Over Heating Ideas? Urgent help needed.

Evening all I'm going to try keep this as simple as possible but if someone can help it would be great.

While on Dragonball my cars temperature would increase to above half when going over 65mph. (its an NA)

What I have seen is the temperature is getting far to hot and the pressure in the system seems high, as the hoses feel firm. The rad also seems to be filling the expansion bottle.

It has also sucked the top rad hose inwards a couple of times after use as well.

On the last day of dragonball I put a new rad cap on and this did not resolve the problem.

Yesterday when running the car all the above was happening, but the lower rad hose was cool, thought it could be the thermostat stuck shut so I have removed it, and am now temporaryly driving around with no thermostat, but the problem is continuing. But the fluid levels seem ok today and no sucking in yet, but pressure is still building and getting hot.

I have the rad/coolant tested today to see if there is any hydrocarbons in it and it was reading zero so hopefully its not the head gasket.

Also checked the viscous fan and this is working fine so its not that either.

So the only thing can I think of now is

-Blocked rad?

-Water pump?

-Air lock?

Any one else got any ideas? also is there any bleed nipples hidden anywhere to bleed the system if not then i cant see it being an air lock.

Any help MUCH appreciated.

good job it's not a mk3 - would be BHG

if the bottom hose is cool sounds like a blockage somewhere. on my Cortina it was a case of remove the hoses from the rad and insert hose pipe and flush the system...

My truck used to overheat like this but only over 60mph or when towing, after replacing the thermostat and waterpump which didn't help I put on a new rad and this cured it.

Your rad is full of debris....could also be leaves etc between your aircon rad and your coolant rad.....also, check that your viscous clutch in your fan is up to the job mate.

There aren't any coolant bleed valves on the supra. Allegedly, it's self-bleeding.

So, you said the overheating problem persists even when the thermostat is removed? That's unusual. Usually removing the 'stat makes a car run cold such that it never reaches normal operating temperature.

That, and coupled with the fact the overheating got worse above 60mph might suggest a tired/blocked radiator. The supra's longitudinal engine probably means the cooling effect of travelling at speed isn't enough to overcome the extra heat that driving at speed usually generates. Does the rad fan spin OK?

Probably not an airlock as that wouldn't be speed-dependent.

the only other tiome i saw this and it was gthe heater matrix that was blocked. get a regulated pressure line and bolw through the two hose at the bulkhead. build pressure gently and feel the other hose to see if it passing through at the same rate. you would be amazed at the crap that comes out of them

the only other tiome i saw this and it was gthe heater matrix that was blocked. get a regulated pressure line and bolw through the two hose at the bulkhead. build pressure gently and feel the other hose to see if it passing through at the same rate. you would be amazed at the crap that comes out of them

This is good advice and on my old NA it took loads of air followed by flushing to get rid of all the crap. Also, I know there are much more knowledgable people on here who say they do not suffer air locks and no special method of filling is required, but on mine, if I didnt park it so the filler cap was at the highest position in water system, I always suffered air locks and pressurisation. I found the best method was to park it on a hill with the filler cap up high, fill it with coolant and let it come up to temperature at tick over while constantly topping up the coolant. The switching off and letting it cool down again and then from cold toping up again. Due to a few problems I was having with mine at the time I had to drain the coolant several times and only this method only worked for me.

I've had a lot of fun with My NA and overheating over the years. First I had a faulty Rad Cap, then a buggered Water Pump and not I have a Blown Head Gasket lovely. So I'll be throwing a new engine in there now and hopefully won't have to do it all again.

Thankyou everyone for your input, I'm going to get some flush and clean the rad out and flush the system if this doesn't work I will try the heater matrix trick and if thats no good i shall, get a new water pump and rad.

This happened to mine just before dragonball, the water pump went which fried the headgasket (why i drove the corsa) so i would check the water pump as soon as you can

This happened to mine just before dragonball, the water pump went which fried the headgasket (why i drove the corsa) so i would check the water pump as soon as you can

Really, did you run it on high temp causing the blown HG?

i was driving home from work didn't even notice the temp got to the petrol station to fill up when i noticed steam coming from the engine bay thats when i seen the temp was high but it was running normal, i have changed the head gasket just waiting for the new water pump to arrive, do you know whats up with yours yet?

Jake you should know it was overheating because it's N/A and doing over 60, that's far to fast, plus being off the Island you did more than 10 miles

Seriously though follow the advice above starting with flush throughs. Did you change your rad cap whilst blinging the bay? If so try putting the old cap back on. If the problem continues give me a shout and I'll pop over and give you what help I can. Hope it's an easy fix buddy.

i was driving home from work didn't even notice the temp got to the petrol station to fill up when i noticed steam coming from the engine bay thats when i seen the temp was high but it was running normal, i have changed the head gasket just waiting for the new water pump to arrive, do you know whats up with yours yet?

Same reason my HG went. Except water pump was fine.

Same reason my HG went. Except water pump was fine.

Its a pain isn't it, how much did it cost you to sort yours out just out of interest ?

If it's vacuuming in the hose the one way valve in the rad cap is shot, buy it a new GENUINE cap.

If it's vacuuming in the hose the one way valve in the rad cap is shot, buy it a new GENUINE cap.

It doesnt always do this, it has had a new one fitted but it is a TRD one, going to Toyota on monday i shall get a new OEM one and see.

I yesterday took the rad hoses off and washed it though also used rad flush on the whole system but with no sucess. Will get a new oem cap asap as its suposed to be going in to the garage on monday. for some checks.

And cheers for the offer adam, i may well take you up on it if i need a hand

If it's not the cap, which sounds likely as it has a new one, then look at the hose from the side of the cap to the reservoir, and the dip hose IN the reservoir, sounds like it's bunged up, it needs to be totally clear. When the engine cools it sucks water back from the reserve in the reservoir that's blown past the cap as the hot water in the engine / rad expands. if it can't suck it back the hoses collapse under the vacuum.

Its a pain isn't it, how much did it cost you to sort yours out just out of interest ?

I'm getting a new engine put in the car £600 in total.

If it's not the cap, which sounds likely as it has a new one, then look at the hose from the side of the cap to the reservoir, and the dip hose IN the reservoir, sounds like it's bunged up, it needs to be totally clear. When the engine cools it sucks water back from the reserve in the reservoir that's blown past the cap as the hot water in the engine / rad expands. if it can't suck it back the hoses collapse under the vacuum.

the hose turned out to be clear, so its not that but its not vacuming now so maybe there was a slight blockage, the heating up hasnt stoped though, and the rad is still pumping water into the expansion bottle. hopefully should know what it is tomorrow.

right the car has a perfect water pump so starting to become a little stumped, but i need a vicous fan apprently would any one think that this would be the issue with the results described?

or in your opinion would there be somthing else wrong too?

The car is no longer vacumming since the new cap, flushed system and cleared pipe, but it is heating up and the water(coolant)/ hot air is being pumped into the expansion tank, causing a bubling. If i remove the expansion cap lid, it hiss's hot air and little spurts of water come out. It can not be the water pump as it has bee strpped down and looks fine, its not the thermostsat as there is no longer one fitted, but the fan is apparently not working to full ificancy.

right the car has a perfect water pump so starting to become a little stumped, but i need a vicous fan apprently would any one think that this would be the issue with the results described?

 

or in your opinion would there be somthing else wrong too?

 

The car is no longer vacumming since the new cap, flushed system and cleared pipe, but it is heating up and the water(coolant)/ hot air is being pumped into the expansion tank, causing a bubling. If i remove the expansion cap lid, it hiss's hot air and little spurts of water come out. It can not be the water pump as it has bee strpped down and looks fine, its not the thermostsat as there is no longer one fitted, but the fan is apparently not working to full ificancy.

Sorry dude but with no thermostat in, even with no fan it should take quite a long time to start overheating and if on the move I would have said even with no fan it will never even get up to temperature let alon overheat without a stat. I am guessing that it is overheating quite quickly?

Possibility of a BHG? Have you checked the oil dipstick for white residue/build up?

Possibility of a BHG? Have you checked the oil dipstick for white residue/build up?

Although not 100% conclusive, in his first post he says he has had a sniff test carried out so unlikely to be HG.

no its taking a while to over heat but it doesnt take long for the expansion tank to start filling up. have ordered a new thermostat,water pump, and fan, so we shall see as after talking to keron he made it sounds like water pump issues. i shall update accordinly.