Temp Gauge still rising slightly.....

[Stubs]

Hi guys, I recently had a new Ali radiator and hoses put in my 4Y, new thermostat, also the bearing on my viscous fan was buggered so I had a new one also put in, now my question is this, I am not using Anti Freeze, I am not using Oil and there is no water in the oil...however when gearing down on hills, or driving into headwinds the Temp gauge moves up above halfway, sometimes a fraction more and then when the motor is not working as hard it drops down etc. I have been monitoring this closely with different gear selections higher revs lower revs etc...but still the same, could it be a faulty temp gauge etc as this i have not replaced as yet, or with wiring. If it was the head then I would be using oil, loosing water, and loss of power...any thoughts on this would be great, or is this normal that the engine will chain temperature do the various work levels...I have chatted with various guys on the subject and they say that the gauge stays static????

[Muz]

Have you changed your Radiator cap? If you losing presure, the water will tend to reach boiling point. Your head gasket may be leaking between your piston into your water jacket, heating the water as well, but you say not using antifreeze.

[AM Racing]

Check the water pump. We have had issues with the impellers corroding off.

[Stubs]

No brand new radiator cap along with the bigger new Ali radiator, and i am using anti freeze....

[Muz]

I Suspect you may have a blown head gasket...

[AM Racing]

I Suspect you may have a blown head gasket...

Go to yout local Silverton agent and let them do a dye test. This will confirm this 100% if its blown.

[Stubs]

thanks guys for the advice, will also put a new water pump on whilst i am at it to be sure....!!! ok off to my Silverton agent !!!

[Mr_B]

Pressure and dye test, but it may well be the water pump that on it's way out... easy to replace on the 4Y!

In SA conditions I firmly believe in using coolant, besides raising the boiling point, it has anti-corrosion properties and lubricates the water pump bearing!

I doubt it's the HG... seriously hope not!

[Stubs]

Pressure and dye test, but it may well be the water pump that on it's way out... easy to replace on the 4Y!

In SA conditions I firmly believe in using coolant, besides raising the boiling point, it has anti-corrosion properties and lubricates the water pump bearing!

I doubt it's the HG... seriously hope not!

thanks Brett, I am gonna go and order a water pump and do that first, then test and if still issues will do the pressure and dye test....will keep you posted....!!

[Stubs]

Pressure and dye test, but it may well be the water pump that on it's way out... easy to replace on the 4Y!

In SA conditions I firmly believe in using coolant, besides raising the boiling point, it has anti-corrosion properties and lubricates the water pump bearing!

I doubt it's the HG... seriously hope not!

thanks Brett, I am gonna go and order a water pump and do that first, then test and if still issues will do the pressure and dye test....will keep you posted....!!

Ok new water pump ordered, R250, gonna attempt to fit myself !!

[Mud Dog]

A piece of old takkie, Stuart ... not difficult on the 4Y. From what has been said, it's unlikely that it's radiator related unless it's choked, either outside with grass / mud etc. IRO air flow, or internally (the core) with debris in the coolant (again unlikely, but a possibility). Also remember that a new thermostat can play up from the start. If you're not using / loosing oil / water it's also unlikely to be the HG, but if it is, it's also not a big job. That leaves the water pump ... poor circulation. I very much doubt that it's the gauge itself .... they don't give hassles, and the sender unit either works or doesn't, so it's not that either.

Good luck mate, hope it's just a small issue!

[Stubs]

A piece of old takkie, Stuart ... not difficult on the 4Y. From what has been said, it's unlikely that it's radiator related unless it's choked, either outside with grass / mud etc. IRO air flow, or internally (the core) with debris in the coolant (again unlikely, but a possibility). Also remember that a new thermostat can play up from the start. If you're not using / loosing oil / water it's also unlikely to be the HG, but if it is, it's also not a big job. That leaves the water pump ... poor circulation. I very much doubt that it's the gauge itself .... they don't give hassles, and the sender unit either works or doesn't, so it's not that either.

Good luck mate, hope it's just a small issue!

thanks Andy, at first i thought it might be the radiator, hence i got hoppy to put me in a new bigger Ali one, I have ordered a water pump and will fit next week, then test and see whats going on......I wasnt running with a Thermostat and when I had the Radiator put in I added the thermostat, i know the school is out on whether its best to run with one in or out....however should the guage always remain just below the halfway level, or is there a minor fluctuation everynow and then....I just get concerned when it gets to the 3/4 level...when we were on the dunes last week it hovered just above halfway and then would drop back to below halfway...probably sounds like not a big issue but its just irritating....

[LouisZ]

Radiator Radiator!!! Please check yours. Mine did the same and the motor uneccessary blown a headgasket.

[conversion man]

If the gasket is blown between two cylinders you wont loose water but temp will rise when motor labour and will go backto normal the moment you stop accelerating . Do a compression test and if two cylinders next to each other are lower than the rest you will have to remove the head .

[Hi-Hilux]

As ek n klip in die bos mag gooi...my lux se temp het altyd konstand gele op half maar as ek lang pad gery het en dan stop om n plaashek oop te maak het die hitte gestyg. Het die lux gevat na n mech toe, hy het my radiator se prop se seel uitgehaal omdat ek nie n expansion bottel gehad het nie, en die probleem was op gelos. Ek het toe wel n viscous fan , alu radiator en expansion bottle nuut ingestit en naald het altys so onder half gebly....

[Mud Dog]

If the gasket is blown between two cylinders you wont loose water but temp will rise when motor labour and will go backto normal the moment you stop accelerating . Do a compression test and if two cylinders next to each other are lower than the rest you will have to remove the head .

This is true and also a possibility .... if it's blown in this way it will most likely be between no. 2 & 3 cylinders.

I know the school is out on whether its best to run with one in or out....

In moderate or hot climates a thermostat is not essential but IMO is still recommended. I believe it to be better for the motor to run at a constant temp ... without a thermostat it will waver. Also, if the temp climbs with a thermostat it's an immediate early warning that something is amiss. I would keep the thermostat in.

[kfxnando]

1st, know that my experience is with a different motor that is know for heat problems!!

however the symptoms are the same!!
self also checked every thing, also got a bigger and better radiator, new water pump, new thermostat, new cap . . . . . . . . .mechanical fan and electric fans!!
also looked at Temp sender units!!
my one was even worst, had on the hottest days in summer, in bumper to bumper traffic where the temp would stay cool/normal!!
and on some other days would get hot, yes under load, and while towing!!
did extensive reading on cooling systems and airflows!!

did pressure test, did the dye test about 4 times, the dye test would sometimes show problem and sometimes all good, so be ware of that inconsistency!!

self also had no oil/water mixing!!

self did 42 000km, with towing and normal driving while hunting for problem!!

the radiators were only lasting about 18months before they stated having issues, yep had two 4-core radiators!!
the last resort was to fit the BMW 740 radiator that I had new for the Lexus conversion, and with that the Golf water bottle!!
went from a system with a reservoir, to a system with a pressurised water bottle, and here the problem became constant!!
and pulled the heads off!!

in the end it was the steal ring on the head gasket, that had a crack,(between cyl and water) it was not a quality gasket, however had bought the motor like that!!

however have seen quality gaskets fail as well!!

and now the rook and kook runs constant temp with no issues!!

not saying your HG has a prob
am saying, check every thing before pulling the head, where one might find the ans!!

good luck!!

[pietpetoors]

The purpose of the thermostat is only to help the engine reach working temperature quicker. Once it is at working temp. it is fully open and have no purpose anymore. If the thermostat is faulty and does not open properly it can cause overheating. In summer you do not really need a thermostat so if you want to test and see if that is the problem take it out and drive without it for a while.

Before you fiddle with the temp. gauge you can replace the sender unit on the head, it is probably much cheaper than the gauge, see perhaps it is just the sender unit.

Feel the temp. of the pipes at normal working temp. and then when it is rising stop and feel the temp again, that way you will feel if the water is really warmer or if it is just a wrong reading

I know some other makes of vehicles tend to rise in temp when working had, but generally Toyotas do not have such problems

[Spartan]

Ek het nou nie alles gelees nie maar gaan koop vir jou n radiator-cap by Toyota hulle het ook n mannier om jou te laat kyk op plekke wat niks makeer nie. M2cw

[kfxnando]

thermostat:
helps to regulate the temp

if there is no thermostat it just helps to mask the problem, ask me been there done that!!

if you still have the old one, maybe put that one back!!

also the bearing on my viscous fan was buggered so I had a . . . . .

how do you know that the viscus is operating correctly??

[pietpetoors]

When the engine is cold, thermostat is closed and water gets circulated in engine only not radiator. When water reach about 80 degrees thermostat opens and stays open. It is fully open at 94 to 103 degrees. So unless the temp falls under 94 degrees it won't do much in regulating the temperature.

You can check how the thermostat works by putting it in a pot of water which you put on the stove. Heat up the water while the thermostat is in the pot, you will see how it starts to open as the water heats up.

Very old versions had alcohol in a confined space which expanded and pushed open the valve, more modern versions I think have some type of wax in a confined space. As it heats up the wax melts and then expand and push open the valve.

Point is that at working temp. it is supposed to be fully open and will stay fully open unless it cools down to under 94 degrees. This of course also depends on the heat range of the thermostat, the days when I was still playing around with it they had the heat range stamped on the body, don't know if it is still the case.

[Mud Dog]

Pieter, in our temperate climates a thermostat is not a necessity unless you are living in areas that get winter frost / ice / snow. However the benefits of running with a thermostat in place are that the motor reaches operating temp quicker and this reduces wear on the motor a little. Also in cold weather where one makes use of the heater, the cooling may be more than what is ideal and the thermo will close a little keeping the motor operating temp constant and within optimal perameters. This is why I believe that is better to have one in place.

[Stubs]

thanks for all the info, am gonna do the water pump this week, I had a new viscous fan put in as well, can here it whine as I drive so I presume it works, not really sure how one would test that it works, radiator cap is a genuine one from Toyota, thermostat is brand new, all hoses and ali radiator are new, am going to change the sender unit as well this week, and check all the wiring, once all this is done will update this thread. !!

[Stubs]

Ok, truck is goin in tomorrow for the water pump and a new timing chain, have been busy hence delay, also my coil packed up so replaced with a new one plus new bogey leads. Got a slight shudder when engine ticks over like its missing, also put new ngk plugs in, miss is still there ! Am hoping its a worn timing chain...when driving and approaching say robots, gearingh down, etc it just dies ! I can start straight away again !!
But its frustrating !

[Mr_B]

Hi Stubs,

Check that the idle cut-off solenoid(on the carb) is getting power when the ignition is on, else the engine won't be able to idle.

Mr B

[Stubs]

well I replaced the water pump, it had half the impellers missing, and the rest were frot !! while I was at it had the timing chain replaced as well, and fingers crossed the temp gauge has stopped rising, well it did rise at Tierskloof when my top radiator hose came off !!!

[Willied]

[Revive on]

Hey Stubs, did you manage to sort this issue and what was the final cause of the rising heat?

[/end revive]