Cooling question time again.

[Taliesins]

Nothing's wrong with the viscous fan as far as I know. It goes round and it makes a right old racket when I put my foot down so I think it's probably alright. Could probably do with refilling or whatever people do to it, but I've got no real concerns with it. Why? Should I be frightened?

I'm talking about the electric fan on the radiator that doesn't come on. Could be the sensor or whatever, maybe I should put a switch on it etc. In the meantime, whilst it's summer and I don't want to be stuck in the Malverns with a screaming kid waiting for my engine to cool down, I was wondering why I shouldn't just leave it switched on the whole time.

Doesnt that electric fan work when the air cons on to cool the A/C rad??

[Sancho]

Doesnt that electric fan work when the air cons on to cool the A/C rad??

From what I can see, there are approximately 100 fans in there. There is the viscous one (big, noisy, behind radiator, connected to belts), the two AC ones (tiny, full of mud, useless) and the radiator fan (medium sized, in front of rad, supposed to come on if the cooling system starts struggling). There are probably others that are yet to be discovered by humans.

My radiator fan has never come on. If I disconnect it from the sensor (so it thinks it has been told things are warming up) it switches on. Hence the sensor is probably toast. They cost about 50 quid and I don't even have a meter to test it with, so I was thinking I could just leave the fan on for now until I felt like trying to sort it out properly.

[MattF]

Personally, I'd have it running all the time if I were in your position. Extra
cooling of the rad ain't gonna hurt diddley, whereas insufficient cooling,
well, need I say more. Unplug the sensor, I would.

















Go on, you know you want to.

[MattF]

If the electric fan didn't come on with the guage in the red I reckon it's u/s!

FYI I've got a 16" pacet fan, just fitted a new rad (old one was rusted away) and a new auxiallary ATF cooler. System is running sweet as now. Even a long steep hill ascent in the recent heat wave only moves the needle a mm or so, then settles right back down as soon as the hill peaks. Before, the saem hill was taking me 3/4 the way along the gauge. When sat at traffic lights, you can see the temp gauge drop to below what was my previous normal!

Is that instead of, rather than in addition to, the viscous fan? Any pics of
it installed?

[Big Jonah]

Is that instead of, rather than in addition to, the viscous fan? Any pics of
it installed?

No, that is instead of. Means I can switch the fan temporarily off when wading/playing in the mud...

Will try to get some pics.

Back to the main thread though -

If you are that worried about overheating, then it wouldn't hurt to have the fan on all the time. One new electric fan £40.00. One new cylinder head £800

If you've got the time (and can be bothered!) it wouldn't hurt to take the rad out to give it a damn good clean. It not hard to get out, and it's quite supprising how much Sh!t£ lurks behind the chassis cross member, aux fan and cowling etc! I should know, even after 4 jet washes I couldn't believe how much was still caked in the fins from Salisbury earlier this year!

Definately worth doing a back flush on the cooling system, and the cab heater matrix (at the very least)

If the matrix is working well, can be switched on full blast when going up hill to take away quite a lot of extra heat out of the coolant. Just dissconnect the two hosses, and I think the outlet is the rifght size to push a standard garden hose onto. Leave for a few mins & voila!

[Sancho]

Personally, I'd have it running all the time if I were in your position. Extra
cooling of the rad ain't gonna hurt diddley, whereas insufficient cooling,
well, need I say more. Unplug the sensor, I would.

That's the spirit. I'm going to pull the bugger.

Incidentally, I noticed two things whilst dilligently trying to put more coolant in and chasing air around on Sunday:

1. My coolant is cloudy (a bit, when I lovingly squeeze the hoses and thank Mr Toyota for building his cooling system with the rad cap half way down).
2. No hot air comes out of the pointless heater at the back.

My understanding is that this could indicate one of two things. Either I still have air in there, in which case I am going to kill myself, or something, probably the rear foot warmer, is full of $hit. Is there an easy way to clear it out? Something about brake cables off a bike??

Whatever I do is just going to let the coolant out again isn't it? I don't have another decade to top it up one millilitre at a time. I have a bleed valve in the hose at the highest point in the system (up by the bulkhead), maybe I should try filling it through there????

[Sancho]

Back to the main thread though -

If you are that worried about overheating, then it wouldn't hurt to have the fan on all the time. One new electric fan £40.00. One new cylinder head £800

I know how much cylinder heads cost already that's why I get so funny about the temperature.

I'm going to throw money at it in the near future to sort it out properly. Until then I think I might be getting a $hit load of coolant, a brake cable, a pressure washer, a bit of hose pipe and more patience than I've ever possessed before....

[Big Jonah]

Where's your rad cap?!

Mine have always been on top of the rad....

Have you started the engine from cold with it off yet?

Not sure about the back heater matrix - I've striped mine out so don;t have that problem! the small bore pipes are renound for silting up with cr@p though.

[MattF]

Where's your rad cap?!

On the 2.4, the rad cap is on the 'stat housing on the block.

With regards to the rear matrix, whip the pipes off and keep flushing one
way then the other until the devil clears. Heater slide control on full heat,
obviously. Best way I have found of filling the cooling system is to get
a small funnel, pop it in and fill through that. You can't pour the coolant in
too quickly otherwise it will just flow over, so it maintains a nice steady
fill rate. Using that method, when I last flushed the system, probably only
needed topping up with two or three cupfuls over the next few days. It's
fast filling that causes most of the air locks.

[Big Jonah]

I'm sure my old 2.4 had a rad cap on the rad........

someone back me up - unless I'm going mad -

[Sancho]

I'm sure my old 2.4 had a rad cap on the rad........

someone back me up - unless I'm going mad -

Nope. You've totally lost your mind .

It's not actually half way down, but it isn't at the top. Which is just f'ing stupid.

[Gazbo]

anyone tried jacking up the front of the car before they fill it up?

[Chillitt]

if the pipes to the rear heater are really blocked, what you do is... where the pipes join to the short hoses to join the thermostat housing, use one of the hoses to take the rear heater out of the loop. then you can remove the solid pipes and take an airline/ brake cable inner whatever to them to un block em.i have got as far as the disconnect bit cos one of the hoses where it goes into the heater is split, one day i'll finish it..

[Sancho]

Ooh, take the back heater out of the loop sounds like a plan (i.e. easy). Which hoses? I'll probably plug a fuel line into the radiator if I don't get a picture.

[Gazbo]

these hoses, shortened then modified, could become a greta home for a veg oil heater? right in the place where the egr used to live?