Possible head gasket - arrrgh

Peter C said:
How about having a pressure test done on the cooling system?
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Yesterday when I had this running I could see significant pressure in the system - I checked to see it wasnt too hot, then released the pressure in the overflow tank. This was a good 10-15 minutes after I shut it down, and there was a lot of pressure. So at least it is holding :)
 
COL said:
And also a leak down and compression test.
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COL said:
Better off doing some simple diagnostics before trying out all the bush mechanics remedies which may not work and also create other issues.
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I am looking to get that down soon. Just need to work work out who, and how much. Covid is ravaging mechanics availability as much as anyone else - plus i have an undying curiosity to learn as much as I can - which includes wanting to take part or at least observe the leakdown test
 
From my scant knowledge, doing a pressure test on the cooling system, with a cooling system pressure tester, is one way to give a heads up on a possible head gasket leak.
 
Peter C said:
From my scant knowledge, doing a pressure test on the cooling system, with a cooling system pressure tester, is one way to give a heads up on a possible head gasket leak.
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I believe you need to pull the injectors or glow plugs on the suspected cylinder - and if there is a coolant leak into the cylinder - it will flow out. At least that is my understanding of the process ( and I am sure one would want to empty said cylinder before trying to crank it over under pressure for obvious reasons ).

Once you pull the head, this cylinder should also be nice and clean - it has been nicely steam cleaned for you while the engine was running :cool:
 
Hmm, what I'm thinking about is a hand pump type of cooling system pressure tester. Engine isn't started, take off the radiator cap and attach the tester, then pump it up ( but not too much) and see if the gauge needle stays the same.
 
Peter C said:
Hmm, what I'm thinking about is a hand pump type of cooling system pressure tester. Engine isn't started, take off the radiator cap and attach the tester, then pump it up ( but not too much) and see if the gauge needle stays the same.
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Yep - that is what I was picturing. You then watch to see if the pressure stays up in a given time window, or if it is leaking too fast you can inspect everywhere to see where the coolant is leaking from. If it is a head gasket, then you need to see inside the cylinder- else how will you know it is leaking in there - hence removing the glow plug/s.
It makes sense to me that it would be done in tandem with the compression/leak down test - each test will give you different, but corroborating information to make a diagnosis. At least that is my understanding - quite happy for someone to correct me as I am very much "internet" taught :p (what i didnt pick up from dad, neighbourhood mechanics and breaking shit)
 
AussieMozzie said:
I took that to mean having the heater on
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What Dave was saying is that the position of the cabin heater control is irrelevant - it only controls flaps to allow or block air flow. The heater core has coolant flowing through it all the time.
 
Update.

I ordered a whole bunch of goodies to test the cooling circuit and compression - and as they are turning up I am getting to test. First to arrive was the T&E 55 glow plug adaptor (but still waiting on the compression tester). Next to arrive was the Liquid Intelligence Blown head gasket tester - this came this afternoon - so after ignoring the car for a week, I rolled it out and started to poke around

One thing I did during the week was talk to a few knowledgable people (including Gary and Mark from Lion auto - who were both very helpful), and Mark in particular said this all sounded fishy, and encouraged me to look at the plugs, make sure there was no water in them, and all the hoses. so, on to today

1. First thing I checked was the turbo hoses between the rear turbocharger and the butterfly intake. Bingo - I could see that the butterfly hosing pipe wasnt seated correctly, and digging down under the front egr one of the turbo hoses had partially blown off. This would explain some of the symptoms at least.

2. Then I put in the blown head gasket tester, cleared out the error codes - and started her up. Idling for almost 30 minutes, no change of color in the fluid - however - there was an almighty pressure difference when the temperature got to about 90 C - and I had to pull it out at that point as the fluid was compromised. At least I know the Thermostat opens, and that at idle there is no exhaust gas leakage.

3. I then put on the new radiator cap I had purchased (I am going to dismantle the old one to make a pressure test rig - if I can work it out), and proceeded to test out accelerating the car and ensuring that it was bled properly - previously it would stall at 1500rpm, now it is revving with no hesitation... at this point I have a big grin. It

Then of course it is time for a test drive - pulling up a few times to check radiator and coolant is all still intact - no issues. I did notice the coolant temperature get up to about 105C at one point as it was doing a FAP regen on the highway (when I got stuck in traffic) - but quickly cooled down again as soon as I got back up to speed again. I had the FAP obd2 program running the whole time, I really like this app for the real time diagnostics it gives me :)

At this point It is crisis over for now, and the jury is out on whether the issue was just the turbo piping popping off, or whether there was an issue with wet connectors, head gasket leak, and/or coolant bleeding not complete. I suspect at least two of these but in the weeks ahead I am still going to

1. Flush (to get rid of any latent Nulon stuff) and pressure test cooling system
2. Compression test. Followed by a leak-down test if I see any issues with compression
3. Change oil

Thanks all for your help, this is a great forum, and has helped a lot to steer me in the right direction (and to justify buying more tools)
 
Been away from here for quite a while, have just caught up and the news is looking good. Take it out somewhere and give it a bit of welly to get the juices going. You have earned the right to at least enjoy it a little bit!!:cool:
 
Fuelman49 said:
Been away from here for quite a while, have just caught up and the news is looking good. Take it out somewhere and give it a bit of welly to get the juices going. You have earned the right to at least enjoy it a little bit!!:cool:
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I did just that.

However first i had to fix an annoying problem with the injector return lines popping off on the rear bank of cylinders. After a bit of head-scratching I realised I had the clips on backward. That was a right pita job, for something so simple in concept :-/. Its all going now though, and had a few good runs out to the Clare valley with no issues since.
 
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Further update - Just had the coolant flushed and system pressure tested - all good, local guys appeared to do a great job - pretty happy with the service - they did a few extra little things by request (and some that I didn't ask for) and didn't charge me for them - and gave me an excellent rundown of work done.

If I get the time I might do the compression test tomorrow, do the oil change on the weekend, and start putting all the sound deadening panels back on :cool:
 
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