Took my 4Runner out for the first time today after finally getting the shocks bolted on and 9 months of work bringing her to her current form.

Wheeled all day with the engine running for around 6 hours total and the temp was fine all day - driving to the trail (50 miles) and about 50 miles of trails. On the way home after about 30 miles I notice the temp gauge is way high - touching the red. So I crank on the heater and drop the RPMs a little and it seems to go down a little. But when I get off of the freeway onto City Streets and stop at a red light it goes into the red again and my RPMs at idle in Neutral at the light are around 1900 rpm.

As part of my build I did replace the alternator and drained all of the coolant. Does what I describe sound like I potentially have air in the system? Weird thing of course being that it ran fine without overheating for 6 hours of wheeling!

 

you might have a small leak theat is sucking in air.

 

how's the coolant level? Is something blocking the air from getting through that radiator? Is you fan shroud still in tacked? Is the fan damaged? Possible air in system did you burp it?

 

Will air in system cause the high idle to tho?

 

Could be related or could be a seperate think, The idle on mine needs adj. from time to time. Have you used any fuel additives lately?

 

Ahh yes - I did put a bottle of fuel injector cleaner through it a while ago, as it had been sitting for a year. Plus I seafoamed her a few weeks ago - but none in the fuel. Just used the Brake Booster line and sucked about half a bottle of Seafoam through.

 

I do have some cracks along the top of the radiator, looks like the JB Weld didn't do the job. Just ordered a new radiator from Radiatorbarn, so once that arrives I'll have to drain the system again anyway. Will make sure to burp this time after re-filling tho.