I have a 1980 with a 45 dcoe weber. Im 90% confident i have a stock radiator on her, no cracks or leaks. What im wondering is is the stock radiator efficient enough to keep it cool nicely? My nightmare is overheating. Plus my temp gauge doesnt work. Not certain why. Does anybody know anything about the stock radiator?

 

stock cooling system in good nick should be fine. But get a gauge on there stat if you are worried about it, and you are right to be worried as its an old car, the temp gauges aren't renowned for their reliability, and the rubber o-rings ect are sensitive to overheating.
typical aftermarket rads are thicker and claim %30 more cooling capacity but that is open to dispute with the extra resistance to air flow-through.

 

the stock cooling system works really well, if its in good shape. pretty common for the radiators to be plugged, and the thermostat to be bad, both are pretty easy

 

Is the temp gauge sender plugged in?

Download a user manual at foxed.ca if you're not sure where it is.

 

I dont know which the temp gauge sender is but I had to clean off those 2 plugs at the top of the radiator(btw what are those?), and i checked out the plug on the thermostat housing and i looked at the thermostat from the top and i didnt see much gunk. I didnt take it out and check the actual housing, should I have? And another question i didnt see a bleeding screw. Do they have one?

 

My 80 has NO bleed screw. I think later FB (81+) do? You drain by loosening the bottom hose/or the bottom heater hose.

The Q that should be asked here is WHEN was the last time the rad was pulled and professionally cleaned at a Rad Shop? We are talking a 36yr old car! If you haven't done so on your Watch, and have no knowledge of PO performing a recent (last 3 yrs) cooling service, well you are driving a Time Bomb. Cooling is _everything_ to a rotary.
If you have any back-yard wrench skills, these are VERY easy rads to pull and get serviced. You are prob looking at all of $75 if you drop off the Rad at a reputable shop and get it chemically dunked and leak-tested. And new hoses all around are a must, esp the _Heater_ hose running off the firewall over the rear engine under the oil filter!! This suffers years of exposure to oil and softens, then fails -and could take the rotor motor with it! $$ and unique but important!
There IS a drain for the Block at the base of the center housing (one with the oil filler neck) - 14mm - on the driver side, that you will need to open too to correctly drain the block. Obv a new thermostat would be smart now too.

Sender for temp gauge is right UNDER THE OIL FILTER tower - you will see the small sender there. These are usually bullet-proof, but new ones can be had on ebay for $15-ish if you think its bad. Betting the connector wire is loose?

Stu Aull
80GS
Alaska

 

just got my car,,,,the temp gauge was screwy....I unplugged it at the block and removed the gunk....a bit a sand paper (just a touch or 2)...and now it always works....don't know what the temp is...lol...but the needle moves. car came with an electric fan and I had to adjust his thermostat and the needle pretty much stays in the middle now----or just a bit to the right of middle. used to hang around that tick on the RT side...and I thought that as too high.

 

I run a street ported 12A, Weber 48IDA, RB headers in 105 degree Kansas heat with a stock radiator and electric fan. 80 MPH for 20 minutes to and from work every day. Stop and go around town on the weekends, A/C blowing. No issues - at all. Get that gauge fixed.

Hope that helps!