Pajero Owners Club of South Africa

Hi Senache

There is another thing the mechanic could have checked while the engine was open, which is to see if there are any cracks in the cylinder sleeves. They are very difficult to spot, but this could be a cause, depending on the symptoms. I also ha issues with a brand new thermostat, which got stuck after only two day of use - the water/anti-freeze mix/ratio was fine. See if the car uses water, or if the water level actually rises in the overflow bottle. If it rises, it is gas that is getting into the water system - possibly from a crack in the block or cylinder head.

Hope this helps.

Johann

Thanks a lot for your answer.
I took the thermostat out and the temp gauge was still going up.
I will see the water level in the bottle today. But I really hope its not the cilinders head or sleves.

There is an abnormal heating of the floor underneath the front passenger feet .... ?? Canu relate that with the oberheating somehow?

I really hope is something small othewise I'm in a very big trouble...

Run it from cold this morning.
After driving for 5 min (!!), aprox 5 km, the gauge went from cold to overheat. In the bottle the freezer freezer went up 2 cm.
Now I'm really concerned!...

If not the cilinders what else can be?
Nee u guys...

Hi Senache

when the water level of the overflow bottle rises, it can mean two things - you still have an "air-bubble" in the water system - this can be fixed by "bleeding" the water system.

Number two is more serious as per my previous response, whereby you have hot cylinder gasses escaping into the water system, most probably the cylinder sleeves, which would require a re-sleeve and new rings etc. A new sub assembly may be called for here depending on the costs.

Cheers

Johann

Senache,

I would have thought you have covered these points but:-

Check thermostat, is it operating correctly (drop it in a pan of boiling water and check it opens)
Are the top and bottom hoses of the radiator at equal temperatures?
Can you feel any significant differances as the car gets warmer between the two hoses?
Have you double checked for an air lock, did you fill it up with the rad at the highest point it often helps to stop air locks.

Good luck in sorting it out.

park the car with the nose as high as possible.

start car with radiator cap off. Fill with coolant while car is running. Tell us how much it took.

PS : How clear is the coolant in your radiator?

This is a sad story!

I think all the work was done to repair the symptoms and results of a fault which has still not been identified.

This

Tested the cooling system and noticed the left hose (as you face the car) is cold and the right pipe is hot.

was taken as a clear indication that the water pump had failed.
Most people would have agreed.
It is also normal to then assume the head gasket was a victim and not a cause.

When the water pump and head gasket were replaced and the problem did not go away, it is clear that the diagnosis was incorrect.

Are the hoses still hot and cold?


What is the problem then?

• Water pump? Highly unlikely that a new pump will be duff.
• Blocked water passage in the engine block?
• Blocked / collapsed water hose? I would have replaced ALL hoses as part of such a major repair.
• Blocked radiator? The cold and hot top hoses nearly eliminates this
• Cracked sleeves? (as suggested)
• Bad head (cracks)? (This is my guess)
• Bad gasket?
• Bad engine block, allowing leakage?
• Bad radiator cap? (would not show up as hot & cold hoses)
• bad thermostat?
• ???

A systematic check needs to be done to find the fault, not the results of the fault.

• is the water circulating?
• do the top hoses still show different temperatures?
• are there exhaust gasses in the coolant?
• does the thermostat open at the correct time?
• is the radiator core open?
• etc.

I think a cooling specialist needs to look at the patient.

Just got back from mechanic.
08:30 Show him the water level difference between cold and overheat engine. He said that's not necessarily a sign of cylinders sleeve or head damage/crack.
Then:
Before starting the engine, which was still hot, he checked the hoses. Both warm this time but not the same temp.
Tested the coolant circulation by releasing a hose (the right) and asked one of his guys to blow the radiator head. Good result.
He took out the thermostat and tested in boiled water. The thermostat opened well.
He did another test of free water circulation in the radiator and to the thermostat. Positive results.
"Radiator not blocked!" he said. Then he added "Water pump working".

09:30 After mounting the cooling system back without thermostat and checked the gauge again he decided: "There must be a small crack to one of cylinders heads". He also explained to me : The fast release of gas into the radiator explains: 1. Fast temperature increase (from cold t overheat in less than 5 min.) and 2. bottle water difference (2 cm.)
That was the worse I could hear...

We decided that he will take the heads out and replace them with some spare ones he's got from another engine. In the mean time he will book mines for a X-Ray diagnostic at the Mozambique Airlines (LAM) workshop.

I found it making sense and agreed. If my heads are cracked the engine should not overheat again.
If the engine will still overheat I am very tempted to return the car as I still have to pay the seller USD 5000 for it.

Let me please review and reply your checklist 4ePajero.
A systematic check needs to be done to find the fault, not the results of the fault.

What d you think?

senache wrote: 09:30 After mounting the cooling system back without thermostat and checked the gauge again he decided: "There must be a small crack to one of cylinders heads".

4ePajero wrote:Bad head (cracks)? (This is my guess)

Why did he not check or have the heads checked when he had the opportunity (heads off and stripped) ?

I hope you don't pay for the mechanic's incompetence / new gaskets / labour etc!

You are totally right.
But I guess he was very sure of the gaskets issue when he saw them. Likewise he is now of the heads crack.
Asked him if he will replace the gaskets again. He said he thinks he wont because they are metallic ones and have been changed yesterday, not tightened...

No I will not pay for his errors.
Many thanks.
I will come back after getting the heads changed.
In the mean time please let me know how much should I pay in SOuth Africa for the good heads if it proves to be the case?
And should I still have the cooling system thoroughly checked? where in Mpumalanga? And how much would it be?

Many many thanks for your assistance.