No thermostat

Discussion in 'V8 Discussion' started by Pablo sho, Jun 12, 2019.

  1. Pablo sho

    Pablo sho SHO Member

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    Well I tried to read the thermo thread but got lost in it.
    My car was running up in the 3/4 range last summer so I went to change the thermostat. I like to test mine on the stove against a thermometer. The new one started to open around 195. I live in the country so I put it together with out it. Ran it the rest of the summer that way and all winter. Now its getting warm again. Up to about 95 today. My temp guage is running up 3/4 plus and rising. Seems to hot but after reading the other thread seems normal.
    What's the consensus on running without a t stat? I know some engines need one to run cool. What's the recommended t stat? The Toyota one.
    It's been a long day and my brain ain't right.
     
  2. gamefanatic

    gamefanatic SHO Member

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    Running without a T-Stat is only an issue when its cold, and the car cannot get to an operating temperature (recommended >158°F). Summer time, I wouldn't see much of an issue really.

    The Toyota factory version would be the closest to the factory Ford for the SHO. The one I got was off a 2002 Toyota 4-Runner. Ford has discontinued the SHO version. Not sure if they used a different part number in other vehicles yet.

    I would recommend using an OBD-II reader to monitor you actual temps, as the gauge doesn't provide good feedback. You could go from normal to over heating in a few seconds if your car is having issues.

    Both of mine do have issues this time of year, so I have alerts setup on my phone to let me know when its getting too hot.
     
  3. Pablo sho

    Pablo sho SHO Member

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    I will try to check my radiator
    I'm getting to old for this crap.
    I have a obd2 but not sure how to read temps.
     
  4. STAN SCHWARTZ

    STAN SCHWARTZ Member

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    I wouldn't run without a t-stat. it's possible for the water to flow too quickly through the radiator, reducing the potential for heat transfer.
     
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  5. Pablo sho

    Pablo sho SHO Member

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    Yes. I know it is possible but was curious if anyone had experienced it with a v8 sho?
     
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  6. Pablo sho

    Pablo sho SHO Member

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    If I remember right I took the valve out of my thermostat so there still is restriction.
     
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  7. luigisho

    luigisho SHO Member

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    If you are worried about temps you need to get a more accurate reading than the gauge can provide. That will help you make the right moves to keep temps in line. You have OBDII which opens up more options than us old OBDI people. You can always run an old school gauge somewhere if the electronic OBD port plug in version gives you the willies.
     
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  8. NoSlo

    NoSlo GoldMember

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    From Harbor Freight, if you don't want to buy an $80 one; point at the metal of the engine water outlet and thermostat housing:

    [​IMG]

    In general, a thermostat sets the low temperature of normal operating. Below about 160, the car is in open-loop mode, warm-up mode with different engine management, and will run rich. With no thermostat, or even its restriction when open, you risk running too cold for engine management and proper emissions control, setting codes.

    A good thermostat you can put in the pot of near-boiling water like you did, but remove it from the burner and stir the water first when you take the temperature. There are "OE Standard 180 degree" and also 170 degree thermostats on RockAuto, so maybe you got the wrong type. A good thermostat also will have a jiggle valve(s) at the top position when installed to let air or vapor out of the engine, you can drill a pinhole if you want just a bit more unmanaged flow.

    The top temperature is maintained by the cooling fan (unlike an old pickup where the fan is always spinning or has a mechanical clutch that barely works).

    If the high temperature cannot be managed, like you overheat parked in traffic, it is probably cooling fans kicking in too late, or the radiator or coolant not working well, from deposits or too much coolant vs water (even water pump impeller wear from cavitation on G3 SLO; my impeller on my 93 instead looked brand new 190k miles later...). Non SHO G3s had terrible problems with rust, it was typical to find the green coolant instead colored brown and these need lots of back-flushing.

    G3 has a weird semi-, or non pressurized system without a radiator cap, if I'm remembering correctly.

    I just looked into this on my car, the voltages and resistance measured by the coolant temperature sensor indicate 5-10 degrees below the infrared measured temperature, putting temperatures uncharacteristically right in the middle of "normal" when the fans kick in later than you'd expect; I've got another sensor to put in and try out some time.
     
    Last edited: Jun 14, 2019
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  9. gamefanatic

    gamefanatic SHO Member

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    Not sure what you mean by non-pressurized system without radiator cap? Isn't that how it works?
     
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  10. Pablo sho

    Pablo sho SHO Member

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    I tried to get my reader to read temps but it doesn't seem to.
    Might look into another one. It was only about 85F today and it ran about the middle guage. Maybe I will just stay home when its above 90F. Lol. To hot to drive an old car anyway.
    The thermostat I got was from O'Reilly.
    It was the same as the one I took out but that doesn't make it right. I will order the toyota one probably or pick one up next time I go to town.
     
  11. NoSlo

    NoSlo GoldMember

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    "Works" is relative, considering the big problems and TSBs in G3 cars. One only needs to Google "Taurus rust brown coolant" for pages of results about rust and sediment, or enjoy this TSB for the G3 vulcan engines:

    Some vehicles may exhibit cooling system conditions such as:
    • Contaminated/corroded coolant
    • Leaking/Cracked/Discolored coolant overflow bottles
    • Vibration or thumping from engine
    • Leaking heater core
    • Coolant overflow
    • High temperature gauge readings
    • Fluctuating temperature gauge
    • Stuck thermostat
    • Heater hose leaks
    • Leaking head gasket
    • Lack of heat
    The G3 cars use a de-gas bottle reservoir with a pressure relief cap above the air of the bottle.

    On a G2 (and most cars) is a traditional radiator-mounted pressure cap, overflow tube through the first stage of the cap, and unpressurized reservoir bottle. Adequate pressure is maintained which raises boiling point without any air within the enclosed system.

    (Offtopic, the coolant reservoir system, which captures overflow and removes air, was patented in 1970, and there was an interesting lawsuit against an wantonly infringing company that had sold aftermarket and OEM systems.)

    I would shop for brand-name Rockauto.com 180 degree thermostats and see that they are recommended in other threads here.
     
    Last edited: Jun 14, 2019
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  12. gamefanatic

    gamefanatic SHO Member

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    Yeah, Vulcans are iron blocks and prone to the rust and all the glory that goes with them. Water pumps are all metal too, making them chip away slowly. Conversely SHO's & Duratecs are all aluminum blocks and heads, not prone to rusting and the water pump is a composite, more likely to have bearings fail first.

    Gen3+ Tauri all utilize a pressurized system no different in functionality from older style radiator systems. These typically don't use runoff tubes as the cap pops up allowing the air and coolant to be relieved from the system directly from it. Some plastic tanks do have a run-off tube.

    As the same of older models, the system operates up to 16 psi, moving the boiling point of the water to 216°F before it starts to lose thermal efficiency when turning to gas. This is why the high-speed fans come on at 215°F. In other words, don't open your bottle cap once the temps are nearing 210°F or above. I speak from experience... :eeeeeek:.

    These systems were designed with enhancements to safety, but leave it to a SHO owner to work around that...
     
    Last edited: Jun 14, 2019
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  13. NoSlo

    NoSlo GoldMember

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    The compromise is the air that is in the bottle - air is easily compressed, so it allows considerable expansion of the coolant before pressure can be built up. The good advice of the TSB is to fill the bottle nearly full.

    (can't complain though, after running about 90% coolant and a 0 PSI cap, I switched back to normal with a new radiator, and the damn thing still leaks like an SR-71 on the tarmac right out of the box)
     
    Last edited: Jun 14, 2019
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  14. gamefanatic

    gamefanatic SHO Member

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    I recall once I took my car to the alignment shop. The resevoir hight sensor was going bad, but they were nice enough to fill the bottle nearly full without telling me. I had a nice suprise of coolant all over when I got home. At least it wasn't over heating...
     
  15. stephen newberg

    stephen newberg Moderator Staff Member

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    For OBDII readers, these are handy:

    https://www.scangauge.com/

    I own a couple and they are very reliable. Not all that expensive either.

    pax, smn
     
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  16. Pablo sho

    Pablo sho SHO Member

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    Thank you. I will check it out.
     
  17. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    If you're going in easily at 3/4, there is probably something going wrong (but as others said, we cannot know "how hot is your 3/4"...). But you can also watch your temp needle when your fans will kick in and also the high speed kick too.

    2 simple things to check before starting to dig :

    1) Watch if the 2 fans are working, if only one works, as Paul said elsewhere, hot air will just turn around the engine and will become hot very soon (like 3/4)

    2) The reservoir cap loose strength overtime (the spring into them), Ford made a improved version in 2010 which is working on our bottle, their spring are bigger. With a weak cap, it will permit to water to boil at a colder temp creating bubbles in the system (needle could go somewhat crazy), the remaining coolant trying to keep all the heat will give a higher temp signal. (around 12$ new / can be found at scrapyard too for less)
    2010 bottle cap.jpg
    Older versions have a sticker on it rather these symbols painted.

    3) (bonus) Gamefanatic told me that propeller of waterpump are made from some kind of plastic, talking about that with my mechanic (many years of experience), he said me that these could broke with heat over time. This is more difficult to check however. Aftermarket with metal propeller. can be found easily.

    Good luck,
     
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  18. Pablo sho

    Pablo sho SHO Member

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    Fans seem to work on low not sure about high. Cap seems to hold good pressure but haven't tested it either. Haven't taken water pump off so dont know about that.
    I need a good obd2 reader but I'm cheap and not sure which one to get. Kinda hard to know what's happening until I get one. It may be fine but I get nervous when a guage is at 3/4 and rising. Thanks for the suggestions.
     
  19. NoSlo

    NoSlo GoldMember

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    The cheapest, and yet most versatile, scanner is an ELM327 clone USB computer interface and your laptop with ForScan.
     
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  20. Pablo sho

    Pablo sho SHO Member

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