[Mk2] [Turbo] Coolant issue

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willbutler1
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[Mk2] [Turbo] Coolant issue

Post by willbutler1 »

Hi everyone

Bit of an odd problem.

I had some work done recently and this resulted in having to refill the coolant system and bleed it, I did this without too much hassle making sure the car was level, filled it slowly making sure that the clear pipes connected at the from of the car were both full of fluid. Ran the engine and bled all the air out.

Once bled I closed all the taps and all seemed well.


After driving for a short distance I could hear air/rushing water throughout heater matrix (by turning it from hot to cold I could make the noise stop) so drove home and sure enough there was air in the system again so started the bleeding process,again.


I have checked for leaks as best as I can round he heater matrix, no wet carpets etc, and also pressure tested the system up to 1.4bar and it holds quite nicely, I cannot see any leaks either but every time I bleed the system in no time at all it's blowing bubbles and if left for long enough it stops blowing hot air thought the vents so the level is going down.


Could I be looking at a cracked block? I have checked and there is no muck in the oil filler cap and it never runs any hotter than just below the half way mark, is it drawing air in from somewhere?


Any advice would be appreciated, before I make a trip to a specialist.

Regards

Will
Ryan S
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Re: [Mk2] [Turbo] Coolant issue

Post by Ryan S »

making sure the car was level



this could be your problem, i was always under impression the rear of the car had to be jacked up to get the air out?? they are notorious for airlocks mate :(

EDIT: i've never actually had an airlock even though i've done a couple of coolant changes.
going4the1
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Re: [Mk2] [Turbo] Coolant issue

Post by going4the1 »

Did you have the heater control set to fully hot? If not an air lock may result. What I've done the last couple of times is to 'burp' the heater pipes to get the last of the air out.

By this I mean - have the car running - set the controls to fully hot for a few minutes. Then while the car remains running, set the controls to fully cold for about 30 seconds. This seems to allow any trapped air to collect together. Then open the heater controls fully again.

Doing this a few time has managed to express the last of the air from the channels.

Good luck.
bobhatton
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Re: [Mk2] [Turbo] Coolant issue

Post by bobhatton »

willbutler1 wrote:Hi everyone

Bit of an odd problem.

I had some work done recently and this resulted in having to refill the coolant system and bleed it, I did this without too much hassle making sure the car was level, filled it slowly making sure that the clear pipes connected at the from of the car were both full of fluid. Ran the engine and bled all the air out.

Once bled I closed all the taps and all seemed well.


After driving for a short distance I could hear air/rushing water throughout heater matrix (by turning it from hot to cold I could make the noise stop) so drove home and sure enough there was air in the system again so started the bleeding process,again.


I have checked for leaks as best as I can round he heater matrix, no wet carpets etc, and also pressure tested the system up to 1.4bar and it holds quite nicely, I cannot see any leaks either but every time I bleed the system in no time at all it's blowing bubbles and if left for long enough it stops blowing hot air thought the vents so the level is going down.


Could I be looking at a cracked block? I have checked and there is no muck in the oil filler cap and it never runs any hotter than just below the half way mark, is it drawing air in from somewhere?


Any advice would be appreciated, before I make a trip to a specialist.

Regards

Will


What was the work you had done and why was the water not filled by who ever did the work?

We have never had to bleed the cooling system on any MR2. We fill it, run the engine with the heater on hot and cap off, keep topping up then take it for a drive. Get back and top up again, job done
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s
JD
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Re: [Mk2] [Turbo] Coolant issue

Post by JD »

http://mr2oc.co.uk/know-your-2-knowledg ... bartid=161

This is a really helpful guide - I followed the coolant section of it when I changed the coolant last time and didn't have any problems. You have to make sure you do things methodically when you've got engine at one end and radiator at the other.

edit - just read the above post - maybe you don't have to but like i said, this worked for me.
willbutler1
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Re: [Mk2] [Turbo] Coolant issue

Post by willbutler1 »

Hi there thank you all so much for the responses.

I had repaired a coolant pipe on the heating system, the copper pipe had fractured and was leaking onto the fuel tank so I cut out the cracked section and installed a section of hose so this is why I initially had to bleed the system. Once I had completed this and was bleeding the system I found the radiator had failed at the bleed point, probably from the amount of initial bleeding of the system, actually to think of it I probably had the air in the coolant system issue at this point but didn't realise and just thought it was due to the work I had done. After that I couldn't face replacing the radiator my self so took it to a specialist. I had the radiator replaced by a specialist MR2 company who I am completely confident re-filled and bled the system but would have been unaware aware of this bleeding, pressure testing (and passing the pressure test process) problem that I have now, like I said the car is bled free of air then after a while the gurgling starts and I know air is in the system again. The repair shop wouldn't have known and especially as it seems that the car looses it coolant quicker now than it did when I initially had the job done.

While my wife was running the car I did try the "turn the hot off for a while and then back on again at about 3000rpm) and this did expel a lot of air, but then again shortly after more air would come through.

When I did the bleed I read all the articles I could on line even the one you mentioned JD, and followed them exactly. Maybe I am dealing with an air lock but I even had my wife sit in the car, varying the rpm while I watched the air come out, and no sooner did I think that all the air had gone there would be another constant stream of air coming through the pipe.

Kind regards

Will.
ashley
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Re: [Mk2] [Turbo] Coolant issue

Post by ashley »

bobhatton wrote:We have never had to bleed the cooling system on any MR2


:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:
Peter Gidden
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Re: [Mk2] [Turbo] Coolant issue

Post by Peter Gidden »

willbutler1 wrote:I had the radiator replaced by a specialist MR2 company who I am completely confident re-filled and bled the system but would have been unaware aware of this bleeding, pressure testing (and passing the pressure test process) problem that I have now


willbutler1 wrote:it seems that the car looses it coolant quicker now than it did when I initially had the job done.


willbutler1 wrote:I did try the "turn the hot off for a while and then back on again at about 3000rpm) and this did expel a lot of air, but then again shortly after more air would come through.




willbutler1 wrote:I had the radiator replaced by a specialist MR2 company who I am completely confident re-filled and bled the system but would have been unaware aware of this bleeding, pressure testing (and passing the pressure test process) problem that I have now.


Assuming you told them the full history, I respectfully disagree.

Any MR2 specialist, if doing a proper job would have filled, bled and road-tested the car.

They would also have investigated your coolant loss issue and reported back to you.
willbutler1
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Re: [Mk2] [Turbo] Coolant issue

Post by willbutler1 »

I apologies I'm probably not being clear

As I said the issue is one that manifests it's self quite slowly so it's entirely possible once the system was bled it could have seemed ok even passing a pressure test, it's only once the car has been driven that you start to notice the bubbles and noises start, so it seems to me it could be easily missed, as I said it also passed the pressure test and when I pressure tested it (with a correct tool) it holds pressure. I do have faith in the garage as the issue could have been there before I took it to them.
Peter Gidden
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Re: [Mk2] [Turbo] Coolant issue

Post by Peter Gidden »

Rev3 Turbo?
willbutler1
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Re: [Mk2] [Turbo] Coolant issue

Post by willbutler1 »

Rev1 turbo


Gut feeling is either a leak that I can't find (and doesn't show up on a pressure test) or cracked block. Just can't imagine an air lock being this much of a pain.
Peter Gidden
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Re: [Mk2] [Turbo] Coolant issue

Post by Peter Gidden »

willbutler1 wrote:Rev1 turbo.


Highly unlikely to be a cracked block on a Rev1.

Still got it's original head gasket? If so i bet that's your problem.
Last edited by Peter Gidden on Tue Jan 07, 2014 9:28 pm, edited 1 time in total.
willbutler1
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Re: [Mk2] [Turbo] Coolant issue

Post by willbutler1 »

It's a rev1 if that makes any difference, wouldn't it have muck in the oil system?
Peter Gidden
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Re: [Mk2] [Turbo] Coolant issue

Post by Peter Gidden »

willbutler1 wrote:It's a rev1 if that makes any difference, wouldn't it have muck in the oil system?


No. Not if combustion gases are getting into the cooling system.

Your specialist should be able to confirm the diagnosis that for you.
willbutler1
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Re: [Mk2] [Turbo] Coolant issue

Post by willbutler1 »

Ok thanks.
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