Is the bleeder hole on the bottom of the radiator? I'm losing antifreeze from a " plug" that is made of rubber with a screw in the middle of it. It is located in the front of the rad lower near the center of the car. I'm losing it very slowly, but losing it all the same. When I felt around it the gasket doesn't feel flush. It's higher on one side and lower on the other. Please help me in identifying this...

 

Does anyone know what I'm talking about? My car is an 86 XJS V12 5.3L. My post is above.

 

if its got a screw in the middle of it, its likely some sort of spreader screw for the rubber plug. try backing the screw out, readjusting the rubber grommet, and tightening the screw again.

other things like RTV sealant, work great in such an application.

 

Hi start another thread with your question so as not hijack the OP's. Post a pic of the offending bit.

BTW the way the radiator drain is on the RH bottom of the radiator as you sit in the car.

 

Sounds like someone removed the factory drain valve (leaking prehaps?) and replaced it with a plug.

 

if its got a screw in the middle of it, its likely some sort of spreader screw for the rubber plug. try backing the screw out, readjusting the rubber grommet, and tightening the screw again.

Thank you sooo much for your assistance. By the way... What's a spreader screw?

 

well, i call it a spreader screw. it basically works sort of like this.



its got a bolt that goes through the center of it which, when tightened, causes the rubber plug to expand until it fits tight in the drain hole.

 

I will take a pi of it and post it.

 

I went to the mechanic yesterday, was told the rad, and expansion tank is fine. All lines are fine. Passed a pressure test with flying colors. Had two new rad caps put on. Mine were a little funky. None of its leaking. Took the car out for a spin today, and low and behold... antifreeze in the driveway!!! What the heck can be causing it??

 

That's it!!!!! It's inside the valance under the front end of the car smack in the middle

 

whats it?

 

That pic of the screw. I went back to the shop today while I was actively leaking, and they are going to see if the bottom of the rad is rusted out. Can that be repaired or does it need to be replaced? You guys know sooo much more than I do.

 

Sounds like you have a leaky radiator. if you have one of those temporary rubber plugs in the body under the radiator someone was trying to hide the coolant leak. That is not even part of the radiator. Remove it and toss it in the garbage where they belong. Remove the radiator, send it for repairs, clean the debris from the space between condenser and radiator, replace all the hoses, install new thermostats and replace the foam surrounds so all the air flows through the radiator instead of around it. The cooling systems on these cars are adequite but there is no margin for a performance decrease so you have to maintain it to the highest standards.

If you have not done so already. Download "The Book" by Kirby.

 

Thank you. I have an appt. on July 5 with the mechanic. Would it be cheaper to replace or repair?

 

Usually replacing the core is the most cost effective repair. Especially since the aftermarket replacement radiators have much thinner metal for the tanks.

 

I had mine re-cored last year. I think this is your best option, the radiator will be old anyway.

There are 2 different cores make sure who ever does the job uses the later core a bit more expensive but has more fins/inch (according to parts the list I saw) but the radiator guy said it was a better core.

Take the opportunity to replace all the hoses while the Rad is out, much easier job.

 

Based on this you need to replace the fan clutch as well.

Oil pressure will go down as the engine heats up this is due to the oil becoming more viscous as it walms.

 

I can't thank you guys enough. You've been so helpful!

 

How do I know if the fan clutch is no good? I have 2 fans in the front of the car under the car under the hood. 1 runs constantly, the other I believe is for AC which I don't use and is shut off in the car so it doesn't spin. ( on the drivers side)Based on this you need to replace the fan clutch as well.

Oil pressure will go down as the engine heats up this is due to the oil becoming more viscous as it walms.

 

Driver's side is relative to the market in which it was originally sold. Left or right is the description to use here. You are getting advice from all over the world.

The fan clutch is the viscous coupling for the mechanical fan. There is no real good test that is foolproof. The best is to just replace it if in doubt. The electric fan comes on when the coolant temp reaches a certain level or when the A/C is activated.