Coolant Leak From Pipe Under Intake - Whats It Called?

[damono]

hello.

I've got a bad coolant leak from what seems to be a metal pipe that comes off the block, under the intake (on the drivers side).

I need to find out what the part is so I can order one, then whats the best way to tackle it. Im guessing it would be easier to get it on a hoist, but dont have access, im guessing ill have to take the whole intake off to get to it.

It feels like the metal pipe is a 90degree elbow, then goes onto a standard coolant hose. Sorry cant be more specific, havent had a good look at it myself yet...

Any ideas?

[tm_r33]

its the thermostat housing pipe. Order a new thermostat. Get genuine. Buy a tube of good quality rtv silicon gasket maker.

Take hose off. Unbolt pipe. Change thermostat. (your doing this because you might as well while u have the pipe off). Clean old gasket from both block and pipe. Apply gasket glue to both surfaces. Allow 15 mins cure. Put pipe back in position. Bolt back up. Put hose back on.

Would be a good idea to drain coolant before u start.

once back together you can flush it brfore u refil with colant if you like.

So probably but coolant also.

[tm_r33]

You can buy a gasket for the thermostat housing but ive had plenty of luck using liquid gaskets (rtv silicon gasket glue).

buy a genuine thermostat from nissan parts. Cheap repco ones can give poor results. They dont seat properly and they dont open and close as reliably as genuine.

Thermostat maybe 50 bucks.

gasket maker maybe 15 bucks.

coolant... All depends on what u buy. A concerntrate from repco will do the trick.

[damono]

Thanks mate,

I just had a bit of a feel around and look and it does seem to be the thermostat housing where its leaking from, I thought it was another pipe coming off the block below the thermostat housing. Thats a relief.

If the thermostat housing itself needs to be replaced, any ideas where and how much i'd be looking at?

[Nur33]

It could also be a heater hose/pipe they can fail from old age aswell!!!!

[damono]

Could be. Hard to tell from where i'm looking. Does the heater hose/pipe come off the block, behind the thermostat housing, towards the firewall?

Repco or supercheap auto a good source for the heater hose/pipe or thermostat housing?

[tm_r33]

Thermostat housing is just a cast alloy bit of pipe. Nothing can really go wrong with it. Would certainly be very rare or even unheard of if one was to split or crack from normal use.

It will just be where it seats against the block that the gasket is leaking or even where the hose slides over the housing that the hose is a bit perished and leaking.

Does the hose on this pipe u speak of go straight to the radiator? and its farely larger diameter hose? if so then yes its the thermostat housing.

Edited February 2, 2011 by tm_r33

[Nur33]

Yes there is a heater hose that comes from the thermostat housing and the block (well on a RB26 it is RB25 should be the same). Here's some pic's i tried to clear it up for you to make it easier to understand. Hope this helps you.

[damono]

Yeah, I know the thermostat housing, not sure if its coming from the base of that where it joins to the block, or the heater hose that comes from the block behind it.

If i were a betting man, i'd probably say its coming from the heater hose/pipe. I think ill have to take off the intake on the weekend and check it out. Seems like a bit of a jerk of a job to get the intake off tho

Thanks for all the info guys, been heaps of help!

[Nur33]

No worries mate give us a yell if you need more info, but i would be leaning towards a heater hose, i've had one fail one me before so i repalce them all with silicon hose kit, bit of a bastard to do but hey these cars are getting a bit long in the tooth now

[damono]

Cheers mate. So you think its likely to be a hose, and not the actual t-piece metal flange/pipe that comes directly off the block?

[Nur33]

yeah that depends i guess on how old it is and how much corrosion its been subjected to, you need to pressure test the cooling system without the engine running and see if that makes it show up more clearly.

[damono]

Awesome. Thanks again for the info buddy, ill get onto it on the weekend. The amount and speed it was leaking when under pressure, I think it will be pretty obvious when I get the intake off and have a good look at it. From memory, even under no pressure when I fill the radiator, it leaks from the spot.

[jpoc_noel]

that ill be the heater hose and the easyest way is to whip off the starter motor and it's above there, and it's bloody tight to do too, also you'll get coverd in coolant too because it's below the block

[simpletool]

Change all the hoses now. There is about 11 down there, it only takes 1 to fail and it could be your head gasket. I posted a diagram of all the hoses under there on these forums before.

The diagram is on my external drive at home...sorry.