Thermostat questions and study

Discussion in 'V8 Discussion' started by GEN 3 SHO FAN, Jun 6, 2019.

  1. gamefanatic

    gamefanatic SHO Member

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    Well, my memory is fading on the SLO, but the SHO housing has two sensors near each other under the throttle body. The closest one will have a 1 wire (dash cluster) connection like the oil cooler. The one tucked a little further is a two wire (computer). If the computer one was missing, this would lead to the fans not turning on unless the A/C was cycled.

    I don't see any danger with this testing. It's going to let you know if there are issues at your cluster gauge.
    My hypothesis, without the backplate on the thermostat, there is potential for heated water from the engine to turn back around into the engine and not get cooled. However, it's just as probable that the cold water mixes with the supplying hot water headed to the radiator and helps to cool it more.

    The SLO does not support the backplate, so it's possible somewhere down the line you may have gotten one of those. I know I have had issues with the wrong reservoir and A/C compressor. Some of the systems don't do a good job of ensuring the part is correct for the engine.

    I agree that 180°F is the sweet spot between the engine not being too cold, and efficient burning of the fuel (< 210°F).
     
  2. SHOZ123

    SHOZ123 SHO Member

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    The 'tail' does not interfere with normal cooling. It only becomes active at high temps (+230F or so) and then it helps to provide maximum flow through the radiator for cooling. And until you get an OBDII data reader you do not know how hot you are running.

    If you have cooling problems more than likely it's the radiator clogged externally with debris.
     
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  3. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Thanks all of you. I will run it as is for the moment and watch it. I will take time to go at scrapyard and find 1 or 2 on scraped low mileage Toyota. According to the interchange list I have, any Corolla or Camry from 1998 to 2015 have it.

    I also observed that the fans kick in exactly at 2/3 which is the normal setting IIRC.

    I replaced the rad like 2 years ago so it can't be clogged as the car roll only some months by year too.
     
    Last edited: Jun 11, 2019
  4. SHOZ123

    SHOZ123 SHO Member

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    How hot is 2/3s on the gauge?
     
  5. gamefanatic

    gamefanatic SHO Member

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    Just a word of caution, aftermarket head gaskets start to fail around 233°F, and should be well in the red on your gauge.

    Never let the car get over 225°F. The high speed fans kick on at 215°F.
     
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  6. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Paul, I understand your point, the mesurement of the sensor is relative.

    Before, fans go very often in high speed. Seems to not be the case anymore. I can confirm the engine is cooler by his behavior though.

    Ok thanks Gamefanatic. It's where I want to go. At which temp the fans go on ? The car computer can give us the temp for 2/3 (my comtuter is stock).

    T-stat opening at 180 F
    Effficiency threshold to burn gas : 210 F
    Fans kick in at 212 F (at 2/3)
    Fans high speed kick in : 215 F (somewhere around my 3/4)
    Coolant boilling point : 216 F
    Activation of the tail (back plunger) : 230 F
    Destruction of some aftermarket head gaskets : 233 F
     
    Last edited: Jun 19, 2019 at 12:05 AM
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  7. gamefanatic

    gamefanatic SHO Member

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    Low speed kicks on at 212°F, turns off at 208°f, IIRC.

    I have my low speed kick on at 204°F on the TweeCeR.
     
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  8. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    So fans kick in at 212F and go high speed at 215F ? It's only 3F difference...
     
  9. gamefanatic

    gamefanatic SHO Member

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    Yeah,there isn't much play room there. Mine don't even kick on in the winter in most conditions, only sitting still or when the A/C kicks on.
     
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  10. stephen newberg

    stephen newberg Moderator Staff Member

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    For what it is worth, mine runs the same as Paul's. Once it is up to operating temperature the water temp gauge, sitting at a touch above center, never moves again at all.

    pax, smn
     
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  11. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    I will give antoher check up there too. (At which mileage freqency this must done ?)

    "After the clean radiator went back in, the car was back to normal with the 2nd or high speed fans never coming on again after a good test run and 20 min idle."

    https://shoforum.com/index.php?thre...blem-solved-story-and-pics.35725/#post-307497
     
  12. gamefanatic

    gamefanatic SHO Member

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    Its all based on how much debris gets in there. Someone may never clean it, while others do it regularly (dirt roads).

    One of mine had some couch material between it and the accumulator when I bought it. Was suprised it ever worked.

    Depending on the material that is clogging it, a high pressure spray will not always clean it, before bending the fins. Some places have clay in their sand that will kick up. Presoak with a concentrated degreaser / bug remover. They make wands to attach to hoses that make the job easier.

    I'd like to find the right temp sender. I have one car with normal temps at the 1/4 (pointing at the 25 mph) and the other pointing at the 3/4. My SLO never had a problem with it being dead center.

    But truthfully, I never pay attention to the gauge anymore. Always use the Torque App for daily driving. Have alerts set when temps reach certain levels, so I don't have to pay attention on long drives through the desert heat...
     
  13. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    I will try to spray some air from behind it when I will have some time.

    I also observed that I still have some minor air leaks some misfires stay. I added a PCV catch can and valve cover catch can which cannot be perfectly sealed (hone made). A leaner mix can make the engine be more hot too.

    Can you pm me infos on your gadget ? I tryed some wallmart gadget plugging into OBD2 but the car seems to old to be "read"...
     
  14. gamefanatic

    gamefanatic SHO Member

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    The last Bluetooth OBD-II I got from some vendor at SEMA a few years ago. It's an MCR USA like the one in this ebay link. It's a Chinese device, but haven't had any issues with it and keep it plugged in all the time.
    https://www.ebay.com/itm/263350303134

    The one that I will always recommend is the OBDLink MX simply because it's the fastest of them and has a bit more security tied to it if that is of concern. Of course, the Torque App can't take full advantage of this speed, but has no issues querying over 30 on-screen monitors and several background checks. I have the first version of the MX, so the version that is out now is a little more advanced than mine and about half the price I paid originally.
    http://www.obdlink.com/mxbt/

    Besides the Torque App (Android) I recommend FORScan. It's a little buggy, but can access more PID's out of the box. I have yet to make a list of all the PID's I have imported into Torque such as Torque Converter lockup, A/C clutch cycle, etc.
    FOR(d)Scan
    https://forscan.org

    Torque App
    https://play.google.com/store/apps/details?id=org.prowl.torque&hl=en_US
    https://torque-bhp.com
     
  15. PaulTAutoX

    PaulTAutoX Member

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    I'll second the OBDLink MX, Amazon B006NZTZLQ, it has worked great for me on another car (don't have an OBD-II SHO). A little over $70 on Amazon; there is a newer version, the MX+ that is ~$80 and claims "professional level", unsure what that means. Yes, for the Gen III SHO (heck, any car) important to know where the temp sensor that is being read, is actually located. I've used the MX with Torque Lite so far, and am going to pay for the full version once I get some questions answered.
     
  16. gamefanatic

    gamefanatic SHO Member

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    The real difference between the ODBLink MX vs the MX+ is just the enhanced PID's will be made available only through their app.
    If you use another App like Torque, it doesn't add any value over the standard MX. Keep in mind nearly any ODB-II reader will have access to those modules, its the software that needs to know how to access them.

    FOR(d)Scan is an out-of-the-box tool (free) for Ford vehicles that will scan and give you access to all those additional functions at no additional cost.
    You can also create custom PID's for Torque to do the same things.

    I personally hooked my PC up with a USB packet sniffer and ran FORScan through a USB OBD-II adapter to get the PIDs I wanted for my daily Torque usage.
     
  17. Pablo sho

    Pablo sho SHO Member

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    What kind of high temps do you have there Stephen. Mine stays cool around 85F but at 95F my temp guage goes above 3/4. I noticed my water pump belt has oil on it so it may be slipping at higher rpms.
     
  18. gamefanatic

    gamefanatic SHO Member

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    Both of my SHO's react the same. Getting into the 90's, becomes problematic to maintain temps. Can't really use the A/C for anything but down hill when near 105°F. New hoses, radiator, accumulator, and even on one car new head gaskets. Still the problem persists.
     
  19. stephen newberg

    stephen newberg Moderator Staff Member

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    Overall Vancouver Island is pretty temperate, but the world is warmer than it was when I bought the car. :) The day before yesterday it hit 31C here, which would be, let me think, about 89F. And that is in early June. By late July and into the first couple of weeks of August we regularly will get into the mid 30sC, which is 95F and above.

    I have not had any overheating problems of note during that except when going over the mountain on the way to Victoria. On the going up side the water temp gauge has, on occasion, gotten as far up as maybe 2/3rds. Mainly I watch oil and auto trans fluid temps, though, as I have gauges for both. Even in the heat and mountain climb conditions, I almost never get transitions on either above 200F, and in normal use the oil temp will be 160-170F while trans fluid tends to hold in the 140-150F range.

    pax, smn
     
  20. gamefanatic

    gamefanatic SHO Member

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    Sounds like yours is working like it should. With my tranny cooler my fluid barely makes it to 170°F before I am stopped. I have one mountain that I have to go through on my commute which is where the system gets tested when temps are above 95°F.

    On thing I have noticed is when I have a second person in the car the problem is exhasporated. Situations that wouldn't be an issue with just me, are worse. I hadn't been looking at oil temps. Something to figure out. The temp sensor is off the oil filter housing, but with it being a 1 wire, I doubt the computer is monitoring it...
     

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