Mucca Mad Boys
heater tap or heater core
I have another little issue i'd like to get sorted, still learning :P
my car looses coolant, but only when the heater is turned on inside, it went through almost the whole overflow bottle in about 20 minutes, but doesnt use any when it's turned off, i can't really smell any "sweet" smell inside the car, and it's been pressure tested but no luck, so is there any simple ways to check wich one it is?
Look for white reside around the heater tap as it indicates dried up coolant but at the rate you said it should be all wet around the tap if it leaking, if its the core pressurise the system and look for coolant running out the AC box over flow as it should run back then out the same hole as condensation does when the AC is on.
Donating Member
Strange as it may seem, if the heater is leaking, it will leak if it's turned on or off. This is because the heater tap only closes one hose off which stops the flow of coolant through the heater.....however it is not the flow of coolant that makes it leak but the pressure of the coolant that is still in the heater which is still connected to the cooling system by the other hose, which is at the same pressure as the engine coolant.
"If anyone disagrees with anything I say, I am quite prepared not only to retract it, but also to deny under oath that I ever said it." --T. Lehrer
"The secret of success is sincerity. Once you can fake that you've got it made." -- Jean Giraudoux
QuickVR95II 2010 Survivor
5 Miles 2 Go Champion!
Not saying you're wrong man, because I'm interested, but why then did tying the heater tap control arm off with a cable tie stop my heater core leak? Heat expansion crack?Originally Posted by hako
The hall of fame:
ಠ_ಠ
Mucca Mad Boys
It hasn't used a drop since like 4-5 days ago, so i would have thought if the tap is leaking, it would still be going down, tommorow ill turn the heater on as high as it will go and see if i can find water coming out
Donating Member
The flow of coolant would increase the pressure slightly but I think you are probably correct that the heat expands the crack. I guess also that the return end of the heater enters the block at the suction side of the water pump, so with the heater tap closed, the heater internal pressure would be reduced...probably quite a bit. However, once the engine is turned off , the water pump no longer sucks, so the internal pressure in the heater must equalise with that of the engine, which can be anything up to 1.35Kpa or 20 psi.....
Therefore, tying/closing off the heater tap would reduce the leak, but not stop it completely.....how does that sound?
"If anyone disagrees with anything I say, I am quite prepared not only to retract it, but also to deny under oath that I ever said it." --T. Lehrer
"The secret of success is sincerity. Once you can fake that you've got it made." -- Jean Giraudoux
Mucca Mad Boys
you lost me after the first line, could i just try and look for it while i have it on full tommorow? the leak that is
Donating Member
Sorry about the diversion....I'd disconnect both hoses where they connect to the heater on the engine side of the firewall, and either block both hoses or connect them with a piece of tubing. If you still lose coolant with the heater disconnected it will not be the heater.
If it's losing an overflow bottle of coolant in 20 mins you'd imagine the carpet would be saturated. From my personal experience I've found that when you lose coolant especially from the overflow tank, it may be the radiator cap not sealing correctly which allows the engine to boil at 100C after you switch the engine off (heat soak) and also the bad cap prevents coolant being sucked back into the radiator when the engine cools.
"If anyone disagrees with anything I say, I am quite prepared not only to retract it, but also to deny under oath that I ever said it." --T. Lehrer
"The secret of success is sincerity. Once you can fake that you've got it made." -- Jean Giraudoux
Mucca Mad Boys
Thanks for all of your help, the radiator is leaking, i should have mentioned, just seeping out the sides a little. Ill block those hoses and try and find the leak, it only loses water then the heater is on though so i really have nfi
anyone know where the heater tap vac line on a VR V8 calais comes from?
Donating Member
Just watch that radiator....they eventually blow out completely...new ones are $100 delivered.
"If anyone disagrees with anything I say, I am quite prepared not only to retract it, but also to deny under oath that I ever said it." --T. Lehrer
"The secret of success is sincerity. Once you can fake that you've got it made." -- Jean Giraudoux
Mucca Mad Boys
yeah it is getting a bit worse, im thinking of getting a aluminum one but no to sure if its worth the extra cash
Posting Permissions
LinkBack URL
About LinkBacks
Reply With Quote