Overheating

[madder]

Thanks for all the help and suggestions :-)

[madder]

You're not gonna believe this. There is now a new leak. This time in my radiator top hose. Pinhole size. I have tried to close it temporarily with Duct Tape but it didn't work. Probably because the hole is on the area of the tube where it curves close to where it meets the engine. I couldn't close the DUCT tape tightly and perfectly around the hose because of the curve.

Obviously the best thing to do is to get myself a new top hose, but it could be days or even a week before I can get one? Unless anyone knows where I might find one in Dublin?

The Radweld Plus obviously wasn't able to find this hole? Or maybe I didn't run the car for long enough, but with a spray of water/coolant coming out, running the car doesn't seem like a great idea? So I'm grounded again until I get a new top hose. :-(

[Jack Taylor]

To be honest if I was you I would ask a Toyota dealer to see if they have the hose and then me personally would also get a nice new rad as well to make sure that the whole thing is sealed. I have never been a fan of these temporary rad fixes as they often just start leaking again about 5 months later and can clog of the small water paths in the head of the engine.

jack

[KPARRIS-JONES]

If you have steam coming from the top of the Radiator yet you aren't overheating then the Radiator is just leaky and does need replacing.

Check to see if it overheats again, if the gauge whips right up to the top and I'm talking within a couple of seconds (not a couple of seconds of driving I mean just randomly it's fine and then shoots up) then you also have an air lock you will need to clean out.

KP

[madder]

I tried to get a hose from toyota in Dublin and none of them have it. I have to order it in. However, I found a bit of a miracle cure again. Rescue Tape. Google and youtube this stuff. I'm well impressed. It fixed the leak in the hose. Absolutely no indication that the leak is thinking of returning yet either. It will probably last for an extremely long time but I aim to get the replacement hose anyway.

[madder]

Ok, so I'm still waiting for my hose to arrive from Toyota. The rescue tape is holding well. Problem now is that the temperature gauge started to rise slowly, heading for the red when I was driving the other day. The only way I could stop it was to blast the cars heater on up full. Then the temperature lowered to normal again. I checked under the bonnet and there seemed to be a lot of coolant thrown back into the expansion tank and it seemed very hot. I have driven the car a couple of times since then, and whenever the temperature starts to rise, I have to belt the heater on to keep it normal. It's baking me in the car. I have checked the fan in front of the radiator, which seems to be working. At least one of the times when I got out with the car running to have a look the fan was on. Perhaps the fan is only coming on when the heater is on? I haven' fully confirmed that yet.

I have also checked as much of the radiator as I can for cold spots when the car is running hot. I can't get in behind the fan but it seems to be hot on all the parts that I can touch. Maybe not the same exact temperature, but most definitely hot. I can't keep my hand on it for too long.

I have noticed too that the top hose, and the hose going from the radiator cap to the expansion tank are getting very hot too. It seems to me that the coolant might be boiling. The leak in the top hose is absolutely sealed at the moment with the silicon rescue tape and it shows no signs of leaking.

Even after a short drive of say 20 minutes, when I open the bonnet, it just gives a sensation of heat. So it really must be the coolant boiling? But why? And what can I do to fix it?

[petroleum]

Like i originally stated if it turns out it is a consatnt fault your head might need fixing might need skiming!

[madder]

Thanks for the reply petroleum. We have more or less ruled out head problems. No white smoke and no oil in the coolant. We're thinking either a partial blockage somewhere in the cooling system or perhaps a faulty radiator cap.

I remember one of the many times I was topping up the radiator and expansion tank recently with the coolant, and as the radiator filled there was some radweld at the top of the coolant just where the cap goes? Could this have slipped into the hose between cap and expansion tank and caused a partial blockage and is there an easy way to find out or test it?

Anyway, I'd say one of these 2 things is the problem. I just have to hope that if there is a partial blockage that it's not in the radiator or somewhere hard to get at in the cooling system.

[madder]

Just finally in case this can help to confirm something one way or another. I've gone out and started the car. As soon as the engine heated up to normal level I checked the top hose for heat arriving rapidly and the radiator for constant heat and both were fine. This probably eliminates the thermostat. Upon startup there may have been a very tiny amount of bright-ish, smoke, only not in a continuous flow, just occasional. And after a few minutes the exhaust fume gave no colour. I waited for the temperature gauge to rise and when it did start rising I took a close look at the radiator, coolant expansion tank and hoses. No leaks but it was at this point exactly that the coolant starts to suck back into the expansion tank. Not aggressively, just pouring back in slowly, but continuously. I was able to open the expansion tank and see it flowing back in. Once I put the in car heater on, the expansion tank seems to slow down with the coolant sucking. And the temperature gauge starts to fall until it stays somewhere near the half way mark. That's all I can report.

If it is a block in the radiator, would a flush work? Or is it a replacement that's needed?

[petroleum]

It does seem that these cars suffer later on in their lives having radiators replaced If the water was very rusty looking before all this trouble could be the core was on its way out anyway!

Its a pity you cant take the thermostat out and see if the temperature falls a lot lower but if it continuse to carry on until near boiling point its either the rad blocked like you say or maybe a warped head after all the over heating

[madder]

Thanks Petroleum. I guess I need to have the system flushed for starters. Don't think I could do it myself, and doubt I have the right location to do it myself anyway. Is it costly to have the system flushed and have the coolant refilled?

[petroleum]

All yer got do is get some rad flush from a motor factor or from Halfords and do it yer self and the cost of a new thermostat woudent be much either

Sounds like me, hate having to pay out if you can avoid it!

[madder]

Yeah, you've got me in one! It can be pricey enough maintaining and running a car at all, especially an older one! But at the same time, it's really difficult to find a newer car as reliable and sturdy as the carinas! I'm handy enough at learning stuff like this, and if I could do it myself at all, I would usually try to. But I don't really have an area that I can jack the car up freely and release the coolant from the radiator, or to flush the rad. I was thinking too that if I flush the rad, it may clear any potential blockage but it will probably remove and of the radweld filling also, and I'd be back to a leak. So do I flush, fix the leak with radweld again and hope it doesn't block something else again, or do I just try to get a replacement rad from the breakers? It might be time to just go and do that. Thanks for the advice and suggestions though. You've been helpful.