Boiling over. Help please.

[SimonT]

I really hope someone can help with this as I am at my wits end with my Gen3 3 litre TD KZN185 Surf.
This is a long one so here goes. I got the Surf a couple of months ago and it was in need of a new bumper and valance. Unfortuanately I didn't realise the head was cracked. A mechanic I have used regularly sourced me a new non genuine head with reconditioned cam, valves headbolts and gaskets etc. This was fitted and the thermostat replaced. All at great expense but I thought the vehicle is to good to not repair. After running it for two day we found that the fuel pump was not working properly so a lift pump was fitted.
Now the big problem. When I first got the vehicle back I read that I should leave it over night for the engine to cool down and check the coolant level when cold. The following morning I noticed that the level in the expansion tank was at full but when I looked in the radiator I could not see any water/coolant so I topped it up. I took it for a run and I noticed that the coolant was well above the F mark in the expansion tank but it was not cominig out of the cap. I was told by a couple of mechanics that when cold it woul drop down but it didn't. For three weeks the car ran great and emissions were really low and there was no smoke from the exhaust. I then took the car for a longer run, about 60 miles and I got stuck in a slow moving jam for about 25 minutes. The temp gauge stayed just below half as usual, until I accelerated off where it went up to above 3/4's. I pulled over and the gauge dropped back down and when I lifted the bonnet I noticed coolant had been forced out of the expansion tank. I limped all the way home ensuring the car did not go in the red and the gauge moved up and down contstantly and just touched the red for about 10 seconds and went back down. She seems worse under load. The following day I noticed that for the first time the level in the expansion tank had sropped over night. I then checked the radiator and once again could not see coolant in the radiator. I took her for a run and the gauge stayed still but coolant still came out of the expansion tank. I did the same run the following day without topping up and the gauge went up to just below the red. Since then the coolant has been dropped and another new cooler therostat has been fitted and still the same problem. I can take the expansion tank cap off and touch the coolant after the temp has almost been in the red and it it hot but not unbearable.
Sorry for the realy long post everybody but I am really fed up now and the latest info I am now getting is the block could be cracked.
Please help as I can no longer afford to throw that sort of money at my Surf.
Thanks in advance Simon.
PS sorry for any spelling errors my keyboard is not working properly and I can't delete or insert.

[BUSHWHACKER]

Sounds like you need a new rad cap.
When hot, the coolant 'expands' into the expansion tank and is then 'sucked' back into the engine/radiator as the engine cools. If the cooling system isn't sealed (airtight) the coolant will just stay in the expansion tank and then be topped up the next time you use the truck resulting in lost coolant as it will be lost out the overflow.

Re-new the rad cap and check all the coolant system hoses are secure and not dripping, 'cos if coolant can escape, then air can be drawn in too.

Check the condition of the rad as well.

Also, after a run, remove the rad cap (carefully) and leave it off. When the engine has cooled, top up the coolant and leave the cap off overnight if possible so that any air in the system can escape.

[SimonT]

Sounds like you need a new rad cap.
When hot, the coolant 'expands' into the expansion tank and is then 'sucked' back into the engine/radiator as the engine cools. If the cooling system isn't sealed (airtight) the coolant will just stay in the expansion tank and then be topped up the next time you use the truck resulting in lost coolant as it will be lost out the overflow.

Re-new the rad cap and check all the coolant system hoses are secure and not dripping, 'cos if coolant can escape, then air can be drawn in too.

Check the condition of the rad as well.

Also, after a run, remove the rad cap (carefully) and leave it off. When the engine has cooled, top up the coolant and leave the cap off overnight if possible so that any air in the system can escape.

Thanks Vince.
I take it this will cause the engine to run hotter as well. There is no smoke and she runs really sweet and has only done three hundred miles on the new head. Do I need to buy a genuine rad cap or can I get a one from my local parts supplier and does it need to be a certain pressure rating?
I just hope I have not done any damage to it. Are the blocks cast, because a mate back in England reckons that the people up here are talking rubbish to even suggest a cracked cast block. I take it my fan will be viscous? Sorry for all the questions.

Cheers, Simon

[SimonT]

A really dumb question from a really dumb person. Do I top up through the rad or expansion tank and is it the rad cap I leave off overnight or expansion cap and just run her to temperature. Sorry for all the questions.

Simon.

[stormforce]

A really dumb question from a really dumb person. Do I top up through the rad or expansion tank and is it the rad cap I leave off overnight or expansion cap and just run her to temperature. Sorry for all the questions.

Simon.

always fill up via the rad

[SimonT]

Spoke to my nearest Toyota dealers and they really have made me feel much better, not. One said the new head must have failed and the other reckons the blocks cracked. I have ordered a new rad cap but I really am worried now.

Cheers, Simon.

[SimonT]

Ordered my rad cap and I'm going to try and Burp the coolant system as well, although I am not 100% sure how to. My mate has also suggested that the heater matrix switch could be at fault.

Simon.

[stormforce]

Ordered my rad cap and I'm going to try and Burp the coolant system as well, although I am not 100% sure how to. My mate has also suggested that the heater matrix switch could be at fault.

Simon.

i would also change the thermostat at the same time.

have all heaters set to hot and full blastrad cap off and start the engine then keep topping up the rad until all the air bubbles have sopped and you cant get no more water in.Put cap on and take for a spin.Allow to cool and check levels again and if needed top up again as before.
If you can leave the rad cap off over night and that way any air left can escape also.Put the rad cap on the drivers seat tho so you don't forget to put it on again in the morning

[Tallyman]

First thing, when you top up the coolant, make sure that both (if you have separate rear heater) taps are fully open (i.e. on hot). If possible park the car so that the front is higher than the bacxk, so any air in the system will move to the highest point, which you want to be the rad cap. Run the engine with the rad cap off until it starts to get warm and watch the level. Top up through the rad cap hole with coolant until the level is just at the base of the rad cap opening. Once it starts to get hot put the rad cap on an turn tight.

Check the level in the expansion bottle. Make sure it's no higher than the Min mark on the bottle. Also make sure the base of the rubber tube from the rad cap overflow is below the top of the water in the expansion bottle.

Once you've done that, take it for a run around the local area, so you're not too far from home if it does overflow.

Also make sure your viscous fan is working properly. To check, get the car up to normal working temp, then stop and gently rev the engine for a bit so that the only airflow through the rad is from the fan. If it's working properly, the fan should kick in when the temp rises and you should hear it roar until the temp drops back again. If not, it may need topping up with silicon oil.

[BUSHWHACKER]

i would also change the thermostat at the same time.

have all heaters set to hot and full blastrad cap off and start the engine then keep topping up the rad until all the air bubbles have sopped and you cant get no more water in.Put cap on and take for a spin.Allow to cool and check levels again and if needed top up again as before.
If you can leave the rad cap off over night and that way any air left can escape also.Put the rad cap on the drivers seat tho so you don't forget to put it on again in the morning

Slartybartfast.

[SimonT]

Cheers for the advice. The thermostat has been changed and it still does the same. My missus remembers me turning the rear fan on in the back and pushing the lever to the left, cool to blow some air in to the back for the children the day all the problems started. I think this was the first time the rear heater had ever been used since the new head was fitted. I also don't think the mechanic switched this heater to hot and turned it on when he filled the cooling system.
What is the significance of having the heaters on an on hot when filling and also if the block was cracked wouldn't this have shown the first time the car was run to temperature after the new head was fitted! Up until last friday the car ran perfectly for almost three weeks with no boiling over.
Once again thanks for all your help.
What makes it worse is I am now having to use my dads Frontera lwb petrol which won't pull the skin off a rice pudding.

Cheers, Simon.

[Tallyman]

Having all the heaters on hot opens all the waterways, so that the water can fill and flow everywhere it's supposed to go. Could be if the mechanic who fitted the head didn't open the heaters when refilling then there would have been a big airlock in the heater pipes, because they would have drained down when he emptied the water jacket.

With the taps closed, the water would have only got so far and then the air pressure would have held it back. OK until you put on the heat for the kids, when all that air would have escaped to the top of the system. If there was that much it could have dropped the level sufficient to stop it circulating properly, thereby causing the engine to heat up too much.

Commiserations on the Frontera. I looked at one when I was buying my Surf but was put off it, despite being around £1500 cheaper, by the fact the previous owners had carried dogs in the car and there were hairs and that wet dog smell in it. Obviously a lucky escape.

[SimonT]

Having all the heaters on hot opens all the waterways, so that the water can fill and flow everywhere it's supposed to go. Could be if the mechanic who fitted the head didn't open the heaters when refilling then there would have been a big airlock in the heater pipes, because they would have drained down when he emptied the water jacket.

With the taps closed, the water would have only got so far and then the air pressure would have held it back. OK until you put on the heat for the kids, when all that air would have escaped to the top of the system. If there was that much it could have dropped the level sufficient to stop it circulating properly, thereby causing the engine to heat up too much.

Commiserations on the Frontera. I looked at one when I was buying my Surf but was put off it, despite being around £1500 cheaper, by the fact the previous owners had carried dogs in the car and there were hairs and that wet dog smell in it. Obviously a lucky escape.

Thanks for the advice Mike. The Frontera isn't all bad as my dad only paid a grand and it is LPG. It is absolutely gutless though. I hope to get the rad cap on monday and I am going to drain the cooling system and start again hopefully this will help sort it out. I may even get the heater matrix switch looked at and a new sensor as well. Hopefully I can get her back running, with all the initial problems I had begun to hate the Surf but for the three weeks it worked okay I really began to love driving and owning it. At the moment I am at the seperate beds stage with it.

Cheers, Simon.

Cheers, Simon

[fatfires]

Slartybartfast.

Eh?

[SimonT]

New cap, burped system and still overheating. See burping system thread for more details. I am going for a cry into my horlicks now.

Cheers, Simon.