easy spark plug question . . . maybe

[93RugbyXJ]

so i changed my spark plugs and after looking in the back of the Haynes manual it looks like im running hot. i used to run mid grade in my I6, should i drop back down to 87. My engine runs at about 210 maybe a bit more at long stoplights in mid summer. oh and its a 93 with 170K on it

 

[BBeach]

Have you had a coolant flush lately? If you didnt I would imagine it could get clogged up and not be able to cool the engine so easily. What about the condition of your waterpump and thermostat? Just my guesses.

 

[1985xjlaredo]

How long were the plugs in before you changed them? If too long it can sometimes look like they have been "hot"

 

[lighthouse jim]

lots of factors involved in heating up at lights, slow speeds etc., rugby. BBeach touched on a couple of culprits, but there are other easy things to check on, as well. Fan clutch--lots of advice around of how to check for correct performance; Is your Rad clean on the outside? I just shop-vacced mine and made a large difference after removing crud from between the fins (both rad and a/c). good luck

 

[dutchjeep]

I had this too, until recent. The jeep was running 200-210 with the electrical fan on most of the time. Last week I replaced the water pump and thermostat (because the pump started leaking), and...voila. Runs nicely at 190-195, and I haven't heard the electrical fan since then. So I am unsure whether the thermostat or the pump made the difference (or both), but if you are going to drain the cooling system and replace either one you might as well replace the other also.

Just my 0.02.

Tim

 

[BBeach]

If you do in fact change the coolant, make sure to flush it out and not just drain it.