engine temp
06-30-09 | 10:10 AM
#1
engine temp
alright well i've already searched, tried to fix and my temps are still high.
im using the stock s4 temp gauge in my 88 vert and almost everyday its at half. i know the normal range is 1/8 to 1/4. i even saw a post by icemark that said that 2/5 is normal but its early in the morning so i will figure out the fraction later.
ive done the coolant flush, OEM mazda thermostat, new upper and lower hoses, new heater hose because one kind of cracked and leaked a lot of my coolant away. no engine damage though.
one thing that makes me think its beyond my control is the heat here in texas. its been up to 100+ the past few days. its ok if i drive at night because of obvious reasons. im in school right now and im not required to actually go to the class since thats how it is set up so i can avoid driving it during the day, but even so its kind of annoying to drive it during the day and have it try and overheat. i've turned on the heater on full blast to try and help cool the coolant. i know the clutch fan works because i hear it bc i drive with the windows down.
the belly pan is also installed. the radiator should be fine but i really want to invest in a corksport of a koyo radiator, but lack of funds right now.
are there any other things i can do to help the temperature? i refuse to drive it hard during the day. the coolant mix is about 50/50. im pretty sure i installed the thermostat correctly. the FSM said to install with the jiggle pin between north and east.
so...im pretty much have no idea what else i can do.
im using the stock s4 temp gauge in my 88 vert and almost everyday its at half. i know the normal range is 1/8 to 1/4. i even saw a post by icemark that said that 2/5 is normal but its early in the morning so i will figure out the fraction later.
ive done the coolant flush, OEM mazda thermostat, new upper and lower hoses, new heater hose because one kind of cracked and leaked a lot of my coolant away. no engine damage though.
one thing that makes me think its beyond my control is the heat here in texas. its been up to 100+ the past few days. its ok if i drive at night because of obvious reasons. im in school right now and im not required to actually go to the class since thats how it is set up so i can avoid driving it during the day, but even so its kind of annoying to drive it during the day and have it try and overheat. i've turned on the heater on full blast to try and help cool the coolant. i know the clutch fan works because i hear it bc i drive with the windows down.
the belly pan is also installed. the radiator should be fine but i really want to invest in a corksport of a koyo radiator, but lack of funds right now.
are there any other things i can do to help the temperature? i refuse to drive it hard during the day. the coolant mix is about 50/50. im pretty sure i installed the thermostat correctly. the FSM said to install with the jiggle pin between north and east.
so...im pretty much have no idea what else i can do.
06-30-09 | 10:23 AM
#2
MECP Certified Installer
Joined: Feb 2009
Posts: 3,176
Likes: 2
From: Mesquite, TX-DFW
2/5th is 40%.
My S5 runs at 45% usually. Your rad could be clogged. Go pick up a infared thermometer and let the engine idle until it hits operating temp on the gauge, but dont drive it around. Kill the car and immediately start scanning the radiator core with the thermometer and look for cool spots. It'll still be warm because of heat soak, but still cooler than the rest of the rad. You could also have multiple clogs.
My S5 runs at 45% usually. Your rad could be clogged. Go pick up a infared thermometer and let the engine idle until it hits operating temp on the gauge, but dont drive it around. Kill the car and immediately start scanning the radiator core with the thermometer and look for cool spots. It'll still be warm because of heat soak, but still cooler than the rest of the rad. You could also have multiple clogs.
06-30-09 | 11:58 AM
#3
Your radiator is probably in need of a replacement, or it's just too hot outside. On an S4 temp gauge, 1/4 is 180*F, 1/2 is about 200*F & 3/4 is about 215- 220*F. I just measured all of these values last weekend with my Rtek. 1/4 to 1/2 is fine, but anything over that is starting to get a little too warm.
You can't really compare your S5 gauge to an S4 gauge. 1/2 way on an S5 is 180*F - 220*F, so by the time it moves higher, you're overheating. The S4 gauge is completely linear unlike the S5.
2/5th is 40%.
My S5 runs at 45% usually. Your rad could be clogged. Go pick up a infared thermometer and let the engine idle until it hits operating temp on the gauge, but dont drive it around. Kill the car and immediately start scanning the radiator core with the thermometer and look for cool spots. It'll still be warm because of heat soak, but still cooler than the rest of the rad. You could also have multiple clogs.
My S5 runs at 45% usually. Your rad could be clogged. Go pick up a infared thermometer and let the engine idle until it hits operating temp on the gauge, but dont drive it around. Kill the car and immediately start scanning the radiator core with the thermometer and look for cool spots. It'll still be warm because of heat soak, but still cooler than the rest of the rad. You could also have multiple clogs.
06-30-09 | 12:15 PM
#4
In the shade
Joined: Jun 2009
Posts: 249
Likes: 0
From: PA
2/5th is 40%.
My S5 runs at 45% usually. Your rad could be clogged. Go pick up a infared thermometer and let the engine idle until it hits operating temp on the gauge, but dont drive it around. Kill the car and immediately start scanning the radiator core with the thermometer and look for cool spots. It'll still be warm because of heat soak, but still cooler than the rest of the rad. You could also have multiple clogs.
My S5 runs at 45% usually. Your rad could be clogged. Go pick up a infared thermometer and let the engine idle until it hits operating temp on the gauge, but dont drive it around. Kill the car and immediately start scanning the radiator core with the thermometer and look for cool spots. It'll still be warm because of heat soak, but still cooler than the rest of the rad. You could also have multiple clogs.
06-30-09 | 12:25 PM
#5
k i'll check the radiator later today. i just started it a few minutes ago after checking for any visible leaks and i checked to see if there were any loose bolts or nuts.
i also burped the system and got some of the bubbles out.
it is really hot outside. so im not surprised the temp gauge goes up.
is there any way to unclog a radiator? or does a radiator shop have to do that?
i also burped the system and got some of the bubbles out.
it is really hot outside. so im not surprised the temp gauge goes up.
is there any way to unclog a radiator? or does a radiator shop have to do that?
06-30-09 | 12:29 PM
#6
MECP Certified Installer
Joined: Feb 2009
Posts: 3,176
Likes: 2
From: Mesquite, TX-DFW
You can have the radiator cored out at a rad shop if one is around, but if you have the platic end capped stock radiator, you might as well chunk it and replace it anyway. Those plastic caps tend to fail, which is bad juju.
06-30-09 | 12:45 PM
#7
In the shade
Joined: Jun 2009
Posts: 249
Likes: 0
From: PA
k i'll check the radiator later today. i just started it a few minutes ago after checking for any visible leaks and i checked to see if there were any loose bolts or nuts.
i also burped the system and got some of the bubbles out.
it is really hot outside. so im not surprised the temp gauge goes up.
is there any way to unclog a radiator? or does a radiator shop have to do that?
i also burped the system and got some of the bubbles out.
it is really hot outside. so im not surprised the temp gauge goes up.
is there any way to unclog a radiator? or does a radiator shop have to do that?
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06-30-09 | 12:56 PM
#8
Sorry, I'm not trying to thread jack, but I have another question. How do you properly burp the system or bleed the air out? Perhaps I am doing it wrong. The haynes manual says to leave the filler cap off and put the heat on full and start the car. Wouldn't that end up spraying coolant everywhere?
06-30-09 | 02:56 PM
#10
Refined Valley Dude
Joined: Oct 2001
Posts: 2,283
Likes: 2
From: Kitchener, Ontario (Hamilton's armpit)
Have you checked the temp gauge itself per the FSM? Why not do a simple test before you spend more money? Also, what about putting in an aftermarket gauge (in addition to the stock gauge?) Something spiffy and high tech, with actual numbers instead of just H and C.
I'd change your coolant mixture to 60%-70% water, and use 20w50 in the engine if you aren't already.
If you want to try this without buying the unit, go find a crew paving a road. Somewhere nearby will be an 'inspector' (usually a college kid) who's there to check compaction and other things. One of his toys will be just such a thermometer, used to check the temperature of the hot-mix asphalt as it either enters the paver or is about to be smooshed down onto the roadway. The device is used like a radar gun - point it at the target and look at the display. Ask somebody on the crew if the inspector is around, find the guy and offer him a few bucks or a coffee or something to 'shoot' your rad.
That being said, you're chances of actually finding a crew are probably a little low. I'd just put a aftermarket gauge in and eliminate this kind of excessive song and dance...
I'd change your coolant mixture to 60%-70% water, and use 20w50 in the engine if you aren't already.
Go pick up a infared thermometer and let the engine idle until it hits operating temp on the gauge
That being said, you're chances of actually finding a crew are probably a little low. I'd just put a aftermarket gauge in and eliminate this kind of excessive song and dance...
06-30-09 | 04:09 PM
#11
new pump. replaced it last year in august/september
ive been running 20w50 since my last oil change. im almost due for another oil change. ive been adding water when i burp the system.
honestly, i have no idea how to install an aftermarket gauge as far as how to wire it and get it to work. i'll research and see what i can find though.
honestly, i have no idea how to install an aftermarket gauge as far as how to wire it and get it to work. i'll research and see what i can find though.
06-30-09 | 04:36 PM
#12
Here is an exerpt from this thread. https://www.rx7club.com/newreply.php...eply&p=8467323
I see 1/2 on my S4 gauge sometimes and I have got 217 max temp running hard, but not more.
Sigh. So much misinformation, so little time.
Minimum water temps, once the car warms up, are controlled by the thermostat. It opens&closes to send more/less coolant into the engine to try and maintain proper operating temperature. In the case of the FC, this should be around 190F, maybe slightly lower.
Cruising down the highway on a "normal" (80-90 degree) day with minimal load on the engine, you should be able to maintain that temp.
Yes, water boils at 212F in normal atmosphere. At higher pressures, the boiling point is significantly higher. (Conversely, the lower the pressure the lower the boiling point which is why water boils at a slightly lower temp at higher altitudes.) The pressure cap on the radiator maintains a higher pressure in the cooling system and thus allows a higher boiling point. Why did you think it was there?
Other contributor is coolant. Adding it to water raises the boiling point (and lowers the freezing point at the same time).
http://auto.howstuffworks.com/cooling-system3.htm
While driving, your temps will obviously vary depending upon external temps, load on the engine, etc. In general you should be running under 200 (as indicated earlier) but if you keep it under 220 you are fine. Running 220-230 is getting a bit warm and you should be looking for a place to pull over because there is something wrong. Near 230 and you should definitely pull over and cut the engine.
Obviously, these are general rules and depend on the situation. If you are cruising on a cool day and notice that the temps are at 210 and rising, you should of course pull over, because there is something wrong. On the other hand, when I run my FC on the track, it pretty much constantly sits around 205-210, with occasional trips above that.
As for max temp your engine can withstand, again that depends. When I blew a coolant hose off at the track, the temps spiked well above 230 before I got her back to the pits. Too much longer and I would have just pulled off the track. But I have a lot of oil cooling capacity (dual FC coolers) and the engine survived. I wouldn't recommend this, however. :-)
-bill
Minimum water temps, once the car warms up, are controlled by the thermostat. It opens&closes to send more/less coolant into the engine to try and maintain proper operating temperature. In the case of the FC, this should be around 190F, maybe slightly lower.
Cruising down the highway on a "normal" (80-90 degree) day with minimal load on the engine, you should be able to maintain that temp.
Yes, water boils at 212F in normal atmosphere. At higher pressures, the boiling point is significantly higher. (Conversely, the lower the pressure the lower the boiling point which is why water boils at a slightly lower temp at higher altitudes.) The pressure cap on the radiator maintains a higher pressure in the cooling system and thus allows a higher boiling point. Why did you think it was there?
Other contributor is coolant. Adding it to water raises the boiling point (and lowers the freezing point at the same time).
http://auto.howstuffworks.com/cooling-system3.htm
While driving, your temps will obviously vary depending upon external temps, load on the engine, etc. In general you should be running under 200 (as indicated earlier) but if you keep it under 220 you are fine. Running 220-230 is getting a bit warm and you should be looking for a place to pull over because there is something wrong. Near 230 and you should definitely pull over and cut the engine.
Obviously, these are general rules and depend on the situation. If you are cruising on a cool day and notice that the temps are at 210 and rising, you should of course pull over, because there is something wrong. On the other hand, when I run my FC on the track, it pretty much constantly sits around 205-210, with occasional trips above that.
As for max temp your engine can withstand, again that depends. When I blew a coolant hose off at the track, the temps spiked well above 230 before I got her back to the pits. Too much longer and I would have just pulled off the track. But I have a lot of oil cooling capacity (dual FC coolers) and the engine survived. I wouldn't recommend this, however. :-)
-bill
07-03-09 | 03:10 PM
#13
Refined Valley Dude
Joined: Oct 2001
Posts: 2,283
Likes: 2
From: Kitchener, Ontario (Hamilton's armpit)
It's mostly easy. The hard parts are wiring the gauge if you're not used to doing wiring in your car, and deciding where to tap in the sensor. I got a shop to do the actual tapping for me. I think I paid the guy $10. I'll post a photo of it when I'm next online...
07-03-09 | 10:37 PM
#14
well i actually somehow fixed the temps for now. i had a bad exhaust leak from the header to the 1st cat and there wasnt a nut on the lower left stud on the manifold. im going to take the manifold off and get a new gasket and put it on to prevent further leaks.
my temps never went above 1/4 or 2/5 whichever makes more sense. in the future i will get the guage and a pod or figure out where to mount it.
thanks for all the help. it was kind of a nooby thing on my part but its fixed for now, i hope.
my temps never went above 1/4 or 2/5 whichever makes more sense. in the future i will get the guage and a pod or figure out where to mount it.
thanks for all the help. it was kind of a nooby thing on my part but its fixed for now, i hope.
07-04-09 | 10:40 AM
#15
Refined Valley Dude
Joined: Oct 2001
Posts: 2,283
Likes: 2
From: Kitchener, Ontario (Hamilton's armpit)
Grats on fixing it. I'm gonna post this anyway. 
This is the quick and easy spot to install the sensor. Being situated downstream of the thermostat, you won't see the temp rise until the thermostat starts to open, which in my mind isn't a big deal since you don't generally care about engine temps 'til they start to reach the 180F neighbourhood...
This is the quick and easy spot to install the sensor. Being situated downstream of the thermostat, you won't see the temp rise until the thermostat starts to open, which in my mind isn't a big deal since you don't generally care about engine temps 'til they start to reach the 180F neighbourhood...
07-04-09 | 10:42 AM
#16
Engine, Not Motor
iTrader: (1)
Joined: Feb 2001
Posts: 29,793
Likes: 119
From: London, Ontario, Canada
Loads of cooling system troubleshooting:
http://www.aaroncake.net/rx-7/cooling.htm
http://www.aaroncake.net/rx-7/cooling.htm
07-04-09 | 10:50 AM
#17
@ Amur_
thanks for the picture. i will probably do something like that.
first thing i followed when the weather started to get warmer and warmer.
thanks for the picture. i will probably do something like that.
Loads of cooling system troubleshooting:
http://www.aaroncake.net/rx-7/cooling.htm
http://www.aaroncake.net/rx-7/cooling.htm
07-04-09 | 10:52 AM
#18
I know a autometer gauge comes with a alum, adaptor, when my vert was s4 I had the adaptor welded to the housing, I felt it was a better mounting solution then tapping.
When the car was NA there was almost no reason to even look at the temp gauge, it NEVER moved! Car ran so nice and cool.
When the car was NA there was almost no reason to even look at the temp gauge, it NEVER moved! Car ran so nice and cool.
07-04-09 | 01:23 PM
#19
If your factory gauge is ok, I question your factory water thermosensor (Rtek reading). I bought a brand new OEM one and it reads a lot higher at those points on the s4 gauge than you are seeing. 1/4 up is around 185, and when i hit about 203 F (95 C on my Power FC) that is maybe 1/3 up the gauge. 1/2 up has got to be in the 210-220 range at least. I have seen multiple old OEM thermosensors read inaccurately, anywhere from 30-40 C too cold or 5-10 C too hot.
07-05-09 | 12:12 PM
#20
If your factory gauge is ok, I question your factory water thermosensor (Rtek reading). I bought a brand new OEM one and it reads a lot higher at those points on the s4 gauge than you are seeing. 1/4 up is around 185, and when i hit about 203 F (95 C on my Power FC) that is maybe 1/3 up the gauge. 1/2 up has got to be in the 210-220 range at least. I have seen multiple old OEM thermosensors read inaccurately, anywhere from 30-40 C too cold or 5-10 C too hot.
07-17-09 | 09:22 AM
#21
Refined Valley Dude
Joined: Oct 2001
Posts: 2,283
Likes: 2
From: Kitchener, Ontario (Hamilton's armpit)
07-19-09 | 03:00 AM
#22
Rotary its a way of life
Joined: Feb 2009
Posts: 724
Likes: 1
From: Fredericksburg, VA
hey im wondering if there is a site to order a OEM mazda thermostat i have been searching and havent found one yet and also i was thinking about getting a aftermarket temp gauge but putting it on the water pump kinda is bad in my opinion due to the fact that you are going to have to replace it some time and then you are just going to have to redo it again and again
07-20-09 | 10:56 AM
#24
Refined Valley Dude
Joined: Oct 2001
Posts: 2,283
Likes: 2
From: Kitchener, Ontario (Hamilton's armpit)
Again and again? Are we talking about a water pump or engine oil?
Even if the pump needed to be replaced every few years, it was only $10 cash-and-goodbye at a local machine shop to get the pump housing tapped for the sensor. If you're going to complain about $10 every 2-5 years, you're driving the wrong car...
07-20-09 | 02:23 PM
#25
Engine, Not Motor
iTrader: (1)
Joined: Feb 2001
Posts: 29,793
Likes: 119
From: London, Ontario, Canada
And for that matter, a hand drill and a tap makes it a 5 minute job to move the sensor to a new water pump. But since the tap is about $20 for a quality unit, that's two trips to the machine shop before you come out ahead.