP mentions isn't meant to be a "service port". I don't know the thread size involved here but for any thing other than maybe it's use to drain the oil for a cooler change seems maybe foolish. Any conventional engine oil drain plug uses a gasket or seal to prevent seepage and I'm quite sure this could only be some sort of an NPT plug and that's not a conventional method used for engine oil service ports.

[secondchance]

Learned something new today. Mine being a 94 explains why I didn't notice even with the cooler out of the car.

[MuRCieLaGo]

Originally Posted by secondchance

Sorry to hear of your predicament.

I didn't even know the oil cooler has a drain plug. Are the drain plugs on 90 - 92 model year coolers only? I had my oil cooler out and flushed it out with mineral spirit but didn't notice any plug.

Ebay has a used 90-92 oil cooler plus AC condenser for sale.
http://www.ebay.com/itm/90-91-92-COR...9SPMoP&vxp=mtr

Also, a new one but listed as for 93-95 ZR-1.
http://www.ebay.com/itm/94-95-C4-COR...UkygPw&vxp=mtr

Does anyone know what the difference is? If it's just bolt hole location, I would buy a new one for later years and modify as needed.

That used one is $350 shipped in Canada. I hope I can fix it by simply installing a bigger drain plug there. Or I can always ask a local shop to weld over the plug, you think it would be a good idea?

At the moment I'm trying to remove the radiator, big pain in the *** to remove the 7mm bolts especially driver side!

[Dynomite]

Originally Posted by MuRCieLaGo

That used one is $350 shipped in Canada. I hope I can fix it by simply installing a bigger drain plug there. Or I can always ask a local shop to weld over the plug, you think it would be a good idea?

At the moment I'm trying to remove the radiator, big pain in the *** to remove the 7mm bolts especially driver side!

Replace only the bottom 7mm.

To remove the radiator housing, disconnect the Oil Cooler lines manifold (one bolt in the center). You can then squeeze/bend/pry the radiator housing up (drivers side first) and out.

There are a couple bolts each side that have to be removed from the chassis frame rail. And.....maybe electrical connectors that are obvious and fan housing disconnected (bolts top and bottom) and the Dryer mounting disconnected from radiator housing.

[Dynomite]

Originally Posted by MuRCieLaGo

There you go: drain plug is now inside the oil cooler.

Originally Posted by Blownrunner

The cooler uses the same plug as the rear differential drill/drain kit that CorvetteCentral has. I bet it could be screwed in too far and be stuck inside the cooler. As far as not being a service port, the FSM gives oil refill quantities if you drain the block, block and filter, block and oil cooler, block and cooler and filter, and engine overhaul.

Yes......apparently the Oil Cooler Drain Plug is like the Differential Drain Plug provided by Corvette Central.

[MuRCieLaGo]

Originally Posted by Dynomite

Yes......apparently the Oil Cooler Drain Plug is like the Differential Drain Plug provided by Corvette Central.

When the cooler will be in my hands I'll be able to remove the drain plug stuck inside but it's leaking, threads in the cooler seem to be worn.

[Dynomite]

Originally Posted by MuRCieLaGo

When the cooler will be in my hands I'll be able to remove the drain plug stuck inside but it's leaking, threads in the cooler seem to be worn.

If it is leaking the female thread in the Oil Cooler could be cracked which would also make it possible to screw the plug in further than normal.

I have never removed the Oil Cooler Plug for any reason. Some others have actually drained their Oil Cooler Oil during an Oil Change which I also do not do.

[MuRCieLaGo]

Originally Posted by Dynomite

If it is leaking the female thread in the Oil Cooler could be cracked which would also make it possible to screw the plug in further than normal.

I have never removed the Oil Cooler Plug for any reason. Some others have actually drained their Oil Cooler Oil during an Oil Change which I also do not do.

I hope it is only leaking from the threads... How I am supposed to sleep tonight?

[Dynomite]

Originally Posted by MuRCieLaGo

I hope it is only leaking from the threads... How I am supposed to sleep tonight?

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.