Cooling system diagnosis/upgrade
#1
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Copy paste from cooling system thread:
My current cooling system- Stock WP, 20psi radiator cap, FM crossflow from 2016, FM Stage 2 Fans, OEM 2002 coolant routing, minimal ducting but aluminum under tray is installed, 70/30 distilled water/coolant, 185F thermostat
Problems- My car runs generally hotter than I would like to see city driving (210-220) and will hit 230 in stop and go traffic when using AC.
Upgrade path:
1. FM reroute, leave everything else the same.
2. TSE radiator and the recommended single spal fan for ac cars.
What route do you think I should take here? I don't mind spending the cash on the TSE I just cant believe I don't see other people having this problem. Maybe less people have AC turbo street cars than I think.
Things I wont do:
Hood vents
Originally Posted by shuiend![](https://www.miataturbo.net/mt2011/images_td/buttons/viewpost.gif)
How do you burp the coolant? Those temps seem way high for what you are doing.
I totally agree they're way too high. I burp the coolant using on of those radiator filling funnels. I let the car idle with some periods of holding the rpms at 2000 with the funnel attached and filled up the whole time. I will usually then let the car cool down and repeat for another heat cycle.
Quote:
Originally Posted by skylinecalvin![](https://www.miataturbo.net/mt2011/images_td/buttons/viewpost.gif)
My assumptions would be one of the following
1) Air in system
2) Head gasket
3) Bad radiator cap
4) pinhole leak somehwere
Are you losing any coolant? When's the last time you checked.
A mechanical problem has crossed my mind before as-well.
1. My burping procedure is as above so I think I should be air free, also with a few thousand miles since I last flushed coolant I would expect any minor bubbles left to have been worked out.
2. No signs of a head gasket. Oil comes out coolant free, coolant in overflow is clean and car makes good power. No white smoke out of exhaust.
3. Just swapped from the one FM supplies to a 20PSI CSF unit same results with both.
4. I'm not loosing any visible amount of coolant. No spots under the car ever, no signs of it in the engine bay, overflow pretty much always at the same level.
I should mention crusing the highway or backroads is fine the only time I experience these heat issues is when using the AC in stop and go traffic. Even on track my temps stay pretty cool for a long time and improving that is just a ducting issue which I am waiting to address.
Edit: To confirm the pinhole leak/headgasket theory I'll rent a radiator pressure tester this weekend and see if it holds pressure.
My current cooling system- Stock WP, 20psi radiator cap, FM crossflow from 2016, FM Stage 2 Fans, OEM 2002 coolant routing, minimal ducting but aluminum under tray is installed, 70/30 distilled water/coolant, 185F thermostat
Problems- My car runs generally hotter than I would like to see city driving (210-220) and will hit 230 in stop and go traffic when using AC.
Upgrade path:
1. FM reroute, leave everything else the same.
2. TSE radiator and the recommended single spal fan for ac cars.
What route do you think I should take here? I don't mind spending the cash on the TSE I just cant believe I don't see other people having this problem. Maybe less people have AC turbo street cars than I think.
Things I wont do:
Hood vents
Originally Posted by shuiend
![](https://www.miataturbo.net/mt2011/images_td/buttons/viewpost.gif)
How do you burp the coolant? Those temps seem way high for what you are doing.
I totally agree they're way too high. I burp the coolant using on of those radiator filling funnels. I let the car idle with some periods of holding the rpms at 2000 with the funnel attached and filled up the whole time. I will usually then let the car cool down and repeat for another heat cycle.
Quote:
Originally Posted by skylinecalvin
![](https://www.miataturbo.net/mt2011/images_td/buttons/viewpost.gif)
My assumptions would be one of the following
1) Air in system
2) Head gasket
3) Bad radiator cap
4) pinhole leak somehwere
Are you losing any coolant? When's the last time you checked.
A mechanical problem has crossed my mind before as-well.
1. My burping procedure is as above so I think I should be air free, also with a few thousand miles since I last flushed coolant I would expect any minor bubbles left to have been worked out.
2. No signs of a head gasket. Oil comes out coolant free, coolant in overflow is clean and car makes good power. No white smoke out of exhaust.
3. Just swapped from the one FM supplies to a 20PSI CSF unit same results with both.
4. I'm not loosing any visible amount of coolant. No spots under the car ever, no signs of it in the engine bay, overflow pretty much always at the same level.
I should mention crusing the highway or backroads is fine the only time I experience these heat issues is when using the AC in stop and go traffic. Even on track my temps stay pretty cool for a long time and improving that is just a ducting issue which I am waiting to address.
Edit: To confirm the pinhole leak/headgasket theory I'll rent a radiator pressure tester this weekend and see if it holds pressure.
#2
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Update: Rented a pressure tester from autozone and checked my system for leaks. The pressure tester itself would slowly leak out at the connection to the radiator but I was still able to pressurize it up to 25psi and besides the slow leak from the tester did not see or hear any other leaks.
I have confirmed both fans come on and are pulling air the proper way.
I have confirmed both fans come on and are pulling air the proper way.
#3
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Coolant flow issue?
I'd give the system a good flush to try and clear out any crap in the coolant galleries.
And if that doesnt work, take the rad to a shop for flow testing and/or a proper clean (ie: remove end tanks, pressure clean core)
It's possible that if there's a blockage somewhere the coolant isnt able to flow quickly enough at low engine speeds, and it gets warmer.
I presume you've replace the thermostat to confirm it's not just sticky.
I'd give the system a good flush to try and clear out any crap in the coolant galleries.
And if that doesnt work, take the rad to a shop for flow testing and/or a proper clean (ie: remove end tanks, pressure clean core)
It's possible that if there's a blockage somewhere the coolant isnt able to flow quickly enough at low engine speeds, and it gets warmer.
I presume you've replace the thermostat to confirm it's not just sticky.
#4
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Thermostat is a year old Stant SuperStat that I tested in boiling water when new and confirmed good.
System was always flushed often. A few months ago I swapped coolant colors so filled, ran and dumped 3x with distilled water between and it was coming out crystal clear by the second cycle.
The flow restriction is a tempting possibility because it seems the car always runs cooler at higher rpms than it does at idle.
System was always flushed often. A few months ago I swapped coolant colors so filled, ran and dumped 3x with distilled water between and it was coming out crystal clear by the second cycle.
The flow restriction is a tempting possibility because it seems the car always runs cooler at higher rpms than it does at idle.
#9
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With what you’ve said, I can’t see how you’re having overheating issues.
How are you measuring the water temp? OBD/ECU sensor or after market gauge? If aftermarket ecu, is the sensor calibrated correctly?
i had an aftermarket water gauge that matched calibrated ecu water temp from 50-90 degrees C but then reads 8degs C high above that which made my heart skip a beat the first time I was in traffic with AC on.
New gauge sensor fixed that.
How are you measuring the water temp? OBD/ECU sensor or after market gauge? If aftermarket ecu, is the sensor calibrated correctly?
i had an aftermarket water gauge that matched calibrated ecu water temp from 50-90 degrees C but then reads 8degs C high above that which made my heart skip a beat the first time I was in traffic with AC on.
New gauge sensor fixed that.
#10
Cpt. Slow
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Just had an identical problem with an FM radiator, stage 2 fans, 2560r, blah. blah. On the dyno we actually had better cooling with the small fan unplugged, which gave more amps to the large fan. Food for thought.
Double check your sensor calibration in the ECU, and if that doesn't help, I would also try replacing the thermo sensor on the back of the head.
Double check your sensor calibration in the ECU, and if that doesn't help, I would also try replacing the thermo sensor on the back of the head.
#11
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Just had an identical problem with an FM radiator, stage 2 fans, 2560r, blah. blah. On the dyno we actually had better cooling with the small fan unplugged, which gave more amps to the large fan. Food for thought.
Double check your sensor calibration in the ECU, and if that doesn't help, I would also try replacing the thermo sensor on the back of the head.
Double check your sensor calibration in the ECU, and if that doesn't help, I would also try replacing the thermo sensor on the back of the head.
#12
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In this situation... stop and go, the turbo does not enter the picture except with regards to the FMIC.
Does all air going through the radiator have to pass through the intercooler?
I still have stock fans and do not have a problem with stop and go. So, this seems strange. My setup is Koyo 37mm (newer one), FMIC and Oil Cooler stacked in front of the condenser; good ducting that bypasses about 2" x full width of air below the intercooler. It is a small FMIC, so some air also bypasses between it and the oil cooler. Fans turn off at 45 MPH (maybe A/C fan stays on if A.C is running, I forget). Reroute with stock thermostat. I track at only 175 HP. I think if I ran full boost, I would have cooling problems.
Re-Route is #1.
Good ducting, possibly with some of the air bypassing the intercooler and going straight to the condenser / radiator stack is #2.
Does all air going through the radiator have to pass through the intercooler?
I still have stock fans and do not have a problem with stop and go. So, this seems strange. My setup is Koyo 37mm (newer one), FMIC and Oil Cooler stacked in front of the condenser; good ducting that bypasses about 2" x full width of air below the intercooler. It is a small FMIC, so some air also bypasses between it and the oil cooler. Fans turn off at 45 MPH (maybe A/C fan stays on if A.C is running, I forget). Reroute with stock thermostat. I track at only 175 HP. I think if I ran full boost, I would have cooling problems.
Re-Route is #1.
Good ducting, possibly with some of the air bypassing the intercooler and going straight to the condenser / radiator stack is #2.
#13
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What temperature are the fans set to come on at?
What temps do you see when when not in traffic and moving at speed?
Since you are only complaning about low speed driving and traffic, that says, to me, that the rest of the system is cooling fine, just not enough airflow from the fans for some reason.
What temps do you see when when not in traffic and moving at speed?
Since you are only complaning about low speed driving and traffic, that says, to me, that the rest of the system is cooling fine, just not enough airflow from the fans for some reason.
#14
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What temperature are the fans set to come on at?
What temps do you see when when not in traffic and moving at speed?
Since you are only complaning about low speed driving and traffic, that says, to me, that the rest of the system is cooling fine, just not enough airflow from the fans for some reason.
What temps do you see when when not in traffic and moving at speed?
Since you are only complaning about low speed driving and traffic, that says, to me, that the rest of the system is cooling fine, just not enough airflow from the fans for some reason.
#17
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In this situation... stop and go, the turbo does not enter the picture except with regards to the FMIC.
Does all air going through the radiator have to pass through the intercooler?
Re-Route is #1.
Good ducting, possibly with some of the air bypassing the intercooler and going straight to the condenser / radiator stack is #2.
Does all air going through the radiator have to pass through the intercooler?
Re-Route is #1.
Good ducting, possibly with some of the air bypassing the intercooler and going straight to the condenser / radiator stack is #2.
What temperature are the fans set to come on at?
What temps do you see when when not in traffic and moving at speed?
Since you are only complaning about low speed driving and traffic, that says, to me, that the rest of the system is cooling fine, just not enough airflow from the fans for some reason.
What temps do you see when when not in traffic and moving at speed?
Since you are only complaning about low speed driving and traffic, that says, to me, that the rest of the system is cooling fine, just not enough airflow from the fans for some reason.
Same thought I have. Not sure if this was checked, but make sure the fans are pulling air through the opening vs pushing air through them. In a rush to get my FM crossflow and stage 2 fans in before the sun went down, i wired the fans backwards and noticed I had issues with the car keeping cool at idle. Quick swap of the wires and car was sitting at tstat temp all day at idle.
Yes I have the shroud and have it sealed to the radiator and spaced as far back as possible.
#20
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OEM thermostat is also hotter than 180 degrees Fahrenheit.