Overheating issues - Help.

[easty-5]

Car is being a pain in the ar$e. It is overheating on long journeys. When it does it, I let it cool down, open up the radiator bled valve let air out, and top up with water. It lasted about 10 miles before doing ot again, so I done the same again and this time it lasted me about 150miles of motorway driving. During those 150miles the heater was occasionally going cold and the temp gauge would start to rise, but then it would go hot again and the temp would come back down.

What's everyones opinion on this? I think it is an air lock, or should I say, I hope it is just an airlock. I am going to jack the back o the car up tonight and flush the coolant and bleed at the radiator and heater matrix.

Is the anything else that I should do?

[Si_Crewe]

You can buy a chemical gizmo from Halfords that can detect whether the coolant is contaminated, indicating a dodgy head gasket.
It looks like a big cork with a thermometer stuck in it.
You remove your header tank cap, jam the cork in there and run the car. if the tube turns a different colour (I forget what, exactly. It's ages since I used one) it means you have a leaky head gasket.

If the head gasket is leaking very slightly it can pressurise the coolant system and cause all sorts of odd faults.

*EDIT*
A bit of googling turned this up: http://www.arrowheadradiator.com/head_g ... k_test.htm

Should help explain it if you want to buy one.

[Quigonjay]

is this just while cruising?

[easty-5]

is this just while cruising?

Yip, just at a steady 70/80. It had been fine for daily driving, just doesn't seem to like driving at motorway speeds for any lengthy period of time.

[Quigonjay]

i wouldnt worry just yet then, does sound like an air blockage/flow issue

[easty-5]

That's what I am hoping as I have taken it for a few spirited cou try roads blasts over the weekend and it had been fine. Flushed through the system tonight, topped up with boiling water so the thermostat open ands circulates properly, bled off at the radiator and heater matrix then topped up again with antifreeze and took it for a blast to get it up to temp. Will wait and see if it needs topped up once it's cooled down.

[Heiko-mr2]

I have had a similar problem on my 93 rev2 turbo.

Every time I made a longer journey the car starts to overheat.
After topping up the coolant it was fine for sometimes 1k miles...

Turns out, that my waterlines to the turbo have had a minor crack.
Very small crack, so coolant was only expelled when the car was hot.
I noticed the crack only because of stains/spots of burn coolant on the water line.

[RENOFOXX]

had the same issues with my turbo !! ok on short runs but motorway cruising it would overheat and the heater would blow hot and cold.
I found that i had a leak in the copper heater pipes that run up behind the the engine heat sheild and also a couple of rubber pipes that carry the coolant from the engine to the pipes that run under your car had rotted and were leaking a very small amount.You may not see any coolant loss until you take off the plastic undertray beneath your car which is why its hard to detect because it doesn't drip down to the floor.

[easty-5]

It had been fine on motorway runs up untill the coolant was changed. It got me from Bradford to Aberdeen without a hickup. And also a few runs to Stirling from Aberdeen.

I have bled off from the radiator and heater matrix. Hopefully it was just another airlock but if it overheats again then it might be time to start taking things apart.

[toxo]

The issues the guys have referred to above are known as the hose from hell and the pipes from hell, they are a real pain when they go!

[easty-5]

The issues the guys have referred to above are known as the hose from hell and the pipes from hell, they are a real pain when they go!

I was hoping nobody would mention that

Ah well F*ck it, if that's the case then Oliie from Olbermotive will have the joys of fixing it.

[GMLMR2]

Hi guys I'm very much a newbie here but I coulnt help seeing this and had to reply with my knowledge of the subject of over heating, this nearly drove me round the bend, I nearly lost any engine due to heater pipes.


Yea does sound like pipes from hell, I had a similar problem back last summer, but my engine would over heat after a good blow out, it’s due to a crack that forms up on the heater pipes bracket (see pic below), what happens is when the engines working hard the coolant gets hotter and expands more so it usually goes back into the expansion bottle and obviously when it cools down the coolant gets sucked back in from the expansion bottle (this wont happen if there is air getting in) instead of doing what it normally does when cooling down it just sucks in air though the cracks on the heater pipes, so you have air in the system which eventually causes it to over heat, if the heater pipes are leaking then it will keep leaking coolant so the engine keeps wanting to pull water from your expansion bottle to keep it topped up.

Sometimes if the heater pipes are badly cracked like mine were then the water in the expansion tank will stay there and not move an inch because of the amount of coolant being forced out those cracks so the amount of coolant you lost is being replaced by air on cooling down time, so it's very misleading. Sorry to be so technical but I had to get my head around the cooling system to be able to fix the problem



A good test is to pull back the centre tray underneath the car, if it’s got water on it then they need to be replaced soon as, also if the coolant system has been bled properly coolant is visible in the filler kneck when you remove the pressure cap in the engine bay (cold engine), coolant won't be visible if the heater pipes are leaking or you have other leaks else where, but 9 times out of 10 it's the pipes from hell sadly

I found mine by accident in the end, on removing the centre trays to replace handbrake cables there was coolant every where, the fuel tank was dripping in the stuff so I bypassed my heater pipes with high grade duel walled 19mm coolant hose that I ran under the car, see pictures below I did it to mine last year and it’s worked a charm, I just didn’t see the point the in throwing good money away by buying the same pipes from Toyota when after xxx amount of miles I would have to do it all over again.

[easty-5]

That was a very useful post, thanks very much.

I can see coolant in the filler neck, does this mean my pipes are okay?

I will take the undertrays off and see if any coolant comes flooding out.

[GMLMR2]

That was a very useful post, thanks very much.

I can see coolant in the filler neck, does this mean my pipes are okay?

I will take the undertrays off and see if any coolant comes flooding out.

You might be lucky fella, is there still coolant in the filler neck after about 20 or so miles after a full system bleed because that’s when mine would drop, I do about 30 miles a day but every morning I would have to pop in a litre before coolant was visible.

Once you got the under trays off look up at the heater pipes as you can see them coming out from the backside of the fuel tank, usually there wet if leaking and you should see drip stains on the fuel tank too

I must admit my first instinct in any over heating is thermostat; I replace that first “even if it looks like it’s working with the old string and hot water method lol I’ve been cault out by one before on my G/Fs Ford KA” and if it still overheats then look else where.

Head Gasket is a last resort though, the biggest sign of one going is water in the oil, check the dip stick, if the oil looks grey then you got a problem, a lot of people are also convinced that if there car pushes out a lot of steam through exhaust then HG is blown….but this is not always the case, all cars push out steam especially FORDs and especially this time of year when the weather so cold, all cars steam in this cold weather were having it’s just damp, the only time a car shouldn’t steam is in summer time heat like 25 – 35.c etc

Just one other thing mate, if the pipes from hell are ok and stat it replaced and it’s holding its water then I would be inclined to look at the radiator

[easty-5]

I have only driven it about 10miles tops since topping up, I will check again tomorrow before leaving for work.

I will get the car up on some ramps tomorrow and take the undertrays off. I have never had them off on this car so god knows what is hiding underneath them. I will report back with my findings.

Thanks very much, I appreciate you taking the time to respond and give me some very very useful information. Have a cyber pint on me

[GMLMR2]

I have only driven it about 10miles tops since topping up, I will check again tomorrow before leaving for work.

I will get the car up on some ramps tomorrow and take the undertrays off. I have never had them off on this car so god knows what is hiding underneath them. I will report back with my findings.

Thanks very much, I appreciate you taking the time to respond and give me some very very useful information. Have a cyber pint on me

No worries buddy , always happy to help in this area I been there except I was going it alone.

Oh by the way, be careful undoing the bolts on the under trays mate cus there usually rusted in quite good, if you have any WD40 them give them a quick spray and leave for 5 mins otherwise you may take the heads off, and put a smearing of grease on the bolt threads when putting them back, it makes it easier and less chance of cross threading on rusty threads, not to mention easier to undo if ever you want to do any other work in the future.

[easty-5]

Checked coolant level this morning, it wasn't full to the brim but a very gentle squeeze of the hose brough coolant right up to the hole. I am hoping that it was just an air lock and it has done it a few time because I never bled the heater matrix. I have bled the heater now. I will still check under the undertrays when I get a chance. Proof in the pudding will be when it is taken on it's next long journey. Fingers crossed

[Moo]

Just worth mentioning that the pipes from hell have been redesigned by Toyota to stop them cracking around where they bolt to the car which is the place they normally let go. Mine leaked a few years ago and I replaced them with new as opposed to bypassing them, cost me around £220 for the 2 heater pipes!

[easty-5]

Just to bump this up a bit and update slightly. I have just returned from working offshore, I was away 6 days. The car has not moved, checked the coolant and it hasn't moved a touch. So there doesn't appear to be any leaks.

[tkl]

These pic's look very familiar to me!
If you link to this thread below that I made in April 2008 you will find other information that other members have added to help with the fitting of the by-pass hoses, as well as the pic's of my car shown above, get the full story because everyone's input has made the job a better one.

http://www.mr2oc.co.uk/forums/198/91450.html

Cheers
Trev