What temp is too hot?
Discussion
Hi guys,
on the temp gauge on the Esprit it goes to 120. Mine went to just over the 100 a few weeks back (had an air trap in the coolant system after replacing a hose). I turned it off straigt away and left it to cool for a few minutes. After turning it back on, it was fine.
The temp gauge goes to 120, is just over the 100 far too hot, or just a touch?
It was went the car had been sitting on idle for a while.
Thanks in advance guys,
Stevie
on the temp gauge on the Esprit it goes to 120. Mine went to just over the 100 a few weeks back (had an air trap in the coolant system after replacing a hose). I turned it off straigt away and left it to cool for a few minutes. After turning it back on, it was fine.
The temp gauge goes to 120, is just over the 100 far too hot, or just a touch?
It was went the car had been sitting on idle for a while.
Thanks in advance guys,
Stevie
If nothing leaks and the caps are good, the pressure in the system should prevent the water boiling until over 120 degrees.
I've scoured the manual, the fans are under ECU control and turned on by the ECU at 100 degrees, so 100 on the gauge is ok!
A couple of other snippets ..
... the excessive coolant temperature light comes on at 118 deg, turns off at 110 deg, flashes at temps over 115 deg
In order to control coolant temperature during conditions of ‘heat soak’ after engine switch off, an electic
coolant circulation pump is fitted in the heater feed line, in conjunction with a diverter valve. The engine
management ECM switches on the pump and radiator cooling fans, at coolant temperatures over 105°C on
rise, 90°C on fall, as sensed by the coolant temperature sensor, during a 20 minute period following engine
switch off.
I've scoured the manual, the fans are under ECU control and turned on by the ECU at 100 degrees, so 100 on the gauge is ok!
A couple of other snippets ..
... the excessive coolant temperature light comes on at 118 deg, turns off at 110 deg, flashes at temps over 115 deg
In order to control coolant temperature during conditions of ‘heat soak’ after engine switch off, an electic
coolant circulation pump is fitted in the heater feed line, in conjunction with a diverter valve. The engine
management ECM switches on the pump and radiator cooling fans, at coolant temperatures over 105°C on
rise, 90°C on fall, as sensed by the coolant temperature sensor, during a 20 minute period following engine
switch off.
Having spent almost 4 years becoming somewhat intimate with the V8 cooling system (bloody all of it) I would offer the following info and advice:
First, the system is under capacity, period. The V8 engine simply generates too much heat and the R134a A/C puts additional strain on the system, add hot weather where the ambient temps are above 90F and the V8 will run near 100C with the A/C running and the fans blowing away, yet the thermostat is an 82C unit. Any doubt on capacity?
Second, the oil coolers have no forced airflow and during slow traffic and stop/go conditions they become heatsoaked and this adds further to increased engine temps. IMHO running at 90C is too hot for the V8 (remember, they fitted an 82C thermostat) so some changes are needed to optimize the system.
If you plan to keep the car stock, do the following:
1- Flush out the entire front radiator duct and radiator/condensors to ensure they are free of debris and have optimum airflow. Don't forget to check the oil coolers for same.
2- Check to ensure all 3 fans are running properly and spin freely without binds or dragging. Check the fan fuses, if they look oxidized/stressed at all, replace them.
3- Change the coolant, the pressure cap and the thermostat. I recently replaced one and there were black pieces of material binding the movement of the valve section and yes, temps were high and wild. I also recommend a leaner coolant mix for summer, ~ 60/40 water/antifreeze and I have switched over to Mercedes-Benz antifreeze which keeps the system significantly cleaner than Prestone Green Gunk Juice.
4- Check ALL hose clamps as the cheap stock ones stretch and have their limits before they turn to jello. I've replaced some already and will be replacng the rest during the next round of work.
5- When completed, bleed the system cold (front radiator and front engine pipe) and then pressurize the system from the coolant tank overflow hose to at least 16psi. If it doesn't hold start looking for leaks at any and all hose clamp connections... there's plenty to inspect and check. I've seen new pressure caps that won't seal at all. The plastic header tank seating surface becomes leached over time and tends to leak and the overall plastic tank header wears and the tabs on the cap may need to be formed a bit to ensure adequate pressure sealing.
6- Be certain to bleed the system hot and top off the coolant when cold afterwards. This is about as good as it gets... and yes, it will probably run in excess of 90C most of the time with the A/C running unless cruising on the highway. Note that many owners swear that adding a bottle of Redline water-wetter helps. From the testing I've done, it had no real affect. I found leaning the mix to 60/40 did help.
I worked with Griffin to make a custom high-capacity radiator which has been very successful. Under the same conditions (95F ambient temp, A/C running, stop/go traffic) the V8 maintains an engine temp of around 84-86C. Once I add fans to the oil coolers I expect a proper 82C. With the Griffin/Spal setup, highway temps usually stick at 81-82C (all read from the ECM via scantool). Hope this helps.
Regards, KM
2000 V8
First, the system is under capacity, period. The V8 engine simply generates too much heat and the R134a A/C puts additional strain on the system, add hot weather where the ambient temps are above 90F and the V8 will run near 100C with the A/C running and the fans blowing away, yet the thermostat is an 82C unit. Any doubt on capacity?
Second, the oil coolers have no forced airflow and during slow traffic and stop/go conditions they become heatsoaked and this adds further to increased engine temps. IMHO running at 90C is too hot for the V8 (remember, they fitted an 82C thermostat) so some changes are needed to optimize the system.
If you plan to keep the car stock, do the following:
1- Flush out the entire front radiator duct and radiator/condensors to ensure they are free of debris and have optimum airflow. Don't forget to check the oil coolers for same.
2- Check to ensure all 3 fans are running properly and spin freely without binds or dragging. Check the fan fuses, if they look oxidized/stressed at all, replace them.
3- Change the coolant, the pressure cap and the thermostat. I recently replaced one and there were black pieces of material binding the movement of the valve section and yes, temps were high and wild. I also recommend a leaner coolant mix for summer, ~ 60/40 water/antifreeze and I have switched over to Mercedes-Benz antifreeze which keeps the system significantly cleaner than Prestone Green Gunk Juice.
4- Check ALL hose clamps as the cheap stock ones stretch and have their limits before they turn to jello. I've replaced some already and will be replacng the rest during the next round of work.
5- When completed, bleed the system cold (front radiator and front engine pipe) and then pressurize the system from the coolant tank overflow hose to at least 16psi. If it doesn't hold start looking for leaks at any and all hose clamp connections... there's plenty to inspect and check. I've seen new pressure caps that won't seal at all. The plastic header tank seating surface becomes leached over time and tends to leak and the overall plastic tank header wears and the tabs on the cap may need to be formed a bit to ensure adequate pressure sealing.
6- Be certain to bleed the system hot and top off the coolant when cold afterwards. This is about as good as it gets... and yes, it will probably run in excess of 90C most of the time with the A/C running unless cruising on the highway. Note that many owners swear that adding a bottle of Redline water-wetter helps. From the testing I've done, it had no real affect. I found leaning the mix to 60/40 did help.
I worked with Griffin to make a custom high-capacity radiator which has been very successful. Under the same conditions (95F ambient temp, A/C running, stop/go traffic) the V8 maintains an engine temp of around 84-86C. Once I add fans to the oil coolers I expect a proper 82C. With the Griffin/Spal setup, highway temps usually stick at 81-82C (all read from the ECM via scantool). Hope this helps.
Regards, KM
2000 V8
kmaier said:
First, the system is under capacity, period. The V8 engine simply generates too much heat and the R134a A/C puts additional strain on the system, add hot weather where the ambient temps are above 90F and the V8 will run near 100C with the A/C running and the fans blowing away, yet the thermostat is an 82C unit. Any doubt on capacity?
Ok, 90F ambient isn't a problem in the UK, but with the ECU not turning fans on until 100c, no matter what the capacity of the system, it WILL reach 100c before the fans cut in unless the A/C is on and cuts the fans in earlier.
Lotus decided to put an 82 deg thermostat in there and 100 deg fan cut in point so anything from 82 to 100 is fine with AC off. I would expect mid 80's while cruising. It does seem a wide operating range of 18 deg, the 4 cyl cars had 82 deg thermostat and 90 deg fan operation.
I'm not arguing about increasing cooling capacity and checking operation of the system, all good stuff, especially in your climate!
I'll second what Kevin said after just removing my radiator (it was leaking) and having it rebuilt with a heavy duty four row core replacing the stock two row core. I kept the stock fans as Dave Simkin the Lotus tech in The USA said they are more then adequate.
After several thorough flushes with tap water then several with distilled water (sodium free mind you) I switched to Zerex phospahte, silicate free coolant (the orange stuff in The USA) as the green stuff is not friendly to aluminum. Bleeding the system was easy once I jacked the rear of the car in the air and opened the bleed tube to get the air out. The aluminum connector at the bottom of the radiator (drivers side in The US) was so badly corroded and pitted I replaced it. Considering your coolant comes in contact with 3-5 different types of metal the silicate and phosphate free coolant seems sensible. These are HOAT type of coolants approved for use by Honda, GM, Toyota, Audi, Mercedes, etc.
Drove the Esprit (1999 V8) yesterday in humid, 80 degree Farenheit weather and the temps stay between 80-85 on the temp guage. Much less erratic with added capacity.
One note, become good friends with a screw/bolt supply house to replace the connectors on your Esprit with stainless steel whenever possible. The bolts, nuts and screws were a mess around the front of my car. From now on any Esprit project I do, the bolts/nuts/screws are being changed to stainless as I did with the radiator replacement.
Mark (Much Cooler in St. Louis) Pfeffer
After several thorough flushes with tap water then several with distilled water (sodium free mind you) I switched to Zerex phospahte, silicate free coolant (the orange stuff in The USA) as the green stuff is not friendly to aluminum. Bleeding the system was easy once I jacked the rear of the car in the air and opened the bleed tube to get the air out. The aluminum connector at the bottom of the radiator (drivers side in The US) was so badly corroded and pitted I replaced it. Considering your coolant comes in contact with 3-5 different types of metal the silicate and phosphate free coolant seems sensible. These are HOAT type of coolants approved for use by Honda, GM, Toyota, Audi, Mercedes, etc.
Drove the Esprit (1999 V8) yesterday in humid, 80 degree Farenheit weather and the temps stay between 80-85 on the temp guage. Much less erratic with added capacity.
One note, become good friends with a screw/bolt supply house to replace the connectors on your Esprit with stainless steel whenever possible. The bolts, nuts and screws were a mess around the front of my car. From now on any Esprit project I do, the bolts/nuts/screws are being changed to stainless as I did with the radiator replacement.
Mark (Much Cooler in St. Louis) Pfeffer
Hi All,
Here is all the coolant temp related data with the stock Lotus 4-Cyl. S4(s) code.
Boost control temp. min. is 74.8°C (below that figure you will not see more boost than 0.65 bar, if your wastegate capsule is adjusted corrrectly)
Boost control temp. maximum is 115°C (above this figure you will not get more boost than 0.65 bar, if your ....)
The fans come ON at 92°C and go OFF at 87.5°C.
Engine overheat temp is 110°C (code 14)
Engine overheat reset temp is 105°C
Cheers
Marcus
Here is all the coolant temp related data with the stock Lotus 4-Cyl. S4(s) code.
Boost control temp. min. is 74.8°C (below that figure you will not see more boost than 0.65 bar, if your wastegate capsule is adjusted corrrectly)
Boost control temp. maximum is 115°C (above this figure you will not get more boost than 0.65 bar, if your ....)
The fans come ON at 92°C and go OFF at 87.5°C.
Engine overheat temp is 110°C (code 14)
Engine overheat reset temp is 105°C
Cheers
Marcus
come on guys.... dont tell me you are driving an esprit and you dont know basic high school stuff...
Water boils at 100 C freses at O C (if you dont know this then sell the car.... )
antifreeze keeps the water from freezing in below zero temps...
there are additives that help with corrosion and a slight increase in the boiling point. ( not significantly )
Car cooling systems have a pressure cap to allow the coolant to pressurise slightly - mostly to keep expanding coolant from escaping from the car..this also raises the boiling point ( a few degrees ).. ( again if you dont know this from grade school - get out of fancy car lust )
I dont know how to say it because it is soooo obvious that when you reach 100 ( and your gauge turns to red ) that is DANGER >>>>>>>!!!!!!!!!
as soon as the coolant boils.. you have near to ZERO cooling capacity any more.... the engine will skyrocket in temperature and for sure do SOME damage..
If you had a temp approacing 100 on the gauge then for certain there were parts of the engine ( the temp sensor is not in the hottest location ) that got hotter...
when you see a needle in the red zone, or see a warning light on.. switch off the engine.. it is not a warning like amber alert.. ( heheh ) it is an immediate action warning..
Bruce
Water boils at 100 C freses at O C (if you dont know this then sell the car.... )
antifreeze keeps the water from freezing in below zero temps...
there are additives that help with corrosion and a slight increase in the boiling point. ( not significantly )
Car cooling systems have a pressure cap to allow the coolant to pressurise slightly - mostly to keep expanding coolant from escaping from the car..this also raises the boiling point ( a few degrees ).. ( again if you dont know this from grade school - get out of fancy car lust )
I dont know how to say it because it is soooo obvious that when you reach 100 ( and your gauge turns to red ) that is DANGER >>>>>>>!!!!!!!!!
as soon as the coolant boils.. you have near to ZERO cooling capacity any more.... the engine will skyrocket in temperature and for sure do SOME damage..
If you had a temp approacing 100 on the gauge then for certain there were parts of the engine ( the temp sensor is not in the hottest location ) that got hotter...
when you see a needle in the red zone, or see a warning light on.. switch off the engine.. it is not a warning like amber alert.. ( heheh ) it is an immediate action warning..
Bruce
bojangles said:
come on guys.... dont tell me you are driving an esprit and you dont know basic high school stuff...
Water boils at 100 C freses at O C (if you dont know this then sell the car.... )
antifreeze keeps the water from freezing in below zero temps...
there are additives that help with corrosion and a slight increase in the boiling point. ( not significantly )
Car cooling systems have a pressure cap to allow the coolant to pressurise slightly - mostly to keep expanding coolant from escaping from the car..this also raises the boiling point ( a few degrees ).. ( again if you dont know this from grade school - get out of fancy car lust )
I dont know how to say it because it is soooo obvious that when you reach 100 ( and your gauge turns to red ) that is DANGER >>>>>>>!!!!!!!!!
as soon as the coolant boils.. you have near to ZERO cooling capacity any more.... the engine will skyrocket in temperature and for sure do SOME damage..
If you had a temp approacing 100 on the gauge then for certain there were parts of the engine ( the temp sensor is not in the hottest location ) that got hotter...
when you see a needle in the red zone, or see a warning light on.. switch off the engine.. it is not a warning like amber alert.. ( heheh ) it is an immediate action warning..
Bruce
Yes, another thing learned in high school was proof-reading... maybe you were out that day. You are certainly correct on freezing/boiling temps for water (at normal atmospheric pressure) but antifreeze mixture and coolant pressure alters those values and they are more significant than you are stating.
Here's a few facts on coolant I found... normal recommended mixture is 50% antifreeze 50% water (preferably distilled). This results in a freezing temperature of -34F (-37C)and a boiling temp of 225F (107C). If you have 20psi (1.4 bar) pressure the boiling temp rises to 275F (135C).
The Esprit V8 has a pressure cap rated at 145kpa (1.45 bar or ~ 21psi) and the result is a boiling temperature of 275F (135C). The ECM also has limits... like fans on at 100C, off at 92C and flashing warning lights at 110C reflecting the increased temperature limits both antifreeze and pressure provide.
Still, I prefer to keep engine temperature as close to 82C as possible as this is the standard engine temperature and going above or below this reduces both engine performance and longevity.
Regards, KM
2000 V8
Kmaier,
well pointed out. If the pressure / coolant didn't effect the bioling point, then why would Lotus has the fans set to come on at 100C? Now that would be a little silly.
Thankfully, as you have rightly pointed out, these chnages in conditions DO effect the boiling point, providing that the coolant mix is correct and there are no leaks in the system.
PS: I can't rememeber ever talking about this kinda stuff at school, but certainly learned that on sites like this!
Every days a school day, even if you are 25!
Cheers,
Stevie
well pointed out. If the pressure / coolant didn't effect the bioling point, then why would Lotus has the fans set to come on at 100C? Now that would be a little silly.
Thankfully, as you have rightly pointed out, these chnages in conditions DO effect the boiling point, providing that the coolant mix is correct and there are no leaks in the system.
PS: I can't rememeber ever talking about this kinda stuff at school, but certainly learned that on sites like this!
Every days a school day, even if you are 25!
Cheers,
Stevie
Yep, pressure and boiling points were interesting physics stuff. I remember seeing water boil at room temperature and was dead impressed! In the same way that increasing pressure increases the boiling point, reducing pressure reduces the boiling point. Put water in a vacuum and it boils.
This is how they dry out air con systems .. put the whole system under a vacuum and the water boils off and is sucked out by the vacuum pump.
Anyway, getting back to the point, it is essential the system has no leaks and maintains pressure because of the 100 deg cut in of the fans, much more so than in cars with fans that cut in at 90 deg!
This is how they dry out air con systems .. put the whole system under a vacuum and the water boils off and is sucked out by the vacuum pump.
Anyway, getting back to the point, it is essential the system has no leaks and maintains pressure because of the 100 deg cut in of the fans, much more so than in cars with fans that cut in at 90 deg!
stevieBV8esprit said:
Wonder why in doesn't cut in till then?
Strange.
its a typical practice for auto manufacturers to let cars run "hotter" than they used to in the '70s to help with emmissions.
as a result of this practice and tight packaging under the hood, a lot of care is taken by the manufacturers to manage engine compartment heat.
chris
90SE
Some great info on this thread.
My personal experience is that for european weathers the system copes just fine. Only once have i seen the temp guage above 100. That was stuck in traffic in paris in 35 degree (C) heat for about an hour after a long drive. No dash lights but it got up to about 110 or so. Thats also the only time i've had the fans cut in after switching off the car and walking away..
Very good advice about keeping the rads clear of debris. I had the rad re-cored (sercks) last year when the car was dismantled for another job - definitely ran cooler after that..
I always put the aircon on if i'm sitting in a traffic jam, even if i don't need it - that way the fans cut in and keep the temps low.
My personal experience is that for european weathers the system copes just fine. Only once have i seen the temp guage above 100. That was stuck in traffic in paris in 35 degree (C) heat for about an hour after a long drive. No dash lights but it got up to about 110 or so. Thats also the only time i've had the fans cut in after switching off the car and walking away..
Very good advice about keeping the rads clear of debris. I had the rad re-cored (sercks) last year when the car was dismantled for another job - definitely ran cooler after that..
I always put the aircon on if i'm sitting in a traffic jam, even if i don't need it - that way the fans cut in and keep the temps low.
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