The little water outlet on the thermostat housing (the one thats supposed to run through the intake and around the back of the motor to that little y pipe) has pretty much had it. (see picture)

Does anyone know where I can find this? I tried several parts stores, which told me to check out some hardware stores, no luck there either.

I'm not even sure what type of threads this has. I found a few fittings that had similar diameter tapered threads, but the pitch seemed to be off ever so slightly. How are tapered thread dimensions specified? If I know that, I can probably find something that will work on mcmaster-carr or something when their website is working for me again (it's not right now).

I figure i'll call courtesy nissan tomorrow (since they are about 45 minutes from me) and see if they have it, but i'm not expecting much really on that front.

Any help anyone could give me would be much appreciated!

I got those fittings from the Nissan dealer a couple of years back. Believe it or not they had them in stock! Maybe they use the same fittings on newer model cars?

I went through the opposite of what your going through. I was on the search for a plug for that fitting. Never found any in that pitch. I went to about ten different part's stores, hardware stores, plumbing shops, heating and cooling etc... I ended up getting a 1/4 npt pipe tap and retapping the hole. Like you said the pitch is off ever so slightly like one or two threads per inch.

Good luck.

I got that fitting from Courtesy Nissan last summer, so it's probably still available. If they don't have it in stock, they should be able to get it in a day or so. Like Ed, I couldn't find anything at the hardware store that fit properly.

Thanks for the replies. Guess i'll stop wasting my time checking out hardware stores and just make the drive up to courtesy tomorrow

That fitting and similar one in the intake manifold have "BSPT" threads (British Standard Pipe Thread). There is a slight differance in thread counts from NPT and hence are not interchangeable to purists. Plugs are available and made by Parker fittings ....... can be ordered thru speciality stores dealing in hydraulic hoses.

I have one in perfect condition. This thing looks almost brand new. Its on my 1970 L24 (e31) that is only a straight thru piece. I think 73's came with a "y" shaped one with two outlets. Any way I am going to remove it because I am not running water to my carbs. Reply to this post so we can discuss how I can send it to you. Hope this will put an end to your search.

Saro Fagerian

Thanks for the offer Saro,

I ordered this piece from Courtesy this morning(they didn't have any in stock) and should be able to pick it up Tuesday.

No prob Andrew. Did you ever find a cap for the fitting on your search for one? I guess now im on the mission to find the proper threaded plug for the housing. I remember when I bought freeze plugs for my block it came with some small threaded caps, maybe those would work. Oh well.

GL

Saro Fagerian

Nah, everything was NPT that I saw. I've seen some people post about drilling and tapping it with an NPT tap and using a standard plug then.

Kinfish mentioned a company called Parker Fittings that sells BSPT threaded stuff in the US, you could try that.

I've read some stuff about blocking this off being bad. I'm not sure about the internal coolant path inside the block, but people have said that the coolant doesn't really flow when the thermostat isn't open if this line is plugged up. Apparently it can cause hotspots inside the block around the cylinders and result in a blown head gasket or something worse.

But then again, i've read about a lot of people plugging this off and being fine.

It would be nice to have a diagram showing the paths of all the oil and coolant lines inside the motor. The FSM diagrams are kinda vague

Originally posted by Inf

..........I've read some stuff about blocking this off being bad. I'm not sure about the internal coolant path inside the block, but people have said that the coolant doesn't really flow when the thermostat isn't open if this line is plugged up. Apparently it can cause hotspots inside the block around the cylinders and result in a blown head gasket or something worse.

But then again, i've read about a lot of people plugging this off and being fine.

It would be nice to have a diagram showing the paths of all the oil and coolant lines inside the motor. The FSM diagrams are kinda vague

I have had this fitting plugged (no coolant flow through intake manifold) on several 240Z's and have never had any problems relating to it. Water still flows from lower Radiator outlet, through block, up into the cylinder head, into the Thermostat housing and out to the Radiator.

I have never been able to find a plug that was properly threaded to use even though my local hardware store carries BSPT fittings. I just JB Welded a small bolt into the fitting and let it dry, put the standard issue hose back on and no one knows the difference.

I can't see how not having coolant flow through the intake would affect anything.

What I mean is when the thermostat is still closed up, how does the water flow about within the block/head, or does it even flow at all? Thats what some were posting about on zcar.com.

They were basically saying that the line thats supposed to go through the carbs around to that y-pipe on the passenger side was the only path for water to flow before the thermostat opened up. So without it there would be little hotspots until the water in the thermo housing got hot enough to open the thermostat.

Well, the fitting is below the Thermostat, and the Thermostat is what allows water to flow out of the engine and into the radiator, so until it opens you are not going to get any cooling anyway. The thermostat opens at 180 degrees (or whatever stated temp of thermo that you use) and at that point water (coolant) flows through the entire system including the radiator.

Think about where the water in that pipe comes from. It comes from the small nipple on the "inlet" pipe on the front, passenger side of the engine, water flows around the back of the engine (through hoses, outside of the block), through the intake, out the intake, and into the Thermo housing. IF the Thermostat is open, the water will flow into the top of the radiator, and down the cooling tubes, and back to the inlet pipe. If the Thermostat is closed, no water can flow out of the Thermostat housing, engine block/head, or through the intake.

It is my opinion that who ever stated the tale you are relating, doesn't know their butt from beans.