What is the difference in a Tech4 & Quad4

I hear quad 4 but not any mention of the Tech 4. What's the difference? And any suggestions on how to make this engine run cooler?

I hear quad 4 but not any mention of the Tech 4. What's the difference? And any suggestions on how to make this engine run cooler?


Night & day difference.

The 4Tech was GM's OHV 2.5L (if I rember Correctly) 4cyl motor... nicknamed the Iron Duke. Rattle trap of an engine, prone to smoking. But supposedly real reliable (basically because they had like 50hp...lol). Basically an "Old Technology" Econo engine.

The Quad4 was GM's attempt at an Econo. motor with some actual performance.... major differences were DOHC, 4 valve per cyl, aluminum head, MPFI... Basically a higher performance engine... reliability is in question... seems to boil down to how well they were maintained. But have seen some with 300k+ & no major repairs. That engine design is still in use today. Came in 2.3L to start & are now 2.4L.

Looking for something specific???

This engine is in fact the 2.5L and runs a little hot, not overheating, but close. Someone told me that these engines run hot normally. The guage reads about 240 - is THAT normal? I have drained the system and replaced the thermostat.

the engines do run hot but normally not that hot. You replaced the thermostat and flushed the coolant. The other things i can think of is the gauge not reading properly, a coolant blockage in the system, or the fan isn't kicking in. Generally speaking the 2.5L run around 200-220 temp. Is you Service Engine light on? or any loss of power while driving? The only time i've had mine get that high besides sitting on a highway in the middle of the summer, was My SES light went on, the computer had malfuctioned and screwed up my timing on the car...causing the car to run extremely hot.