I recently installed my Rtek 2.1 and I have been taking temp logs (AFM, intake and coolant). Conventional wisdom has held that normal operating temp for an S4 TII is about 180-200*F this corresponds to a gauge reading of 1/4 to 1/3. Since my gauge has for the most part (auto x, and busted oil cooler line...) stayed in this range I never thought much of it.

However when I logged my temps on a 95* day and intake temps were 150*+ the gauge climed to 5/8 but the coolant temp never broke 180*!?! I confirmed this with subsequent logs , even heatsoaking for 20 min the temp (as per the Rtek...as per the thermosensor) only got to 181 at its highest. Something is amiss

If these readings are correct it seems to suggest that my thermostat never opens (>185*) This leads me to believe perhaps the thermosensor is going bad. or maybey the gauge/sending unit is going out? Has anyone ever had a thermosensor go out? what were the symptoms?

Thanks

***BTW the thermo sensor is on the back side of the waterpump housing and feeds the ecu. There temp gauge sending unit is in the driver side of the block next to the oil pressure sending unit .

 

there are testing procedures for each in the FSM...i would rather spend the $50 and get an aftermarket gauge...

 

I already have an aftermarket gauge, just haven't installed it yet. Honestly I was more concerned w/ the accuracy of the thermo sensor as that is what the ecu relies upon. But if there are testing procedures, I guess I'll look into that...

 

Pin 2I. Voltage reading of less than 2volts (.4v to 1.8v) on warm engine and greater than 2v (2v to 3v) on a cold engine. When fully warmed up the value drops to around .5v.

 

never broke 180, seems like it's broke to me.. did you look at it before it got warm? like from ambient-to 180? the ECU default's the value to 180 if it's broken/dissconnected.

 

i would do some checking. the ECU sensor is quite accurate, but they do get slow as they age.

you can kind of go be color, new they are a pretty deep green, if yours is turned brown, or white, its probably older than you are

possible you have some cooling system issue too, like an air bubble or something

 

just take it out and test it as the FSM suggests., only take about 5-10 min of your day max.

 

It's certainly not "deep green" so I'll test it @ the ecu. Sucks if it's bad cause I just installed a parallel fuel system and FPR this past weekend, it would have been real easy to replace it then.

 

its really easy to replace period. i think i pulled mine off with everything attached. might have moved the alt, cant remember

 

Well, the other night it got up to 203* , guess its working a little bit. Either way I ordrered anotherone cuz i found a loophole at the parts store that let me get em for 39 cents

The reason the temp got so high you ask? Apparently theres a leak at the driver side heater core inlet. I pulled the hose (which was replaced 2 years ago) and there were no cracks or holes. and I cleaned and checked the pipe, no holes. Pulled the cover for the heater core under the dash (btw LMMFAO at everyone who pulled a dash to get to the heater core) and all the pipes look brand new

 

those pipes are really thin and easy to tweak it so its not round and won't seal with the hose

 

True, I looked at the pipe and about an inch back its shaped more like a "D" than an "O" , so I took some water weld and filled in the area so that should no longer be a problem.

It just seems strange that that pipe wols start leaking now, its been untouched for 2 years (when I replaced the hose that goes to the block). ...I guess I might have bumped it when installing my FPR, bust sheesh, that was just a graze.

 

dunno, i just remember i took my t2 apart wrong, and when it went back together i had a really hard time getting those hoses to seal...

actually if its a factory hose, they get harder over time, so maybe it lost enough flexibility? aftermarket rubber gets soft

 

What did u have to do to get them to seal?

This is an aftermarket hose, replaced 2 years ago. I wraped it w/ heater pipe insulation, and it is far from brittle.