Gs430 Heater Stopped Working Temporarily.

mrdoofa · September 22, 2015

I have a 2001 GS430 mk2. Last night on the way home from work I decided to set the climate to 23 degrees, the heater then just blew in cold air. The temp gauge was at the halfway point where it normally is. I decided to pull over and switch the car off, leave it for a minute then restarted it, the heater then worked fine for the rest of the way home.

Do you think this is a one off glitch in the climate control or is it a sign of something more serious?

Cheers for any help.

mrdoofa · September 27, 2015

***UPDATE***

Tonight when I was driving the car I set the climate to 25c and within a few minutes from starting cold I was getting nice warm air, the temp gauge went up to the half way mark perfectly normal and stayed there. However, just driving at a steady 40mph the heater then went cold. The engine only revs at about 1200rpm when cruising at 40mph. I decided to rev the engine a bit harder to about 3000rpm and then the heater came back warm again. The temp gauge stays at the halfway point.

It seems that when the engine isn't revving much you lose heat but when you rev the engine it starts working again. Any ideas on what could be causing this?? Cheers for any help!!!

KayCee · September 27, 2015

is your water pump ok

i had this same problem with a ford many years ago

dave1 · September 27, 2015

Something is obviously amiss. Is it the same on all the fan settings, is it the same on both external air and recirculate settings? Even on tickover you should be getting heated air if the air is set to that. Out of interest it may be worth adjusting temp to 16, high fan and see if the air is really cold without having to use high revs......try on tickover.

ColinBarber · September 27, 2015

sounds like you may have a partial airlock in the heater matrix. The GS430 is particularly difficult to refill the coolant and get all the air out.

mrdoofa · September 27, 2015

Thanks for all responses so far, I really hope it isn't the water pump!!!

What is the best way of attempting to clear any air locks?

emcclariion · September 29, 2015

first thing to do is burp the system it is quite easy, but it takes time.

start the car and turn the temp up to full take the res cap of and wait.

you will see the water rise and burp air out after every burp add coolant keep going till no more burps, this can take 20 to 30 mins.

also change the thermostat it is very easy to do, it will take 10 mins.

one more question do all vents blow cold are just or two, if that is the case you have a servo issue?

mrdoofa · September 29, 2015

first thing to do is burp the system it is quite easy, but it takes time.

start the car and turn the temp up to full take the res cap of and wait.

you will see the water rise and burp air out after every burp add coolant keep going till no more burps, this can take 20 to 30 mins.

also change the thermostat it is very easy to do, it will take 10 mins.

one more question do all vents blow cold are just or two, if that is the case you have a servo issue?

Thank you for your help, I will try burping it on Thursday as its my day off work. Just a couple more questions to make sure I do it right!!!

When you add coolant after each burp, do you add it straight to the radiator or the expansion tank?

How do you change the thermostat? (I'm not that mechanically minded lol)

When the heater goes cold it affects all vents. What happens is when the car drops to idle or close to it such as gently cruising without really working the engine the air goes cold, the climate control tries to compensate by putting the blower motor on max speed but that just pumps in more cold air. If you apply a bit more gas and up the revs to 2000 or more the warm air immediately returns and all is well again, in fact when it's working the heater is very warm and toasty!!!

emcclariion · September 29, 2015

hi,

you open the expansion tank to burp and fill the expansion tank.

thermostat is just 2 bolts where the top rad pipe goes into the engine.

must make sure your new thermostat comes with a new seal as the old one will be buggered

mrdoofa · October 2, 2015

Today I decided to tackle burping the cooling system, I parked the car pointing up a slight hill then had a look in the expansion tank and quite shockingly found it at least 1.5" below the min line!!! Anyway, I set the heater to max setting 30 degrees with blower on fastest setting and let the car idle without the lid on the expansion tank. I added some ready mixed coolant to the tank to just below the min line, I didn't see any obvious bubbling or burping but the level fell by about an inch or 2 within a couple of minutes, this process was repeated 3 times until the coolant held its level in the tank. I then took the car out for a quick drive, then checked the expansion tank again, it had risen slightly probably due to expansion. I'm now going to let it sit overnight and see where the level is tomorrow once fully cold again then just top up to the max line and see how it goes.

I have some hopefully good news though, the heater now seems to stay warm when it is idling, so hopefully the issue may be fixed, fingers crossed. I'll keep my eye on it for any leaks although looking around the pipes, radiator etc there is no evidence of any leakage.

Anyway, my question now is, does the sequence of events above seem normal and have I done it right more to the point?!?

Cheers guys.

PS: Whilst I had the car running still cold I decided to take the cap off the radiator but within seconds the water level started to rise and I quickly put the cap back on before it overflowed everywhere. Is this normal?

TigerFish · October 2, 2015

PS: Whilst I had the car running still cold I decided to take the cap off the radiator but within seconds the water level started to rise and I quickly put the cap back on before it overflowed everywhere. Is this normal?

Yup, it is.

Sent from my Iphone using Lexus OC

mrdoofa · October 4, 2015

So far I've put about a litre of coolant into the car, I haven't had any problems with the heater losing heat since. I do have a concern though, yesterday I filled the expansion tank to the max line when the car was cold then after the car had been run then left to go cold again the coolant settled just under the min line so I topped it up to the max line again. Today I drove it again to work and before I set off home again I checked the level and it was just under the min line again. I don't know whether to keep adding coolant and hope eventually it will stay on the max line or is there a sign of another problem?

Thanks again for all your help!!!

emcclariion · October 5, 2015

Keep a eye on it, these radiators are getting old now, I have just ordered one from Rock auto as the rad is starting to seep at the top join.

cruisermark · October 5, 2015

So far I've put about a litre of coolant into the car, I haven't had any problems with the heater losing heat since. I do have a concern though, yesterday I filled the expansion tank to the max line when the car was cold then after the car had been run then left to go cold again the coolant settled just under the min line so I topped it up to the max line again. Today I drove it again to work and before I set off home again I checked the level and it was just under the min line again. I don't know whether to keep adding coolant and hope eventually it will stay on the max line or is there a sign of another problem?

Thanks again for all your help!!!

hi

just to add - i have an ls430 and the coolant levels always ( and has done so for the last 3 years) sat roughly half an inch below the min mark - when i bought the car i thought it was low and topped it up but it just overflowed.

AmbroseJohn · October 6, 2015

If the coolant level is dropping it must be going somewhere. Check your oil level, if it's over max, that's where your missing coolant may be. Also check your exhaust for steam.