Offroad-Express

Bugger typed a whole heap and then hit submit. Didnt notice that Rangimotors had submitted something and lost everything - Arse.

Basically the proceedure they should have followed was

Bleed the system "properly" (as I aked not how they did).
Check the radiator cap (pressure and vacuum)
give the vehicle a week with the system cleared and maybe a new cap.

if symptoms persist

Pressure test the system
Check for presurisation of the cooling system while running
check for presence of combustion gasses

If the first two had been done maybe I would not be out of pocket. if the last three proved to be bad news then "off with its head".

Unfortunately they weren't so the work was done purely on the evidence of bubbles in the radiator when running. There may have been some presurising of the system but it was not 100% apparent and was never checked.

Lessons to be taken from this is do the basics first, cross off all the simple fixes (10 dollar cap vs 3 grand for a head) before going for the biggies. Be confident with the "professionals" and tell them what you want done and dont settle for less - you are paying after all and the customer is always right until proven wrong. Get them to explain their reasoning behind their ideas.

Now I have to prove the head was fine (the gasket was fine) and the work done was unnessesary which will cost me extra $$$. Of course I am happy to pay for the head (it is fitted after all) but maybe the labour is too much. I will sell the old head if its okay to offset the costs - If its okay. If it isnt then this is all just a waste of time and the work done was justified. Just not approached in the way it should have been and they/I got lucky.

Bit of an update I guess.

Bled the system and I think I got most of the air out (couldnt get the front as high as I wanted - got some weird looks from the neighbours when I drove part way up a big pile of dirt at the end of the street, popped the bonnet and ...)

Drove for the last few days and it appeared to have improved and no bubbles heard in the system at all (Yay ), but when I shut off the heater control and stopped the flow through the heater and switched it on later on (5 mins).

Bubbles could be heard again for a few seconds. - bugger!!

Thought I had it sorted this time. Bled it again tonight and will see what happens tomorrow.

I am beginning to wonder if I have a loose hose that (as someone here suggested) when flow is present seals the connection but when it is shut off a vaccum is present in the line which draws air in. I have to find some hose clamps and replace the factory springloaded ones. Might look at replacing the hoses too just incase.

To be honest I had a smile on my face a mile wide until the bubbles returned then you could have heard a pin drop in the car - even the wife said nothing...

I am gutted.

Maybe a firey death is on the cards (the wagon not me)

Were the bubbles as bad as before?

for the time the system was switched to cold and then back to hot it was the same as before and quickly dissappeared.

After the head change the sound was almost constant (the mechanic should have noticed...).

After bleeding it and driving for a day it improved to not hearing any bubbles at all(but I never switched the heater to cold and back so I cant be sure) and I thought it was sorted.

I even replaced the radiator cap just in case it was the issue (the old one was buggered - rubber staring to perish / deteriorate and the small oneway valve set into the rubber was gummed up so it didnt close properly). That should have been the one of the first things I/they checked.

I have noticed the temps are up from before too, 4 degrees C over what they were before. I guess thats because the head,water pump is different and the gasket may flow differently too so no surprise there I guess. At least it is constant.

Going to do the fan hub next weekend if I can get some of the silicon stuff this week and rule that out as a problem in the future.

When running the engine with the nose pointing up hill I go around and squeeze all the hoses to help try push all the air out. You can also pressure bleed the system to.

Does your shorty have a rear heater? It could have air in there?

Pajero's can be hard to get all the air out of as well an can just take time and the 'front up a hill' trick.

I wouldn't worry about the fan hub myself, if you have been driving along the road the hub shouldn't be hard as the air coming through the radiator isn't hot enough to make it go hard. If your temps are all good then your fan will be fine. Mine is never hard driving along the road as the radiator is cooling properly just from air flow. Its only on real slow going it might come on, and when the vehicle is cold it will roar.

I also wouldn't worry about new hose clamps as they would show up as a leak. if they were letting air in, they would also let coolant out when the system is under pressure as the water heats up.

As your engine warms up, the coolant in your cooling system expands.

The expanding coolent causes an increase in the pressure in the cooling system.

The pressure is controlled by the radiator cap, which bleeds off coolant into the overflow bottle through the hose in the filler neck of the radiator. This maintains the cooling system pressure at a safe and consistent level.

When the engine cools down, the coolant contracts.

The radiator cap allows the coolant that was bled off into the overflow bottle to be drawn back into the radiator via the same hose in the filler neck of the radiator.

In order to draw the coolant back from the overflow bottle during the cooling down of the system, the cooling system must be free from leaks and the radiator cap must be in good shape.

If its not, as the cooling system cools down and everything contracts, rather than the coolant being drawn back into the system from the over flow bottle, air will be drawn in from the leak in the system.

If your radiator cap is not good, air will be drawn in from around it
If you heater cock is no good, air will be drawn in from around the plunger.
If your over flow bottle cap is knackered or split where the hoses run through it, air can be drawn in
If the pipe from the radiator filler neck to the over flow bottle is split or a loose fit, air can be drawn in
Same goes for the pipe from the over flow bottle cap down into the bottom of the bottle.

So two things to do:

Fill your over flow bottle to a level you can easily see but not higher than the Max level, mark the water line with a vivid. Fill your radiator right up.

Drive until properly hot, check to see that the level has increased in the over flow bottle.

Leave over night to cool down properly, check to see if the water level has returned to the vivid line.

If above the line, air is being drawn in on cool down through somewhere.

If below, you have a coolant leak and are loosing coolant when the system is pressurised, the same leak could also allow air to be drawn in on cool down.

Fit a new radiator cap.

Bypass the heater cock. By pass the rear passengers heater cock also. They have rubber seals in them that can go hard and air can be drawn past them on cool down, but the cooling system pressure forces them to seal when hot.

Problem solving is always tricky

Sorry to hijack a thread...
Diesel Boy, when my engine cools after being at operating temp, the top radiator hose starts to contract as the pressure is presumably lost from the system. This means that when ever my engine cools the top rad hose is all sucked in (if you get what I mean). If I loosen the rad cap, the hose pops back out as I let air into the system. Does this point towards a faulty rad cap, as it is not letting air back into the system through the overflow pipe? (This pipe is unblocked as well)


Cheers

DieselBoy wrote:As your engine warms up, the coolant in your cooling system expands.

The expanding coolent causes an increase in the pressure in the cooling system.

The pressure is controlled by the radiator cap, which bleeds off coolant into the overflow bottle through the hose in the filler neck of the radiator. This maintains the cooling system pressure at a safe and consistent level.

When the engine cools down, the coolant contracts.

The radiator cap allows the coolant that was bled off into the overflow bottle to be drawn back into the radiator via the same hose in the filler neck of the radiator.

In order to draw the coolant back from the overflow bottle during the cooling down of the system, the cooling system must be free from leaks and the radiator cap must be in good shape.

If its not, as the cooling system cools down and everything contracts, rather than the coolant being drawn back into the system from the over flow bottle, air will be drawn in from the leak in the system.

If your radiator cap is not good, air will be drawn in from around it
If you heater cock is no good, air will be drawn in from around the plunger.
If your over flow bottle cap is knackered or split where the hoses run through it, air can be drawn in
If the pipe from the radiator filler neck to the over flow bottle is split or a loose fit, air can be drawn in
Same goes for the pipe from the over flow bottle cap down into the bottom of the bottle.

So two things to do:

Fill your over flow bottle to a level you can easily see but not higher than the Max level, mark the water line with a vivid. Fill your radiator right up.

Drive until properly hot, check to see that the level has increased in the over flow bottle.

Leave over night to cool down properly, check to see if the water level has returned to the vivid line.

If above the line, air is being drawn in on cool down through somewhere.

If below, you have a coolant leak and are loosing coolant when the system is pressurised, the same leak could also allow air to be drawn in on cool down.

Fit a new radiator cap.

Bypass the heater cock. By pass the rear passengers heater cock also. They have rubber seals in them that can go hard and air can be drawn past them on cool down, but the cooling system pressure forces them to seal when hot.

Problem solving is always tricky

Cheers DB (Solid Gold responce) I'll print it out and take it with me to give the "mechanic" something to think about.

The heater seems to be a common issue and the bubbles seem to be connected in some way. Something they never thought about (nor me either) when they did the "diagnosis". I wonder what the valve thingee is worth...

It would appear that the heater control valve may have been the culprit (well done those who picked that obscure fault - the mechanics didnt until I told them to look there as well as doing their own checks.

Pick it up tomorrow for hopefully what will be a long time of worry free motoring.

Too good to be true...

Its been at a radiator/cooling specialist and they have decided that the fault probably lies withing the heater core. They have checked everything else they could. Going to wait a month until I have some extra cash and go in for another round of "fixing". The mechanic has been asking everyone what it could be as they are stumped. I'll admit I am too at this point.

Heath

Now that summer is coming, bypass the heater and see what happens.
Then you will know for sure !

been scouring the net (as you do) and came across a yota forum in the us (deals with 4runners etc) and found a few threads about heater failures and they all seem to fit my profile in one way or another. I just havent had a failure with fluid in the cab yet...

Have a look here .

http://toyotasurf.asn.au/forum/

Had the head checked and its fine. Been poked, prodded, heated hardness tested and now its been reassembled with new bits (basically reconditioned) and will be installed in another vehicle soon. So I get some cash back for my troubles I guess.

Came to an arrangement with the garage and I am happy with the outcome.

Just got to sort the bubbling noise now

All sorted.

Was the heater core. Almost blocked completely. About 20% flow left and when a low flow (at idle) it was okay, but when you reved the engine the water flow increased and the restriction came in to play and cavitation due to the blockages caused the noise. I am a little concerned about the state of the radiator now, but as it has been swapped for a new one maybe that was when the issue arose and after a flush of the system the crap was pushed into the heater core.

Good opportunity to fit a new stereo too while it was in bits (okay just the console area).

So a long and convoluted way to the solution but maybe this will help others with the same issues. Only advise I would give is do the simple stuff first and then do the head as a last result.