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View Full Version : No heaters and bad circulation.. help please


ZANDER
24th October 2009, 06:33 PM
Know that this is a a common thread, but interested in your views in my situation..First of all there is no heat if driving on a cold day, very small amount of heat if day if not cold...
My first steps were
I removed the 2 pipes that go to and from the heater rad, water very rusty colour... hooked up garden hose and ran water through the heater rad so its not blocked,
i also tried this with temp dial at hot and then turned to cold... water passed through when heater set to hot and stopd when turned to cold.. so that valve is working...
one thing i noticed when i took off heater pipes was that there was little or no flow until you revd car up...and i think heaters get better if you sit in on spot and hold her at 4 or 5k revs..and heaters seem to die again when revs die down..
Top tank of rad was very hot, core of rad was cold.. bottom pipe cold and top pipe roasting but when i pulled top pipe off had nothing in it...
all the above were pushing me and anyone i asked to conclude water pump with fins broke off.. so i purchased and went to the hard job of fitting it today... bad news is the old pump looks fine and thermostat is opening and closing in boiling water aswell... fitted the new pump anyway but havent her running yet as the Anydarkness caught up on me tis eve...Temp gauge always stays around half way and ive never heard gurgling from behind dash??
i am puzzled now, was sure the pump wasnt pushing the water around
help appreciated

ZANDER
24th October 2009, 06:35 PM
4got to say.. car is 95 Jap TT Manual

Martin F
24th October 2009, 07:19 PM
I was reading that and thinking straight away water pump, then I got to the bit where you said you'd changed it :(

It definitely sounds like a blockage, or circualtion issue of some sort and it seems you have eliminated the thermostat.

Would you have any reason to suspect the radiator is blocked? How old is it?

Although a blocked radiator shouldn't really effect heating in the cabin.

Gambit
24th October 2009, 11:44 PM
I take it when you say you pulled top hose off, you waited for it to cool down.....
Is your radiator brimmed to the top and expansion tank carrying fluid?

You will get more heat if you sit there and rev the nuts off it, that's logical as the engine is running hotter.

When you turn the temp gauge from hot to cold can you hear the louvers turn?

Are the two main hoses from the rad firm when at engine running temp?

If the bottom one is cold and soft when the top one is hot, sounds like a blocked rad. Take bottom hose off and poor water in the top one and see if it passes out the bottom through the rad.

ZANDER
25th October 2009, 02:40 PM
rad doesnt seem to be blocked either.. expansion bottle i topped up... i have spent a lot of time at it today, filling and re filling and i filled the top hose of rad first, parked on a hill and then last of all filled rad from piece of hose and funnel.. seems to be water in top hose.. bottom hose seems to be now warm.. rad core is still cold??? heaters seem better but today is warm.. so 2mro morn with trip to work will be the test.. fingers crossed

Gambit
25th October 2009, 03:06 PM
The rad core won't get anywhere near as warm as the top tank, heat rises.

Switch the climate control to full auto and turn the heater to max now take the car for a nice run 2 junctions of the motorway should be good, also speed forces the water round better so if you do have an air lock this could help. At the end of the trip you should be sitting in a puddle of sweat, if not you still have a problem.

Have you checked that you can hear the louvers moving in the heating system when you turn the dial from hot to cold?

Martin F
25th October 2009, 03:48 PM
WHen you refill the system you are running the engine with the rad cap off and continuing to top up as required?

You need to do this to try and get the air out of the system.

ZANDER
25th October 2009, 09:37 PM
i havnt listened for the noise of lourves moving but hav had the two hose going to heater rad disconnected and hav run water from garden hose in one heater pipe and it comes out the other when the heat dial is on full heat and nothing comes out when heat dial is on cold, so i assumed that was everything i needed to work in behind dash

Gambit
26th October 2009, 05:31 PM
I was just thinking as your water system seems to be working, maybe the electronic flap that dictates external cold air or hot air through the matrix was stuck on cold....

Martin will no doubt tell me I'm talking arse in minute as that tends to happen. :o

ZANDER
26th October 2009, 07:18 PM
Could be anything at this stage.. the Supra has a wicked complicated heating/cooling system.. think it may have been designed by Renault or something:rolleyes2:
I have seen diagrams and they are hard to follow, but there is an IAC valve shown that looks like something that could cause trouble.. dont know where it is or what it is

Martin F
26th October 2009, 10:20 PM
I think Zanders problem is a bit deeper than just the internal heater.

I suspect the coolant diagram you're thinking of is this one:

http://www.mkiv.com/specifications/ncf/ncf93/ncf084.jpg

The Idle Air Control (or Idle Speed Control) valve is a very small part of the coolant circuit so I doubt it is responsible for your problem.

If I was you i'd be taking the radiator out and running the hose through it both ways.

ZANDER
29th October 2009, 10:27 PM
Ive run water everyway i can through both rads....there isnt or wasnt any blockages.... but good news is.. god im almost afraid to say it... but i think the heaters are working alright now, havent had a real cold morning since i operated on her.. typical... but its defo warmer.. fingers crossed

Martin F
29th October 2009, 10:42 PM
Both rads ???

ZANDER
30th October 2009, 11:54 PM
Yep, power hosed the main rad when had it out doing water pump and ran water through the heater rad with garden hose

Gambit
31st October 2009, 12:03 AM
Right!!

Flushed the rad and the matrix.

So if you turn the temp to max, do you get hot or slightly warm?

ZANDER
1st November 2009, 09:04 PM
i think its sorted now... seems to be fairly hot... dnt think toyotas are known for great heaters anyway.. since i done it, the weather has warmd up a bit, not as cold, getting lot of rain and havnt had a good cold morning to put her to the test.. fingers crossed she stay wam in the frosty weather... all the pipes are full of water now, so maybe it was just full of air before wen someone else had been at it and system wasnt full of coolant.. but the rad was full???? anyway i thought it was the water pump so its changed now anyway, wasnt putting old one back on after getting the hardship of getting it off