Can a trans cooler cause the motor to overheat? I have a small aftermarket one and just got the correct one and was going to install this weekend

 

Shouldn't. Unless the cooling system is marginal to begin with. (which I suspect, your is. )

 

T stat is @ 190 but not getting higher but Truck is running hot what I mean by that is if I try to take rad cap off it boils put

 

That's normal. Here's how it works:

Pressure X Volume = Mass X R (constant) X temp.

Volume, mass, and R, are fixed values in the case of your cooling system. So when temp changes, pressure does too. Warmer it gets, higher the pressure. (up to about 17 PSI or so, when the cap lets some pressure bleed off, which reduces volume and mass as well.) So if you suddenly release the pressure...... two things happen, the temp climbs as pressure decreases...... which tries to increase pressure..... basically, the coolant flash boils..... (in the right conditions.) and is just a VERY bad thing to have happen to you. Do NOT open the cooling system when it is under pressure. You can do serious damage to yourself in short order.

 

Probablly because I didnt turn the motor off 1st huh? So then its not overheating. If it was a blown headgasket it should be overheating non stop right? I Checked the t stat not it, gonna rwplace water pump in a bit

 

Ok so I noticed a hole on the driver side of the water pump its perfectly round & its leaking water.I thought the only hole was @the 7 oclock position
Im in Missouri, heres what's going on as of right now bought a new t stat but boiled old 1 it opened up so t stat is fine.I drove 50 miles no overheating. But everything felt really hot should I still put in new t stat? I Have a kid who Im building a custom subframe for his car&he is renting a pressure tester&buying a water pump.Now if the headgasket is bad Im guessing the pressure tester will tell us so?

 

If you have the new stat, install it. Sure can't hurt.

If your water pump is leaking coolant ANYWHERE, replace it. (looks like that is exactly what you are doing.)

The coolant may be 195 degrees, but, some of the engine parts (the turbo, in particular) get a LOT hotter than that...... and stay that way for some time, even after shutdown.

Get the new pump installed, cooling system refilled, verify no external leaks, then hit it with the pressure tester..... the gauge shouldn't bleed down very much, if at all. (sometimes, the seal at the radiator isn't perfect.....) If it bleeds down quick, you have a problem. (and if its external, should be easy to find.)

Another test would be to simply start it up, stone cold, and start squeezing the upper radiator hose. If it's hard as a rock right away, you have a problem. If it doesn't get hard until the engine starts to actually warm up, you are probably golden.

 

quick answer needed I don't know what I'm doing but this pressure tester but I pumped it up to 50 pounds and it held is that good or bad

 

Don't do that. 18 lbs or so MAX. Otherwise, you risk blowing your radiator apart.

But, if it held 50 lbs, I think you are fine.

 

Sorry 26 psi