85 Running Too Hot only Highway (4 Viewers)

[Spike Strip]

Stock thermostat is 88c or 190F. Your numbers are a bit lower than what I'm used to but I run the stock 190 thermostat.

You really need the secondary Temp reader, at a minimum, for peace of mind. Mechanical or electrical are fine fine. The stock gauge as has been said is notoriously inaccurate, + if it gives you any information at all, it will be too late.

 

[CruiserTrash]

Here’s what I run:

Autometer Sport Comp water temp gauge, electronic sender

The sender is in the upper radiator hose. I use this adapter by Glowshift. Cut the upper radiator hose in half and shorten one end by about 1”. Stick the Glowshift piece in there and thread the sender into it.

Takes probably 90 minutes to install everything. Super easy. Pass a wire through a firewall grommet. Screw a bracket under the dash. Done. Obviously you don’t have to install all the other gauges I have…

 

[toy_tek]

x2 on @CruiserTrash post above. Autometer is a decent gauge for the money, don't cheap out on that. I tried a lower cost brand at first and when I tested it, I found it was off by 10-15 degrees (compared with 2 other thermometers). I returned it and got an Autometer model 2635 which tested within 2 degrees. The Autometer 2204 mounting cup works well for a single gauge.

 

[seattlefj60]

What @DrRock said.

I have an '85 FJ60 also and recently refreshed my coolant system for exact same issues. My stock temp gauge did the usual spike towards high but normal temps via my IR gun. I had changed the water temp sending unit, water pump, and have a HD fan clutch as well. Radiator has no leaks. Because of the stock temp gauge always showing 'elevated' temperature but normal temps with the IR fun, I put in a Koso unit (got idea from @HemiAlex) and its probe is in the BVSV port location. Perfect location for the cig lighter location using the awesome @TRAIL TAILOR bezel (which will likely last well after the rig has decayed lol).

Due to location BVSV probably gets the highest readings and the highest I’ve got was 212 (during summer) but even then with use of IR gun the rest of the engine and the rad hose was never above 200. The 212 was after 30 min highway run at 70 and then idle. Temp dropped to 190 after 1-2 minutes. Can also consider upper rad hose if you go similar route.

The stock gauge will just not be accurate most likely.

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Ok so now that I have to figure out a temp gauge..have you posted anywhere on your setup @WartHog73? I like the look of that koso unit. I'm not super handy on the electricals so am specifically interested in how you set that up and what you mean by bvsv port location.

 

[Spike Strip]

The bvsv port is on the lower thermostat housing. You can only use this if you're desmogged. That's why most people just put an adapter in the upper radiator hose.

 

[WartHog73]

@seattlefj60 -

Check out this thread too for info and ideas - it was quite helpful:

External water temperature gauge

I know I've seen external gauges installed and spoken about, but cant seen to find them. I though @OSS posted about them......Im looking for a gauge to double check and verify water temps while in use....

forum.ih8mud.com

I liked the Koso unit and my bezel finally cracked fully at same time - since I had the TT bezel (the bezel doesn't work with a functional cig lighter) - it just made sense for my situation. I am desmogged so my BVSV port was available. You do need to get an adapter due to different threads (BPT vs NPT).

 

[seattlefj60]

I am desmogged! If I can just my existing port that sounds clean and maybe easier...ok thank you for all the help on this...I appreciate it.

 

[Squash]

I have a 1991 hzj75 with over 500,000 on the OD.
212F is nothing to worry about at highway speeds. With proper coolant and a functioning rad cap, your engine should easily withstand 220F, I'd say more but won't push it.
The important thing is that I keep driving after a passing adventure or hill climb to get the temps back to normal operation range.
Water boils at 212
Coolant boils at:
Pressurized system + coolant =