Blown hg on the 144.

[Citizen.Agfa]

Originally Posted by adamsky01

ovious one take thermo stat back out and check it using the ketel trick

First one we did, Mike, but thanks anyway.

Water pump off, no damage, no play, now we're REALLY stumped.

To recap - all pipes/hoses have been inspected prior to refitting during rebuild. Rad re-cored, heater removed, matrix dismounted, flushed, remounted and refitted. Water pump in good nick. Thermostat works. Blow-off caps work. Compression tests revealed good compression, no hydrocarbons in coolant.

Some years ago I recall someone telling me that the old red-block was a bugger to bleed after refilling the cooling system - anybody heard anything of this, cos if this is a bleeding problem (boy, is this ever a bleeding problem!) then that would explain the sudden increase in pressure with no obvious cause.

All thoughts, please, and thanks for all the comments so far,Nick H.

[222s]

Does sound a bit extreme for an airlock, but then I'm not familiar with the 140 series cooling & heater plumbing. However for the Amazon, this is how I usually bleed the cooling system:

http://www.volvoforums.org.uk/showpo...8&postcount=10

HTH

[Citizen.Agfa]

Originally Posted by 222s

Does sound a bit extreme for an airlock, but then I'm not familiar with the 140 series cooling & heater plumbing. However for the Amazon, this is how I usually bleed the cooling system:

http://www.volvoforums.org.uk/showpo...8&postcount=10

HTH

Thanks for that, I will certainly give it a go, beats the method recommended to me some years ago - "Drive it for a bit, then ease the top of the bottle, drive it a bit more, ease the bottle top again, repeat as needed until eventually it'll stop venting air".

Thanks again.

[john h]

If it's not an air lock, a few more straws to clutch at...

A blocked hose, with pressure building up behind it? (Maybe some deposit from within the block's water jacket has moved, post rebuild?)

Heater valve self-destructed internally & caused a blockage

Something wierd with the head gasket... e.g
A compression leak that only happens when it's hot
A tiny compression leak that doesn't show in a comp test, but gradually builds up when the cylinder is pressurised many times per second when running.

Something else causing overheating & hence extra pressure... timing way out, binding brake, partially blocked exhaust?

Some hoses connected the wrong way round? E.g if the hoses to the heater valve were on the wrong way round, would this cause anything? (Is there a non-return valve anywhere in the circuit?)

Does it have a water heated inlet manifold? I think my old carb 164 I had years ago did. Could something be blocked/airlocked there?

None sound very likely, but you've tried all the logical things!

Best of luck

John

[Citizen.Agfa]

Right, been a while since I posted, apologies for that.

Sooooooooo, what's been occurring, then?

Car has been over at Malcolm's for the last couple of weeks just sitting. I went over today and started to eliminate the last possibility, the water pump. I removed the 'stat, bolted the cover back without a gasket then removed the top hose at the rad end. Started the car up and, sure enough, water flowed - BUGGER, not the pump then!

Replaced the 'stat and top hose. Filled system with top quality rain water from the gutter-butt, fired it up and waited.

Followed the Manuel as per bleeding, viz run engine at various revs for a few minutes with expansion bottle cap loose; tighten bottle cap, vent as necessary. Time passed, vented air from the system. More time passed, more air vented. Bugger, level rising to top of bottle! Engine off, allow cool-down, level returns to normal.

Followed this routine three times then thought, bugger this, let's get Malcolm's wheel ramps out and get the front end high in the air.

More water, more venting; some more venting; even more venting 'til I realised that the last few times I'd vented the bottle no air had been forthcoming and the level had not altered - had I got a result?

Provisionally it looks that way. No road test as yet as it was about 18:30 hrs by this time, and I'd been over the garage since 13:00hrs, time to go home.

Work tomorrow and Thursday, I'll be back over the garage Sat to give it a thrape, sorry, ROAD TEST and will post in the evening.

Nick.

[john h]

Good luck!!

John

[Citizen.Agfa]

Sigh.

What with one thing and another I only managed to (attempt) to bring the 144 back to Lampeter late yesterday arvo...

Note 'attempt'.

Cwrtnewydd to Lampeter is seven miles of unclassified, 'B' and 'A' roads; managed five miles then, 'hisssssssss', clouded-up windscreen, pool of coolant in passenger footwell and usual clouds from under the bonnet - BUGGER!

Recovered the car yet again back to Pensarn Volvos and left it there.

Initially, without any checks but just on the evidence of last evening, it looks like this time the heater matrix has ruptured (oh joy!); it could, of course, just be one of the heater hoses has been blown off but I won't know 'til I physically check it.

As to the main problem, well, I am approaching the end of my rope. In light of all we have so far attempted nothing presents itself as a solution.

I have just read back through the thread and realised I have made an omission - the car was not only in for a thermostat change (originally) but had in fact gone in to get the inlet manifold gasket changed. Reason for this? The week before I had been up to Pensarn for an un-related reason when Malcolm spotted a 'chirruping' noise coming from the general direction of the engine. By leaning gently down on the inlet manifold he could stop the noise. He tightened the manifold bolts but this made no difference so the decision was made to replace the gasket.

My point is - could this leak in the inlet area have caused a hot-spot? Could it, in fact, be the cause of possible h/g rupture? I know there has been no evidence of hydro-carbons, but as John H suggested:

Something wierd with the head gasket... e.g
A compression leak that only happens when it's hot
A tiny compression leak that doesn't show in a comp test, but gradually builds up when the cylinder is pressurised many times per second when running.

I really am at my wits end.

I will collect my thoughts. Which won't take much collecting!

Nick.

[ClassicVolvoShop]

Well... Don't go bite my head off... OK? - Did you by any chance put the thermostat upside down?..

And.. instead of being all sure of the "new" thermostat - why not just give it a try - take it out and run the car - does it act the same?

Your symptoms are 99% a matter of no circulation in the cooling system.

[Citizen.Agfa]

Originally Posted by ClassicVolvoShop

Well... Don't go bite my head off... OK? - Did you by any chance put the thermostat upside down?..

And.. instead of being all sure of the "new" thermostat - why not just give it a try - take it out and run the car - does it act the same?

Your symptoms are 99% a matter of no circulation in the cooling system.

I am beyond biting heads off; I'm beyond trying to be smart about this, ALL help is gratefully accepted in the spirit in which it is offered.

The problem with running the engine with no 'stat is sealing the housing; the 'stat has a rubber ring round the edge which acts as a gasket; no 'stat, no ring, no ring, no watertight seal.

It was deffo in the right way up, too.

Thanks for your input, and keep it coming 'cos this fool is out of ideas.

Nick.

[john h]

Interested to hear about the timing of this problem, in relation to getting the inlet manifold gasket changed.

I would not have thought a gasket leak would have caused HG failure, but it's possible I suppose. Running lean on one cyl, detonation/heat frying something?

The other thing that occurs to me is does it have a water heated inlet manifold, like some 164s and 240s?

If so, there could be a different link between your gasket change and the overheating. Maybe the new gasket was faulty, or slightly the wrong spec, and blocked a water-way through the manifold? Maybe it had one of those pre-cut "holes" where you have to push out a bit of the gasket before fitting; may not have been done?

John