Weird stuff under the hood
 

Hello, new member here.

I have a 1979 GS all stock and original except RB header and exhaust and the rats nest has been removed.

The previous owner installed a ball valve to shut off coolant from the rad to the heater core. Does anyone know why the previous owner would have done that? Photo is attached.

Also, I see that there are four washer/coolant containers on the right side of the engine. I've identified three of them: coolant overflow, windshield antifreeze, cold start fluid, what is the fourth one in the centre of the pic with the hose coming out of it?

Neil
1979 SA
Vernon, BC, Canada

https://cimg7.ibsrv.net/gimg/www.rx7...46fe9a9cfc.jpg


https://cimg8.ibsrv.net/gimg/www.rx7...886c87c42d.jpg

At this point, all of our cars are 30 years old, and heater cores tend to go out over time due to internal corrosion. My het is the PO hooked up the ghetto ball check valve to prevent flow from the core back tot he block, but he's missing the feed from the radiator to the core. In any case, you'd know if your core is bad because the valve will leak first resulting in ypur right foot getting sprayed with hot coolant everytime you step on the gas. Inconvenient, to be sure, but a sure sign that the valve needs replacement and possibly the heater core, too.

I bypassed my heater system through a braze on the radiator feed and a block plug on the return. Given that I live in the desert, I don't miss heat, as my A/C had to fight against a little bit of heater core flow all the time.

On the washer bottle sitch: you'd need to trace each hose to a function. You have a lot of bottles in there! Subzero system can be removed easy enough. Washer fluid might be important, and the radiator overflow is definitely needed. What that 4th one goes to is anyone else's guess.

Thanks for your quick reply LongDuck. I've had the valve open for a while now. Fortunately, no coolant leaks and the heater is nice and warm for our Canadian spring weather. The additional bottle's hose goes to the oil filler neck. It has a sticker on it specifying the type of coolant required. I filled it when I got the car. Fortunately, I checked my oil right away because coolant got sucked into the crankcase. After flushing the crankcase with oil several times I decided to not use it. Still wondering why it's there.

Welcome fellow Canuk-
As said, this is a useless (to you certainly) bottle. The actual bottle, as you have prob figured out, is a rad overflow bottle, off an 81-85 FB RX7. The line it runs to at the base of the oil filler, THAT line originally went into the base of the carb manifold as part of the fuel venting. The parts book actually calls it a "ventilation hose". It normally runs to a metal pipe that run thru the rats nest (but is a separate pipe!) to the front right corner of the intake mani. I attach a pic off the 79 parts book. This all might have disappeared with the rats' nest removal. If you pull the air cleaner you may see a fitting on the main where this is supposed to attach. indeed, with a longer piece of hose (like the one now running to that bottle!), you could re-attach it.

Whether your previous owner was maybe trying to rig up some sort of...oil feed?...from that bottle. Regardless, you can certainly pull it...

Stu Aull
80GS
Alaska

If it attaches to the oil filler neck, do you think the PO intended it to be some kind of vent?

When I purchased my 79, the PO literally had an airfilter attached to the feed cap because he said there was consistently white residue around the cap. I have read multiple things on the forum about that being a sign of near detonation but the car was recently rebuilt and runs flawless. He said he did a lot of research and multiple people have vented the oil filler neck to prevent this same issue... (Maybe due to some kind of built up pressure? I looked into it as well but do not recall what the cause of this substance was, maybe someone else can comment on this possibility)

That is definitely a radiator overflow bottle from a 81-85 ,I'm not sure on a 79,but on my 85 that is where the charcoal canister goes.

The white residue is the result of not venting the engine. The nipple on the oil filler should be hooked
to a vacuum source with a pcv valve inline. This is not the result of near detonation LOL!

The current setup isn't doing jack for you.

Thanks for all the feedback gents. It's appreciated.

I've seen a bit of info on the forum about "lung butter" which is the pasty cream colored foam that forms on the inside of the oil filler cap. NISxMO, maybe you're right about it being some kind of vent...when I got the car this coolant tank was filled with an oily paste. Can anyone comment on the value of keeping it for that purpose?

Any other thoughts about why the PO installed a ball valve in the coolant line to the heater core? I have a replacement pipe and am considering getting the ball valve out of there and going back the stock pipe.

Stu, did you go to SAIT in Calgary in the early eighties? I had a classmate by the same name who had an RX-3 I think.

Neil Scott
1979 GS
Vernon, BC Canada

The one he's got or I got or both?
All I know is I haven't seen the white residue since I've had it....then again I've only driven it about 500 miles before tearing her apart.

Unhook it. At worst, you're creating a path for moisture (coolant) to get sucked into the oil passages which will cause rust and oil breakdown, and at best, you're wasting coolant in a bottle that goes nowhere. Take that line and unplug it from the bottle, remove the bottle, and find a nipple on the intake that you can attach the hose to. It should pull vacuum, which will pull any oil vapor into the intake when the engine is running. One of the other guys pointed out that this is where the charcoal canister belongs - and that's to hold the oil vapor after you shut it down until you start it and get vacuum again.

Also, I'd take a close look at the other parts of the car because the prior owner sounds like a complete dumbass as he explained the purpose of the bottle to you...

I bet the heater core leaks and thats why he put in the ball valve. I agree with Duck the PO
isn't the sharpest knife in the drawer.

I bet that coolant container is a homemade oil catch can of sorts. If I'm right, it shouldn't be filled with anything. Its only purpose is to catch the oil vaper instead of letting it go into the engine. But since I don't see a vent on the container, I doubt how good it would work. But I could be wrong...

I thought his charcoal was part of the carb lid for 1979/1980?

It is. You can see the nipple on top of the lid in one of the pictures hooked to absolutely nothing.

Does look like the PO was using the FB overflow bottle as an oil catch can. There is a pinhole vent in the lid but without a source of vacuum I doubt it does any good.