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Overheating Dilemmas '79 210

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Recently, I bought a barely used radiator from a guy on Ratsun. Waaaaaay better shape than the one I had. Fixed the leaking problems, but she still overheats!

It is bigger than the one that came out of my car, I wonder what car it came from?


Funny thing is, since it is a larger radiator, it should keep my car cooler. . . . . right? Aaaaannd it really only gets to that overheating point on the freeway. Also, once it starts to run hot it continues to do so until the engine is turned off and cools down for several minutes to an hour.


Like.... what the fuck? hahaha. no airways are restricted by a bag etc., coolant is 50/50 premixed. . . i've replaced the cap, thermostat, water pump.... shit, even the coolant reservoir. Even removed the thermostat altogether, which helped, but still. . . when i get on the freeway, it'll steaily climb to almost H. I didnt replace the hoses, could they be collapsing at high RPM's? Like, that is very literally the only cooling system related thing that I haven't bought new.


And I bought my behbeh for $250, it had sat there in this lady's driveway for almost 8 YEARS. There were rodents living in it at some point, so is it at all possible that they could have got into the tail pipe, creating backpressure or some shit?


Fuuuuuuuuuuuuuck...... I'm stumped.

Any help will be immensely appreciated


plz respond to this post, or my email. . .



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When's the last time you changed the thermostat

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said he removed the thermostat so constantly open system.


burp it and see what happens?


and then replace hoses. i do things the expensive way though

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I can sure try to burp them whenever I get back to work, but I already did that whenever I replaced the fluid. I flushed it real good too. For about an hour.

Is it possible that since the radiator Is bigger than my old one that the hole in the front of the car is too small, also restricting air flow?

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Do u have a fan clutch fan or just fan blade, clutches can cause issues. Ign timing correct? Plugged up cat converter. Having no tstat could at higher rpms move water too fast thru rad. Pretty rare tho

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Watch the lower rad hose and rev the shit out of it. Does the hose collapse under pump suction? If so you may need a new one with a wire coil inside to prevent this from happening.



Any chance the belt is loose? Slipping would reduce water pump output but I think it would have to be a lot to over heat..


Clutch fans don't do much at highway speeds in fact you could remove the blades and the vehicle speed would push more than enough air through the rad. A failed (loose) clutch fan is not good in stop and go or waiting at the light.


I've heard it said that having the thermostat out moves the water too fast through the rad to cool it. If anything I think it would cool more. It's six of one, or half dozen of the other. Slower flow and less water is cooled more or huge flow and lots of water is cooled a lesser amount. Think about it. The hotter something is the quicker heat radiates away into a cool environment. When the temp difference is only a few degrees the change is much more gradual. Now the hot rushing rad water is HOT with lots of cool air. The slowly moving water is cooled much more but it becomes harder to extract the heat that is left.  

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I will look into it, P.S. everyone.... I failed to mention I upgraded to an electric fan


be right back to elaborate

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DatzenMike, the thermostat (or lack thereof) definitely does seem like a factor. I never really thought of it that way. That, coupled with the likely collapsing radiator hose, is creating the situation I am in.


At first, removing the thermostat considerably helped my overheating problem (so I thought). I work about five miles from my house, so I didn't notice till point "C" would be thrown in there and sure as hit, it'd overheat.


Also, the car doesn't cool down at all until after I turn my car off and pressure decreases (since water pump turbine isn't rotating)

Which MAAAAAYBE means the hose could very well still be collapsed even though I'm parked but car is still running (since the pump is keeping the pressure consistent)?


Well, fuck yeah! I am going to try this tomorrow, and see what happens.


P.S. Datzen Mike you are goddamn right


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Well you could squeeze the hose to check for softness. Compare to the top one.


Another thing is that rad may be part plugged up. May be larger and cleaner on the outside but who knows on the inside? The pump has to suck harder and harder to pull water through it and the hose will collapse. Only does this when revved up.

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It is softer, specifically in two areas (that's what she said)

-the part immediately after the radiator

-the longest part before it hooks left into the engine


This Thursday, I'm picking up an upper and lower hose. . .

but you had mentioned something about a wire coil to prevent hose

collapsing... This did not come with one. Should that be an issue?

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Also, how do I go about getting a wire coil? Allegedly AutoZone does not carry it. Or... should I just hold off until I can gather enough cash to get an aluminum radiator, and then purchasing the good shit with wires in them?

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OoooooooKay. . . . . . Work has been immensely hectic this week, sorry I have not had the time to post

. . . till now. Er-hem, anyways, so I also had a few other problems (alternator & battery took a crap) but

that shit is taken care of.


P.S. replaced hoses, still overheated. ***MANNNN FUUUUCK***




I began to study the good ol' Haynes manual, my old air cleaner, the air cleaner for my Weber DGV (32/36).

As much as I wanted to keep all the emissions from the Hitachi setup, alas I could not, for the EGR valve was too

large. So i proceeded to hump Mother Earth instead, capping off/ "deleting" any emissions port I could so the

vacuum would be up to par (yet no tools to verify if it really was par haha)


There is a device on the old air cleaner called an "idle compensator" that is not on the Weber air cleaner. Acc. to

Haynes, it is a "thermostatic valve located in the air cleaner to compensate for over-rich mixture when under bonnet (hood) temperature is very high. The valve opens under temperature conditions of 140 to 167 degrees Farenheit." Did some drilling on the TOP of the air cleaner, and put that shit in.


Voila. HAS NOT OVERHEATED SINCE. It was 94 degrees out today in this pit (Fort Worth, TX), a day I would get close to  overheating in a matter of minutes. But I didn't even have to use the electric fan till after sitting at a few stoplights. By then,

I was almost home anyways.


FUCKING YES. . . . and as a consolation prize: I have replaced every cooling system part in the B310. Which probably needed to happen eventually anyways.


Thanks to everyone who helped,


Such a tiny part, such a immense impact on the engine.


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Now that my mind is at ease, I feel like I can really start to enjoy my Datsun the way I've wanted to

since I bought her.

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Odd that leaning the high speed mixture cooled the engine.

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