Coolant issues, head gasket gone??

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arcascomp

Well-known member
Joined
Jan 20, 2012
Messages
775
Gentlemen and ladies,

It's been a while since I've been on here, combination of ridiculous amount of work recently and the peace of mind having such a reliable old gal of a truck. How are you all doing? Sadly, I think my T2's having a dig at me right now for the lack of TLC over the past few months.

The other day I noticed after about 3-4 miles that the temp gauge had moved three quarters of the way up to the red area instead of it's usual 1/4 of the way mark. I stopped and popped the bonnet, but it all seemed fairly okay appart from the expansion tank was full and possibly overflowing slightly, but hey, the engine was saying that it was hot so I guess that's what it is for sort of.

Got back in and the temp had dropped a bit so nursed it back home without any issue.

Next morning, she was hard to get started, eventually popped into life with a big cloud of smoke (mix of black and white I think) a bit like she usually does in the winter when I forget to thin the veg oil enough. Drove in the 3 mile journey to work, no worries, but then it barely warms up much over that distance.

Took her back home at lunchtime and the temp gage didn't move all the way home at all, but should have shown that the engine was warm at the very least. Opened up the bonnet and the expansion tank had a small amount in it, but there was air bubbling through. Also, there was no heat from the heater either, which made me think there was air in the system. Thinking that she'd not be that warm yet and the fact that the top of the rad wasn't that hot, I killed the engine and loosened the rad cap to create a short but spectacular water feature! Ho hum, there may have been air in the system, there certainly was now!

So, topped up gently, knocking the pipes and then left running over lunch with the odd top up to make sure all the air got out. Heater was on full and by the end of it, blasting out hot air. Temp gauge back in the normal position. Drove back to work, everything was hunky dory. On the way back, no temp gauge, no heat from the heater until just before my street when the temp gauge jumped to halfway mark instantly. Forgot to check heater at that point. Expansion tank full to over flowing again.

Tried last night taking out the thermostat and that definitely seems to be stuck closed, so had a run about without any stat. Engine was warm, but heating barely and expansion tank way full again. I could tell when I stopped that the water pipes from the rad were under pressure as I couldn't squeeze them at all so it looks like the coolant is getting pressurised some how.

Oil filler and dip stick both are showing lovely black oil, no signs of emulsion there and no obvious loss of power, but did have trouble starting for a bit last night and ended up with a cloud of white smoke (water getting into a cylinder maybe?).

Any suggestions or ideas? If it's the gasket, what sort of price is it usually to get fixed? Difficult job for doing at home? The old gal's a second car, but it's amazing how you get used to having her around and I prefer driving the T2 to the wife's Mazda 5!

Cheers,

Craig.
 
Sounds like head gasket failure between cylinder and water jacket. Have a smell if your coolant and see if you can smell exhaust fumes or get a garage to test it. Means a new hg and preferably getting the head skimmed or at very least checking for true ( side of a steel rule or other straight edge will do) about a days work plus machining time if you've not done it before, less if you know what you're doing.
 
Sounds like head gasket failure between cylinder and water jacket. Have a smell if your coolant and see if you can smell exhaust fumes or get a garage to test it. Means a new hg and preferably getting the head skimmed or at very least checking for true ( side of a steel rule or other straight edge will do) about a days work plus machining time if you've not done it before, less if you know what you're doing.

Does sound like gasket as mentioned above, a compression test will probably say which cylinder, and will help to confirm.
 
Yeah, sadly I think you're all correct - will need to find a suitable place to test her out. Interesingly, last night I chucked some of her maj's excessively axed diesel in the tank and this morning she started fine with no white smoke.

Decided to lave her and take the wife's motor instead though, don't really want to inflict any more damage than I already have!
 
Your symptoms are not consistent though, that's hat gets me :nenau

I was thinking thermostat, then you mentioned it :thumb2
 
Thermostat has definitely failed shut, but would appear to be getting pressure in the coolant even without a thermostat in the housing.

Presumably, no stat would mean it'll take longer to warm up, but otherwise be as usual?

Where is the temp sensor used for the gauge on the mk1 T2? Last run about without the thermostat it didn't seem to register any warmth in the block.
 
shine a torch into your expansion tank ....... can you see any little bubbles ? ...... obviously when engine is running tho :doh
 
When the duff 'stat was in, I would get quite obvious bubbles coming through. Since removing the 'stat I've not driven far, but I could see the water swirling about in the tank (it's quite overfull now) so I'm fairly sure the system is still getting pressurised.
 
Have a read of this!!!!!!!!!!!!!!!!!!!!

http://www.nissan4x4ownersclub.com/forum/showthread.php?t=17410

I was 100000% convinced it was my head but they are stronger than you think, mine turned out to be a leaky water pump leaking water out and air in and a failed thermostat that had failed shut

Read all the way through, some pics of the failed shut thermostat towards the end as well
 
Have a read of this!!!!!!!!!!!!!!!!!!!!

http://www.nissan4x4ownersclub.com/forum/showthread.php?t=17410

I was 100000% convinced it was my head but they are stronger than you think, mine turned out to be a leaky water pump leaking water out and air in and a failed thermostat that had failed shut

Read all the way through, some pics of the failed shut thermostat towards the end as well




Now this is real "medal" material..
+ 5 if you are right...

:lol:lol
 
Well, fingers crossed I owe Banshee and Terrano Bob a few beers!

Fitted a new stat today and lobbed in a bottle of K-Seal for good measure. Jacked up the front, heaters on full and ran her with the rad cap off to get all the air out. Warmed up to usual reading on the gauge and stopped bubbling so took her out for a 10 mile run about and full heat from the blower and gauge stayed at the normal quarter mark. :clap

The expansion tank has filled right up,but I guess that's it's job really. Just hoping it drains back when the coolant cools and contracts.

As I said, finger crossed! and thanks for the suggestions. :thumbs
 
Don't know if this has already been said but start the engine from cold then immediately go and feel the coolant hoses. If they're rock hard, you have cylinder pressure venting in to the cooling system. If you have bubbles venting in to the expansion tank then you have pressure over 1bar in the cooling system and this is not normal unless a) the headgasket has failed allowing combustion pressure to bypass in to the cooling system, b) there is insufficient coolant concentrate preventing the solution boiling at 100C but this is inapplicable on a cold start, or c) the rad cap is defective and blowing by under 1bar.
Sorry to be pessimistic!
 
Don't know if this has already been said but start the engine from cold then immediately go and feel the coolant hoses. If they're rock hard, you have cylinder pressure venting in to the cooling system. If you have bubbles venting in to the expansion tank then you have pressure over 1bar in the cooling system and this is not normal unless a) the headgasket has failed allowing combustion pressure to bypass in to the cooling system, b) there is insufficient coolant concentrate preventing the solution boiling at 100C but this is inapplicable on a cold start, or c) the rad cap is defective and blowing by under 1bar.
Sorry to be pessimistic!

Sadly my friend, you seem to be right.

Have replaced the 'stat, dropped in a bottle of K-seal and replaced the rad cap and still she's pumping excess into the expansion bottle, though the top pipes aren't getting so pressurised now as they were so I guess the rad cap was wearing thin too.

So, as she runs (and has a fairly full tank right now) on 90-100% WVO, would the standard 'sniff' testers detect exhaust gases? I can only smell chips when I'm trying to sniff the bottle myself as the standard exhaust odour is fairly noticeable!

Next question, anyone got any good recommendations on where to have the gasket changed, preferably in central belt of Scotland? I know that if I lived nearer to Rick and co., it would already be there, but I'm not convinced she'd make the journey without possible further damage - not to mention the time factor driving down and back.

If I was to tackle this on the drive, apart from a 6'7" gorilla to help with the lifting of parts, what bits do I need to do the job? Should I just do the water pump anyway while it's in bits?

Cheers all!
 
Instead of the sniff test you could try the condom test (seriously). Take the cap off the rad and fit a condom over the neck. Start the engine and if there's exhaust gasses in the system the condom will start inflating.
 
Surely, that will only tell me that the coolant is being pressurised, which I know already, bubbles in the expansion tank tell me that and I can keep the condom for better uses! :naughty :augie
 
If there's exhaust gasses leaking in the condom will keep inflating, ideally do it when the engine is cold.
 

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