Swap details - Hopefully this helps a bit? Car is an '87 325is. Sorry in advance for the wall of text. Two possible issues here and I'm not quite sure which way to go yet.
S52/ZF320 (stock)
Running 140amp alternator
m50 manifold swap
Stewart WP
e30 radiator (late)
No Mechanical fan
Factory aux fan
80/88ºC fan switch
Harness done by Robert K.
ECU flashed by Markert
Since I've completed my swap, I've noticed the factory temp gauge is sometimes erratic and will jump/creep into the red even though I don't think the car may actually be overheating. At this point i wind up shutting the car down since I don't want to chance any damage. I'm using a Go-Point OBDII dongle and DashCommand on my phone. The highest I've seen the coolant temp read is only about 205º at which that point the aux fan comes on at low speed and helps (somewhat). Now - i understand I'm pressing my luck running with only one fan - the car is basically running on half the fans it was designed for. And, while I admit the car is probably running hotter than it should, the discrepancy between what the gauge is reading and the temp the ECU is seeing in the app have me confused. I do have the thin euro mechanical fan ready to drop in but there's only millimeters of clearance from the radiator and I'm concerned about how it would handle high revs and "spirited driving". In the meantime, I've chosen not to run it (though I haven't driven the car much to be honest). I'm also considering running an 80ºC thermostat instead of the stock t-stat to see if that helps.
Back to the temp gauge - part of me is wondering if there's an electrical issue here because I've noticed when the temp gauge is erratic, using other accessories in the car cause it to "jiggle" and move more. For instance - it may read a tick over halfway, but if I turn the heater blower to max, it will move up to the 3/4 mark. Or if I use the power windows, it will bounce around slightly. I didn't touch the cluster at all during the swap (and things were working perfectly before!), but I'm wondering if there should be some grounds or other connections I should be checking. I'm considering having the cluster rebuilt, just to rule that out - and the car is 29 years old anyway.
It also occurred to me that while the battery in the car is about 2-3 years old - it is the battery designed for the factory m20, not the s52. I have a digital volt meter in the dash and it seems to stay mainly in the low 13.x volts range, which while not bad seems to be a bit lower than I remember. I checked on Interstate's website and the e36 M does have a different model number than what the e30 has. I also checked AutoZone's website and the batteries offered for the e36 have about 100-150 more CCA that what is offered for the e30. Is it possible this could be contributing to my issue as well? Or is it not a significant enough difference to matter?
Hoping I can get this figured out over the winter so she's ready to come spring. Unfortunately a lot of this "testing" has been done while idling in the garage and with no mech fan, I can't help but wonder if there's some heat soak coming into play here to...
Thanks in advance folks :drink:
S52/ZF320 (stock)
Running 140amp alternator
m50 manifold swap
Stewart WP
e30 radiator (late)
No Mechanical fan
Factory aux fan
80/88ºC fan switch
Harness done by Robert K.
ECU flashed by Markert
Since I've completed my swap, I've noticed the factory temp gauge is sometimes erratic and will jump/creep into the red even though I don't think the car may actually be overheating. At this point i wind up shutting the car down since I don't want to chance any damage. I'm using a Go-Point OBDII dongle and DashCommand on my phone. The highest I've seen the coolant temp read is only about 205º at which that point the aux fan comes on at low speed and helps (somewhat). Now - i understand I'm pressing my luck running with only one fan - the car is basically running on half the fans it was designed for. And, while I admit the car is probably running hotter than it should, the discrepancy between what the gauge is reading and the temp the ECU is seeing in the app have me confused. I do have the thin euro mechanical fan ready to drop in but there's only millimeters of clearance from the radiator and I'm concerned about how it would handle high revs and "spirited driving". In the meantime, I've chosen not to run it (though I haven't driven the car much to be honest). I'm also considering running an 80ºC thermostat instead of the stock t-stat to see if that helps.
Back to the temp gauge - part of me is wondering if there's an electrical issue here because I've noticed when the temp gauge is erratic, using other accessories in the car cause it to "jiggle" and move more. For instance - it may read a tick over halfway, but if I turn the heater blower to max, it will move up to the 3/4 mark. Or if I use the power windows, it will bounce around slightly. I didn't touch the cluster at all during the swap (and things were working perfectly before!), but I'm wondering if there should be some grounds or other connections I should be checking. I'm considering having the cluster rebuilt, just to rule that out - and the car is 29 years old anyway.
It also occurred to me that while the battery in the car is about 2-3 years old - it is the battery designed for the factory m20, not the s52. I have a digital volt meter in the dash and it seems to stay mainly in the low 13.x volts range, which while not bad seems to be a bit lower than I remember. I checked on Interstate's website and the e36 M does have a different model number than what the e30 has. I also checked AutoZone's website and the batteries offered for the e36 have about 100-150 more CCA that what is offered for the e30. Is it possible this could be contributing to my issue as well? Or is it not a significant enough difference to matter?
Hoping I can get this figured out over the winter so she's ready to come spring. Unfortunately a lot of this "testing" has been done while idling in the garage and with no mech fan, I can't help but wonder if there's some heat soak coming into play here to...
Thanks in advance folks :drink:
:hitler:
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