Overheating............Again

I've came home from work to pick your brain.

My car has had an overheating issue for a little while now, I thought I had it sorted as the expansion tank was empty and thus allowing air into the system.

I had my car in having a fmic fitted and got it back the other day, since then my water temps are starting to pi55 me off.

The temps usually go to 205 oF or 96 oC, they used to be way lower than that especially on motorway runs. When I turn the ignition off the temps then go through the roof and the expansion tank starts gurgling. If I go to turn the gnition back on I get crazy readings of 240/260 oF.

I flushed and changed the coolant today thinking that would help but useless, it's still just as bad.

Can anyone give me any help as to what is wrong?

What rad cap do you have? If you turn the heaters on what happens?

What rad cap do you have? If you turn the heaters on what happens?

The rad cap is the standard one, as for the heaters they seam to be normal. they heat up etc. I always have the heating on when I'm driving. Even when I put it on full blast the temps still won't budge.

The temps will go crazy when you turn the ignition off, the pump isn't pumping water round

The temps will go crazy when you turn the ignition off, the pump isn't pumping water round

Cool bud so that's normal, Sound like a fooked rad to you?

Cool bud so that's normal, Sound like a fooked rad to you?

That would be my first thought as adding an FMIC will show up any problems with the cooling system. Check for cracks in the rad near the cap to begin with...

That would be my first thought as adding an FMIC will show up any problems with the cooling system. Check for cracks in the rad near the cap to begin with...

I'll have a look in the morning, to be honest I'd rather just say feck it and go for a new rad. Can you recommend any?

Your fmic is cutting air flow to the rad, so I'd expect slightly higher temps now. 96 sounds a tad high but not bad high. Don't forget the pressure in the system. As soon as that drops the temp will go up.

Your fmic is cutting air flow to the rad, so I'd expect slightly higher temps now. 96 sounds a tad high but not bad high. Don't forget the pressure in the system. As soon as that drops the temp will go up.

Is there anything that can be done to stop the expansion tank emptying out after every run though?

I'll have a look in the morning, to be honest I'd rather just say feck it and go for a new rad. Can you recommend any?

I'm using a Fluidyne one but I've heard of some other good ones recently that have a better shape. Can't remember the name right now though.

could be your stat mate might be worth changing it . Have you taken the big fan off the front of the engine to?

could be your stat mate might be worth changing it . Have you taken the big fan off the front of the engine to?

No mate not removed a thing. How do you check the stat if you don't mind me asking?

Take it out and boil a kettle mate. The activation temp may well be marked on the body.

only way to properly test it is to remove it mate . also check you elec fan is kicking in as it sounds like it may not be if it's over heating ?

Stat should open at 86 deg c

Take it out and boil a kettle mate. The activation temp may well be marked on the body.

Mate you have lost me, forgot to mention I' totally useless

I don't even know where it is.

Gonna have to dash back to work, on till 3

Thanks for the help folks

Could well be just a doggie rad cap mate get yourself a new one asap that should sort it .

Usual suspects are air lock, thermostat (though im under the impression you wouldnt get hot air from the heaters if the thermostat was on the blink), failed water pump or knackered radiator.

So is the standard gauge going into the red and the coolant boiling over?

96°C is not that high, the fluid is under pressure so will boil over quite a bit higher than that normally. If your radiator cap is not holding the pressure though the fluid will boil over at a lower temp. A new radiator cap is cheap, so worth trying that first, if you do fit a new one make sure the area where the seal sits is clean.

Hi Nic

The standard gauge in the cluster just stays in the half way position rarely ever moving. on the way back to work tonight I was getting a reading of 210oF or roughly 99oC.

Don't know why but I just assumed that the rad had died and stopped shedding heat, I'm gonna get hold of a new cap 1st thing tomorrow and se how it goes from there.

If the stock gauge is not going into the red, you are worrying about nothing, it is perfectly normal. Remove the aftermarket water temp gauge it's making you paranoid

LOL

It is actually, I've been spending more time reading that than looking on the road.

The other thing that concerns me is the gurgling and rapid loss of coolant in the expansion tank?

Have you put a brand new rad cap on it yet?

Where is the aftermarket sensor mounted ?

Have you put a brand new rad cap on it yet?

Not yet, I'll need to phone Steve Manley Tomorrow as Toyota up here don't stock anything for the Supra, and the one TMS stock doesn't fit.

Where is the aftermarket sensor mounted ?

The sensor is in the top rad pipe mate, the pipes being renewed with a Greddy one shortly.

Any motor spares place such as Halfords will stock a rad cap that will fit.