Hot Head - grab a cuppa and take a seat, this is an epic....

[Morning_Campers]

Hi guys,

I need your Again.........

My posting seems to be getting more and more regular which concerns me! fortunately, there only seems to be one reccurring problem with me truck, not lots of them!

I know its a much debated issue, but i needs to ask y'all about overheating and head gaskets! (sorry if its becoming boring for you now)

Basically, my surf seems to have an aversion to speeds above 60mph or inclines, i've done a number of things to rectify this, nothing seems to work, it just seems that i am going to have to accept that if i try and go up a hill or over 60Mph, i will suffer with a very very hot truck!

It all started a few weeks ago, i travelled to Cornwall for a weeks holiday, on the way down, (about 45minutes in to the journey), my temp guage went up from the midway point to about 3/4 of the way up, i slowed and it came down slowly, but each time i accellarated, the turbo came on or i attempted to go up a hill, the temperature would rise sharply, i managed to limp to Cornwall at speeds between 40-50mph which i can tell ya, is no fun on motorways.

Fortunately i was meeting some members of my family, one of who is a mechanic, although i didn't want to bother him on his holiday, it was inevitable, i had had to stop on the way down, top up the water etc.... and also apply some leak fix to the several leaks which my rad had sprung, when he looked at it, he reckoned it would be ok to potter around in until we could get home and give it a proper looking at, to be fair to him, i potterred around very nicely without much drama for the week, until, boom, the radiator starts heamoraging (apologies for poor spelling) steam, we managed to get the radiator professionaly repaired (at a cost of £160.00) and was assured all would be well. On my Journey home it did indeed seem ok, but again, as soon as i hit a hill, (they don't even have to be steep) it began to overheat, it got so bad this time that i had to be recovered from a service station by Green Flag, the guy they sent told me the Head Gasket had gone and put me and the car on the back of a low loader to be towed to a garage.

I called the afore mentioned mechanic and asked for some advice, fortunately he had set of a while after me, and was just passing me as i called, he pulled in a few moments later and reckoned that it was infact nothing to do with any gasket failure, but that the system was pressurirsing because of a blockage in the coolant system, on his advice i drove the car home, albeit slowly, his theory seemed to be validated, there was no misfire, no nasty white somke or any other signs of gasket failure, when we did get home, we decided to thoroughly flush the rad and coolant system, we did this and i was astounded by the muck that came through the pipes and flooded this drive, once connected up, she ran lovely, i was happy that we had avoided a major crisis, i got some coolant flush, and a few days later repeated the process, we wanted to be doubly sure the system was clean, i bought heavy duty rad flush, and the water once flushed ran clean as evian, i was happy, my heaters even started working again! (yay)

I ventured to Wiltshire this weekend, gingerly building up speed, taking it easy on the long slow hills, just in case it all went pete tong, and it did, there i am, stood at the side of a road, steam "persisting" from my expansion tank, cold and frustrated, i wait for it to cool enough to top up the fluids, but its not lost a great deal of water, i'm puzzled!

On the way home, she gets hot, but nothing dramatic, i must stress, that on normal driving, she's fine, the occurances i'm talking about she's full of people and camping gear and doing long laborious motorway journeys, i'm at my wits end, i don't know what to do, i'm assured its not the head, its been flushed, she's not losing water until the pressure really builds up and its only coming from the expansion tank, i really need some ideas of what to try next, sorry this has been such a long thread, i just felt it was importnant to give you the full picture!

You've all already been such a help to me both by direct posts and by the info available through this site, i hope you can help me again!

Many thanks,

Iain

[BUSHWHACKER]

Is the viscous fan working properly? (free to spin when engine is cold, but stiff when engine hot)
Is the auxillary fan coming on when the temp rises? (Small electric fan in front of rad that switches on when the temp gets above 90ish degrees.)

Both subjects covered if typed into the search box.

Auto box fluid correct level/colour?

[Morning_Campers]

Hi,

Erm, depends what you mean by working properly, i damaged a perished fan switch not long ago, i've been meaning to replace it but haven't gotten round to it yet, to make it worse my computer if broken so my internet access is limited to using the works PC (this makes it more difficult to get in touch with you lot or find/order the part i need!) it sounds like that the fan is constantly on, as far as i know the aux fan is kicking in as necessary, not sure about the auto box fluid, but will check this, would that have any affect on the coolant then? (sorry, i've no mechanical backgorund so am trying to get my head round all of this) i've been told that there may also be a problem with the thermostatic transmitter which i should replace as good practice, the thermostat itself has been checked and is ok, as its looking quite old though, it's gonna be replaced just incase.

Iain

[Maverick]

If you start her up without the radiator cap on does water start coming out?
This is a sympton of a crack in the head which allows the exhaust gases to pressurise the coolant system resulting in coolant steaming out the expansion tank.

Have you had the system pressure tested?
This is the definant test for a cracked head.

When my head went is was when the engine was under full load, after recovery home I was able to drive it 30 miles to Tony's without any problems.

[Morning_Campers]

Hi,

From memory, yes, when started/idling with out a rad cap, the coolant/water does bubble up, i had assumed that after the radiator was repaired, a full pressure test would have been done, nothing was mentioned after i picked it up so assumed all was ok, this was perhaps quite naiive of me, i use the car everyday for short trips to and from work, and other normal trips, the car doesn't seem to suffer under these conditions and runs as normal. is this symptomatic of a craked head too?

Iain

[Maverick]

Before mine did it's big let go, I was also using it daily for short journeys, with the only symptom being water coming out the rad cap.

You could be lucky and it may be a fault with your cooling system. But I would deffinately get a pressure test done.

[Tallyman]

Iain,

Going back a bit, when you flushed the radiator, etc did you refill with water or the Toyota Red coolant mix (recommended)? Also, did you just fill it, then slap on the cap and hope for the best or did you run and refill for a while?

I replaced a leaking radiator on mine a couple of weeks ago. One thing you must do is open both the front and back (if you have one) heater taps to hot, both when draining and refilling the system. Once refilled you need to run the engine at idle from cold with the rad cap off, letting the water settle and the air escape from the system. This can take 20 mins or more. Then rad cap on, take it for a run (about 3-5 miles) to get it hot, let it cool again and then check the level. It will probably have dropped and need topping up. Do this three or four times until you check and find the level is right under the rad cap. That should make sure all the air is gone. Mine needed about 3/4 lire extra by the time it had fully settled.

If you do / have done that and you still have problems, check to make sure the cooling fins on the rad are clear of any muck which will stop air flowing around the fins and cooling the water. If that is clear and you still get overheating problems then, if you have eliminated the viscous fan, you do probably have either a broken gasket or, on a 2.4L, more likely a cracked head. As previously mentioned a pressure test should prove that one way or the other. Hope it's something easier though.

[Morning_Campers]

Hi,

When the rad was flushed, it was flushed several times, then filled with just water to start off with (the intention was to flush it again in a few days so didn't see the point in buyin coolant just to let it drain away again in a few days time) it was checked for air locks, left on a fast idle, checked, taken around the block and checked again, on the second flush, radflush was used (the 2 part heavy duty stuff) the instructions were followed to the letter (i'm assuming this should also have cleared the rad fins as mentioned previously), but the process is basically the same as what you described. i'm leaning further away from the beleif that it is to do with the water levels or a blockage, she doesn't seem to be losing water unless its through steam because of massive pressure, and although there may be a small build up of gunk in the heater rad or other area of the system, i've seen all of the pipes flushed meticulously and clear water come out of them at an ok flow rate, so i'm guessing (and i'm sorry that its not more concrete than a guess) that any blockage would be minimal and would not have the affect that i'm getting!

Iain

[Apache]

Mike meant check the fins externally. its not uncommon for these to fill with mud and cr@p if the truck has been offroad. That leads to cooling issues - just ask the guys who play on the Plain regularly!

[Morning_Campers]

Ah, my mistake, the fins look ok externally, no visible blockages, i would have thought this was checked when the rad was removed and repaired, and as much as i would love to take her off road, the closest i get to going off road is my drive. i'd be scared to take it off road as this might involve a hill, it would then sit sobbing in a corner until it went away.

Iain

[Mitchos]

Your story sounds very similar! I pretty much had exactly the same experience as you. Which resulted in a new head, not before the following:
Changed the thermostat and rad cap
Flushed coolant and filled with Toyota red coolant
Changed the rad as it had cracked and leaked - In hind sight I think this was due to the exhaust gases over pressurising the coolant system and an old weak rad

I too was able to drive the vehicle carefully and for short distances. But as soon as I tried to tow or longer journeys with hills etc. I lost coolant or water-got expensive topping up with coolant all the time.

Eventually forced to bite the bullet and got a new head fitted been running fine since.
Sorry if this is not the news you want and I hope its not the head thats gone on your truck!

[Big Jonah]

Have you checked the water pump?

My 2.4 died after the impellor on the pump came 'off'. The truck would only over heat every now and again, and I couldn't find the reason out as it wasn't a constant fault.