No announcement yet.

Temperature Limits

  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    What you are saying temp wise in deg C all looks normal.
    680deg F is about 380 deg C which is spot on cruise condition egt 👍

    i was thinking logically if blocked it would retain heat, but I haven’t seen engine data on this. And to be honest looking at that hadn’t crossed my mind but I think it could be a possibility for a symptom.

    I did a regen for sh1ts and giggles once to see what would happen under poor driving regen conditions and this included it finishing off in my drive. Result was 145km before next regen. Nothing wrong with DPF just not cleaned out. Next regen was flogged on highway hard and I got 367km before next regen.

    Nothing seems unusual if the 680 deg cruising is actually Fahrenheit not degrees Celsius
    a true indication will be voltage out of that DPF pressure sensor....


    • #17
      As my interest in all things DPF on my Prado borders on the obsessional I take great interest in monitoring mine. I have noticed exactly the same as DaveC has pointed out. (Have you seen my PM DaveC?)
      I have left the car on fast tickover when the burn has almost completed, 1200 rpm as it is a manual. The burn does finish and the % goes further down than if driving. However I have left the car at fast tickover with the burn only down to say 30%, in this case the temperature drops back to normal after a few minutes. The burn restarts and completes as normal once the engine came up to temperature the next time it was used.
      You still haven't said what tool you are using to monitor what is happening and also not said which DPF reading is not working.
      Attached are a couple of screenshots from my head unit running torque, the first shows the temperatures etc while a burn is taking place driving along, the second shows what they drop back to when the regen is finished and the % is building up again. The highest temperature I have seen at fast idle is 750C this is always less when driving.
      Click image for larger version

Name:	Screenshot_20180208-094423.jpg
Views:	18
Size:	89.8 KB
ID:	9435Click image for larger version

Name:	Screenshot_20180208-095209.jpg
Views:	11
Size:	89.8 KB
ID:	9436


      • #18
        I find what DaveC and JohnLynn are posting very interesting that the regen stops if parked up and % accumulation over 30.
        I take this that Toyota has programmed the above because they know an idle regen is poor. Which when you consider city driving and engine load there is not much difference.


        • #19
          I noticed that with a stationary regen, after the engine drops it's speed to idle, if you give the thing a good rev, the regen starts up and the idle speed goes up gain. It runs for another 5 to 10 minutes before ending the regen. Also I have 3 egt readouts. One always goes significantly higher than the others after a while. Last time I gave it a boot to get it started again the high one went to 700 deg C . No kidding mate 700 deg C. That's near enough 1300 deg F.. Th other two went to about 500 deg C or 930 deg. C. After a coupleof minutes they all started to drop slowly, very slowly until when back to a more reasonable level the idle speed dropped. At that time all the engine parameters went back to normal.


          • #20
            So the cars don’t like stationary non forced regen, this coincides with once I had a scope on the injector as the DPF% went to 100. Now car was stationary at idle and regen never started. I thought I had a bad connection with the scope probe but nope was good.

            Davidd the one temp probe being significantly higher is EGT2 then EGT3 will eventually catch up too. Being a lot hotter is the catalyst heating up from fuel being injected upstream. Think of the DPF as a self cleaning oven.

            normal driving regen temps for EGT2 will be between 580 to 750 deg C. Depending on driving conditions and it always gets hottter once below about 30%

            a student reported regen temps of over 900 deg on forced regen that had blocked DPF.

            Try and avoid stationary regens they are not the best, I always drive car harder when in regen.

            your car is working fine mate with what you are saying, it’s doing what it should.


            • #21
              Thanks Luke. I know I'm a pest to some of you blokes with much more knowledge and formal education in this stuff, but if there is something happening I don't know about I just have to find out. The DPF won't clear while driving now unfortunately has to be a stationary one and is still drinking fuel. Now up to about 11l/100. I think there is an injector problem as well which I will have to look into.
              Thanks a lot all of you.


              • Spook1205
                Spook1205 commented
                Editing a comment
                Mate always happy to help out
                As for not clearing when driving are you aware that it holds on to the regen much longer due to the exhaust velocity? In saying this I have had regens go for over 70kms and most last about 50 kms for me.

              • Spook1205
                Spook1205 commented
                Editing a comment
                If you disconnect your battery it will reset your fuel average usage. Mine is on about 11 too.
                Your injector would be a more consern, but if you can put a multimeter in the middle wire I showed you that will give me a good indication on your DPF.

            • #22
              I am curious which sensors are bank 1 sensor 1, 2, 3 as torque has 4 by default but only 3 work. I have attached a couple of not very good pictures to explain what I mean. The first shows what looks to me like 3 temperature sensors and the second picture another one lurking just before the beginning of the exhaust pipe.

              Click image for larger version

Name:	20180210_092427_001.jpg
Views:	6
Size:	133.6 KB
ID:	9464
              Click image for larger version

Name:	20180210_092746.jpg
Views:	5
Size:	164.4 KB
ID:	9465


              • Spook1205
                Spook1205 commented
                Editing a comment
                Going by the orientation of your pic
                EGT1 is at the bottom
                EGT2 is the middle
                EGT3 is the top

                If looking in the engine bay it’s right to left or EGT1 is the first sensor the exhaust hits on way out.

                The other pic is showing an air/fuel ratio sensor, it’s a flash version of an O2 sensor which will actually tell ecu how rich or how lean Engine is running, Will also tell ecu if EGR is functioning properly too.

              • JohnLynn
                JohnLynn commented
                Editing a comment
                Thanks Luke, I had guessed the first three correctly but had no idea what the last one was, they all look the same from the outside!