Bad radiator cap?

[Slow99x]

I took the Cobra for a short drive today to the store and I noticed the smell of radiator fluid. I got home and popped the hood. There was fluid on the coolant overflow tank (stock unit) and it seemed to be mostly arount the cap.
Anyone else have something like this happen? Did you have to replace the cap or did you do something to fix it?

 

[01cobravortech]

These caps tend to go bad.

 

[mysticsvt]

Done anything to the car recently? Over heated at all? They do go bad from what I have read. Worst case scenerio blown head gasket, check for coolant out of the tailpipes or in the oil. Like I said..worst case...but check. Happened to me and started off with some coolant around the cap.-Shane

 

[Slow99x]

SHIIIIIIIT!!!!! Just went back out and checked the overflow and it was empty. Filled it with some water and let the car idle for a while with the cap off so I could watch it. Once it started to get to normal temp the coolant started puking out of the overflow. It was bubbling out. I checked the tail pipes and they were wet. I don't have the money to get the head gasket changed let alone buy the gasket to attempt something like this myself. I have to go pick up my kids in a few hours and they live 200 miles away and bring them here for the weekend. WTF!!!!

 

[04sleeper]

You can't fill the cooling system through the overflow tank. You have to fill it from the coolant crossover tube.

But it sounds like you might have other issues if you have water coming out of your exhaust. Are you sure it's not condensation?

 

[mysticsvt]

Did you do anything to your car? Was it coolant out of the exhaust or just water? Try burping your system from the cross over tube. Funnel with electrical tape works great. Search is your friend on here for that trust me. Keep in mind if you have coolant in your cylinders like I did after time it will ruin your block. I blew mine and got deployed for 8 months. Now I have an Aluminator long block..lol.-Shane

Here was mine...

 

[Slow99x]

I'll check it again because it was dark and it was cooler. I've never overheated the car and in fact I have a 160 deg Tstat so the fan kicks on earlier. My question is why would the tank be empty then when the car reached normal temp just spill everything I added back out?

 

[mysticsvt]

I'll check it again because it was dark and it was cooler. I've never overheated the car and in fact I have a 160 deg Tstat so the fan kicks on earlier. My question is why would the tank be empty then when the car reached normal temp just spill everything I added back out?

With my blown head gasket it did that constantly. How long since you changed out the T-stat? How much have you run it since then? You def need to burp the system and see if your getting either air bubbles like my video or coolant in your oil. Hopefully, you dont have one. -Shane

 

[Slow99x]

I changed my Tstat almost 3 years ago.
So I started it and ran it for a while and no smoke other than early morning condensation and no coolant on the tailpipes. I drove it and when I gave it a little gas it fell on it's face and the temp started to rise. I pulled over and let it cool down for 15 minutes and limped it home. I'll try to burp the system and check the pugs for any coolant. I'm hoping it's just a bad overflow tank. I was planning on replacing it with the Morosso unit anyway.

 

[Root1022]

Let us know after you get the system burped. Hopefully its something small and simple.

 

[Slow99x]

So my friend and I added coolant into the crossover tube and burped it. No white smoke at all. I took it for a quick rip down the street. No white smoke and power feels normal. I'll be keeping an eye on the overflow tank and cap to make sure they didn't warp. If it needs replacement I'll be going with the PFAB unit from Lethal.

Thanks for all the responses and help guys

 

[Root1022]

Glad it seems to be something simple :beer:

 

[svtscott01]

any update? I have exactly the same issue looking at the rad cap. did it work for you?

 

[Jimmysidecarr]

A bad rad cap is what can allow the air in, in the first place and then all these other symptom erupt.
When it lets over boils through it very often warps the tank opening sealing surface. This can be put back straight and flat so your new cap will seal better if you true it with a flat file.

I don't like that design or the quality of the tanks and caps.

I like tanks with the old school rad caps, that's what I have, they are MUCH more reliable.

 

[svtscott01]

Once again JIMMY DA MAN!

 

[Slow99x]

Drove it a little over the weekend and so far no more spewing from the radiator cap or tank.