5.3L Running Around 185 degrees after thermostat replacement

[jcoggins7]

Hey guys,

New to the forums here. I have a 2006 LT with the 5.3L in it, and I just had the thermostat changed and coolant flushed by my local shop. I'm fairly savvy when it comes to fixes myself and could have probably done it myself, but it needed something else done that I don't have the ability to do at home, so I let them do it all. Anyways, though the truck is running fine and has no codes throwing currently, it looks like it's running kinda cold. Is this supposed to run around 210, around the middle of the gauge? If so, I'm running at around 185 after it heats up just doing quick in-town drives. I've done a little digging here and I have some notes based on what I'm seeing that may be of help - the thermostat installed is from NAPA, not from the dealer, so I doubt it's OEM, but I won't know until Monday. It's pretty cold here in Nashville right now, but I'm not sure what I should be expecting and thought I'd ask y'all. Thank you in advance for your help!

 

[Scottydoggs]

if its cold, like 30's or less short trips are not enough to get up to 210 like your used to seeing.

 

[rockola1971]

research the part number on the receipt and it will tell you what the opening up temps is for the thermostat that you bought.

 

[Fless]

In addition to the above, put a code reader / scanner on it and see what the ECT PID tells you the operating temp is. Compare that to the gauge reading.

 

[swathdiver]

Hey guys,

New to the forums here. I have a 2006 LT with the 5.3L in it, and I just had the thermostat changed and coolant flushed by my local shop. I'm fairly savvy when it comes to fixes myself and could have probably done it myself, but it needed something else done that I don't have the ability to do at home, so I let them do it all. Anyways, though the truck is running fine and has no codes throwing currently, it looks like it's running kinda cold. Is this supposed to run around 210, around the middle of the gauge? If so, I'm running at around 185 after it heats up just doing quick in-town drives. I've done a little digging here and I have some notes based on what I'm seeing that may be of help - the thermostat installed is from NAPA, not from the dealer, so I doubt it's OEM, but I won't know until Monday. It's pretty cold here in Nashville right now, but I'm not sure what I should be expecting and thought I'd ask y'all. Thank you in advance for your help!

These coolant temperature gauges are purposely designed to be vague so as not to startle the women and fill up the service department at the dealer. That being said, it's supposed to be a 195, begins opening at 187 and is fully open at 195. They also make one that begins to open at 174 and another at 160. It's also cold out now, so it may stay a little cooler no matter what right now. check your receipt, make a phone call and ask and wait for warmer weather.

 

[MassHoe04]

I have never had any issues with NAPA parts. They are re-branded from big name manufacturers. Thermostats from NAPA are most likely made by Stant, which is one of the best for thermostats.

I would be REALLY surprised, if your shop called NAPA for the part and asked for one of the "Alternate Temperature" parts (180 or 160 degree open settings). I am willing to bet they called and ordered an OE temp. thermostat, set to open at 187. The likelihood, that they went with something other than a standard OE temp. part is probably close to none.

As @swathdiver suggests, very cold winter temperature and short drives are not going to get you up to 210. Today, it was about -3F. It took a while to get all the way up to 210 for me. I drove at least 15 minutes on the highway, before it got there.

Whether a stat opens at 160, 180 or 187... All of the engines would reach a temp near 210 (+/- a couple) at some point. All depends on ambient temperature, engine RPM and run time. A 180 or 160 open might delay reaching full operating temperature, but would still get there eventually.

If you go for a longer drive, you will probably get up to 210 too. If running fine, I wouldn't lose sleep over it.

 

[Fless]

These coolant temperature gauges are purposely designed to be vague so as not to startle the women and fill up the service department at the dealer.

The men aren't startled, either, just confused. Ask a woman and she'll confirm.

 

[SnowDrifter]

These coolant temperature gauges are purposely designed to be vague so as not to startle the women and fill up the service department at the dealer. That being said, it's supposed to be a 195, begins opening at 187 and is fully open at 195. They also make one that begins to open at 174 and another at 160. It's also cold out now, so it may stay a little cooler no matter what right now. check your receipt, make a phone call and ask and wait for warmer weather.

Yep

From my digital readout, lower bound for temperature is about 192 if I'm coasting down a hill, to 197 if I just get off the freeway and come to a stop, excluding activity from radiator fans.

And that's with OEM.

Previous aftermarket tstat would be anywhere from 203 to 217. And that was from a 'reputable' company.

In all cases - temp gauge was pegged at center. The cluster has quite a bit of fudge factor to it such that it stays in center under 'normal operating temperatures.' I can't seem to locate numbers for it right now, but I remember GM giving a fairly generous range for it. But... I like to split hairs. Just because nearly 220 is 'in spec' doesn't mean I want it running that hot. Not with aluminum heads anyway.

Take the thing on the freeway for 10 mins and check temperature. The heaters in these can suck a pretty phenominal amount of heat from the engine and if you have it cranked in cold weather, you won't actually get the engine up to full temp if you're just toodling / idling.

 

[jcoggins7]

All of these responses are super helpful and exactly what I was hoping to get. Thank you. I did a quick look and all current NAPA thermostats are OE temp, just as a PSA

 

[MassHoe04]

All of these responses are super helpful and exactly what I was hoping to get. Thank you. I did a quick look and all current NAPA thermostats are OE temp, just as a PSA

When I plugged in my 04 on NAPAonline.com, I did get a couple results that included the OE temp units as well as a couple listed as "Alternate Temperature".
The Alternate Temperature ones included 180 and 165 degree thermostats.

Someone would have a specific reason for going with stats that open at cooler temperatures than the OE 187 degree stats.
Just thought I would clarify what I was seeing under available options...

Like I said, I would be almost 99.99% certain your average repair shop would stick with standard OE thermostats.