1996 Tacoma Overheating Problem

Howdy Tacoma world,
I have a mystery I am trying to solve. I overheated back in March after driving 150 miles towards the coast for vacation. I did not notice I was overheating until I blew the top radiator hose off. I replaced the hose, (luckily a friend was heading down as well so I had a ride to auto zone) refilled the coolant/water and got back on the road only to overheat again 15 minutes later. Left the vehicle at a hotel and had it towed back to my mechanic after the trip. At first it would not overheat for them. I suggested the water pump as my radiator and fan clutch were both done 3 years prior. It was the original water pump, so seemed like a possibility. They replaced pump, hoses, belts, and thermostat. After the job it overheated right away and they diagnosed a blown head gasket. I gave the green light and they replaced the gasket and sent head to a machine shop. All was good again for a couple of months driving it around town. Two weeks ago I tried to take another trip, an hour or so in and after going up a long hill it overheated again. Again I had it towed back, and again it would not overheat for the mechanics and we can't diagnose until it does. Any thoughts?
1996 2.4 liter manual, 4 cylinder, 220000 miles.
New head gasket, thermostat, water pump, hoses, fan belts, radiator cap.
3 year old radiator and fan clutch.
No loss of coolant, still looks fresh and full
Noticed a little more of a roaring sound before it overheated
Still driving short trips around town, temp staying where it should.
Afraid to drive more than an hour now
Thanks is advance

 

How are you monitoring temperatures?

I ask because the first time you overheated, you had clear visual indicators IE blown radiator hose.

After all that work, I would guess you shouldn't have overheating issues so when you did, were you following the gauge on your dash?

Not sure how a 5 lug Tacoma's dash is any different, but temp senders can go bad and give you a false in-cab reading.

 

see if the A/C condenser is clean, the fins are straight and there are no obstructions. In addition there should be a fan shroud.

 

I have been monitoring the in dash temp gauge. Before the hose blew I was not paying attention so never saw it go red, after the hose was replaced and I drove 15 minutes, I watched it climb and you could hear the hissing etc when I opened the hood. I think it is working but I agree it could be worth looking into. I will check AC condenser as well. Thanks for the input.

 

Ya, it does sound like an air flow problem. Around town with not much load on the engine it’s fine. could also be a defective thermostat not opening enough, I’ve seen a couple just in the last year, brand new not opening enough or at all. If ya do try a new thermostat go OE Toyota there is a difference.

 

Check this out from Scotty:

https://www.youtube.com/watch?v=pvYy-P0-9VQ

 

Any updates? I hope you and your '96 are well. Going out on a limb here but "roaring" can be a sign of cavitation in pumps, i.e. pump suction side vaporization. Typically that's caused by flow problems on the suction side. I'm saying this as a chemical and power plant guy and I have no idea if this can happen on a Yoda...but a old scale breaking loose could clog up a new radiator and starve the suction side. If that's crazy talk, tell me why. - I have a '96 2.4L . I replaced my OEM Radiator in Feb ('21) at 320K and was shocked at the total P.O.S. replacement. BTW - Any leads on a bad a$$ all metal radiator for a 2.4 L Tacoma would be greatly appreciated, the quality of the replacement was so poor I can imagine all sorts of failures.