The Toyota Landcruiser Owners Club

[darianva]

Hi All,

I have a S (1998) reg 3.4l v6 Colorado. 95k miles on the clock.
All was running well engine wise, but i had some drive hum i had investigated.
Last year in April at the same I had a garage replace the timing belt and water pump. It appears that the pump was never sealed properly after and there would be minor egress out the system and as a result every 1200-1500miles I had to top up the water. I never had the garage undo/repair the fault as they claimed this must be a new issue.

However of late with all the refills there is only water in the cooling system, and if the car is subjected to heavy load like a hill etc, the car when comes to stand still has a bubbling sound from the engine. Its pressure is bubbling from the overflow cooling tank and results in a little bit of water being pushed out the system, but never too much and the heat of the car at these points is only ever just over middle, at worst 3/4.

Driving behind my wife last week i did notice a clear/opaque smoke, but its not always there if i try replicate seeing it.

Is this the start of the engine needing a overhaul? or should i start by refilling the system with coolant?

any advice appreciated.

thanks
darian

[Google]

[darianva]

I just wanted to also add that the car is now in South Africa, it was imported with me last month, so its a little warmer here than in the UK.
At present I am following the instructions in another forum where it lists running the engine from cold with the rad cap off to see bubbles...will reply once the engine is at 'normal' running temp which is in the middle.

[darianva]

when the car reached running temp the water pressure raised slightly.
there were some minor bubbles occassionally, never consistently.
i then revved the engine at 3000rpm for 15-20secs and when i went back to the engine bay the water level had dropped slightly and then there were no more bubbles.

I tried the heating, and it barely got warm (27'C at present outside) but I could barely feel it get warmer than the blower alone set to cold.

Any advice at this point greatly appreciated.

[wobbly]

The first thing you need to do is sort out the problem with the water pump.

Sounds like the cylinder head is cracked or gasket blown, probably as a result of the water leak causing low fluid level and subsquent overheating of parts.


Pete

[darianva]

thanks pete.
the waterpump was replaced when the work was done, my guess the old gasket wasnt properly removed hence a tiny weep causing water loss ever so slight that it could never be seen.
if the head is cracked i gather it needs to be removed, crack found and welded, is that correct and you would replace the head gasket at the same time.
Or remove head, check for cracks, if none, then replace only gasket?
would a pressure be the definate test? if so, for a cracked head, or a possible combination of both?

[BobMurphy]

Darian,

If I have understood your post, you are experiencing overheating (or at least coolant loss) now that you are in SA.

Standard Toyota coolant (ethylene glycol & water mix) has a higher boiling point than plain water. In addition, the increase in pressure in the radiator as the motor warms up also raises the boiling point (assuming the cap is in good order and there are no leaks anywhere).

I don't know much about the petrol 3.4 V6, but I'm not aware of them suffering cylinder head failures in the way of the old 3.0 litre diesel 1KZ-T/E motors.

I would start by eliminating all leaks (including removing the new water pump and sealing it properly) then re-fill with Toyota coolant and see what happens.

If it turns out that the motor has been 'cooked' and a head is leaking, I'd suggest replacing the head gaskets and trying it again before opting for new heads.

Its a bit of a pain removing the heads twice but cheaper than throwing away good ones needlessly.

I suspect (I don't know) that new heads will be required if they/it are cracked. Welding heads with their complex water channels is not an easy option.

Start with the simple things and work up the cost ladder   .

Bob.

[darianva]

Hi bob, as always thanks for your detailed response.
Would the bubbles in the rad not represent a cracked head or a gasket without the need for testing any of the other options?

[J66P]

the V6 is ni on bullet proof from what I read, hence my choice. I have to say head gaskets arent unheard of but pretty rare and usually the result of temp increase like water pump, fan belt, radiator or hose failure

As Bob says start by curing the things you can see (water pump leak)
_________________
1998 Toyota Landcruiser Colorado 3.4 V6 (sold)
2001 VW 2.8 V6 Caravelle Surf Bus (sold)
2010 Passat Bluemotion Highline Plus (gone)
VW Amarok BiTdi

[darianva]

hi all
thanks for all the help and detailed responses.
this morning i went for a dye test to test for exhaust gasses in the radiator. The dye remained blue and had no hint of yellow when tested.

The test was done at operating temp after a 30min drive to the mechanic that did the test.

He did note that the test was not done under load as they have no method of doing it other than changing the coolant.

I have now booked the car in for next week to have the water pump refitted to ensure its properly sealed. The mechanic mentioned it is possible that if there is a tiny leak it could be drawing air into the system hence the bubbling.
Anyhow he will reseal the pump gasket next week and to be sure he will replace the thermostat (also with a lower temp stat I have read about if we can get them here), and put red coolant into the system.

From the test this morning I am a little hopeful its not the head gasket and I will report back next week once the work is done.

Thanks for all the help
Darian

[wobbly]

Darian

Can we go back to your original posts.

From re-reading them, it appears to say that you have been topping up with water only, and that there is now only water in the cooling system.

So you mean there is no antifreeze ?

If that is what you mean, then that is almost certainly the problem - antifreeze also acts as summer coolant, so none in there would allow the water to bubble up.

Have I understood your post correctly ?

Pete

[darianva]

Hi Pete
You are 100% correct, at present there is no coolant in the system as a result of the top Ups. There is only tap water as a result and most days recently are upper 20's or low 30's.
Under normal load driving, no bubbling only if you come up a steep hill.
Thanks
Darian

[wobbly]

That is your problem.

The fluid shouild be a mixture of water and coolant - this increases the boiling point of the fluid.

At the moment the water in your engine is simply boiling up like in a kettle.

The mix also contains a rust inhibitor.

Get it filled properly and the leak sorted out and you should be fine. A new thermostat should also be added.

Regards

Pete

[BobMurphy]

Bubbles in the coolant could be caused by the leaking water pump gasket (as the Mechanic has surmised).

As the motor warms up the water/coolant expands. Usually this results in the excess being expelled into the overflow bottle.

As the motor cools the water/coolant contracts resulting in a partial vacuum in the motor & radiator.

Atmospheric pressure then redresses the balance by pushing the excess coolant back from the overflow bottle, through the sprung valve in the radiator cap into the radiator. This stops when the pressure in the cool block equals atmospheric pressure.

However, if the water pump gasket is leaking it will/might be easier for air to be pushed into the system to equalise the pressure that way.

The next time the motor warms up the first thing to be expelled into the overflow bottle is the air in the top of the radiator.

Get that water pump fixed      

Bob.

[darianva]

Hi all,

This evening I have got out Land Cruiser back from the mechanic.
He said there was little doubt the water pump was leaking due to the vast water stains etc underside the water pump once he had got it off.
He also noted that there was little chance the water pump gasket was replaced when the water pump was replaced.

The mechanic was unable to source a gasket for the water pump here in South Africa as its only sold with the pump, so he manufactured his own gasket to fit the pump and refitted the pump and the new thermostat and seal.
He also had Toyota 'red' coolant filled into the system as per other recommendations on Toyota forums.

I took the car for a drive up a few steep hills with a little speed. It was 28'C at the time this evening and the temp remained just below half at all times.
There was no boiling sound when I arrived at home.

Is the ultimate test now to see the coolant colour in the morning to ensure its remained red and not changed to yellow?
If thats the case and the coolant has remained red, thank you all for your help and assistance.

Cheers
Darian

[wobbly]

Hi Darian

Sounds good so far.

Hope all is now sorted.

Pete