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Discussion Starter · #1 ·
Hi Guys, i'm in need of some urgent help if possible... i have a 1991 t16, and i have just had the engine out to have the gearbox replaced. The problem i have is that the expansion tank keeps backing up with water, and overflowing through the cap... i have tried 2 new caps and both do the same. There are constantly air bubbles coming up through both pipes that run to the expansion tank, eventhough i have bled the system many times... it's really doing my head in now, and i can't figure out why it's doing it.

Any help very much appriciated.
Chris
 

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There's an obvious answer - and, unfortunately, it's "HG".

I presume you've done the usual checks in that direction?

Other than that, sure there's no airlock in the system? Got it all warm, heater full on, and bled it at the nipple on the 'stat housing?
 

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Discussion Starter · #3 ·
yeah, tried all that... there is also a fair bit of white smoke, with a tinge of blue on tickover, and runs pretty lumpy on tickover also...
 

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I'm late to this thread but this is cut and dried, head gasket, shiny plug or not. If you've a compression tester, do the test.
 

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Discussion Starter · #7 ·
Unfortunately i don't have a compression tester. I have checked the plugs, and they are all light brown coloured... there is no oil in the water, and no water in the oil...

Chris
 

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Discussion Starter · #9 ·
I have spoke to a local saab specialist, and he seems to think the head may be cracked between pistons, thus giving exhaust gasses into the coolant system... so it looks like it's time for a new head gasket, and to upgrade to the 2.3 head and the white ring injectors i've been promising myself for a while :eek:
 

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I think it's unlikely to be a crack in the head. The 16 valve heads are much tougher in this respect. The 8 valve heads were prone to it. A blown HG doesn't always show on the plugs and it doesn't always leak into the oil, never in my case.

Another give-away on HG is water leaking from the exhaust joint after turbo before the bend. Also hold your hand in the exhaust smoke/steam until your hand is wet. Taste it with the tip of your tongue and if it's HG you will taste the sweet taste of anti-freeze. I'm assuming you have it in the system.
 

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when the car is cold, remove the cap and put your hand over the expansion tank, have someone start the car for you. if you feel a "pulsing" or instant pressure build up under your hand then you have a cylinder-cooling system leak.
i am a little wary about the tasting of exhaust. antifreeze isnt good for you...
 

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i am a little wary about the tasting of exhaust. antifreeze isnt good for you...
Go on, it's good for you. Seriously, I'm not suggesting he drinks it. Just touch it with the tip of the tongue. It's a standard test and it's not hydrofluoric acid. I thought you'd be used to this Chris with your bush tucker feasts of witchety grubs.
 

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I think it's unlikely to be a crack in the head.
Unlikely, agreed. But don't rule it out. My head cracked, between two valve seats. Hairline crack, didn't spot it first time I changed the HG. Spotted it a week later when I changed the HG a second time.

And it's a 16 valve.

I think all our heads are getting old, and aluminium alloy hardens over time.
 

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Given that all the other possibilities suggested equal large expense, you might want to consider the possibility that the thermostat is failing to open. At least it will only take half an hour to rule out. Remove the thermostat. Test in a bowl of boiling water. If it opens, replace, it isn't the problem. If it doesn't, cut the mechanism out and replace the resultant disk with a hole in it. You need to do this to seal the thermostat housing. Top up system and see.

I had very similar symptoms to yours last year whilst on holiday in France. The failure of the French roadside assistance guy to listen to me and do the above resulted in my holiday insurer forking out for taxis, hotels, flights for 3 people and repatriating the SAAB on a low loader. Oh, and I saved 800 miles of petrol!

Sometimes, just sometimes, the answer can be simple.

Good luck

Chris
 

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Go on, it's good for you. Seriously, I'm not suggesting he drinks it. Just touch it with the tip of the tongue. It's a standard test and it's not hydrofluoric acid.
tasting exhaust gas isnt something i have done as yet, i have seen what glycol poisoning can do to people even from a drop of it, which is why i was a little concerned.. either way, whatever floats your boat ;)


I thought you'd be used to this Chris with your bush tucker feasts of witchety grubs.
havent tried witchety grubs yet either.. too busy riding kangaroos :cheesy:
 
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