OVERHEATED !!!!!!!!! URGENT ADVICE

[Bingham]

no one has mentioned the obvious yet. 1. cooling system pressure test any mechanic or radiator joint can do it for you.

(quote Bingham)
start simple ---pressurising?///// thermostats jammed/// caps
then get more serious quickly as not long to go till ttc

[mattsluxtruck]

well bingham are you talking about whether the system is actually building pressure ie pressurising or doing a cooling system pressure check when car is cold. two very different things for the one word

[Bingham]

well bingham are you talking about whether the system is actually building pressure ie pressurising or doing a cooling system pressure check when car is cold. two very different things for the one word

both.....head to tuff trucks tomorrow so hurry, what evers being done

[blackmav]

all good replys so far but with it being a GQ petrol you wont get moisture out of the exhaust. reason being the cat convertor. the second the car fires up the cat gets up to over 1000degrees internally real quick to burn off the gases. water from a cracked head hitting that aint got a hope in hell of making its way out the tail pipe. no one has mentioned the obvious yet. 1. cooling system pressure test any mechanic or radiator joint can do it for you. if something is leaking at 16lb when system is pressurised hot it will absolutely piss out at 22lb while in test. best thing about it it can be done cold so you get to have a good look around with overcoming heat and any water leaks will not evaporate on contact with a hot motor. 2. cooling system CO test. the mechanic puts a dye in your rad runs the car and the dye changes colour is carbon monoxide is present in the cooling system. ie cracked head or head gasket.
good luck hope i was of some assistance

No moisture out the exhaust?????? Dont know what was coming out mine then. I must be seeing things, or a dog has been pi$$ing up it every night.

[ozy1]

all good replys so far but with it being a GQ petrol you wont get moisture out of the exhaust. reason being the cat convertor. the second the car fires up the cat gets up to over 1000degrees internally real quick to burn off the gases. water from a cracked head hitting that aint got a hope in hell of making its way out the tail pipe. no one has mentioned the obvious yet. 1. cooling system pressure test any mechanic or radiator joint can do it for you. if something is leaking at 16lb when system is pressurised hot it will absolutely piss out at 22lb while in test. best thing about it it can be done cold so you get to have a good look around with overcoming heat and any water leaks will not evaporate on contact with a hot motor. 2. cooling system CO test. the mechanic puts a dye in your rad runs the car and the dye changes colour is carbon monoxide is present in the cooling system. ie cracked head or head gasket.
good luck hope i was of some assistance

No moisture out the exhaust?????? Dont know what was coming out mine then. I must be seeing things, or a dog has been pi$$ing up it every night.

if i believe correctly this would only be on EFI models, as Carbys dont normally require a CAT, i may be wrong thou

[blackmav]

all good replys so far but with it being a GQ petrol you wont get moisture out of the exhaust. reason being the cat convertor. the second the car fires up the cat gets up to over 1000degrees internally real quick to burn off the gases. water from a cracked head hitting that aint got a hope in hell of making its way out the tail pipe. no one has mentioned the obvious yet. 1. cooling system pressure test any mechanic or radiator joint can do it for you. if something is leaking at 16lb when system is pressurised hot it will absolutely piss out at 22lb while in test. best thing about it it can be done cold so you get to have a good look around with overcoming heat and any water leaks will not evaporate on contact with a hot motor. 2. cooling system CO test. the mechanic puts a dye in your rad runs the car and the dye changes colour is carbon monoxide is present in the cooling system. ie cracked head or head gasket.
good luck hope i was of some assistance

No moisture out the exhaust?????? Dont know what was coming out mine then. I must be seeing things, or a dog has been pi$$ing up it every night.

if i believe correctly this would only be on EFI models, as Carbys dont normally require a CAT, i may be wrong thou

Mine was a carby, 1988 model. But I would have thought that cause it was unleaded it needed a cat.

[Shorty40]

Well, rather than a technical inspection I did an extended test drive - From Wagga to Sydney - 6 hours

All seems good. Car never got over 1/2 on the guage on the steeper hills with the pedal on the carpet

Anyone have any advice on the idle issue I brought up earlier ? I may even listen to the advice this time

[Tas_Dean]

Replaced the radiator cap - the old one was quite perished and shitty looking.

Everything seems to be fine

Only thing I noticed after putting in the new radiator cap is the engine revs have droppped at idle. Gone from about 750ish to about 600 Is that indicative of some other issue ?

Again, thanks for the advice and tips = fingers are still crossed that it aint the head

Dan, has this affected the idle speed when cold, or only when the engine warms up?

I'm thinking that the new cap is allowing the system to pressurise properly, which will aid in bleeding the air out, which has given the temp switch better contact with the coolant, which is then telling the ecu that the engine is up to proper temp, and the ecu is cutting back the idle speed.

Of course I may be wrong , but it may be nothing to worry about. Do you know the engine specs for idle speed hot/cold?

Cheers, Dean

[mattsluxtruck]

well its certainly thinking outside the square dean but you make a very good point.
all vehicles built after 1986 and running on unleaded require a cat regardless of efi or carby. you may get a tiny amount of shit out the pipe on very first start as the exhaust blows any moisture straight past the cat in the couple of seconds before the cat starts heating up. it would be tiny though or a bloody big leak! anyway hope the truck goes well wish i was going to TTC but its the wifes birthday party on saturday night so im grounded.....

[rOd]

all vehicles built after 1986 and running on unleaded require a cat regardless of efi or carby.

Hmmm. I wonder if mine really did'nt have one from the factory or Previous owner removed the cat. Its a TB42 carby (no cat).

[Paps]

J Top, Do you retorque the head hot, cold or warm?

[Robbeau]

Before embarking on any of the suggestions:

REPLACE YOUR RADIATOR CAP!!!

It could be that simple!

Also check that the hoses on the overflow bottle are hooked up the right way around, and that the dip tube is still attached to the overflow bottle cap.

Cheers, Dean

My GQ was leaving a puggle on the ground, discovered the radiator cap wasn't seating properly ( the locking lugs were not fitting the radiator) replaced the cap and no problems.

[J Top]

You retorque cast iron heads hot and alli heads cold after they have been hot.
J Top

[Shorty40]

Replaced the radiator cap - the old one was quite perished and shitty looking.

Everything seems to be fine

Only thing I noticed after putting in the new radiator cap is the engine revs have droppped at idle. Gone from about 750ish to about 600 Is that indicative of some other issue ?

Again, thanks for the advice and tips = fingers are still crossed that it aint the head

Dan, has this affected the idle speed when cold, or only when the engine warms up?

I'm thinking that the new cap is allowing the system to pressurise properly, which will aid in bleeding the air out, which has given the temp switch better contact with the coolant, which is then telling the ecu that the engine is up to proper temp, and the ecu is cutting back the idle speed.

Of course I may be wrong , but it may be nothing to worry about. Do you know the engine specs for idle speed hot/cold?

Cheers, Dean

It seems to have affected idles speeds when warm. The choke keeps the revs a bit higher when it is cold.

I will have to consult my manual when I get home for idle speeds and adjustments etc. I am still in Sydney after Tuff Truck

Rig ran well up to Sydney. And from Sydney to Tuff Truck

Hope it runs well for my trip back home tomorrow

[Tas_Dean]

Good to hear that it ran well Dan.

Cheers, Dean

[Shorty40]

UPDATE:

Bad news It seems I have a leak "somewhere". I pulled up for a fill up at the servo and after paying I noticed a nice pool of green engine blood under the rig

Crawled under the rig (as much as I could on a stock GQ ) but I couldn't tell where it was coming from

I had to keep driving as I was half way home.

So, it seems that the water level dropped for a reason Now I have to find the friggin thing and fix it

At least it got me to Tuff Truck and back

[bogged]

UPDATE:

Bad news It seems I have a leak "somewhere". I pulled up for a fill up at the servo and after paying I noticed a nice pool of green engine blood under the rig

Crawled under the rig (as much as I could on a stock GQ ) but I couldn't tell where it was coming from

water pump. it happens with them

[mav]

all vehicles built after 1986 and running on unleaded require a cat regardless of efi or carby.

Hmmm. I wonder if mine really did'nt have one from the factory or Previous owner removed the cat. Its a TB42 carby (no cat).

some vehicles have come without cats commercial vehicles i think, a mate had a hilux single cab ute (work vehicle ) '98 model it didn't have a cat.

[planb]

dan

when you say you 'top up' the radiator and overflow bottle

i assume your bleeding the cooling system propertly ?

you obviously have a leak somewhere, but air pockets wont help when your refilling.

if the fluid is pissing out then it is likely its the water pump, but then you replaced it not long ago.

ive got a spare radiator and a fibreglass cowel that looks like it came from nasa

if you fix the leak and continue to have dramas, your welcome to them cheap.

mine started having both cooling issues and idle issues after the lpg was fitted.

you can adjust the idle on the mixers pretty easily, but check that its not a vacume leak before you start winding up the idle.

what mixer is it anyhow ?

i recently changed the

radiator (new)
hub (new)
fan (new)
water pump (new)
fitted an auxillary auto oil cooler to seperate the rad from the auto oil cooler
and it has never run a thermo (will fit when winter hits)

there are heaps of threads on hot tb42

[Shorty40]

UPDATE:

Bad news It seems I have a leak "somewhere". I pulled up for a fill up at the servo and after paying I noticed a nice pool of green engine blood under the rig

Crawled under the rig (as much as I could on a stock GQ ) but I couldn't tell where it was coming from

water pump. it happens with them

Water pump was replaced not so long ago

[Shorty40]

when you say you 'top up' the radiator and overflow bottle

i assume your bleeding the cooling system propertly ? Not sure - I empty it and fill it back up. Then run the engine for a bit with the heater on full. I keep topping it up til it takes no more.

you obviously have a leak somewhere, but air pockets wont help when your refilling. How do I get rid of air pockets ?

if the fluid is pissing out then it is likely its the water pump, but then you replaced it not long ago. Yeah - water pump has been replaced not long back

ive got a spare radiator and a fibreglass cowel that looks like it came from nasa

if you fix the leak and continue to have dramas, your welcome to them cheap. I will see how it goes - thanks for the offer, I may take you up on it

mine started having both cooling issues and idle issues after the lpg was fitted.

you can adjust the idle on the mixers pretty easily, but check that its not a vacume leak before you start winding up the idle.

what mixer is it anyhow ? OMVL R90 - or something like that I wil have to check it tonight

i recently changed the

radiator (new)
hub (new)
fan (new)
water pump (new)
fitted an auxillary auto oil cooler to seperate the rad from the auto oil cooler
and it has never run a thermo (will fit when winter hits)

there are heaps of threads on hot tb42

[Shorty40]

Well, it turns out that it wasn't any of the things I thought it was

Car overheated on the way home from work yesterday afternoon Just around the corner from home - so I coasted into the driveway

As soon as I popped the bonnet I noticed a heap of steam coming from under where the thermostat is. Looked like the bypass hose. Although there is a steel pipe underneath this that goes into the block somewhere (it is out of sight - so I can tell for sure)

I took it out and the hose is fine. But i think the clamp at the base was loose. Didnt click til after I took it off and saw the hose was fine.

Fingers crossed that is the problem. I put it back in nice and tight.

If this isn't the problem, its off to the mechanic as I am at a loss. I am not willing to accept its the head yet Cant face the fact it may be big $$$$$$$

[bogged]

Cant face the fact it may be big $$$$$$$

no, no Maybe big $, it will be big $..

[Shorty40]

Cant face the fact it may be big $$$$$$$

no, no Maybe big $, it will be big $..

If it too expensive, I will "sell" it to the insurance company and get one of those "Concept Patrols"

[dwaynes]

so shorty40 what was the end result on this

[Shorty40]

Wow - forgot about this thread

I haven't had a problem since I took that hose off and put it back in. I now believe it was as simple as the bottom clamp being loose on the thermostat bypass hose

The rig has been running fine since. Hasn't been using water and the temp has not budged from about 1/3 on the guage.

For once, it seems like an easy (read cheap) fix

[dwaynes]

Good to see thats all it was

[Rainbow Warrior]

Exactly the same thing has recently just happened to my 89 Mav. l regularly checked the water bottle and it was fine, then one day the temp guage went right up and I put about 5 litres of water in i at a service station. I replaced the radiator cap thinking it just wasn't recovering fluid from the bottle but checked the radiator every couple of days and it was using coolant. It had vapour out the exshaust well. I canavassed three or four head joints and each one felt it would be a cracked head. They each had about half a dozen GQ heads in their shops. Riped it off and sure enough it was. This was at 260,000 k's. I had it converted for gas with hardened valves, seats and guides at the same time and a modification that puts an outlet for coolant into the back of the head to prevent an airlock occurring again. I took the head off and on myself and it cost $850. With the diesel like bottom end I should seev another 250000 out of it. Sounds like you may have to bite the bullet. Also, initially there was no oil in the water but evetually there was.

Yep, I done a motor the same way, head beyond repair, so I put in s/h motor, recently stripped the bottom end down and despite running water oil mix for 3 months and sitting in garage for 12 months it looks fine. I used to get steam out of the stack exhaust when it was cold and black spots all over the back tray.

[bogged]

theres a fully rebuild head on Ebay too for a TB.

[mav]

where abouts is the outlet for coolant into the back of the head to prevent an airlock, can you supply some pics please.

I had it converted for gas with hardened valves, seats and guides at the same time and a modification that puts an outlet for coolant into the back of the head to prevent an airlock occurring again.