This is a daily use wife's car. 154,000 k's, good nick, well looked after, we are 3rd owners. About 8 months ago car blew bottom radiator hose. Discovered that the drive belt to the w.pump had broken. Didn't look cooked, so replaced thermostat, belt, and all water hoses. No probs for about 6 months. Losing a bit of water - discovered that this was a welsh plug behind the ex. manifold. Tried Bars Leaks - seemed to work, but a week later the bottom hose split, again, same place, about 50mm away from w.pump. Replaced hose, bled sustem - oh-oh, bubbles dont stop. did 'head test' check for CO1 - suggested head gasket leak (yellow).

Replaced head gasket, had it skimmed and pressure tested - all fine. Reassembled, bled system - no bubbles, cool. :D

Less than 1 week later after daily use, the heater stops working. Brain assumes airlock or something, so bleed again. Noooooooooo-bubbles don't stop coming. :rant: Big tanty, bottle of red to de-stress. Heater turns out to be a broken cable termination (hot glue and paper clamp fix this - another story).

Took car to Mitsi - 'Head Check' does not suggest that the head gasket is faulty. All scratch heads:nuts: , no solution. Drive car for 100km, highway and town, AC on. No water loss from system. No overheating. Try to bleed again, lots of bubbles, bit of foam. Drive another 100km. No worries.

Where are the bubbles comiing form? What should I do?

Great site BTW, I like your enthusiasm for the Magna, which I cannot currently share. Any help appreciated.

It may not be a head gasket, but could be a crack in one of the cylinder walls.
Have you had compression tests done on the cylinders?

My nephew who owns a commodore had similar experience, and he had done the motor up himself. After taking the motor back out and dismantling, he took the head to have the cylinder walls inspected, and they found a small crack at the bottom of a cylinder.

Hope the problem is a simple solution.

thanks Ozz - If the block was cracked the water would build up in the cylinder, causing water loss, missing on startup and possible hydraulicing :shock: - no evidience of these.

is ur radiator or hoses got a block in it? how olds the thermostat? can't think of anythings else at the moment. have u got a manual? if so try the trouble shoot area, there shold be a part like that before most sections. or there will be a road side trouble shoot section for more idea's on what it couls be. sorry im not mre help.

Good idea - I will check the Gregory's.

Dennis,

On a non Mitsi FWD 4cyl I had a crack in the block (cylinder lining) due to corrosion (low klm Adelaide car without regular coolant use!) and yet the water loss was so minimal I didn't notice it.

The very slow leak would occur once the block reached temp and vapourise (due to the heat) before anyone could notice ANY sign of it either. The water was escaping OUT not into the oil so no sign of any mixing in either radiator or oil!

We did exactly as you did ... head gasket ... head ... cooling system etc... and when this didn't fix it we stripped the enging FOR A SECOND TIME and only then did we notice the corrosion in the cylinder wall / water jacket.

No idea how we would have found it otherwise ... not sure you can test for it... it appeared as if the problem was there for a while and Bars Leaks "fixed" it until the metal fatigues / craked beyond the area of the "patch" if that makes sense.

Not withstanding this I would go the process of elimination path ..disconnect the heater for starters may be a heater matrix?

I know it sounds silly but what about radiator cap? Sometimes it's the obvious things...

Have you pressure tested the radiator? Might still be worth while swapping it with a known good one... have you checked your ATF / Power Steering fluid... not sure how the Magna radiator is plumbed but on cars that use the radiator for ATF and Power Steer fluid cooling they can sometimes leak between the cooling system and the ATF / Power Steer systems internal to the radiator... might be a long shot but worth a try...

Can't think of much else sorry...

Good luck with it...

Transmission cooler?

I'm going for the 'Chemi-weld' option. It would seem that it is happy to bubble away with the thermostat open, and the cap off (at operating temp). When you put the cap on, and run the car, it behaves as normal. It would seem that the operating pressure of the cooling system puts it back into equalibrium, and stops the production of bubbles. All very wierd. This points to air being sucked into the system, but where could that happen? And if that's the case, then wouldn't it leak out once the system becomes pressurised? It should leak once the engine is stopped too. Dunno:nuts:

Chemiweld working so far, no water loss after a week of daiL driving. :bowrofl: Question - when your car is at full temp, and you squeeze the top hose, does it feel...
1. Loose - easily squeeze the sides together so they touch, as if the cap is off
2. Medium - easily squeeze the sides together about half way
3. Tight as a fish's ar5e - maximum hand pressure will squeeze the sides of the top hose only about 3-4mm each side. This burns your fingers too.:rant:

Guess which one mine is.:shock:

Number 3 seems normal to me....

At "normal" temp the cooling system is operating at about 85 - 95 degrees Celsius and full pressure... that's why when you open the radiator cap under these conditions the pressure spews out and burns the cr!p out of everything! The radiator hoses would therefore be firm and hot!

Hey Dennis

Did the Chemiweld also stop the bubbles/foam from appearing, or just stop any coolant loss??

MJ

Woftam - My Kluger is about No.2 after a 30 min drive, Kombi is......:D .

Madjack - I've been too nervous to check. Chemiweld comes out this weekend so we'll see then.

Fixed. Anyone wanna buy a good Magna, tidy, new head gasket....:cool: