When I am idling my car to cool down the turbos, after a few minutes my temp guage goes up slightly, however the fans turn on and it goes back down. Is this normal, especially in 90 degree weather? It never goes up while I'm driving, however, it has gone up while I've been sitting in traffic on really hot days. My coolant buzzer has never gone off and I have never even gotten close to the red on the temp guage. Should I be worried?

i noticed that the stock gauge shows something like 9:15 when the engine is running, but with engine not running and ignition on i see a perfect 9:00.



install an aftermarket gauge and enjoy(!) your car

FWIW, my stock gauge reads a steady 8:45... and even before my Fluidyne, I don't remember that it ever got to an even 9:00 O'clock position.

I now have a DEFI 'D' series temp guage. Not sure how exact it is, but I see 185 F. during normal driving. Kicks up to 190 F. occaisionally on the recent 95 degree + days we've had while sitting in traffic, but goes back down when the fans kick on or I start moving.

For reference, I'm stock with 50/50 water/coolant, a miata thermoswitch and the "fan mod". And (knocking on wood) A/C doesn't seem to make much difference.

[quote name='Old Splatterhand' date='Jul 19 2005, 04:07 PM']

i noticed that the stock gauge shows something like 9:15 when the engine is running, but with engine not running and ignition on i see a perfect 9:00.



That seems about right. Getting after market temp gauge will scare you. After you shut the car down the temp will go through the roof 120C on a hot day... Hoping when I install the V mount setup it will help with the cooling...

My stock gauge sits at around the 8:45 mark as well.

My Sard temp gauge reads 84C all the time and rises slightly when I shut her off or when driven hard, but only to about 87C.



I'm sure there's a way that you can get your fans to come on a little earlier?

yes and dont sit there forever letting the turbos cool off. heat soaking everything else.

[quote name='treceb' date='Jul 20 2005, 07:29 AM']yes and dont sit there forever letting the turbos cool off. heat soaking everything else.


[/quote]



How long do you recommend on average to cool down the turbos?? Is it worth it to idle a few minutes, if the temp guage goes up slightly??

It moves up enough to where its noticably above normal? My FD doesn't move noticably until 112-113C (234-235F) on NPG-R coolant. If you're running conventional coolant and your needle is going up I would investigate.

[quote name='Trevor' date='Jul 20 2005, 10:33 AM']It moves up enough to where its noticably above normal? My FD doesn't move noticably until 112-113C (234-235F) on NPG-R coolant. If you're running conventional coolant and your needle is going up I would investigate.


[/quote]

Does yours move up while driving or only if you are idling or in traffic? Mine never goes up while driving, but it does when I'm in traffic (on really hot and humid days) or if I"m idling to cool the turbos. Yes i have 50/50 coolant. Do you think a coolant flush would help with adding water wetter?

[quote name='base94montego' date='Jul 20 2005, 10:44 AM']Do you think a coolant flush would help with adding water wetter?


[/quote]



If you're not sure how old the coolant is, that's probably not a bad idea. Water-Wetter...OK. But as you've figured out, the OEM temp guage is pretty worthless in these cars, really no better than just an "idiot light". Instead of wondering, why not just get a decent aftermarket guage so you know for sure?

[quote name='Signal 2' date='Jul 20 2005, 06:21 PM']If you're not sure how old the coolant is, that's probably not a bad idea. Water-Wetter...OK. But as you've figured out, the OEM temp guage is pretty worthless in these cars, really no better than just an "idiot light". Instead of wondering, why not just get a decent aftermarket guage so you know for sure?


[/quote]



I believe the coolant is about 14,000 mi old. The engine was rebuilt at 92,000 and now I have about 106,000. I was planning on changing it sometime this summer. Do you think there has been any major engine damage if the needle has never gone anywhere near the red? The most it's gone up is probably an 1/8 of an inch, then the fans come on.

The red zone on the stock water temperature gauge is also called the 'new motor zone'..



I linearized my stock temperature gauge, it goes up and down all over the place. I know that anything between the two normal marks is fine with a 5% margin for safety. If mine gets to the top normal mark, it's time to shut her down.



My temps do go up at idle.

[quote name='base94montego' date='Jul 21 2005, 08:16 AM']I believe the coolant is about 14,000 mi old. The engine was rebuilt at 92,000 and now I have about 106,000. I was planning on changing it sometime this summer. Do you think there has been any major engine damage if the needle has never gone anywhere near the red? The most it's gone up is probably an 1/8 of an inch, then the fans come on.


[/quote]



If it's going near the red, it sure sounds like you got a cooling issue. I'm no guru, but I guess I'd start with the cheap things first. There are probably others, but these come to mind:

1. Pull the belly pan and drop your A/C condenser (but don't disconnect it) so you can access the front of the radiator and make sure it's clean. Blow it out or wash it out as necessary. Be sure you oil cooler(s) are clean too.

2. Buy some cheap foam to cut and stuff into any openings that might allow air to go around (instead of through) your radiator/condenser.

3. Make sure both fans are working properly.

4. 14k isn't too much on the coolant, but you could probably flush and replace. I'm in the midwest and run 50/50 distilled water.

5. Replace thermostat....maybe it's sticking?

6. IMHO, Miata or FC thermoswitch is a good idea.

7. Kinda tedious, but with a small pick, you can straighten any bent fins on your condensor, radiator and oil cooler(s).

[quote name='Sinful7' date='Jul 22 2005, 10:10 AM']The red zone on the stock water temperature gauge is also called the 'new motor zone'..



I linearized my stock temperature gauge, it goes up and down all over the place. I know that anything between the two normal marks is fine with a 5% margin for safety. If mine gets to the top normal mark, it's time to shut her down.



My temps do go up at idle.


[/quote]





Exactly, do what Sinful did or get an aftermarket gauge. The factory temp gauge is a dummy gauge. It will sit at the exact same point mid-way 90% of the time after the car has warmed up. If it goes up even slightly the damage is already done.

[quote name='sweet7' date='Jul 24 2005, 02:51 PM']Exactly, do what Sinful did or get an aftermarket gauge. The factory temp gauge is a dummy gauge. It will sit at the exact same point mid-way 90% of the time after the car has warmed up. If it goes up even slightly the damage is already done.


[/quote]



So you are saying if it goes anywhere above the midway my engine has been damaged? Mine has never even gotten close to the top white line, or the red so I'm hoping there hasn't been any permanent damage yet.

[quote name='base94montego' date='Jul 29 2005, 07:37 AM']So you are saying if it goes anywhere above the midway my engine has been damaged? to the top white line, or the red so I'm hoping there hasn't been any permanent damage yet.


[/quote]



Maybe not. You can't go back and undue what's been done anyway. But your car is running hot. Just do what has already been suggested, so it won't be repeated.

[quote name='Signal 2' date='Jul 29 2005, 05:05 AM']Maybe not. You can't go back and undue what's been done anyway. But your car is running hot. Just do what has already been suggested, so it won't be repeated.


[/quote]





Precisely. Thats not always the case, but I've seen it go down that way a few times. Also had it happen to me. If you ever see that factory gauge move above the "normal" level, it would be smart to shut her down.

[quote name='sweet7' date='Aug 1 2005, 05:09 AM']Precisely. Thats not always the case, but I've seen it go down that way a few times. Also had it happen to me. If you ever see that factory gauge move above the "normal" level, it would be smart to shut her down.


[/quote]



Well I finally fixed the problem. I took my car to Peter Farrel super cars and they set up my fans so they are running all the time. My guage has not moved since, even when sitting in traffic on hot days.

[quote name='base94montego' date='Aug 8 2005, 01:59 PM']Well I finally fixed the problem. I took my car to Peter Farrel super cars and they set up my fans so they are running all the time. My guage has not moved since, even when sitting in traffic on hot days.


[/quote]



Mmmm. Did they say why you were running hot? Did you or PFS try anything else to try to bring the temps down? There's a reason your car is running hot. Unless your living in Death Valley, or maybe have an engine that's extremely modded, it shouldn't be necessary to run your fans full time for the street.

IMHO, that's not fixing the problem, that's just treating the symtom. The underlying problem could get worse and the "full time" fans may not able to compensate forever.

[quote name='Sinful7' date='Jul 22 2005, 02:10 PM']The red zone on the stock water temperature gauge is also called the 'new motor zone'..



I linearized my stock temperature gauge, it goes up and down all over the place. I know that anything between the two normal marks is fine with a 5% margin for safety. If mine gets to the top normal mark, it's time to shut her down.



My temps do go up at idle.


[/quote]



whats the process to linearized the stock guage again? I cant find it anywhere anymore

http://www.iluvmyrx7.com/3rdgen/how-to/Tem...gauge%20mod.pdf



guide on how to do it if anyone else wants to as well

[quote name='nopistons94' date='Aug 8 2005, 03:17 PM']whats the process to linearized the stock guage again? I cant find it anywhere anymore


[/quote]



For some reason I couldn't get your link to work. Sorry if this is a duplicate:

http://www.geocities.com/sdrx7_club/technical.html

[quote name='Signal 2' date='Aug 8 2005, 05:00 PM']For some reason I couldn't get your link to work. Sorry if this is a duplicate:

http://www.geocities.com/sdrx7_club/technical.html


[/quote]





https://www.nopistons.com/forums/pub...IR#>/bigok.gif thanks signal

wow everyones at 9 or 8:45

why is mine at 12? hahaha

I didn't spot this thread till now, but it's perfectly normal for the temp to rise when the car is sitting still - if there's no air flowing through the radiator it's bound to happen. If the fans are taking too long to turn on then you might need a new fan switch in the radiator.



Mark

[quote name='inanimate_object' date='Aug 9 2005, 07:06 AM']I didn't spot this thread till now, but it's perfectly normal for the temp to rise when the car is sitting still - if there's no air flowing through the radiator it's bound to happen. If the fans are taking too long to turn on then you might need a new fan switch in the radiator.



Mark


[/quote]



Yes, it is normal for temperatures to rise under the hood, but NOT for it to be verified by the Stock needle. It should remain at just under 9:00 (8:45 for me..) until things get super hot, then it shoots upwards to H (Check that linerization FAQ).



Same with the fans, in stock condition, they come on at a really hot temperature, unless you have a switch fab'd in there or you run A/C (with or without the Relay as a trick).



https://www.nopistons.com/forums/pub...IR#>/bigok.gif

The radiator fan switch is totally independant of the thermostat - If it's not working or activating the fans too late the needle will continue to rise until the fans are turned on ie. what this guy is experiencing.



Mark

[quote name='inanimate_object' date='Aug 9 2005, 09:14 AM']The radiator fan switch is totally independant of the thermostat - If it's not working or activating the fans too late the needle will continue to rise until the fans are turned on ie. what this guy is experiencing.Mark


[/quote]



Correct. That's why I recommended he consider a Miata or FC thermoswitch earlier in the thread. But it could be alot of things or a combination of things causing it. I just think that unless he asked PFS to just re-wire the fans, it was irresponsible for them to do it without trying to find out why he's running hot.

Precisely.



Mark

Exactly.



Dan

[quote name='inanimate_object' date='Aug 9 2005, 10:14 AM']The radiator fan switch is totally independant of the thermostat - If it's not working or activating the fans too late the needle will continue to rise until the fans are turned on ie. what this guy is experiencing.



Mark


[/quote]



I'm very much aware of the fan's being controlled independantly of the T-stat. However, both the Stock temp gauge AND the thermoswitch BOTH WAIT very long before doing what they should do (Temp gauge rising, and switching on the fans...)



https://www.nopistons.com/forums/pub...DIR#>/wink.png

Then it sounds like you need a new thermoswitch too.



Mark

[quote name='inanimate_object' date='Aug 9 2005, 10:29 AM']Precisely.



Mark


[/quote]





[quote name='PhoenixDownVII' date='Aug 9 2005, 0314 PM']Exactly.



Dan

[/quote]



Indubitably https://www.nopistons.com/forums/pub...IR#>/bigok.gif



Actually, I haven't heard of the stock thermoswitch going bad very often. But like Phoenix suggested, it waits too long to turn the fans on. I think most only switch it out for the lower threshold temp of the FC or Miata switch, which IMHO, makes sense.

Where is the The radiator fan switch I my fans do not come on at all. I dont drive the car around yet. but I let it idel for around 5 - 7 min waiting to see if the fans would come one and they didnt. the stock gauge was at 9o'clock and the upper rad hose was hot so I turned it off.

[quote name='87GTR' date='Aug 10 2005, 01:44 AM']Where is the The radiator fan switch I my fans do not come on at all. I dont drive the car around yet. but I let it idel for around 5 - 7 min waiting to see if the fans would come one and they didnt. the stock gauge was at 9o'clock and the upper rad hose was hot so I turned it off.


[/quote]



Have you tried just running power from the battery to make sure they work? I don't know, maybe fuse or relay? I'm not good with tracking down electrical problems.

The thermoswitch is behind the waterpump housing, difficult to see until you remove the intake tubes, upper vacuum chamber and alternator. You can then see two sensors, IIRC, the thermoswitch is the lower one. The Service Manual shows you how to test it, but if your already in there, I'd just change it out for an 89 to 91 FC thermoswitch. It will plug right in and turns the fans on at 95 deg. C, where the stock FD sensor switches them on at 108 deg. C.



BTW, if you need a Service Manual, you can download one for free here:

http://www.iluvmyrx7.com/

Good luck.