Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Temperature Oddity

Discussion in 'The Garage' started by Kiqman, Jun 6, 2005.

  1. Kiqman

    Kiqman 1/2 ton status

    Joined:
    Dec 14, 2004
    Posts:
    102
    Likes Received:
    0
    Location:
    Portland Oregon
    When I first start my 89 k5 with tbi in the morning the auto choke kicks in and the truck then gradually idles down as it should as it warms. Problem is the temp rises to about 240 on the gauge as I'm driving before it drops back down to 210 where it stays for the most part. During this "start out" time it doesn't want to idle at a light, stutters as you start from a stop, and acts like there's water in the gas. I have flex-a-lite fans but they don't even phase the temp for those first few minutes when the temp is climbing. I'm worried that getting the engine this hot every day, even if just for a few seconds, will ruin my heads or engine, etc. I'm wondering if I should switch my 180 degree thermo to a 160 degree unit? It can't be good for my engine to get that hot before returning to a normal temp!?! After the day's innitial warm-up the engine runs like a top. I should mention my 5.7tbi has HP heads, headers, cam. Spent a lot and I'm worried I'm doing damage daily!
     
  2. Jagged

    Jagged 1 ton status

    Joined:
    Apr 25, 2005
    Posts:
    11,460
    Likes Received:
    1
    Location:
    SWVA
    Mine used to run kind of hot, I removed the defunct AC compressor and condenser, and installed a 160* thermostat... even out wheeling all day it doesn't even touch anything close to 200*
     
  3. RootBreaker

    RootBreaker 3/4 ton status Premium Member

    Joined:
    Nov 29, 2001
    Posts:
    5,118
    Likes Received:
    173
    Location:
    Williamstown, NJ USA
    Err if your thermo is a 180 and you are puking up at 240... then something is definitely wrong.. (cpt obvious kickin in...)

    my jimmy was going high... and turned out to be my radiator gunked up and waterpump bad.... replaced both... also replaced the thermo for safe measures.... now she sits nice and low....

    remember one thing... I believe computer controlled vehicles.. need certain temp to run at peak... so going lower temp may not be good or adviseable...
     
  4. Jagged

    Jagged 1 ton status

    Joined:
    Apr 25, 2005
    Posts:
    11,460
    Likes Received:
    1
    Location:
    SWVA
    heh, forgot about that... had gunk in the radiator, and had to flush the block out, there was a lot of buildup around the knock sensor.
     
  5. Kiqman

    Kiqman 1/2 ton status

    Joined:
    Dec 14, 2004
    Posts:
    102
    Likes Received:
    0
    Location:
    Portland Oregon
    Temp Continued

    Radiator, thermo, hoses, h20 pump all replaced new with engine rebuild 3 years ago. Cooling system works fine after innitial overheat. A local guy here says he thinks I got a bad 180 degree thermo that sticks until 240 - then stays open for the day. Guess I'll try a new 180 thermo first to see if it is in fact "sticking". Any idea how long a vehicle has to be close to the red before you're doing damage? When I start out for the day it's near the red but only for 1-2 minutes - then perfect all day long.
     
  6. Jagged

    Jagged 1 ton status

    Joined:
    Apr 25, 2005
    Posts:
    11,460
    Likes Received:
    1
    Location:
    SWVA
    you didn't put that thermostat in upside down did ya? ;)
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    Probably a sticking thermostat. Repeatable problem, not consistent during operation pretty much leads away from anything that works the same regardless of time spent "sitting", like the water pump and radiator.

    Aren't doing yourself any favors with the 180* stat, but if thats what you like, stick with it.

    Delco's are supposed to be fairly good "off the shelf" compared to most anything else off the shelf, short of the Robertshaws that are generally highly recommended as well.

    3 years for an aftermarket thermostat can be considered good anymore, when probably 25% anymore seem to be bad before install.
     
  8. Kiqman

    Kiqman 1/2 ton status

    Joined:
    Dec 14, 2004
    Posts:
    102
    Likes Received:
    0
    Location:
    Portland Oregon
    Upside down

    I didn't install it so that's possible. I didn't know you could install a thermo upside down? How do you tell which side is up?
     
  9. RootBreaker

    RootBreaker 3/4 ton status Premium Member

    Joined:
    Nov 29, 2001
    Posts:
    5,118
    Likes Received:
    173
    Location:
    Williamstown, NJ USA

    you looking at my truck again??? I did that.... once....

    spring part goes down into the engine.... :crazy:
     
  10. Kiqman

    Kiqman 1/2 ton status

    Joined:
    Dec 14, 2004
    Posts:
    102
    Likes Received:
    0
    Location:
    Portland Oregon
    Isn't the 180* the stock stat? Are you saying I should be running a different stat temp? If so which one...looks like the only alternative is the 160 but some folks are telling me that could screw with my computer controlled tbi?
     
  11. Jagged

    Jagged 1 ton status

    Joined:
    Apr 25, 2005
    Posts:
    11,460
    Likes Received:
    1
    Location:
    SWVA
    No, but I think we might both be related to some guy named Murphy ;)
     
  12. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    195* is almost universally what GM used in every application.

    It would be stock for yours.

    Lower temp thermostats in most cases are used as an attempt to band-aid an inadequate or improperly working cooling system.
     
    Last edited: Jun 6, 2005
  13. RootBreaker

    RootBreaker 3/4 ton status Premium Member

    Joined:
    Nov 29, 2001
    Posts:
    5,118
    Likes Received:
    173
    Location:
    Williamstown, NJ USA
    exactly.... when I was a younger lad.. I band aided EVERYTHING!!! or used duct tape :grin:

    however now.. do it right or dont do it at all :crazy:
     
  14. Jagged

    Jagged 1 ton status

    Joined:
    Apr 25, 2005
    Posts:
    11,460
    Likes Received:
    1
    Location:
    SWVA
    F4 tape works wonders, I used it a lot in my job in the AF, and also to repair leaky radiator hoses... wrap it good with F4 tape, then zip-tie the ends and it's good to go.
     
  15. mudslinger99

    mudslinger99 1/2 ton status

    Joined:
    Oct 8, 2004
    Posts:
    512
    Likes Received:
    0
    Location:
    East Coast
    I had to replace the thermostat in mine 3 or 4 times because they were bad right off the shelf... I finally went to a different parts store then I got the 1st few from... Turns out the the parts store got a bad batch... Just something to keep in mind...

    You should keep the factory themostat... A lot of people use to do that on non-computer motors with varied results.. But as was stated it is not reccomended for yours.. If you type in ''thermostat'' in to the search you can find alot of info...
     
  16. Wes Harden

    Wes Harden Registered Member

    Joined:
    May 28, 2005
    Posts:
    29
    Likes Received:
    0
    Location:
    Southern Califorina
    thermo and tbi

    Yes if your truck is running GM programing in the puter it realy is disigned for a 195 degree thremo. but if your truck has been modified and you have no cat.
    you'll be fine, it'll run a tad rich, so fuel economy will suffer.
    As for up or down on stat they're noramly marked "this side to radiator" or "This side up" <- also radiator. One question thou is the truck realy getting that hot ? have you popped the hood and started it to see if the engine temp truly that hot.
    But if that stat is 3 years old I would change just because. In my old non-puter cars/trucks I change from a 180 winter to 160 summer stat. other wise newstat every 2 years.
     

Share This Page