leaky coolant cap

My cap for the radiator coolant resivwire is leaking.

Just noticed it a couple of days ago not a big leak, just can see som residue of it leaking, Cant see it lek ing while it is running.

Anyone else have this problem? is there an easy fix?

Thanks

I had the same problem. Replaced cap and haven't seen any residue since.

were did you purchase it at?

get it at dealer. still only a couple dollars...and this is one part i would want to keep stock appearance. don't go w/ the autozone one.

is this a common problem with these cars?

90gt4valve said:

is this a common problem with these cars?

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I have seen several posts over the past years from members on here that have had to replace multiple caps because they weren't holding pressure. Clearly if it becomes a recurring problem the lip on your coolant degas bottle could be subtly warped and be the culprit for a leak and it could also be indicative of a head gasket issue.

But lets not jump the gun. I'm sure its just a banged up radiator cap.

Looks like a slow drip.

Car has 22k on it, no problems what so ever. Does not over heat, Runs between 85-95 C on digital odometer temp reading, depending on outside temp, fan kicks on at 95C I believe. Not smoke or anything from tail pipes.


On a sied not got the car on a dyno 2 weeks ago and it made 502/490, but the torque was kinda jumpy looking, what does that mean?

I had mine replaced under warranty. I had similar mileage to your car, when my cap was replaced.

well i replaced the cap.

But i noticed that it is designed to let out coolant around the edge.

Its not really pouring out or anything, just a little wet spot on the plastic, were u can tell its been dripping, I cant ever catch it in the act though. I just see reisdue were it had been leaking. My coolant level is to the top well above the ADD line. I jsut never noticed it leaking until now, now that its hot out i guess.

This normal?

t t t

If it still leaks with the new cap... NO it's not normal.

It should not be over filled cold or hot, make note of the different full lines.

It could have and likely does have a warped cap mating surface. There is no catch can provision on these cars so over filling is a huge no no!

There is the expansion tank and that is it. If the coolant expands when hot and it is slightly too full, it's going to leak out.

That's why I ditched the stock tank and put a Canton on. It has a normal radiator cap with a nipple for any possible over flows to be caught by a catch can.

No black flags FTW!
If you are on track and it starts spewing, and they see it, you get black flagged and your session is DONE! I DID NOT WANT TO GO THERE!:nonono:

90gt4valve said:

well i replaced the cap.

But i noticed that it is designed to let out coolant around the edge.

Its not really pouring out or anything, just a little wet spot on the plastic, were u can tell its been dripping, I cant ever catch it in the act though. I just see reisdue were it had been leaking. My coolant level is to the top well above the ADD line. I jsut never noticed it leaking until now, now that its hot out i guess.

This normal?

Click to expand...

Well I'm still dicking with mine. Car runs perfect. No smoke, no oil mixture, runs 120 through the quarter, yet I can't keep coolant in it. Bought a LFP tank and I'm loosing coolant out it's nipple. Used a tool to fill the system/burp, pulled down to 25 inches of vacuum, so It would seem I have no blown headgaskets, yet I'm not convinced as my problem won't go away. I'm thinking of flying Jimmy in to burp my car. Or it's forsale for $20K.:cuss:

Guys

As an experiment try running a slightly lower coolant level.

If anyone is running one of the bigger racing radiators(don't know if you are), the added volume of coolant needs more expansion room than the stock amount.
The coolant expands when hot(even normal hot), and there needs to be additional room in the expansion tank if there is additional coolant volume in the system.

If you are running an aftermarket tank with an overflow nozzle run a hose to a clear plastic bottle zip tied in place.
When you see coolant in the bottle, yet the system appears full at the burp plug, then dump the coolant back in your antifreeze gallon jug(not back into the system), and just save it.

Then monitor the catch can for any more pukes(repeat if needed) and see if the lower full level stops it.

Jimmysidecarr said:

Guys

As an experiment try running a slightly lower coolant level.

If anyone is running one of the bigger racing radiators(don't know if you are), the added volume of coolant needs more expansion room than the stock amount.
The coolant expands when hot(even normal hot), and there needs to be additional room in the expansion tank if there is additional coolant volume in the system.

If you are running an aftermarket tank with an overflow nozzle run a hose to a clear plastic bottle zip tied in place.
When you see coolant in the bottle, yet the system appears full at the burp plug, then dump the coolant back in your antifreeze gallon jug(not back into the system), and just save it.

Then monitor the catch can for any more pukes(repeat if needed) and see if the lower full level stops it.

Click to expand...

Good point. A lot of folks forget that the aftermarket radiators from Fluidyne & LFP claim a 1gallon more capacity. If you're still stock and pushing coolant through the cap on the street then there has to be an issue with your cap, overflow tank or worse case scenario HG. I would also expect guys to push coolant through the cap on the track or road course if they are running the stock radiator and tank. Coolant is going to expand big time in that type of environment.

Jimmysidecarr said:

Guys

As an experiment try running a slightly lower coolant level.

If anyone is running one of the bigger racing radiators(don't know if you are), the added volume of coolant needs more expansion room than the stock amount.
The coolant expands when hot(even normal hot), and there needs to be additional room in the expansion tank if there is additional coolant volume in the system.

If you are running an aftermarket tank with an overflow nozzle run a hose to a clear plastic bottle zip tied in place.
When you see coolant in the bottle, yet the system appears full at the burp plug, then dump the coolant back in your antifreeze gallon jug(not back into the system), and just save it.

Then monitor the catch can for any more pukes(repeat if needed) and see if the lower full level stops it.

Click to expand...

I'm gonna try the clear plastic bottle.