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Thread: Battle for Lower ECTs

  1. #1
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    Battle for Lower ECTs

    Hello Tuners,
    Ive Battled high ects ever since i finished my turbo 5.3 swapped colorado build. In traffic with AC on itll climb up to 250. Weird thing is it will also climb up at freeway speeds as well. With las vegas summer coming back around im hoping to figure something out. Ive tried alot. Custom Efans/ bigger radiator, new pump, tstat, hoses, bypass trans cooler etc.
    i was wondering if there was anything in my tune that might be causing this issue. Could someone please review and give me feedback. See tune in link below

    https://forum.hptuners.com/showthrea...t=Engine+temps

    Thank you
    Last edited by Hawaiian_Built; 02-10-2020 at 07:04 PM.

  2. #2
    Tuning Addict 5FDP's Avatar
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    What are you considering too hot for coolant temp?

    Anything in the 180-200 degree range is perfectly fine to see.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
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    Itll climb up to 250

  4. #4
    Tuning Addict 5FDP's Avatar
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    Have you verified that with a temp gun or only from the coolant temp sensor?

    Have you tried a vacuum bleeder for getting all the air out?

    What about your radiator cap, have you tested that? A bad cap will not keep proper pressure in the cooling system leading to increased coolant temps.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
    Senior Tuner mbray01's Avatar
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    First a v8 in a colorado is already a tight fit, add turbos to that, and there is no room for airflow
    i bet your issue is not proper cooling, but lack of airflow through the engine compartment. I see this a lot, need to get air out, through fender wells, get a cowl hood,
    Michael Bray
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  6. #6
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    Quote Originally Posted by 5FDP View Post
    Have you verified that with a temp gun or only from the coolant temp sensor?

    Have you tried a vacuum bleeder for getting all the air out?

    What about your radiator cap, have you tested that? A bad cap will not keep proper pressure in the cooling system leading to increased coolant temps.
    Thanks for suggestions. I have not tested with heat with temp gun just verified via gauge, vcm scanner and torque app. Ive had 3 different radiators in this truck. Bought new caps (never tested) but all have similar results. Thought i tried every way to bleed system but never tried a vacuum.

  7. #7
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    Quote Originally Posted by mbray01 View Post
    First a v8 in a colorado is already a tight fit, add turbos to that, and there is no room for airflow
    i bet your issue is not proper cooling, but lack of airflow through the engine compartment. I see this a lot, need to get air out, through fender wells, get a cowl hood,
    Ive been told that, but have heard of some folks having better luck then. its funny you mentioned airflow through engine bay. I did end up cutting the fender wells for better air flow And picked up a cowl hood. I even tried removing the intercooler to see if it would help but it didnt. My next step is to attempt to build vents to direct the air straight out the wells

  8. #8
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    I assume the tune cant cause too much of an issue?

  9. #9
    Senior Tuner mbray01's Avatar
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    Not too much in a tune thats gonna cause the issues.

    You always have to take into account where people are when they say they arent having heating issues. Just because a guy in pennsylvania doesnt have issues, doesnt mean you wont in vegas.

    I cant tell you how many cars ive fixed over the years that constantly popped head gaskets, by installing cowl hoods, or gaining airflow around back of firewall/fenders
    Michael Bray
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  10. #10
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    Did you checked the heads water lines for obstruction?
    do you have your AC heater hoses connected?

  11. #11
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    Do you have the steam vent ports plugged on the rear of the heads? I did a kit that vented all of the steam ports, I ran the line to my overflow tank, this alone helped my coolant temps significantly on my corvette.

  12. #12
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    Quote Originally Posted by castorjames View Post
    Did you checked the heads water lines for obstruction?
    do you have your AC heater hoses connected?
    I checked out the vent lines in the past but it doesnt hurt to check again. I do have heater hoses connected. I actually daily this truck.
    Quote Originally Posted by ZincGT View Post
    Do you have the steam vent ports plugged on the rear of the heads? I did a kit that vented all of the steam ports, I ran the line to my overflow tank, this alone helped my coolant temps significantly on my corvette.
    I currently have the rear capped. Can you elaborate on your vent setup? All 4 ports are routed to overflow tank?

  13. #13
    Tuning Addict blindsquirrel's Avatar
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    For the rear, use the Gen4 truck front crossover pipe on the rear ports. Run the new hose to a tee in the existing front hose.

  14. #14
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    https://www.motionraceworks.com/prod...am-vent-system

    Some people route it back to the water pump or radiator, I chose the overflow tank so it was unimpeded flow out of the heads, took a bit to burp it but when I had a big front mount intercooler it was the single best thing I did. I later installed a "cover" from my rad support to the top of the radiator to make sure all the available air was pushed through the radiator.

  15. #15
    Tuning Addict blindsquirrel's Avatar
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    12605716 or 12694768 (new number), couple feet 1/4" coolant hose, 1/4" tee, a few clamps = less than $60

    You can only use the 'overflow tank' for the connection if it's the pressurized type, if you have a old style burp tank the vent has to go to the post-thermostat side of the water outlet.

  16. #16
    Senior Tuner 10_SS's Avatar
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    Take your hood off, drive around see what happens.

    Also feel your rad hoses top and bottom, then feel radiator, see if it's all hot, should be. If yes with FAN on you should have alot of heat getting blown out. If not then you a have something else going on. if cool, then you have a flow problem.

    With mine, even with the fan on and hood on or off at anything over 20mph, it would start overheating. Big alum radiator did nothing to fix.

    I've had this issue with other swap engines, 461ici bigblock in a 1988 TA for example. Ended up being the lower air dam, those cars dont have a traditional grill. they look like a Tesla. I didn't have the proper parts in place that apparently created low pressure under the front bumper where the path to the radiator is and was stopping the airflow I needed. I even made ducts to direct it in, like a scoop, but that didnt help. Ended up finding the stock pieces which were part of the curb scraper setup that made a drop down in front of the opening on the way to the radiator.. this completely fixed it! Looking at it though, you would think it would restrict airflow.

    If you take your hood off, this might give you the air path you need but if your radiator is not getting very hot, this may just mask your problem.
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  17. #17
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    Have you tried a vacuum bleeder for getting all the air out?