Announcement

Collapse
No announcement yet.

Car running slightly hot

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Car running slightly hot

    During normal forward motion and at idle my car runs as expected with the water temp needle bang in the middle(even in the recent hot weather!!). When i have to slow for traffic and am running at a slow crawl, the temp needle sometimes creeps up toward three quarters on the gauge and then returns to normal. I'm sure even with the hot weather it shouldn't move at all.

    So far i've tried;

    Replacing
    -Viscous coupling on fan(old one was a bit weak)
    -Thermostat(in case it was running wrong temp range)
    -Fluids

    Checking
    -radiator for damage/blockage
    -aux electric fan
    -fluid circulation

    I've checked for the normal signs of head gasket failure and all seems ok, just running out of ideas now :?

    Anyone had a similar problem before or got any other ideas :?: :idea:
    Black S50

  • #2
    How easy was it to replace the thermostat? do you need any other items (like seals etc) to replace apart from the thermostat itself?

    I bought the thermostat as mine didn't seem to warm up fully half way in winter but never got round to changing it, and it seemed that the top and bottom hose stayed cold until the engine reaches nearly halfway so assume that its probably OK anyway.

    I drove mine over the weekend when it was hot, the gauge stayed central all the time. I did notice the viscous fan being on when setting off from lights though after being stationary for about a minute, but the gauge never moved off central that I noticed.

    Comment


    • #3
      The thermostat is fairly simple to do but involves removing the viscous fan & shroud, throttle sensors and under tray(for draining coolant. While i was doing the thermostat i also changed the water pump & air con belts as they were a bit cracked and the whole job took about 2 hours max.

      There are 2 o-rings that should be replaced when refitting the thermostat housing.

      With my car, apparently up to around year 2000 the water pump had a plastic impellor which can loose its effectivness over time in circulating the coolant :roll:. Well its either that or the aux. fan temp sensor is not reading correctly :?:

      Will post up when i've tracked it down :wink:
      Black S50

      Comment


      • #4
        Originally posted by chippy
        With my car, apparently up to around year 2000 the water pump had a plastic impellor which can loose its effectivness over time in circulating the coolant :roll:.
        This is a well known problem with "normal" Z3's, did not know same pump was used on MC's :shock: Are you sure the impellor was plastic :?


        "Café-Racer mit Raketentrieb"

        Comment


        • #5
          The pump is different to other Z3s but not sure if its metal or plastic impellar.

          Comment


          • #6
            Originally posted by Ivo
            Originally posted by chippy
            With my car, apparently up to around year 2000 the water pump had a plastic impellor which can loose its effectivness over time in circulating the coolant :roll:.
            This is a well known problem with "normal" Z3's, did not know same pump was used on MC's :shock: Are you sure the impellor was plastic :?
            Was told this by an ex bmw mechanic, but have not been able to confirm this yet!!
            Black S50

            Comment


            • #7
              Originally posted by Ivo
              Originally posted by chippy
              With my car, apparently up to around year 2000 the water pump had a plastic impellor which can loose its effectivness over time in circulating the coolant :roll:.
              This is a well known problem with "normal" Z3's, did not know same pump was used on MC's :shock: Are you sure the impellor was plastic :?
              Was told this by an ex bmw mechanic, but have not been able to confirm this yet!!
              Black S50

              Comment


              • #8
                Well, i've now replaced the water pump, pump belt and double temp sensor and still the car goes up to 3/4 on the water temp gauge when creeping (10-20mph) in traffic :evil: :roll:

                This is starting to bug me now!! (hate being beaten by things like this)

                Any other thoughts :?: :idea:
                Black S50

                Comment


                • #9
                  Is it a faulty gauge? ... never known one to go wrong but if all else has been tried??
                  Other than that can you get hold of a thermal scanner to see what the real temp of the engine is?
                  We had some really smart kit for temp readings on bearings where I worked last, did not need to touch anything and gave really good readings showing temps.

                  Not got access to the kit now as moved jobs, but anyone on here may be able to help.
                  Need help setting up a CMMS/EAMS system?
                  S54: P*** Yellow ;-)

                  Comment


                  • #10
                    Kiddle

                    Thought about the gauge but seeing as it reads as you would expect, ie on warm up etc, and also when it shows the temp approaching 3/4 you can hear the viscous fan 'roaring' on acceleration which would indicate the water temps being high, i'm assuming its ok :?:
                    Black S50

                    Comment


                    • #11
                      Radiator is probably stuffed.
                      Black 02 reg S54 M Roadster

                      Comment


                      • #12
                        Originally posted by spunkym
                        Radiator is probably stuffed.
                        Had all the surrounds off the radiator to have a good inspection of it and there is no sign of any damage, corrosion, build up of crap in fins or leaks!!

                        Going to try a special radiator chemical flush on Friday to see if it has a partial blockage :roll:
                        Black S50

                        Comment


                        • #13
                          Originally posted by chippy
                          Originally posted by spunkym
                          Radiator is probably stuffed.
                          Had all the surrounds off the radiator to have a good inspection of it and there is no sign of any damage, corrosion, build up of crap in fins or leaks!!

                          Going to try a special radiator chemical flush on Friday to see if it has a partial blockage :roll:
                          Tony

                          I know you have been working hard to get this sorted and I know you wont be beaten by it

                          No luck with a differnet battery and a possible spike or erratic current?

                          Lee
                          Ex 'V3RY M - MCoupe track monster'
                          New toys

                          Porsche widebody project

                          Cayenne Diesel

                          Comment


                          • #14
                            Originally posted by Lee

                            I know you have been working hard to get this sorted and I know you wont be beaten by it

                            No luck with a differnet battery and a possible spike or erratic current?

                            Lee
                            Hi Lee

                            The gauges read consistantly, ie showing higher reading only under same driving conditions, so doesn't point to voltage spike, irregularity etc. I have a spare good battery in the garage, so might try it anyway :roll:
                            Black S50

                            Comment


                            • #15
                              Tony,

                              How did this work out for you after ? I have noticed recently that mine has started doing the same, just climbs up a bit more than half way in traffic and then when out on the mototway drops a bit. Seems to operate between 1/3 and 2/3.
                              Its really annoying! Havent replaced anything yet only all the coolant has been flushed out of it recently. I'm thinking viscous fan??

                              Paul

                              Comment

                              Working...
                              X