Maybe overthinking but I feel like my suburban runs too hot...

[Cryptothedog]

Backstory: I had a 2004 suburban with the 5.3. The temp Guage always hung at 210 no matter if it was hot outside, I was towing, whatever. My 2015 suburban seems to run really hot. For the most part it stays at 210 unless iget the RPMs up around 3k then it climbs to about 220-235 before cooling back to 210. If I'm towing up hill in the mountains or really trying to give it power while towing it goes as high as 250 (the little line right before the red 260.) It doesn't get all the way to the red and cools itself back to 210. Is this normal with this model year? I've replaced the thermostat, coolant temp sensor, water pump pulley (it was making noise). I have also burped the cooling system as much as I can (no more bubbles come out). It always goes back to the normal 210. I just don't want to cause any damage by it running so hot.

If this isn't normal do you have any suggestions on what to check?

 

[OR VietVet]

There must be a way to see if fans are on at the right time/temp. How does it do when you have the a/c on?

 

[Cryptothedog]

The rad fan is on when the thermostat kicks on and when it's hot

 

[Cryptothedog]

There must be a way to see if fans are on at the right time/temp. How does it do when you have the a/c on?

I checked fans by pulling over when it's hot and the fan is on. A/C runs fine too. Car is cool inside with the ac on

 

[OR VietVet]

What temp thermostat was in the engine and what temp did you replace with?

 

[Rygrego]

Use a scan tool and see what temp the ECM is reading , gauges in these trucks can be way off. One other thing, you could have a bad water pump. But I would go the scan tool route first.

 

[Cryptothedog]

Use a scan tool and see what temp the ECM is reading , gauges in these trucks can be way off. One other thing, you could have a bad water pump. But I would go the scan tool route first.

Is there a way to tell if the water pump is bad other than switching it out?

 

[Rygrego]

Is there a way to tell if the water pump is bad other than switching it out?

A scan tool is the best way to make sure your gauge is good, if good then water pump, thermostat or clogged coolant system would be the logical next choice. You've already changed the thermostat so I would be looking at a pump.

 

[Cryptothedog]

A scan tool is the best way to make sure your gauge is good, if good then water pump, thermostat or clogged coolant system would be the logical next choice. You've already changed the thermostat so I would be looking at a pump.

Alright, I had a little time today so I hooked up my Bluetooth obd adapter and drove around for an hour. Pulled up the coolant temp in torque. After it warms up it runs most of the time at between 215 and 220 degrees. I got up to 237 twice. Each time I was accelerating to get on the highway. Both times I hit that temp it cooled right down to about 217 within about 10 seconds. I wasnt towing anything today but I know it gets much hotter while towing. The Guage seems decently accurate. Is it normal for it to climb that high while getting on the highway or climbing hills?

 

[wjburken]

How long have you owned the 2015? How long has it been heating up like this? Do you know if the radiator is original or has it been replaced?

 

[Cryptothedog]

How long have you owned the 2015? How long has it been heating up like this? Do you know if the radiator is original or has it been replaced?

Had it for about 6 months. I've put about 10k miles on it. It just recently (within the last 1.5 months) started heating up. I changed the thermostat because it would never heat up past about 1/4 of the guage. Happened after I changed my thermostat and water pump pulley (it was chattering). It was winter for four months of that though. I pulled with it a few times over the winter and it seemed fine, but it was also cold outside. I don't know on the radiator. I would assume it's original. I didn't think about the over heating too much because it didn't go past 3/4 until the last couple times I towed something

 

[OR VietVet]

If was me and I could not get a temp readout with a laser temp gun across the radiator surface, find a shop that can do a flow test on the radiator. Are there any shops that do that any more? Maybe. But sure sounds like a flow problem some place.

On my 2005, no matter how hard I pull, it never gets over 210. I have had a scanned attached and monitored, the gauge is correct.

 

[Rygrego]

Alright, I had a little time today so I hooked up my Bluetooth obd adapter and drove around for an hour. Pulled up the coolant temp in torque. After it warms up it runs most of the time at between 215 and 220 degrees. I got up to 237 twice. Each time I was accelerating to get on the highway. Both times I hit that temp it cooled right down to about 217 within about 10 seconds. I wasnt towing anything today but I know it gets much hotter while towing. The Guage seems decently accurate. Is it normal for it to climb that high while getting on the highway or climbing hills?

The standard thermostat for your vehicle is 207 so your temp is not out of line.

 

[Cryptothedog]

The standard thermostat for your vehicle is 207 so your temp is not out of line.

I understand the normal temp is fine but are the spikes I'm getting normal?

 

[Marky Dissod]

I'm still not sure if you have a pair of electrical fans, or a big ol' mech fan.
If you've a pair of electrical fans, GM probably programmed them to come on kinda late to coax another 1 or 2MpG out of your truck.

If you've a big ol' mech fan, then continue getting some more advice.
I got a mech fan (hopefully not for too much longer) that absolutely will not allow temps over 215F, unless it's over 100F stuck in rush hour traffic behind a bus with my AC on full blast.

 

[Fless]

According to Rock Auto the OE thermostat for a Suburban is 190 deg.

 

[Cryptothedog]

So I took it to a mechanic and they told me that "they hooked it up to there machine and it had a hydrocarbon level in the 80's which tells them that it has a cracked head gasket or cylinder head" does that sound right? Or should I get a second opinion? I don't have antifreeze in my oil and am not puffing out white smoke.

 

[OR VietVet]

If you got hydro carbons in the coolant you got combustion gasses in there. Minimum head gasket and maximum cracked head. Either way, needs heads pulled. IMO. Second shop opinion cant hurt but the quick check is an exhaust cas analyzer smelling at rad cap area.

 

[Cryptothedog]

Ouchies...anyone know the rough cost on getting that fixed? The shop I took it to doesn't do them.

 

[OR VietVet]

If you are keeping this vehicle make sure quality work is done. Ask around for good shops and check reviews. Also, look for ASE certifications. If you want cheap, you might as well just drive it. If you want correct, do the search and talk to them. I have always recommended a vehicle owner find a shop they trust. If has cracked heads, you can get a set of reconditioned heads. Make sure you get good gasket sets. Lots of members will chime in. What part of country are you in?