Outer Limits 4x4 Board

trying to drain and flush cool sys on 86 4runner, how much heat does it take to open a thermostat...? 10 mins of running hasn't opened it up, assuming thats whats stopping the rest of the water from the block flowing out.. Does it need a little bit of a hard run get up to op. temp? Does the thermo have enough seal to hold the block water in?? And 10litres in a 2.4 diesel sound about right- I think it sounds like heaps...?!

ta.

The stat will start to open aroun 94deg? there is a small hole in the stat called a jiggle valve its about 4mm round, it will let a small amount of water through but no enough to flush it, the valve is to let air past. U could put some carboard infront to stop the air flow which would make it heat up faster but the best way is to take it for a drive for half an hour, get her hot and working, the more heat u get and the faster the water pump is pumping the better results u will get. 10L cooling system is a good number to use when working on most large cars and 4x4s

If the thermostat is working properly it shouldn't take anything like half an hour to open up, even ten minutes is a lot. The whole idea of a thermostat is that it works to help the car get to operating temperature faster.

Depending on how difficult this is on your particular vehicle, I'd consider taking the thermostat right out, flushing the block (with a hose and no radiator in place) and then putting it all back together with a new thermostat. They are only cheap.

Also, even when fully open they block coolant flow a fair bit.

Jason

Im not 100per cent on how much coolant a 2.4 would hold Ash, But have you drained the block also? there is normally a block drain and it will still be holding a fair amount of coolant.
May be an idea to drain it too...my 2 cent anyhow.

Regards

Daniels

okay, thats not really working, I don't have the opportunity to have a decent drive, so a few laps of the block in 1st haven't cracked 'er open yet...

Is there a cheats way to get it open and flowing? Can I just remove it and let the water flow back out the bottom pipe? The problem is that the water won't flow back out becuase the thermo is holding it there right??? If I pull the thermostat, doesn't that solve the hydraulicing problem (I have no idea) or is it more involved than that. Surely a mechanic doesn't have to flog the guts out of a car to do a coolant change...?!

sorry, didn't see the other posts.

whats this about a block drain?? Have't seen one, but would love to

What does the car temp gauge show?? Remember that a temp sender only registers coolant temp, so if there is a air pocket round it it will not register anything. Possibly an air lock in the cooling system??
Layto....

ash_on_mtb wrote:sorry, didn't see the other posts.

whats this about a block drain?? Have't seen one, but would love to

Yeah Ash, there is a block drain point on ..well most engines I can think of- 12ht ( L/H side below the turbo, TD 42 L/H side bottom back corner of block ...etc )

Im note sure were it is exactly on 2.4L , but there should be one.

any chance that the block drain plug is reverse threaded??? I'm buggered if I can get it out...!

BTW, found the block drain, thanks for the tip.

What a saga for some coolant,

ash_on_mtb wrote:any chance that the block drain plug is reverse threaded??? I'm buggered if I can get it out...!

BTW, found the block drain, thanks for the tip.

What a saga for some coolant,

Wouldnt think so Ash, might just have not been removed for some time.

Glad to have helped.

Daniels

ash_on_mtb wrote:okay, thats not really working, I don't have the opportunity to have a decent drive, so a few laps of the block in 1st haven't cracked 'er open yet...

Is there a cheats way to get it open and flowing? Can I just remove it and let the water flow back out the bottom pipe? The problem is that the water won't flow back out becuase the thermo is holding it there right??? If I pull the thermostat, doesn't that solve the hydraulicing problem (I have no idea) or is it more involved than that. Surely a mechanic doesn't have to flog the guts out of a car to do a coolant change...?!

Ash,

Pull both top and bottom hoses. Open the block drain, and free it up with some wire if it's crudded-up. Pull T-stat. TURN HEATER TO HOT.

You must pull the T-stat as it will close up as soon as you go to flush the system with cold water.

Get into the rad and water jacket with the hose. Flush them both, in both directions. Depending on the system, it also helps to pull a heater hose off the waterpump and flush the heater directly.

Fit new hoses and T-stat (keep old ones as spares) after brushing any corrosion off the connections. Fill the system as per your manual, using any bleeding processes therein.

Don't be tempted to use silicone or the like to seal the hoses to the connections. It actually makes it easier to blow a hose off.

Check your thermostat by using the boiling water method first. Just suspend it in a pot on the stove, making sure it doesn't touch the sides. As the temp rises closer to boiling it should open. If it gets to boiling and it is still closed then your thermostat is stuffed (it does happen even to new ones)

Air will always get trapped in the highest point so if your heater core or tap is above your radiator top tank take of the highest hose while filling up. If your using a hose it should force water/coolant out one end first, cover this end until it flows out the other side (making sure heater tap is on) and the slide hose back into place.

Hope it helps.

Check your thermostat by using the boiling water method first. Just suspend it in a pot on the stove, making sure it doesn't touch the sides. As the temp rises closer to boiling it should open. If it gets to boiling and it is still closed then your thermostat is stuffed (it does happen even to new ones)

Air will always get trapped in the highest point so if your heater core or tap is above your radiator top tank take of the highest hose while filling up. If your using a hose it should force water/coolant out one end first, cover this end until it flows out the other side (making sure heater tap is on) and the slide hose back into place.

Hope it helps.