View Full Version : checking the block temperature

08-27-2009, 03:54 PM
Okay so a lot of guys suggest putting on a cheap mechanical gauge when people have overheating/underheating problems. How does one actually accomplish this? Can I unscrew my OEM sending unit and plug in a new one? School a gauge idiot please...

08-27-2009, 04:31 PM
Some of the 2F heads had extra screw in plugs. They were similar to the factory one but not drilled for the sending unit. You could drill out the blank for a new unit or find another stock one that a unit could screw into. Then you can keep the fatory gauge and have another temp gauge to compare. I might have a spare around. I will check for you.

08-27-2009, 06:19 PM
I know I have an extra port on the 1F and F.5 heads. If you don't have the extra port, go ahead an use your stock port. After diagnosing and fixing the problem (or finding out you OEM sensor or guage is broken and replacing them) revert back.

08-28-2009, 12:13 PM

You can 'tee' the fitting and install both a mechanical temperature gauge (my preference) and the factory electrical one. That big water pipe stem coming up from the block on the driver's side near cyls. 5-6 is the place to do this. I wouldn't buy a true K-mart special gauge - at least get a Sun or something. Pep Boyz-in-the-hood sells competent mechanical temp gauges for less than $20. I prefer mechanical to electrical, as you have a true, direct reading and it's not subject to electrical inteference and bad electrical connections. The downside is getting the fitting to install elegantly into the block, and passing the fat fitting thru the firewall. I used the heater-hose fitting on the FJ firewall and slipped the copper flex line through that. Take your time, get the correct fittings, use Teflon tape or pipe dope, and you'll have a solid gauge job that will last the life of the truck.