bathspray

Hi all Ive a Sti V2 1995 Classic. The heater when turned on blows cold then sometimes goes hot then back to cold again. Does this sound like the thermostat sticking or any ideas what it is please.
Thanks all

banny sti

iTrader: (68)

When you move off again and the revs are up, do they warm up again?

Banny

thewhitewarrior

id check the water level, as it could be pushing air round instead and making your heaters cold.

bathspray

Hi no not always.


Most of the time its blowing cold.. Only occasionally comes hot...


Cheers

banny sti

iTrader: (68)

Could be as you say thermostat sticking or your radiator could be partially blocked and not circulating water properly.

Banny

bathspray

Hi just checked water level and all is ok there.

Whats the best way of checking rad other then pressing all hoses, and if blocked whats needed a flush???

It was in prosport a few months ago @ Manchester and everything was off the car to enable them to replace oil seals etc...

So should this be happening ive not really done a great deal of miles since then...

Thanks again

thewhitewarrior

it still could be the water, it might need bleeding, not sure how to do it, i just leave the cap off and leave it on tick over for about 5-10 mins, but keep an eye on your temp.

SCOOBYNIPPA

iTrader: (3)

I had the same problam mate i went to change the thermostat and there warnt 1 in so i put a new 1 in and it worked ok 4 2 days and then a water leak occured and still carnt find where the poxy thing is coming from.

VeilsideWRXUK

iTrader: (5)

On most car heater systems there are two water pipes, an inlet and an outlet. Warm the car up and then feel the two pipes. One should be hot with the water coming from the engine block, the other should also be hot with the water out of the heater rad. If one pipe is cold then you know that either the heater rad is blocked or there is air in the system. Remove the cold pipe and gently rev the engine to force the hot water through. Mind your hands in case the hot water comes out over you. If the thermostat was faulty the temp gauge would either read cold or hot, ie if the thermostat wasn't opening then the temperature in the engine black would rise rapidly. Hopefully its just an air lock.

dj219957

i would of thought the bottom rad hose should be colder otherwise the rad isnt doing its job of cooling the water. my bottom rad hose is always colder.
when the stat opens it will get a bit warmer.

bathspray

I'll try the refilling of the header tank tomorrow and also taking cap off whilst running for a few minutes.

The temp gauge is always in the normal when heater is cold or hot.

Thanks again

bathspray

Ok. Filled the headertank and it WAS low.

Took it for a spin - the heater got hot, stayed hot then the engine started to steam like it was overheating.

I left it for a while and then took it out again. Looks like it may have just been filled up to much by me.

Ill keep my eye on it for a few days and hopefully it'll be ok.

Thanks for all replies

mad macca mccann

i had the same problem mate i changed thermostat
then rad
new pipes
then took it to a garage turnes out the head was cracked slightly may need to look into that mate
had to put new head on ran perfect after that
hopefully this isnt it but worth checking to be on safe side

Monky

I had this problem, heaters hot and cold. Then it started getting worse and the next day noticed water temp was getting higher than normal but only once, never got to the red. Next day pop the top rad hose exlploded, filled the entire road with white smoke as coolant pissed out everywhere and turned out my head gaskets had gone causing the pipes to be pressurised.

Check your top rad pipe and see if it's expanding more than normal. A sticking thermostat would stick one way or the other, if it was stuck open you would never get any hot air and the water temp needle would stay low, and vice versa. Could be an air lock in the system or could be your heater matrix but mine turned out to be the headgaskets. Lot's of money later it was fine but check the simple things first.

M

joz8968

iTrader: (13)

Monky, how much did you end up paying? And who did the job?

Did your heads need skimming, or were they okay, etc.?

Monky

Think I spent around £500.00 on parts, off my head two new head gaskets, top end gasket set, cam followers, timing belt, idler pulley and a few other bits and bobs all OEM Subaru from GG Racing I'll dig out the invoice tomorrow.

Labour was free as the chap rebuilds all my customers engines and I've known him for 10+ years but probably would have been around £400.00, maybe a grand all in with parts & labour if paying retail? I've seen people quoting garages on here doing them for £700.00 all in parts and labour but think that's with aftermarket parts and not sure what that includes, I just bought what was needed no messing.

M

joz8968

iTrader: (13)

Yeah, £700-800 seems to be the 'starting' price (dependent on what else needs doing while stuff's apart...

Cheers.

bathspray

Bummer!!!

Just been out in the car and I checked the water level first.

The heater is stone cold again..???????????????


Anyone got any ideas what to do next????

The top hose is hot - the bottom was warm

The temp gauge is on normal temp!!!!!



Thanks again

mad macca mccann

get heads checked before you do too much damage obvious something not good happening better to pay now than fork out a fortune when u have fried everything else
any good garage that do high pro cars will take a quick look for free and give you the bad or good news
as i say it doesnt cost to ask they can only say no (if they are pr1ck5)

Monky

Get the car up to temp and see if you are getting pressureised pipes, I mean big ol fat pipes as this is a classic sign of HG as the pressure is leaking from the HG and fills the cooling system with pressure.

Why don't you do a compression test, cheap to do?

T

Underworld

where is that tank???

Underworld

THIS>>??

bathspray

Verdict - mmmmmmmm.!! Top hose red hot bottom hose cold but when you squeeze both bottom and top hoses water comes up out header.

Fans not kickin in either!!!!!!!!

Sounds not to good........