Coolant leak?

[Been a while]

This is a strange one.. every now and again I end up with a small puddle of coolant on the floor so I finally motivated myself to go looking for the leak..
The only place I can see where it could be coming from is the heater pipe to the head and thermostat area, orrrr from between the head and block !.. ok, so if was the head gasket shed be doing it like clock work, you'd think.. but its not, and its not as soon as you turn her off either?? Come out in the morning and she's wet herself ??

The only thing I can think of she's boiling after "turn off" and the coolant is pushing past the barb to the rubber hose from thermostat to heater pipe..
I was going to replace the barb, but! Being mild steel into alloy I'm extremely worried it will crack the housing.. so I've cleaned, rust treated and will use a silicon on refit instead of trying to remove the barb fitting..
I know you love some pics so here ya go...

 

[Been a while]

I could see that breaking that cover trying to remove that barb.. it cleaned up better than I thought it would so it's staying..

 

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I've only just changed to the Blue coolant so I maybe onto something here...

 

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New is Genuine! This bugger was the only one I didn't do when I did the I.pump... she's definitely stretched and got a bit puffy

 

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Where i hope its not coming from...

 

[Been a while]

To do it right i should replace it, but I'm scared shiteless it would be well seized and break that cover and aperture on removal...
It's much cleaner now so I'm willing to give the sealant a try, fit the new hose and give it a few days to set properly and then fit the clamp..

You can see where the lip has rusted away..

 

[Been a while]

First coat of rust treatment..

 

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Doing its thing... this is the end that goes to the thermostat housing..

 

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Any suggestions on what silicone, adhesive etc you'd try?

 

[Old.Tony]

Looks like you might have found the culprit - hope so, anyway!

You could use a good Sikaflex which should be able to withstand around 200C or so, but I don't know that it will withstand much pressure. You should be limited to around 15psi in the coolant system anyway. If you're looking for a permanent bond, why not try an epoxy-based adhesive? Even a 30 minute epoxy holds quite well but you could use an 8 hour one which is considerably stronger. Not on a shiny surface of course, epoxies like a rough surface to grab on to.

 

[Been a while]

G'day Tony.. thanks for chiming in. I don't really know, it can't be the head gasket "you'd think" -so I'm hoping it's the issue...
I am planning on " more working myself upto it" doing the motor rebuild and gearbox but not juuuust yet..

That thermostat housing is actually part of the "oil pump cover" and i didn't want to risk snapping a hunk out of it trying to remove it.. I've actually got a new genuine "oil pump/cover" for it, I was going to give a new oil pump when I did the I.p but, it's a huge job eh I'll keep it for when I rebuild.

I went with the genuine silicone gasket goo from Nissan I had left over from the I.p job.. The red stuff, that'll definitely take the heat and adhere well,, i hope!

Just waiting on the gasket now, turns out they're made from gold - $30 delivered

 

[Been a while]

A piece of gold turned up today ! Part number for anyone in need

 

[Been a while]

These cleaned up better than I thought they would.. 2 treatments of rust converter.. I'll add "just a very lite smear" of silicone to each to help them seat..

 

[Been a while]

I'll give the silicone a good 24hrs "or more" to set before adding coolant. This ones had about 48hrs to set before I added the clamp..
Weather it's the right thing to do I have no idea, sounded good "in my mind" at the time.. we'll see i guess

 

[Been a while]

Aaaand nothing goes to plan on the Navs eh
I had one of the 2 nuts "round off" on me grrr... I had juuuust enough space to get a hacksaw blade in there to cut some of the meat off the nut, then i used the cold chisel and hammer to free it.. dang lucky huh
After that moment,, there was no way I was trying to remove that "Barb fitting" ... me to scared

The new flanged nuts are far better than the original, they have that locking surface on them. These nuts have no spring washer fitted to them.. They must rely just on the locktight from factory, I'll still add a drop on "fit up"..

 

[Been a while]

Dangit dangit daaaaangit! I thought I had it but, nooooo!

Have we all heard about the "cover plate to block" coolant leak? .. seems to be aaaaanother zd issue.. it looks like I've hit the deciding factor regarding a motor build and gearbox
The stinking thing- I've tried loving this nav but it's fkn pushing it... if I hadn't of spent so much time and money on it in the past I'd wreck it out...

 

[Been a while]

In there grrrrr
it's a huge job too... May as well "pull the pin" and rebuild....

 

[Been a while]

I torqued up the cover bolts a touch more... we'll see I guess..

 

[Been a while]

No drip this morning... Reading up on the cover plate leak issue, it only does it when it's cold enough for the metals to shrink.. And that's what mine was doing, weird huh,, got me good that one... you'd think she'd squirt at running temp eh..

 

[Boogieboots]

Fingers crossed BaW. Although I would not want to be in the position of leaking only when hot or only when cold.
There should be no fkn leaks!