2.5L Original ECU
Discussion
Here we go,
I have been told that the newer modle (MBE) reads the temp from the engine up to 90 oC and then the ECU takes over until 110oC. So the ever fluctuating temp doesn't show on the temp gage (this came from Plans talking to Factory).
The older cars with original ECU always measure straight from the engine so temps can be all over the shop.
My car before it went in for Diff replacement was fine and always sat a 90oC on motor ways doing 85 ish. Now it is at about 100oC. Plans have tried evrything to get it back to normaly and now we think that it was not measuring it correctly before the diff replacement and now allthe connections have been cleaned up I get this higher reading.
I wish to know if anyone else with original ECU runs at these temps.
Thanks
Bondy
I have been told that the newer modle (MBE) reads the temp from the engine up to 90 oC and then the ECU takes over until 110oC. So the ever fluctuating temp doesn't show on the temp gage (this came from Plans talking to Factory).
The older cars with original ECU always measure straight from the engine so temps can be all over the shop.
My car before it went in for Diff replacement was fine and always sat a 90oC on motor ways doing 85 ish. Now it is at about 100oC. Plans have tried evrything to get it back to normaly and now we think that it was not measuring it correctly before the diff replacement and now allthe connections have been cleaned up I get this higher reading.
I wish to know if anyone else with original ECU runs at these temps.
Thanks
Bondy
Bondy
Mines upgraded to the MBE but I also had fluctuating temp readings.AFAIK the the switch that turns the rads on is situate just near ,the ECU takes temp readings fron the engine and the temp guage takes them from somewhere else. The only way to check is to link it up to a laptop , see what the ecu says the temp is and compare that to what is happening ion the temp guage.
I have since had the radiator fan switch wired into the MBE ecu so that they come on when the ecu thinks they should. Next job is to get the temp guage wired into the ecu so that everything is reading from the same place.
Mine sits at 90 until I push it then goes up to 100 ish and eventually comes down. I try not to look at it because all I know for certain is that it is probably wrong all the time.
worty
Mines upgraded to the MBE but I also had fluctuating temp readings.AFAIK the the switch that turns the rads on is situate just near ,the ECU takes temp readings fron the engine and the temp guage takes them from somewhere else. The only way to check is to link it up to a laptop , see what the ecu says the temp is and compare that to what is happening ion the temp guage.
I have since had the radiator fan switch wired into the MBE ecu so that they come on when the ecu thinks they should. Next job is to get the temp guage wired into the ecu so that everything is reading from the same place.
Mine sits at 90 until I push it then goes up to 100 ish and eventually comes down. I try not to look at it because all I know for certain is that it is probably wrong all the time.
worty
The temp on my original 2.5l used to be all over the place. As worty says, early 2.5's took the temp reading from the flow into the rad (LHS as you look at the car). Consequently you can easily see 100-102 as the system is pressurised and boils at about 104.
As I went through an engine due to it getting to 110+, if it gets over 102/103 then there is something else wrong, otherwise wandering from 90-100 is pretty normal IME.
As to why your temps have started changing I've no idea, but what you descirbe sounds pretty normal for an original ECU 2.5 (I changed to the MBE after the first engine went, and hence never saw the fluctuating temps again).
J
As I went through an engine due to it getting to 110+, if it gets over 102/103 then there is something else wrong, otherwise wandering from 90-100 is pretty normal IME.
As to why your temps have started changing I've no idea, but what you descirbe sounds pretty normal for an original ECU 2.5 (I changed to the MBE after the first engine went, and hence never saw the fluctuating temps again).
J
Quickly got to 100 and stayed there. As I said, if it gets over 103/104 then panic, as that is the temp coming from the engine and it shows somethings wrong.
If it stays below about 102 then I don't think there is anything to worry about - it's just the temp of the water coming from the engine and if that is under 102 then it isn't boiling and so AFAIK that is fine.
The lotus was similar in that it had the temp output at the rad, so it used to happily go from 90 to 102 and then back down as it did it's heat / lose cycle.
J
If it stays below about 102 then I don't think there is anything to worry about - it's just the temp of the water coming from the engine and if that is under 102 then it isn't boiling and so AFAIK that is fine.
The lotus was similar in that it had the temp output at the rad, so it used to happily go from 90 to 102 and then back down as it did it's heat / lose cycle.
J
Thanks Guys,
Graham at Plans is seeing Lee this weekend and is going to chat about it.
When I got it back from the diff fix I went on a training day. At the end of the day we did a 12 min sesh on a small layed out track and it hit 115 briefly. I then gave it back to Plans and they found that the headgasket had gone. Aftet this fix the car (to me) still was running hot but this time not going above 100 (once it just crept above at over a ton). So not sure how it will behave on a track day.
I'll find out from Plans what the score is next week and try to live with it. I'll get the ECU upgrade next year.
Bondy
Graham at Plans is seeing Lee this weekend and is going to chat about it.
When I got it back from the diff fix I went on a training day. At the end of the day we did a 12 min sesh on a small layed out track and it hit 115 briefly. I then gave it back to Plans and they found that the headgasket had gone. Aftet this fix the car (to me) still was running hot but this time not going above 100 (once it just crept above at over a ton). So not sure how it will behave on a track day.
I'll find out from Plans what the score is next week and try to live with it. I'll get the ECU upgrade next year.
Bondy
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