99 5.3 z71 overheating?

normal should run around 210 degrees. for once autozone told you correct. If the engine doesnt come up to the proper temp, you end up basically driving with the choke on if it was a carb instead of fuel injected. I would also make sure the area between the radiator and ac condenser isn't packed full of leaves and debris, and as its a 99, replace the fan clutch as well. Hope you did the upper and lower hoses as well if they aint been changed before. and take a good look at the heater hoses, hot weather is here, over heating is no fun.

Whitelightning

Auto Zoned is a PITA for me. Nunbskulls at the counter (by and large) and the cheapest of the cheap parts (DuraLAST). Stant produces the most consistent thermostats. If you are unsure take one of your SR's saucepans to the stove filled with water and monitor with a thermometer the point at which it opens AND closes. Test this against your original one. I would not be surprised if by now your radiator isn't failing. Do not trust the guage in the dash. Your problem could also be a faulty sender (located near the thermostat housing).

Thats a bunch of bull s**t. First of all you need to take that damn 195 theromstat that you bought from autozone and get your money back. Then go to performanceproducts.com order you a 160 thermostat. I dont know where the hell people here that your engine has to operate at 210 or your computer will make it run in choke mode thats bullshit. "I PUT THIS IN QUOTES. AS LONG AS A ENGINE IS OPERATING AT AT LEAST 120 THE COMPUTER GOES INTO CLOSED MODE" which means it runs as if it was running at 210. Your engine does not need to run at 210 its points less. the only reason they came up with a 195 if for those dum asses up north where its below 0. Trust me if you know anything about taking care of your engine get a 160 or 180 with out that your putting stress on the motor for nothing. Anthor reason to a 160 is that oil starts to break down some point, oil starts breaking down at about 208 degrees which is not a good thing.

owner of 2002 silverado 4.8 WITH A 160 THERMOSTAT AND USAGE OF 10W40. (thats for all of you people say you have to put what the oil cap says!!!!!!!)

You are right about when the engine goes into closed loop, but you are wrong about running a 160 degree thermostat. There is no reason to run an engine with 160 degree thermostat. They are designed to run a 195 thermostat. There will be more long term damage from running your engine cold like that then running it at the temperature that it was designed to run at.

I happen to be one of those "dum asses up north" and of course you are wrong. At least "up north" here...we know how to spell "dumb".

Right....

Whatever makes you feel better. It's the placebo effect (if you don't know what a placebo is...go look it up).

Ian

You can go ahead and use a 195 but you also have forgotten how easy aluminum heads warp. I not taking any chances. just because you put a 160 in doesnt mean it runs 160. a 160 starts to open 160 and is not fully open until

175-180, 180 starts to open at 180 and is not fully open until 190. 195 is fully open at 210.

designed to run like that huh!! will who is to say it was designed to run like that. just becasue some smart engineer had a bright idea and said gee lets start using 195 thermostats!!!!

So.... what we have here is a guy who can't spell "dumb" but thinks he knows more than the engineers.

Oh, "I forgot that" did I? It takes a lot more then 195 degrees to warp aluminum heads. Do you have any clue what Northstar all aluminum engines can run at (temperature)? I didn't think so!

You really have no clue. Try using a scan tool and watching the temps and see when a "195" thermostat fully opens.

Yep, that's how they decide what thermostat to use. Just pick one out of a grab bag.

You are really "dum".

Ian

So what you think just because it opens at 195 you think its going to stay there. i dont think so not 105 degree weather, maybe up north where its not as hot you dont need to change it!!!!

So you give me one reason why they decided to start a higher temp thermostat, the engines are still built basically the same!

choke

I higher temp stat does a lot for your engine. When you lower it to

160 you lose a about 20 to 30% of radiator efficency in warm weather because its abilty to shed heat is linked to the tempature differentail between core and free air temp which means on hot day more flux in engine temp. A 160 stat also increase fuel consumption due to reduced thermal efficency (more heat loss to block for combustion) and a richer mixture is needed and it is not vaporized as well either. Oil does not start to break down until around 300 degress, not 200 and a 160 stat will not remove moistur from oil and crankcase as well causing oil to go bad sooner for and also increase fuel usage because of increased drag for thicker oil operating below designed temps. Potenailly shorter engine life to due to slower warm ups with colder stat too. A lower temp stat aslo increases emmisions because of reduced burning of mixute in engine due to lower temps.The list goes on but I have made my point here. I can maybe see a 180 degree stat in some uses (like a older vehical with a carb) but not a 160.

How about several, reduced internal drag for lower oil shearing forces. Better evaporation of moisture on fule contamnnats in oil, better vaporization of fule for better burning and lower emissions, better thermal efficency because less of coubustion heat it lost to engine block and more of it is converted to work with a higher temp stat because the heat of expanding gases drives the piston and cooler engine temps squelch these pressures quicker than a higher engine temp. (Just to name a few)

Well guess what for you and everone else who thinks newer vechicles should have at least a 195 degree thermostat (bullshit) i have got news for you!!! Go to Napa Auto parts website type in any new model chevy or tahoe 99-05 with a 4.8, 5.3, 6.0 and look for oem replacement thermostat. You will find in the description that the oem replacement thermostat is a 186 degree thermostat not a 195 big difference. so i seriously doubt that it would hurt if you put a 180 thermostate in it. I never said you should put a 160 in every damn thing. i just stated that i would put at least a 180 if i was going to change. And if going to napa web site is not enough for you i take a picture of my friends thermostat whose truck is stock and on the bottom it will say a 186!!!

Well hell...why didn't you say so before?! "Napa says so"....I'm convinced....heh heh...

Ian