Temperature crept up this evening
Discussion
Sat in traffic at road works this evening, heater to cold, when I noticed the temperature had crept up from its usual 90 to 100. I turned the temp onto hot & the gauge hit 120! Then back to just over 90 with the heater on full blast to dissipate heat! There was no boiling over.
Tomorrow I'll leave it ticking over to check the fans are running, but does anyone have any ideas what that might be about? If it was a home central heating system, I'd have said an air lock!
Tomorrow I'll leave it ticking over to check the fans are running, but does anyone have any ideas what that might be about? If it was a home central heating system, I'd have said an air lock!
bernhund said:
Sat in traffic at road works this evening, heater to cold, when I noticed the temperature had crept up from its usual 90 to 100. I turned the temp onto hot & the gauge hit 120! Then back to just over 90 with the heater on full blast to dissipate heat! There was no boiling over.
Tomorrow I'll leave it ticking over to check the fans are running, but does anyone have any ideas what that might be about? If it was a home central heating system, I'd have said an air lock!
I was taking to Dave at Jetstream regarding the temperature gauge readings ,mine is always 80-90 ,fans cut in at 90 goes back down to 80 .However he said that the 80 -90 area is pretty arbitrary and the needle only rise's when it's way past that .Tomorrow I'll leave it ticking over to check the fans are running, but does anyone have any ideas what that might be about? If it was a home central heating system, I'd have said an air lock!
In short they are not that accurate ,hope you resolve it ok.
Ian Perry said:
bernhund said:
Sat in traffic at road works this evening, heater to cold, when I noticed the temperature had crept up from its usual 90 to 100. I turned the temp onto hot & the gauge hit 120! Then back to just over 90 with the heater on full blast to dissipate heat! There was no boiling over.
Tomorrow I'll leave it ticking over to check the fans are running, but does anyone have any ideas what that might be about? If it was a home central heating system, I'd have said an air lock!
I was taking to Dave at Jetstream regarding the temperature gauge readings ,mine is always 80-90 ,fans cut in at 90 goes back down to 80 .However he said that the 80 -90 area is pretty arbitrary and the needle only rise's when it's way past that .Tomorrow I'll leave it ticking over to check the fans are running, but does anyone have any ideas what that might be about? If it was a home central heating system, I'd have said an air lock!
In short they are not that accurate ,hope you resolve it ok.
The MBE ECU controls the coolant temp gauge, and is setup to be very non-linear. It reads higher than the true temp while the engine warms up, then has a big flat spot and stays at 80-90 for quite a wide range of temps. When the true coolant temp reaches around 105-110, the ECU is programmed to peg the needle. In effect, the gauge has been turned into an idiot light with mostly meaningless numbers on it...
It is possible to have someone who tunes the MBE redo the temp gauge tables so that the gauge reads accurately - I've done it to cars over here in the US, and I would expect that Yellowshed or the guys at Jetstream would be able to do it on the UK cars.
Anyway, if your coolant gauge needle starts wig-wagging, I'd suggest having your cooling system checked out and pressure tested for leaks...
It is possible to have someone who tunes the MBE redo the temp gauge tables so that the gauge reads accurately - I've done it to cars over here in the US, and I would expect that Yellowshed or the guys at Jetstream would be able to do it on the UK cars.
Anyway, if your coolant gauge needle starts wig-wagging, I'd suggest having your cooling system checked out and pressure tested for leaks...
I was told that with the newer MBE - my gauge was now true, and not dampened. This makes sense as it moves regularly between 88 & 98 degrees when I'm in traffic, fan cuts in at 98 and drops back to 90 on the gauge. Once underway again it sits at 88.
I believe the stat is open at 88 degrees also
anyway - doesn't help your situation but I would check the temps in real time rather than the guage
I believe the stat is open at 88 degrees also
anyway - doesn't help your situation but I would check the temps in real time rather than the guage
We are talking 3.0L here.
Worth remembering that the standard thermostat actually doesn't even start to open until 93 deg c and is fully open at 96 deg c.... as said above the temp gauge reading is ' findled' so you can't use the gauge reading as to whats actually happening in your cooling system.
The Ecu sends the signal to the dash gauge... so the fans are set to turn on an off at a different temperature to what the system actually runs if that makes sense.
It does actually make sense... if the gauge wavered up and down and didn't sit in the middle of the gauge lots of people would worry (even though this is quite normal and what happens)... so it reads middle of the gauge and then when it hits a very high temp it suddenly goes off the gauge and catches your eye... hopefully
To confirm what my cooling system runs at I placed 3 thermocouples in the heating system and monitored them in the car for a few months to get a good idea of what was going on... i worked hard to reduce the temp of my system as it used to overheat (well above what i was happy with) very quickly.... it was actually a number of small relatively cheap changes that sorted it out.
Worth remembering that the standard thermostat actually doesn't even start to open until 93 deg c and is fully open at 96 deg c.... as said above the temp gauge reading is ' findled' so you can't use the gauge reading as to whats actually happening in your cooling system.
The Ecu sends the signal to the dash gauge... so the fans are set to turn on an off at a different temperature to what the system actually runs if that makes sense.
It does actually make sense... if the gauge wavered up and down and didn't sit in the middle of the gauge lots of people would worry (even though this is quite normal and what happens)... so it reads middle of the gauge and then when it hits a very high temp it suddenly goes off the gauge and catches your eye... hopefully
To confirm what my cooling system runs at I placed 3 thermocouples in the heating system and monitored them in the car for a few months to get a good idea of what was going on... i worked hard to reduce the temp of my system as it used to overheat (well above what i was happy with) very quickly.... it was actually a number of small relatively cheap changes that sorted it out.
andygtt said:
We are talking 3.0L here.
Worth remembering that the standard thermostat actually doesn't even start to open until 93 deg c and is fully open at 96 deg c.... as said above the temp gauge reading is ' findled' so you can't use the gauge reading as to whats actually happening in your cooling system.
The Ecu sends the signal to the dash gauge... so the fans are set to turn on an off at a different temperature to what the system actually runs if that makes sense.
It does actually make sense... if the gauge wavered up and down and didn't sit in the middle of the gauge lots of people would worry (even though this is quite normal and what happens)... so it reads middle of the gauge and then when it hits a very high temp it suddenly goes off the gauge and catches your eye... hopefully
To confirm what my cooling system runs at I placed 3 thermocouples in the heating system and monitored them in the car for a few months to get a good idea of what was going on... i worked hard to reduce the temp of my system as it used to overheat (well above what i was happy with) very quickly.... it was actually a number of small relatively cheap changes that sorted it out.
So given that mine didn't boil over, did it actually over heat? It was interesting that opening the heater valve did make the gauge drop & remain around 90. I wasn't sat in a traffic jam by that stage, but I was still in town traffic at the lights etc.Worth remembering that the standard thermostat actually doesn't even start to open until 93 deg c and is fully open at 96 deg c.... as said above the temp gauge reading is ' findled' so you can't use the gauge reading as to whats actually happening in your cooling system.
The Ecu sends the signal to the dash gauge... so the fans are set to turn on an off at a different temperature to what the system actually runs if that makes sense.
It does actually make sense... if the gauge wavered up and down and didn't sit in the middle of the gauge lots of people would worry (even though this is quite normal and what happens)... so it reads middle of the gauge and then when it hits a very high temp it suddenly goes off the gauge and catches your eye... hopefully
To confirm what my cooling system runs at I placed 3 thermocouples in the heating system and monitored them in the car for a few months to get a good idea of what was going on... i worked hard to reduce the temp of my system as it used to overheat (well above what i was happy with) very quickly.... it was actually a number of small relatively cheap changes that sorted it out.
Id say yes... opening the heater adds another rad into the system and instantly cools the engine (if it wasn't being used already).... the Fan relays do burn out so worth checking them if it happened in traffic.
The stock system runs at a higher temp than I was happy with... thermostat opens fully at 96deg c so anything much lower than that and water would not be flowing round the rad, (something that will never happen once the car is warmed up)... therefore fans will be actually cutting in another 5 deg c or so above that... pretty sure the coolant will be over 110 deg c when it flicks to off the gauge as yours did (mine did it once in traffic in France when it was stock).
Personally I wanted my car to never go above 100 deg c and i start cutting boost a little above that, fitting the lower temp thermostat was a large help in me achieving that. Only a limited number were made in a group buy a few years back (there isn't an off the shelf low temp stat).
The stock system runs at a higher temp than I was happy with... thermostat opens fully at 96deg c so anything much lower than that and water would not be flowing round the rad, (something that will never happen once the car is warmed up)... therefore fans will be actually cutting in another 5 deg c or so above that... pretty sure the coolant will be over 110 deg c when it flicks to off the gauge as yours did (mine did it once in traffic in France when it was stock).
Personally I wanted my car to never go above 100 deg c and i start cutting boost a little above that, fitting the lower temp thermostat was a large help in me achieving that. Only a limited number were made in a group buy a few years back (there isn't an off the shelf low temp stat).
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