hi i had just gone out to get some fuel in my rx and then on the way back i pulled up to some traffic lights and a cossworth pulled up next to me.... my car had been running for about ten mins and as up to temperature so i left the cossi standing! but then i was just down the road from home a the temp gauage went right up! i pulled into the drive and turned her off. the collant was bubbling loads and just kept overflowing out of the overflow tank!? the bubbling cant be it overheating!? because i have just changed the coolant. i dont know if i changed the coolant correctly!
well, today i was trying to work out what happened so i topped the water up and started the car it was fine for a while (i had the heater on full on hot) i then turned it off and within about 1 min the temp when sky hi! i turned the heater back on to full on hot and it went back down..... so i turned the car off and the coolant was bubbling away but it did not over flow this time!
i couldnt really find any post with the exact same thing! i am really worried! any ideas anyone? thanks!

 

Sounds like you have the signs of a coolant o-ring failure. Exhaust gas under high pressure leak into the cooling system which pushes all the coolant into the overflow tank. Search the forum and you'll find tons of information on this problem.

 

An FD sitting at idle will overheat if the fans are not working properly. Check to make sure your fans are coming on. Also, check to see that you have removed all of the air from your cooling system.

 

Yea it is most likely not burped free of the air yet. Or it wasn't when you last swapped fluid and now you cooked a seal. If your cooncerned with the coolant system having failed. Pressure test the coolant system. Thats the only way to know for sure without speculation.

 

Yes, make sure you have all the air out of the cooling system. It's really hard to do sometimes.

 

so how do i get all the air out??? there arnt any bleed valves or anything!? i had the heater on as i filled the water up! what else do i do to get any air out? thanks

 

burp the system, start car let it warm up, shut off car check coolant level, top off and repeat process until coolant level stays full..

 

open the radiator cap put water in to the top, then crank the engine( keep the cap off) if the coolent comes out of the top (like a foutain) u need a new motor or a rebuild if it is rebuildable.

 

Jack up the left front of your car a few inches. It doesn't have to be off the ground. Disconnect your throttle body coolant line from the back of the throttle body. Remove both filler caps. Fill the ast slowly until it doesn't go down any more, while watching the TB for overflow. If the TB starts to overflow, reconnect it, and tighten it. Cap the ast when it doesnt go down any more. Fill at the filler neck. Connect the TB if you have not done so already.

This should eliminate nearly all the air in your system. Drive it, and check it after cooling down. You may need to add a little for a couple of times to get the last of the air out.

 

Thats one of the worst pieces of advice I have ever heard. Maybe you should explain that ......... if you can. I would love to hear it.

 

How is it a bad motor if it makes a fountain? I also don't understand
this logic you put out!

Please Explain.

-JPs

 

He didn't explain it well but that is a good test for an o-ring failure and I have done it. First off, take the cap off when the motor is completely cold and start the motor. Keep a close eye on the water temp and let the engine slowly come up to temp by letting the car idle while in park. The temperature shouldn't get above about 87 C which well below the boiling point of coolant. If the engine has an o-ring problem then as the car warms up the coolant will start bubbling due to exhaust gasses escaping into the coolant system.
Other symptoms of this problem include oily goo on the overflow dipstick and the coolant appearing orange instead of green because of exhaust gasses and oil entering the coolant system.

 

Thats a good explanation for something that someone else may have said, but not what he said. A fountain indicates water shooting out, which is what he described. Not even remotely the same.

 

Much better explanation!

 

oscy,

unfortunately, sounds like you need a rebuilt.. Same thing happened to me 4 weeks ago..

 

Adam,

I have seen the "fountain effect" twice, once with someone else's FD and once with my newly bought (with a bad motor) FC. Both times there was massive coolant o-ring failure.

 

I could see the fountain effect happen in the case of a really bad O ring failure. Personally I've seen it look like the coolant was at full boil when the water temp was only about 75 C.

 

When did you change the coolant? was this gas trip, when you over heated, the first time you went out after changing the coolant?
I would definitely try to make sure all the air is out of the system before i give in to the idea of a blown engine...

 

Also, how is your coolant mixture ? How much of it is destilled (sp?) water ?

Other than that - refill your coolant system as described by adam and repeat doing so until you no longer hear the gurgling sound when you shut down the car.

 

if i empty the coolant and try refilling it the way adam said can i just fill it with normal water just to it? or will it bubble then? also i changed the coolant a while ago but it was the first time i had put my foot down since! thanks for all your help guys! i am going to try and refill the system now! i will let you know how i get on! thanks again.

 

ok just done that! well it didnt overheat!....... the bubbling has gone down to a minium i am sure it would go away if i did it again..... but it was running in my drive and then stalled itself and now wont start! just dont know whats happened! any ideas? thanks. Osc

 

Pull your plugs and check them. Are they wet ? (oh no, rebuild time)

Also, refill your coolant if the level has dropped a bit (until gurgling sound dissapears).

 

I'm not trying to be negative.. and by my recent experience, I know exactly what you are going thru..

This is what I would suggest.. Let the car completely cool down, open the filler neck, fill the fluid to the top, And Repeat the filler cap off/ starting procedure. If it starts to over flow after this refill or change, you most likely have coolant ring failure.. If the level stays the same, you are golden.. My guess at this point is that your engine is due for an rebuild.. My car did what yours did.. Overheat, overflow.. than everything was cool.. and started back up.. I think I had a small leak at first and just got worse.. Good luck!

Oh.. comment to cruisers post.. If you have wet plugs, most likely you should also see ton of smoke in the back.. especially with 50/50 mix..

 

The heater cooling the engine when on, and the engine overheating when off, would indicate stuck thermostat to me... though of course you need to make sure your fans are working properly.

I might also mention that starting the engine and running it with the filler cap off will cause coolant to overflow out the filler neck as the coolant expands from running through the turbos. The only real tests (in my opinion, of course ) are the bubble test, where you run the engine with the filler cap off at ~ 1000 rpm and watch for a stream of frothy tiny bubbles at the filler neck (place a funnel into the filler neck to catch the overflow discussed above), and/or get a hydrocarbon checker for the coolant. All other symptoms of O-ring failure can ALSO be symptoms of pinhole leaks in the system, though the coolant loss of an O-ring is typically larger in volume (being burned out the exhaust pipe) than with a pinhole leak (loss of coolant scavanging upon cooldown).

Happy hunting...

 

Only thing I could add about this procedure is that I've did this same test to my car and another FD.. Side by side comparison..

Both cars were cooled (sat o/n), filler caps off, topped off with fluid, and only the one with bad coolant seal immediately started to over flow (within seconds).. The one with good coolant seal didn't over flow at all (left on for at least couple of minutes).
I thought it might be something else.. But final result was blown seals.. And I've also considered the turbo thing.. but seeing one over flow and another didnt, tells me that its most likely its my seals..
My guess was that the pressure created by the combustion leaks into the coolant system and starts to expand the liquid... hence the over flow.