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I have one (1) 'Intake Manifold Thermostat' in my parts bin (PN 14100-E8850). As you probably know, this valve is NLA from Nissan and appears to be NLA from all the Z specialty suppliers too. Its job is to control the flow of coolant through the intake manifold heating cavities (which also duct out to the carb bodies for 1972-73 models). I expect that it's arranged to work the opposite of the regular coolant thermostat: i.e. it operates open when cold, then closes off flow once the coolant heats up). According to the Parts Manual, they were fitted to the Z engines right up until July 1973. I want to fit my parts bin unit to my '70 (which arrived with the manifold thermostat missing), but only if it's working properly. I just tried a dunk test in boiling water and it wouldn't close, so I assume that it's jammed in the neutral/open position because of the usual chalky crud that can build up in a poorly-maintained cooling system (my unit hasn't been installed in an operating vehicle since 1980, so it hasn't been 'exercised' for a l-o-o-n-g time) Does anyone have any experience with fixing these little thermostatic valves? I can't find any mention of it in either the Z FSM or the L24 Engine FSM -- not even a note on a diagram to indicate that it even exists. Q1: I'm thinking of soaking it in CLR, on the assumption that it's mineral deposits from tap water that are causing the problem. Has anyone tried this? Q2: What's the correct temp. at which it should start to close? And how long should it take for it to cycle from fully open to fully closed? Q3: Do I have the operating logic correct? (i.e. normally open, then closed when hot). Is it designed to fully close, or just partially close? Q4: There's a tiny phillips-head screw with an equally tiny lock nut on the tip of the internal centre shaft. Has anyone tried to take one apart to assist in cleaning up the moving parts? Q5: Does anyone know of a source for these (either NOS or used)? Any guidance welcomed.

My problem happened after i replaced my alternator belt, my 77 (technically a 76 because of its production date) used to run at around 180-185F , now the norm is 210-230 or really close to over heating after a 7-11 minute drive and considering the weather in california is fairly cool/cold this problem is really weird to me. I already replaced the thermostat and its gasket (no luck) there are no leaks , other things that ive done to my car during this period where , an hks smf filter (mostly for looks) and replaced some worn rubber hoses that run across my intake manifold (which fixed my bad idle) this car is my daily driver to college please any help is welcome.

Picked up a Koyo aluminum radiator for my S30. Got down to installation and ran into a problem - the fan makes contact with the passenger side of the radiator (the cooling tank portion of the rad - see attached picture). After unleashing a few f-bombs, got down to trying to figure this out. Upon closer inspection it looks like the PO had installed a 8 fin fan from a 260z and it looks like the clearance between the fan and radiator are impacted by this (I hope - it appears the 260z fan extends forward further than the stock 240z fan). I've gone ahead and ordered a new fan in hopes that this solves my problem however, unless I'm missing something it looks like Koyo has made a poor design choice here .. why would they not design to have the fan fully behind the cooling fins vs. a portion over the side cooling tank. Are there any S30 owners who have installed the Koyo and run into something similar? I'd like to rule out any other possibilities I'm missing. If the correct stock fan gives me some additional clearance it still looks like I'll have minimal room between the fan and radiator (<1/2"). Pictures attached. New fan arrives Tuesday so hopefully this works and I'll have time during the week to install. PS. How do you get a profile pic up on this site? (does it really have to be a public picture from a website? -TD

The engine is all back together however I last the diagram on the path of these hose. Can anyone help? They come around the back of the L26 from the engine side (passenger) of the engine..