Head or Gasket?

[Aethelric]

I finally got a water pump today. Its taken almost two weeks from ordering the first one. The Royal Mail still has one, that was the last of the suppliers current stock. They were in within a couple of days and I got one sent by courier next day delivery - it took two days.
I ordered it from Mazdabongoshop.co.uk. They could not have been more helpful. They were great, the courier average, and the Royal mail useless.
Fitted it this afternoon/evening, and so far everything seems to work OK. No leaks and no extra gas in the head after couple of mile drive and the engine warm. I still have no stat fitted. I'll give it a few days and a hundred miles or so, then try replacing the stat AGAIN.

[dandywarhol]

Just picked up on this thread - a Ford Ranger pump is identical and cheaper - available from most Motor Factors. I posted a part number somewhere in a compatable parts database on here - can't find it

[mikeonb4c]

I finally got a water pump today. Its taken almost two weeks from ordering the first one. The Royal Mail still has one, that was the last of the suppliers current stock. They were in within a couple of days and I got one sent by courier next day delivery - it took two days.
I ordered it from Mazdabongoshop.co.uk. They could not have been more helpful. They were great, the courier average, and the Royal mail useless.
Fitted it this afternoon/evening, and so far everything seems to work OK. No leaks and no extra gas in the head after couple of mile drive and the engine warm. I still have no stat fitted. I'll give it a few days and a hundred miles or so, then try replacing the stat AGAIN.

Fingers crossed for you Aethelric

[Aethelric]

Just picked up on this thread - a Ford Ranger pump is identical and cheaper - available from most Motor Factors. I posted a part number somewhere in a compatable parts database on here - can't find it

I'll remember that. Don't suppose I'll ever need another one for this bongo, but if I get rammed again.....

[Aethelric]

The bongo (actually its a freda) ran with no problem with no stat.
I put the stat back in today, but the symptoms are the same as before. A slow but steady issue of bubbles, even after idling for an hour at operating temperature. So its either the head or the gasket (unless anyone has any other ideas?)
So the stat is out again, and I'll continue to run statless until I can organise replacement transport and a head check and possible replacement.

Dave

[bigdaddycain]

Sorry to hear that Dave...after all that messing about n' all! I was going to suggest leaving the stat out and keeping your fingers crossed... have you tried removing the innards from the stat,drilling a 1/4 inch hole in the cylinder shroud, re-fitting then trying again? The heat sink effect should be increrased as a narrowing in a pressurised water channel actually speeds up the flow of water (when you'd think that a narrowing in a channel slows the flow, it doesn't... Think of how a jaccuzzi works).

[Aethelric]

Sorry to hear that Dave...after all that messing about n' all! I was going to suggest leaving the stat out and keeping your fingers crossed... have you tried removing the innards from the stat,drilling a 1/4 inch hole in the cylinder shroud, re-fitting then trying again? The heat sink effect should be increrased as a narrowing in a pressurised water channel actually speeds up the flow of water (when you'd think that a narrowing in a channel slows the flow, it doesn't... Think of how a jaccuzzi works).

Thanks BDC. Its been running for quite a while with no stat. When I say "no", the stat shell is there but the inards have been milled out. Cooling is no problem, the temperature guage rarely lifts off the end stop - only in very slow moving traffic. I reckon (i.e. haven't tried it) that switching on the A/C will switch on the radiator fans and keep it cool then too, but I'll try to avoid traffic jams. A guess running at minimum temperature will effect my fuel consumption, and the heater will be a bit wimpish. I have a 200 mile round trip at the weekend to a festival (aging hippy syndrome). Hey, what could go wrong??

Interestingly, with the stat fitted, reving the engine increased the pressure in the head relative to the header tank, and the coolant rose in the bleed vessel and dropped in the header. But with no stat it was the opposite way round. Revving the engine dropped the level in the bleed vessel. I think it may be due to increased flow through the head causing a venturi effect in the bleed pipe. Another datum for the cooling system data bank!

Anyone got any advice on heads - i.e good and bad suppliers? Is a Mazda head out of the question? (of course it may just be the gasket)

Just thought - wearing a pullover in winter and a mile or two less per gallon is a lot cheaper than a new head .

Dave

[Simon Jones]

Anyone got any advice on heads - i.e good and bad suppliers? Is a Mazda head out of the question? (of course it may just be the gasket)

Not sure if he's up for selling it, but Simon Heaton (Bongoing Mad) has a brand new head from Bongo Bits, which fortunately was not required after a recent scare.

With regard to the level rising when the 'stat is present: I think that's normal (or is as least what mine does). I think when the 'stat is closed it is blocking the flow, so the increased flow caused by revving the engine will cause a build up of coolant in the header tank. With no 'stat (or its open), then the pump will be drawing it out of the tank faster than it can flow back in again. The header / expansion tank is designed to be a buffer for the natural increase / decrease in volume & pressure that occur when the liquid is heated & circulated.

[Aethelric]

Not sure if he's up for selling it, but Simon Heaton (Bongoing Mad) has a brand new head from Bongo Bits, which fortunately was not required after a recent scare.

I'm in the same boat. I don't know for sure if the head has gone. It could be the gasket, or maybe it just needs tightening down.

I did a test today, and after a run with stat on the bottom stop I let the engine idle until the needle lift a little. Then I switched on the A/C which brought on the fans. After a minute or two the needle dropped back to the end stop. So I'll set my Mason alarm to around 2, and see how it goes for a while.

[The Great Pretender]

I'm still not convinced that there is a head problem. The turbo has been mentioned before as a possible problem, as the pipework for it is at the stat housing fitting or removing the thermostat could affect air ingress. If a chat about it would help pm me your land line number.

[Aethelric]

I'm still not convinced that there is a head problem. The turbo has been mentioned before as a possible problem, as the pipework for it is at the stat housing fitting or removing the thermostat could affect air ingress. If a chat about it would help pm me your land line number.

Thanks Mel, I'll give you a call.

In the meantime here are some pics

The old water pump

I think the rust stains have developed since I took it out

The bleed set up for single handed operation


Closer view


The old "Stat"

Now fitted.

I've used a half tank of diesel since I put it back together with the sawn off stat and the new pump with no problems, and I have a 200 mile round trip to do this weekend, so fingers crossed.

[Aethelric]

Did the trip, without the stat - no problems. Motorways and A roads mostly at the legal speed limit around 15% of the distance in traffic. I averaged 28mpg. Thats what I would have expected from my last one, but that was 4WD and this one is 2WD so I'd expect a bit more under normal running, so maybe the low temp is taking a couple of mpg off.

Hoping that the head and gasket are actually OK, does anyone know if is it possible to torque the head bolts without a major strip down? And what are the torque settings?


Dave

[stevedon]

ive had a simular issue it would de fine for weeks months ,then all the water would come out.Re bleed it when cold and start over again.I also removed the thermostat and lasted 3 months with no issues,then it overheated again,so ive tried all sorts including products which say they will chemicaly weld up cracks in the block and head,mmmmmmmmmmmmm.
As you will see from my posts i have now pulled the head off ond its cracked between the inlet and exhaust vales on cyl 2,which is common i believe.From what i can find out it is rare for the head gasket to go unless you use a aftermarket one as the Mazda ones are multi plate steel ones this must be for a reason also they have a specified thickness.After lots od uming and arring ive bought all genuine Mazda apart from the head bolts as the price differencs is not that great 900 for a copy head 1100 for a genuine,158 copy 165 genuine head gasket (NZ Dollars)Mazda will haggle as the head has a list price of 1500, i just told them what i could get a non genuine for etc and all dealer parts depts ned to sell parts at the mo so a good deal can be reached.the head bolts i got from a engine reconditioner who had used these bolts before $400 mazda $50.00 non genuine.Whats also worth rtemebering is the mazda head comes with valve stem seals,all studs,water pipe etc where many copies dont. I would say dont use a aftermarket head gasket unless ita a Payen as ive used those for years and never had a problem.Good luck

[stevedon]

I should add with the thermostat out mine averaged 40 deg on a run but once stuck in traffic (there is some here in NZ)it chucked the water out at @80deg (ive got a TM2 fitted).
the head cannot be retorqued as it has an initial torque up of xxNm then 90deg then another 90 deg so there is no specific figure also they are stretch bolts and are designed to stretch,over tightening is not good

[rita]

I'm still not convinced that there is a head problem. The turbo has been mentioned before as a possible problem, as the pipework for it is at the stat housing fitting or removing the thermostat could affect air ingress. If a chat about it would help pm me your land line number.

Thanks Mel, I'll give you a call.

In the meantime here are some pics

The old water pump

I think the rust stains have developed since I took it out

The bleed set up for single handed operation


Closer view


The old "Stat"

Now fitted.

I've used a half tank of diesel since I put it back together with the sawn off stat and the new pump with no problems, and I have a 200 mile round trip to do this weekend, so fingers crossed.

Hi,Dave what is in the bottle