Overheating problem, what can it be?

Saturday was the hottest day of the year, went for a 15 min drive with the missus and everyting was fine. Popped to the post office, came out and she was sat in the drivers seat so drove me home. When we stopped steam started coming out the bonnet. I leaned over and looked at the temp guage, it was in the red.

Popped the bonnet, steam was coming from the overflow pipe and I could hear the coolant was boiling in the rad!

Left it to cool down, opened the bonnet in the evening and opened the rad, couldn't see the coolant the level was so low but as it was boiling it was spitting out the over flow and there was a puddle on the floor so I blamed that for the level being low. I had planned to change the coolant anyway as I am fitting a shiney top pipe. Topped it up with distilled water to test. Started the engine with the rad cap off and all was fine. Revved the engine and the level changed so it is going round the block. Went for a drive and temp guage is fine, all now seems fine.

What could have caused the problem and how has it fixed itself?

I will of course drain the rad and fill with coolant this weekend.

I'll wager its the rad cap failed.

Thats what I thought, but it now seems to be ok. Could it just have been that the seal was not seated right at the time? Would that really cause it to spit out the overflow, wouldn't it have come out the rad cap hole?

Put a new rad cap and thermostat in it and hope. Pressure test the system to see if has any leaks, a weep from the water pump gland can be hard to spot until it becomes chronic. At least if she was driving she pays....

Put a new rad cap and thermostat in it and hope. Pressure test the system to see if has any leaks, a weep from the water pump gland can be hard to spot until it becomes chronic. At least if she was driving she pays....

haha. I will put that one to her and see what she says.

How do you pressure test the system?

Should I bother testing the stat or just chage it? I am guessing you can test them the same as bike stats by dropping them in boiling water and seeing if they open?

Change both for genuine Toyota parts. You pressure test with an adaptor and pressure gauge connected to a glorified bicycle pump. The adaptor takes the place of the rad cap. Most garages will have one. Should hold 15 PSI for 30 minutes. Don't blame me if the heater matrix goes though, they are old and can corrode and burst.

When the rad cap fails it just dumps all the water in to the expansion bottle which then dumps it on the road.

I ran my first supra out of water on a track day due to a failed rad cap. Engine survived a length period without water so mostly they can take a bit of abuse.

You let the wife drive. What did you think would happen

Car was falling out with you.

You let the wife drive. What did you think would happen

Car was falling out with you.

Hahaha. Well I will buy it a nice new stat and rad cap, hopefully that will make it all ok again. Seems ok anyway, must have run through a puddle of magic or something.

Are rad caps and stats in stock at toyota i.e. are they generic toyota parts. Or do I need to order?

Toyota have quoted for £40 for a new stat and rad cap.....does that seem about right? there are loads of different ones on ebay that seem to be £10 for cap and £10 for stat, so pretty much half price

For the sake of saving £20 I would go with Toyota just for piece of mind. They aren't expensive items so the £10 each ones on ebay might in fact be genuine, not worth the risk though.

Remember not to change your coolant before the stat. You don't want to lose all the fresh coolant you just put in there

For the sake of saving £20 I would go with Toyota just for piece of mind. They aren't expensive items so the £10 each ones on ebay might in fact be genuine, not worth the risk though.

 

Remember not to change your coolant before the stat. You don't want to lose all the fresh coolant you just put in there

Haha, yeah good point. I will change the stat first.

Is it a big job to get the old one out? I understand it is down the bottom of the rad instead of the usual place up top.

oh, one other thing. Are UK spec the same as J-spec. The toyota garage would only quote me for UK parts. Typical Mr.T.

Chris, do you have these parts in by the way? might be cheaper to get them delivered from you maybe?

Haha, yeah good point. I will change the stat first.

 

Is it a big job to get the old one out? I understand it is down the bottom of the rad instead of the usual place up top.

bottom rad hose, follow it to the block....its in the alloy water neck....iirc 2 10mm or 12mm nuts and its off. It has a gasket on there too so change that as well.

bottom rad hose, follow it to the block....its in the alloy water neck....iirc 2 10mm or 12mm nuts and its off. It has a gasket on there too so change that as well.

Thanks keron.

UK the same as J-spec?

I have them both in stock. E-mail me if you want a delivered price and I'll check it out, cheers.

Sorry a bit late in the day, but my Soop suffered this about six months ago. It was a faulty rad cap. I can't remember the exact wording (it's on the repair form of my local garage) but something about it being unable to build pressure properly. He only charged me £27.

D

Over heated again last night....missus was driving again! maybe it just doesn't like her at the wheel!

Got a new cap, stat, gasket and 10L of Toyota 4Life red coolant ordered from Mr.T, picking up tomorrow at 9am and hopefully sorting this out!

Going to change the stat today, had a quick look from the top and the bottom rad pipe is hardly visible.... Is it easy to get to the stat from under the car? The standard under tray is there and the active spoiler