Winter Heating

[robnw67]

Wow - I do seem to post a lot on this site!!

Does anyone know if there's a second thermostat in the cooling system - in particular controlling the water entering the heater matrix?

Even with the water temperature needle sitting neatly in the middle of the gauge, it still takes at least 5 more minutes for heat to come out of the heater. Kind of a pain in this weather!

Cheers

Rob

[marky]

scenond thermostat SECOND i think. not that i know of mate. needle always sits in middle check valve on heater pipes to make sure it opens properly when you move lever

[robnw67]

Addendum!

Hi

Just as an addendum to this question, I drove the car to work today, all toasty warm.

Then I sat in the car park for a bit to listen to the radio - of course I mean let the turbo cool down - and the heating went cold. Strange, considering I hadn't touched the heater controls!

Then I pushed the 'Idle Up' switch and the heat came back on - again, no adjustment to heater controls. 'Idle Up' off - heat goes off again.

The general rule seemed to be revs above 1000/min - heater works, revs below 1000/min no heat.

Does anyone have any ideas?

Rob

[Andy W]

Mine did that just before the head blew ! I think its caused by a gunged radiator and numerous airlocks. Also mine used to blow hot and cold when going up hills etc. If i were you i would do a flush and look for airlocks.


Andy.

[robnw67]

Winter Warmers

Ok, so I'm a bit worried now. I took the forum's advice and checked the water levels - this time ignoring the water in the expansion tank.

I had to add 1.75litres to re-fill the system. I am hoping that the cause was an airlock in the rear passenger heater matrix - cos that's what my mate was messing with yesterday and it's only today that I noticed the problem. If it's a more long term thing - heaven only knows what damage I have done to the engine running it on a low coolant level.

I didn't suspect the water level before because the expansion tank was full. Of course I now find that there is an air leak between the expansion tank and the coolant filler cap - so the excess coolant isn't sucked back into the system.

I see an ice berg dead ahead..................

Rob

[da SLUG man]

Hi

Just as an addendum to this question, I drove the car to work today, all toasty warm.

Then I sat in the car park for a bit to listen to the radio - of course I mean let the turbo cool down - and the heating went cold. Strange, considering I hadn't touched the heater controls!

Then I pushed the 'Idle Up' switch and the heat came back on - again, no adjustment to heater controls. 'Idle Up' off - heat goes off again.

The general rule seemed to be revs above 1000/min - heater works, revs below 1000/min no heat.

Does anyone have any ideas?

Rob

that's cos the more revs you got then the faster it's pumping water around at highter pressure, not sur how the heater's plumbed in on these but at low pressure it may be bypassed a bit and the matrix will go cold

[Koi]

Ok, so I'm a bit worried now. I took the forum's advice and checked the water levels - this time ignoring the water in the expansion tank.

I had to add 1.75litres to re-fill the system. I am hoping that the cause was an airlock in the rear passenger heater matrix - cos that's what my mate was messing with yesterday and it's only today that I noticed the problem. If it's a more long term thing - heaven only knows what damage I have done to the engine running it on a low coolant level.

I didn't suspect the water level before because the expansion tank was full. Of course I now find that there is an air leak between the expansion tank and the coolant filler cap - so the excess coolant isn't sucked back into the system.

I see an ice berg dead ahead..................

Rob

keep the rear heater open for a few days (dont need the fan on just set to hot) just check the levels for the next couple of days or so.
After I flushed mine and filled it, it still seemed to move some air locks over the next couple of days or so and just needed topping up.

It may not have been an air lock at all, you say the pipe to the expansion bottle had a leak in it. So the engine gets hot and x amount of coolant expands in to the bottle. So when the engine cools down you are x amount less in the engine because it can't get sucked back in. Next time the engine runs hotter so the coolants may expand a bit more and y amount is pushed into the bottle, again cant get sucked back in. So you are now x & y short in the engine so it runs hot.
Once you replace the pipe of fix the leak all may be well.

[robnw67]

It just sucks

Well I tried the heater on the way home and it is way hotter - much more like I would expect it. Even the rear heater is nice and warm. I am hoping it's the cap on the expansion tank. As advised I'll keep an eye on the levels and take nothing for granted!

Rob

[robnw67]

That iceberg just got closer

Well, I repaired the old expansion tank cap whilst I am waiting for my new one from the Toyota Dealer, however, it doesn't seem to be sucking any fluid back into the system. When I go and check it after it has cooled down, the top hose always seems to be dry. I guess this means that the system is running with a lot of air in it, which means:

1) it will allow the coolant to boil - not a good idea generating steam!
2) it will cause micro bubbling erosion - not good according to many threads on here.

The question is - why is my system pushing so much water out past the radiator cap. It's either a weak rad cap spring, an over pressure of the water system due to a leak in my cylinder head gasket or the water is being lost elsewhere.........some leak in the water jacket perhaps.

I can see pain, dead ahead.

Rob

[Guest]

Well, I repaired the old expansion tank cap whilst I am waiting for my new one from the Toyota Dealer, however, it doesn't seem to be sucking any fluid back into the system. When I go and check it after it has cooled down, the top hose always seems to be dry. I guess this means that the system is running with a lot of air in it, which means:

1) it will allow the coolant to boil - not a good idea generating steam!
2) it will cause micro bubbling erosion - not good according to many threads on here.

The question is - why is my system pushing so much water out past the radiator cap. It's either a weak rad cap spring, an over pressure of the water system due to a leak in my cylinder head gasket or the water is being lost elsewhere.........some leak in the water jacket perhaps.

I can see pain, dead ahead.

Rob

Air lock would do it, knackered rad cap would do it, combustion pressure in the coolant would do it too (busted head). I would suggest you get the system pressure tested.

Cheers

[robnw67]

New hose

Well I replaced the expansion tank cap and associated hoses and all seems well so far. I'll have to check tomorrow morning.

The part was £12 from my local Toyota garage. They seemed ok with getting parts for it and also seemed ok about servicing if I wanted it done. Interesting............!!