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Cold heater / bleeding

Nightshade

Nightshade

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Howdy folks.

Some might remember i posted a q. regarding the icy cold heaters in my 1.4nz. I've put the job off till now, but its getting so cold i'm gonna have a look tomorrow. Just to recap:
Heaters blow fine, but take 3hours+ to get even luke warm.
Only the two outer vents get any heat at all..ever :(

This morning i heard a sloshing sound as i set off, and i'm hoping there's an air lock somewhere in the coolant system. What im trying to find out is where are the bleed screws and how do i bleed the engine (have done before but on different cars a long time ago, with help) And what else could it be?

I'm being lazy as i haven't even lifted the bonnet yet to have a good scoot round for whatever it is i need to do the bleed, but thought if any of you can help i'll be better prepared tomorrow morning.

Cheers folks!
 
I've never encountered a Vauxhall yet that needs 'bleeding'. Ignore the Haynes manual where it says bleed with the dash temp. sender. If you look, Vaux have cleverly made sure the expansion bottle is the highest point.

If you've done more than about 20 miles and it's got nice and warm (on the dash) then it's bled.

If you're hearing a sloshing sound behind the dash it's almost certainly air in the heater matrix. Normally this is casued by a head gasket that has failed between a cylinder and a water channel, meaning you don't get the white gunk in the oil filler cap.

The two centre vents always blow cold.
 
are there any other signs?

when i bought the car i was told that the head gasket had gone 6 months before as a result of a leak that developed from the radiator, and it lost all the water. Aparently he never noticed till steam was pouring out the bonet and the temp gage was off the scale. Its definatly had a new radiator, and apparently a new matrix too, although obviously i can't see that so i don't know. Down the side of the engine i can see what i think is the corner of the head gasket sticking out ever so slightly, but it looks very old and grubby. If thats the bit i think it is then its definatly not 6 months old.

Finally is there any check i can do to be certain before i got ripping the head off??
 
a compression test on the coolant bottle, basicaly a hand pump which puts the coolant system under pressure, if a cyclinder leaks then the pressure will drop, and the car will run **** when you start it because of coolant in the cyclinder.
 
revs run high for a seccond on a cold morning, but presumed that was auto choke. Starts up first turn, and other than raising the revs runs smooth as a baby's bum
 
if the hoses have been off then check theyre on the right way round going into the engine heater and header tank.
 
has it got a stat in it? will take an age to warm up if it hasnt
 
not sure if it has a thermostat, would need to pop open and check - would i need a new gasket if i break the seal on thermostat housing??

Run for 2 months now, serviced and topped up cooland first day. Never needed a drop more since
 
Nightshade said:
not sure if it has a thermostat, would need to pop open and check - would i need a new gasket if i break the seal on thermostat housing??

Run for 2 months now, serviced and topped up cooland first day. Never needed a drop more since
Click to expand...

mine has the exact same problem, blooming freezing on these cold winter mornings
 
Sadie said:
mine has the exact same problem, blooming freezing on these cold winter mornings
Click to expand...


for how much they are i would try a new stat, my old cav was the same, put a new one in and it was loads better.
 
Neve'o said:
for how much they are i would try a new stat, my old cav was the same, put a new one in and it was loads better.
Click to expand...

sorted now, took it off and found out the person before had completley ripped it out so i had no stat at all got one from the local scrapy for a tenner, fitted and it works a treat just in time for the cold days ahead:laugh:
 
told ya! cant believe you paid a tenner for a s/h stat tho. they are only about 10 quid new!!!! s/h stats are like second hand tyres....ya never sure what ya gettin. Now you need to find out why he/she took the stat out. was it cuz it was running hot in the summer.....or was it cuz it fixed another problem like.... cooling fan switch not working.....or head gasket gone?
 
Someone removed the thermostat? God almighty....people like that should not even be allowed near a spare wheel.
 
update

Checked coolant level yesterday, the bottle looks full, till you take the lid off. 4 Litres short of being a happy engine :(
So looks defo head gasket. Filled it up and the heaters work fine. Thing is tho it still starts first turn. Anyone know how much dammage i would do running it and topping it up till early Jan? Don't get paid till then
 
Nightshade said:
update

Checked coolant level yesterday, the bottle looks full, till you take the lid off. 4 Litres short of being a happy engine :(
So looks defo head gasket. Filled it up and the heaters work fine. Thing is tho it still starts first turn. Anyone know how much dammage i would do running it and topping it up till early Jan? Don't get paid till then
Click to expand...


Probably not much damage but enough. What you must remember is while the engine is running....the pressure in the cylinders is greater than in the water system.... so compression from the cyl will pressurize your water system higher than its sposed to be. the cap will let it out at 15 ish psi but it will still cook. THEN....when you switch off the engine...the pressure in the water system is greater than the cylinder...so water will leak into your bore and pass the piston rings and into your oil.


IF you MUST use it then i would say carry plenty of water and a towel with you. Keep it topped up but not too high as it will push the water out anyway. When you switch off to leave it parked for a while/overnight then release the expansion bottle cap to let out the pressure. Open it VERY carefully and slowly. Release it and let it hiss. Close the cap again. This will help stop the water going into the cylinder. The towel is for opening the cap without becoming a burns victim. Other than that....where are you? Is there not one of us lot somewhere near that could do you a quick HG change for a pint?

Just a thought
 
Last edited:
Thanks for the advice sondis. I'm near Bradford in wet yorkshire, and whilst i've had some experience with diesel engines, i would really apreciate any help that anyone can offer. I'd be willing to travel - theres nowhere at my house suitable for the work anyway, but obviously not too far, as I don't want to do any more damage than needed lol.
Will the head need to be sent away for pressure testing and skimming?? Presuming that would take a couple of days. Also does anyone know how long it would take to pull the head off my nz?
 
Bump!!
 
To get the head off....about an hour tops. Then you have to strip it for skimming. If its cooked at all... then yes a skim would be advisable. Its not a big job doin a HG...just time consuming cleaning all the faces and stuff like that. Oil change and fresh anti freeze too.
 
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