Led light bar behind grill overheating issues

sierrathewhitesierra · January 6, 2017

Hey Guys looking for some insight

Installed a led Light bar yesterday behind the grill of my 2016 sierra everything works great, but now it seems that if I floor the truck the coolant temp needle starts to raise up and then will go back to the middle after i let off the gas. also on my way home from work there is a pretty steep hill and when driving up with moderate acceleration the needle begins to climb but will drop back down when I let off the gas and coast. now im not sure if I am being paranoid and my truck has always done this and its just coincidence that i noticed after the install i am just worried that the light bar is blocking airflow. so any other light bar people out there have this too? or is it just normal oh and btw the temp outside was about 55-60f

thanks

Bildoo · January 6, 2017

I have a light bar mounted behind the grill on my Sierra also. I will pay attention to my temp gauge tomorrow. I have not seen it high at all but I don't stare at the gauge. It's a high of 6°f tomorrow maybe I will have to wait till its warmer.

sierrathewhitesierra · January 6, 2017

I have a light bar mounted behind the grill on my Sierra also. I will pay attention to my temp gauge tomorrow. I have not seen it high at all but I don't stare at the gauge. It's a high of 6°f tomorrow maybe I will have to wait till its warmer.

oh ok thanks man I notice when I floor it the needle will creep up a tick mark mark and then drop back down.

thewhitestallion · January 6, 2017

While that is weird, I would not worry about it. I have a light bar behind my grille and went all summer in Houston with it and my truck did not overheat once. The fans do not even turn on 100% power in the middle of the day with 100* heat and 98* humidity sitting in traffic.

Do you hear your fans get louder at all? The fans on these trucks are pretty loud when you truck gets too hot and would be very noticeable if the truck was getting too hot. It is probably a coincidence. But just cover the basics, make sure your coolant level is good and does not have any air pockets in the system and make sure your fans are working.

Unless you have a light bar that blocks 3/4 of the grille I doubt it is causing your engine to heat up that much.

Thomcat · January 6, 2017

May not be the proportion of the surface area of the radiator they block, but the mounting location. Might be at a "sweet spot" where it either blocks or creates greater turbulence directing air away from the hottest fins.

sierrathewhitesierra · January 6, 2017

While that is weird, I would not worry about it. I have a light bar behind my grille and went all summer in Houston with it and my truck did not overheat once. The fans do not even turn on 100% power in the middle of the day with 100* heat and 98* humidity sitting in traffic.

Do you hear your fans get louder at all? The fans on these trucks are pretty loud when you truck gets too hot and would be very noticeable if the truck was getting too hot. It is probably a coincidence. But just cover the basics, make sure your coolant level is good and does not have any air pockets in the system and make sure your fans are working.

Unless you have a light bar that blocks 3/4 of the grille I doubt it is causing your engine to heat up that much.

I can't really tell if the fans are kicking on while I'm in it. At idle and gentle acceleration my truck is fine the needle stays dead center at 210 but for example this morning I was driving to LA for work and if I floor it to pass cars on the freeway the needle will begin to creep up past the middle the most the temp fluctuated was when driving up a hill and accelerating to pass the needle hit the first tick mark after 210 I'm thinking of taking off the light bar and drive around again and see if it continues I'm pretty bummed out I really like the light bar and the inconspicuous location behind the grill. I plan on using this truck to tow my project car so I'm worried that I will have overheating issues with the load and restricted airflow. The led light is a 32 inch and it's in the lower portion of the grill

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Donstar · January 6, 2017

I'm thinking of taking off the light bar and drive around again and see if it continues

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It would be interesting to hear your results. My bet is the light bar makes no noticeable difference! Unmarked police trucks are pretty common around here and they have quite a light show hidden behind their grills. These vehicles get hard use but I'm sure they're not overheating!

sierrathewhitesierra · January 6, 2017

May not be the proportion of the surface area of the radiator they block, but the mounting location. Might be at a "sweet spot" where it either blocks or creates greater turbulence directing air away from the hottest fins.

That's what I am thinking because the light bar is in the lower portion covering one of the three large opening and if you look through the grill it was the one with the least amount of restriction

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kstruckcountry · January 6, 2017

I have had a piece of 50% steel mesh riding in front of my grille for years.... I know it's a newer pickup but I doubt it's that sensitive.

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sierrathewhitesierra · January 6, 2017

It would be interesting to hear your results. My bet is the light bar makes no noticeable difference! Unmarked police trucks are pretty common around here and they have quite a light show hidden behind their grills. These vehicles get hard use but I'm sure they're not overheating!

. Well true I did not think about that although I have been looking around at other pickups around town and noticed some have much smaller grills than our trucks even with that row blocked it just sucks to have to tear the front end all down again lol

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sierrathewhitesierra · January 6, 2017

I have had a piece of 50% steel mesh riding in front of my grille for years.... I know it's a newer pickup but I doubt it's that sensitive.

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really? Yeah i didn't think it was going to be much of an issue either and it's only under heavy acceleration I'm going to try to mount it somehow farther back from the grill to give it some space because the way it is now it's very close and doesn't give much gap between the light bar and the grill for air to flow around so hopefully opening the gap a little may help or even trying to mount it in the lower portion somehow

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tmo · January 6, 2017

I heard in another forum post when I posted pics of my light bar that there was "flappers" that open and close to direct more or less air on the 16s and newer. I have never seen them as I have a 15, but if they are there and you blocked one with he mounting hardware, Its possible that it is where your problem is.

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sierrathewhitesierra · January 6, 2017

I heard in another forum post when I posted pics of my light bar that there was "flappers" that open and close to direct more or less air on the 16s and newer. I have never seen them as I have a 15, but if they are there and you blocked one with he mounting hardware, Its possible that it is where your problem is.

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flappers? Like grill shutters that open and close for fuel economy? I didn't see any when I took the front end apart there wasn't any wires connected to the grill

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tmo · January 6, 2017

flappers? Like grill shutters that open and close for fuel economy? I didn't see any when I took the front end apart there wasn't any wires connected to the grill

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I suppose that's what he was talking about. I would think that the module would be hard to see. And the flappers would be free standing in front of the radiator or even possibly on the sides. If you take it off look around for them and make sure nothing is hitting. It wouldn't surprise me if there are "flappers" since the technology of "flappers" are already used in the headlights for the high and low beams.

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TheGovernment · January 6, 2017

There is no way that's causing your truck to overheat. Either you just started to notice the gauge doing that or there is another problem that happened close to the time you put it in.

That's not enough of a restriction.