Help please - Pressure in coolant when cold

I’d have to check but I think my hoses are firm when cold, not solid. They are solid at temperature but the same size. Under vacuum the large radiator hoses go flat, but I think we perhaps have misunderstanding on vacuum?
This does feel like a head gasket but I would stick with my hose theory for a little while longer. When you relieve the pressure in the header does that ballooning hose shrink noticeably? If so we may be onto something.
You are going to need a set of hoses and they are NLA. @Clackers has recently broken a TDi and I believe @A2Steve will have one shortly. I wouldn’t change the coolant until I have the hoses.
 
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Evripidis said:
The firmness I did experience but the balooning never. Also it is a different engine on ours so the temperatures might be different. Maybe you can also do the vcds test that I did with the measuring blocks and see if it makes any sense.

Have you tried the sniff tester after the car has sufficiently warmed up?
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I’ve done the colour change fluid test using bubbles from the tank yes. It passes
 
Today is day three of driving adn some 250 miles done. Ive just been out and taken the expansion tank cap off from a stone cold engine. the collant has gone down a touch maybe less than a cm form a few days ago.

The cap sounded like opening a can of fizzy drink and coolant shot out the valve on the side of the expansion tank, about 10ml or so came out, the level rose a touch.

Car heats up fine and hold temps ok now its more like 10 degrees here, heater works fine, so guess its the engine lightly pressurising the coolant still from head gasket cruble somewhere. It passes the headgasket test but this must be becasue its a slight leak and I would need to run ot for an hour to get it to fail.
The exhaust doesnt let out any smoke or white smoke etc now it appears to be clean as a whistle. Only when hot and revved do i see some blue smoke clouds.

Looks like a new engine is the way forward for this project, the cost of a head, new timng belt, decoke and skim would be in the region of £1000.+

Gamble didnt pay off but at least another one can be saved on the bright side and I havent gone out an bought a new car :)
Ye gods that would be nice right now though, but only for a a week or so..
 
Why not just run it as is, seems like you just need to add coolant each week (maybe not even that if you overfill it slightly)?

Just a thought - might be interesting to see if the problem worsens or not for a while.

I appreciate the suspense may not be for everyone however
 
dj_efk said:
Why not just run it as is, seems like you just need to add coolant each week (maybe not even that if you overfill it slightly)?

Just a thought - might be interesting to see if the problem worsens or not for a while.

I appreciate the suspense may not be for everyone however
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I know, its not a huge stress but for me I like things to be as they should and it will niggle away at me. Looks lilke I may have sourced a new engine like for liek so that stress is evaporating somewhat! I dont like the idea of blowing up the coolant or gasket in the summer on the m5 near bristol though and waiting 12 hours to get home :cool:
 
Sorry only just remembered to check mine. Just went out to check, last drove yesterday evening so stone cold. To my surprise no hiss when taking the cap off. I did record a video but watching it back the garden shredder in the background is all I can hear 😅 but definitely no hiss this time.
 
CrispyEdd said:
Looks like a new engine is the way forward for this project, the cost of a head, new timng belt, decoke and skim would be in the region of £1000.+

Gamble didnt pay off but at least another one can be saved on the bright side and I havent gone out an bought a new car :)
Ye gods that would be nice right now though, but only for a a week or so..
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CrispyEdd said:
Looks lilke I may have sourced a new engine like for liek so that stress is evaporating somewhat!
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Hello Edd,

Glad you've found a replacement engine and hope it all goes well Sir, it's certainly worth saving this one and I admire you for doing so, it's a great looking car which will be brilliant once you've put these woes behind you.

Kind regards,

Tom
 
2work said:
Hello Edd,

Glad you've found a replacement engine and hope it all goes well Sir, it's certainly worth saving this one and I admire you for doing so, it's a great looking car which will be brilliant once you've put these woes behind you.

Kind regards,

Tom
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Thanks Tom, appreciate it! If it wasnt for chance of engine popping up just now I would be consigned to driving a time bomb.
Yes enjoying the car getting better all the time with each remedy, shame it ended with a rather large fix. Lesson to all dont buy a black car in the dark at -4 degrees with no exhaust

:)
 
Will you take the head off the current engine, once you have the replacement up and running?
My gut, (not that reliable), says it's not the head gasket.
God luck either way.
Mac.
 
Not sure yet will depend on garage and what approach they'd prefer. I think I'd rather leave it as whole for now.
Why do you say your gut feeling? I mean there is surely only one way pressure is getting in there yes?
 
CrispyEdd said:
The cap sounded like opening a can of fizzy drink and coolant shot out the valve on the side of the expansion tank, about 10ml or so came out, the level rose a touch.
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Cap removed with the engine hot or cold? If the former, that would be expected.

RAB
 
CrispyEdd said:
Not sure yet will depend on garage and what approach they'd prefer. I think I'd rather leave it as whole for now.
Why do you say your gut feeling? I mean there is surely only one way pressure is getting in there yes?
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Yes, that's the perceived wisdom, but I can't see it running well with no white smoke, if the gasket, and or head is failed. The coolant loss is into the combustion area after all. Either that, or I'm an eternal optimist! Good luck.
Mac.
 
Hello!

Back with some interesting info. So the head gasket had gone on the car, was when I bought it, just slightly gone. Unusual for an amf but not unheard of.

I ran some steel seal in it, solved the gasket, didn't solve the pressuring! Coolant still painting the inside wing every journey! Odd.

Today I drained coolant. When I took hose off the thermostat (pointless when cold I know) there was a sucking noise, like a builder eyeing a job.

So flushed what I could out of everything refilled and set off, temp to 90, rag it a bit got home and caps leaking and hissing..

I checked the hose off the thermostat. Stone cold.
So the thermostat is blocked or not opening!!! This explains the stress on the system and shows how robust these cars are. I've done 2000 miles on motorway with the rad not in use,, lucky its been freezing cold!!!!

So now another job to do, now how does that altenator come off 🙄
 
Another day another learning!
I took the thermostat out, it was full of crap, slime and chalky stuff. Looked like it would be suboptimal shall we say when opening!

It isn't genuine, its Th branded looks odd compared to my genuine one, especially the little rattly peg that would let stuff through?!!? Glad it's not in the car now anyway.

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So I cleaned it all dried it, fit a new genuine seal and thermostat. Ran it up to temperature and drove it hard. It's now at temp but coolant hose off the thermostat housing is cold, like its empty, and coplant still spurted out header tank.

So i guess more gunk still in there and re blocked the thermostat! So tomorrow I'll take it out again and try and flush it better.

Any tips on removing the lower coolant hoses on the oil cooler? Hard to get on the clips and push hoses off.
 
CrispyEdd said:
Another day another learning!
I took the thermostat out, it was full of crap, slime and chalky stuff. Looked like it would be suboptimal shall we say when opening!

It isn't genuine, its Th branded looks odd compared to my genuine one, especially the little rattly peg that would let stuff through?!!? Glad it's not in the car now anyway.

View attachment 105864View attachment 105865View attachment 105866

So I cleaned it all dried it, fit a new genuine seal and thermostat. Ran it up to temperature and drove it hard. It's now at temp but coolant hose off the thermostat housing is cold, like its empty, and coplant still spurted out header tank.

So i guess more gunk still in there and re blocked the thermostat! So tomorrow I'll take it out again and try and flush it better.

Any tips on removing the lower coolant hoses on the oil cooler? Hard to get on the clips and push hoses off.
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I wonder if it has been run with the wrong type of coolant concentrate in it at some point and there has been a chemical reaction generating nasty gunk in there?

When my thermostat stuck closed a calendar year ago the car would go over 90 degrees reasonably quickly but I was able to stay on top of this in cold weather by running the cabin heater on full with the windows slightly open to avoid poaching my daughter and I during the long motorway journey to Plymouth. Luckily with a bit of A2oc discussion we concurred that a new thermostat was needed and so it proved.

Do you have any locking pliers? I have a set of longnose locking pliers and they are a godsend for removing coolant pipes as you can clamp them onto the clips and then have a hand free to persuade the pipe off the connector.
 
Alternatively get a set of the correct hose clip pliers. Either the short version or the one with the flexible shaft and "remote" end to get to those really difficult clamps.
 
Robin_Cox said:
I wonder if it has been run with the wrong type of coolant concentrate in it at some point and there has been a chemical reaction generating nasty gunk in there?

When my thermostat stuck closed a calendar year ago the car would go over 90 degrees reasonably quickly but I was able to stay on top of this in cold weather by running the cabin heater on full with the windows slightly open to avoid poaching my daughter and I during the long motorway journey to Plymouth. Luckily with a bit of A2oc discussion we concurred that a new thermostat was needed and so it proved.

Do you have any locking pliers? I have a set of longnose locking pliers and they are a godsend for removing coolant pipes as you can clamp them onto the clips and then have a hand free to persuade the pipe off the connector.
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Thanks yes I have the pliers but not locking, I actually have hose clip pliers Medium angled and remote flexi but too large to get on them. I'll give it another go tomorrow morning.
 
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