Not fully warming up - RX7Club.com - Mazda RX7 Forum

3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.

Not fully warming up

Old 01-21-19, 01:49 PM
  #1  
Rotary Enthusiast
Thread Starter
iTrader: (5)
 
Net Seven's Avatar
 
Join Date: Apr 2002
Location: Mesa, AZ
Posts: 1,374
Thanked 0 Times in 0 Posts
Not fully warming up

I just bought an FD that has the greddy v-mount kit and the sakebomb big oil coolers. Originally, it would only warm up to a max of 150F. After I replaced the non-OEM looking thermostat with an OEM one, the car started warming up to 180F iding. The fans kick on and it never goes about 180F. Yesterday, I drove it to the gas station and it stayed around 160F since I didnt let it warm up idling. Any suggestions or thoughts on running it at 180F?
Net Seven is offline  
Old 01-21-19, 02:01 PM
  #2  
Rotary Enthusiast
 
Join Date: Jul 2001
Location: JAX, FL
Posts: 1,205
Thanked 18 Times in 17 Posts
What are your fans set to come on at? The car should hit the tstat temperature eventually... it takes mine about 5-10 mins of driving (easy of course). I dont have a v mount or aftermarket oil coolers ( I do have some heavy ducting work to the smic, rad and oil coolers) but my car consistently runs at the tstat opening temp (82c or 179) while cruising and will go up during idling or in slow traffic. My upper rad hose probe usually shows about 10c less than that until idling or slow traffic. My fans come on at 90c.

I had been meaning to ask this question myself. Im not sure of any negative effects other than fuel economy and emissions?

Last edited by AE_Racer; 01-21-19 at 02:14 PM. Reason: Temperature conversion a bit off
AE_Racer is online now  
Old 01-21-19, 02:06 PM
  #3  
Rotary Enthusiast
Thread Starter
iTrader: (5)
 
Net Seven's Avatar
 
Join Date: Apr 2002
Location: Mesa, AZ
Posts: 1,374
Thanked 0 Times in 0 Posts
Originally Posted by AE_Racer View Post
What are your fans set to come on at? The car should hit the tstat temperature eventually... it takes mine about 5-10 mins of driving (easy of course). I dont have a v mount or aftermarket oil coolers ( I do have some heavy ducting work to the smic, rad and oil coolers) but my car consistently runs at the tstat opening temp (82c or 176) while cruising and will go up during idling or in slow traffic. My upper rad hose probe usually shows about 10c less than that until idling or slow traffic. My fans come on at 90c.

I had been meaning to ask this question myself. Im not sure of any negative effects other than fuel economy and emissions?
I just checked the adaptronic map and the fan is set to come on at 181.4F.
Net Seven is offline  
Old 01-21-19, 02:11 PM
  #4  
Rotary Enthusiast
 
Join Date: Jul 2001
Location: JAX, FL
Posts: 1,205
Thanked 18 Times in 17 Posts
I think id bump it up a bit, I remember reading here (I think from Dale Clark) that 85C is a good number. That should ensure you get the tstat open.
AE_Racer is online now  
The Following User Says Thank You to AE_Racer For This Useful Post:
Net Seven (01-21-19)
Old 01-21-19, 02:21 PM
  #5  
Rotary Enthusiast
Thread Starter
iTrader: (5)
 
Net Seven's Avatar
 
Join Date: Apr 2002
Location: Mesa, AZ
Posts: 1,374
Thanked 0 Times in 0 Posts
Originally Posted by AE_Racer View Post
I think id bump it up a bit, I remember reading here (I think from Dale Clark) that 85C is a good number. That should ensure you get the tstat open.
Will try that.

Last edited by Net Seven; 01-21-19 at 02:24 PM.
Net Seven is offline  
Old 01-23-19, 02:35 PM
  #6  
Rotor Head Extreme
iTrader: (8)
 
t-von's Avatar
 
Join Date: Apr 2002
Location: Midland Texas
Posts: 6,698
Thanks: 0
Thanked 9 Times in 7 Posts
On a side note, I would really reconsider the way you warm up yor rotary. Not sure the reason why so many like to idle their rotaries up by idling. Based on my 28yrs years of experience with them from all generations, that's the #1 way to build carbon deposits.

You have to understand that it takes a very long time to heat up those 9lb hunks of cast iron called rotors. Idleing delays how fast the rotors come up to temp. Cold rotors that are wet of fuel during a cold start is when most of the carbon generates on the rotor faces. That carbon will eventually create hot spots making detonation more prone and can also breaking away causing scorching of the rotor housings (which prematurely wears out the housings anf lowers your engine compression) or apex seal breakage.

Ideally start the car, give it a rev above 2,500 rpms for about 20sec then go drive the car. I promise this is better for your engine in the long run because you more quickly burn off any excess fuel that COULD turn into carbon.
t-von is offline  
The Following User Says Thank You to t-von For This Useful Post:
TomU (01-24-19)
Old 01-23-19, 02:45 PM
  #7  
Rotary Enthusiast
Thread Starter
iTrader: (5)
 
Net Seven's Avatar
 
Join Date: Apr 2002
Location: Mesa, AZ
Posts: 1,374
Thanked 0 Times in 0 Posts
Originally Posted by t-von View Post
On a side note, I would really reconsider the way you warm up yor rotary. Not sure the reason why so many like to idle their rotaries up by idling. Based on my 28yrs years of experience with them from all generations, that's the #1 way to build carbon deposits.

You have to understand that it takes a very long time to heat up those 9lb hunks of cast iron called rotors. Idleing delays how fast the rotors come up to temp. Cold rotors that are wet of fuel during a cold start is when most of the carbon generates on the rotor faces. That carbon will eventually create hot spots making detonation more prone and can also breaking away causing scorching of the rotor housings (which prematurely wears out the housings anf lowers your engine compression) or apex seal breakage.

Ideally start the car, give it a rev above 2,500 rpms for about 20sec then go drive the car. I promise this is better for your engine in the long run because you more quickly burn off any excess fuel that COULD turn into carbon.
I don't usually idle my cars to warm them up.. unless of course its my non-rotary daily and it's freezing outside and I remote start it.

I guess my question is, at what temp is it ok to start going WOT with boost?
Net Seven is offline  
Old 01-23-19, 03:33 PM
  #8  
RX-7 Bad Ass
iTrader: (52)
 
DaleClark's Avatar
 
Join Date: Jan 2002
Location: Pensacola, FL
Posts: 11,016
Thanked 231 Times in 200 Posts
Yep, there is no good reason to let it idle and warm up. When it's running it's ready to drive. Start it up, put it in gear, and go.

Try and keep out of boost until you are at 80 deg. C or higher. Part throttle boost is fine, you just don't want to gun it when it's not warmed up yet. Not to mention with the cold enrichment it will be slow .

Dale
DaleClark is online now  
Old 01-23-19, 03:38 PM
  #9  
Rotary Enthusiast
Thread Starter
iTrader: (5)
 
Net Seven's Avatar
 
Join Date: Apr 2002
Location: Mesa, AZ
Posts: 1,374
Thanked 0 Times in 0 Posts
Originally Posted by DaleClark View Post
Yep, there is no good reason to let it idle and warm up. When it's running it's ready to drive. Start it up, put it in gear, and go.

Try and keep out of boost until you are at 80 deg. C or higher. Part throttle boost is fine, you just don't want to gun it when it's not warmed up yet. Not to mention with the cold enrichment it will be slow .

Dale
Thanks, so about 80 C.

Not sure why you guys keep talking about idling to let it warm up. Like I said, I replaced the thermostat and let it idle that time to see if the thermostat resolved the issue. With the old thermostat, it never got above 150F, even during the 45min drive home after buying the car. That means the car was tuned, driven, etc all at a max of 150F coolant temp before. The seller confirmed this issue. That's kind of why I started the thread, to get a better idea of what issues the engine might have as a result of running 26PSI on an engine that isn't fully warmed up.

Last edited by Net Seven; 01-23-19 at 03:54 PM. Reason: Adding more details
Net Seven is offline  
Old 01-23-19, 03:54 PM
  #10  
RX-7 Bad Ass
iTrader: (52)
 
DaleClark's Avatar
 
Join Date: Jan 2002
Location: Pensacola, FL
Posts: 11,016
Thanked 231 Times in 200 Posts
Also, you really only want to use Mazda thermostats. I have (and have had friends) burned by aftermarket thermostats - either sticking open or sticking closed.

Stock thermostat is 82 deg. C if memory serves. No reason to get a thermostat with a different heat range. There are some aftermarket ones that are colder or whatever but it won't do you any favors.

Dale
DaleClark is online now  
Old 01-23-19, 03:58 PM
  #11  
Rotary Enthusiast
Thread Starter
iTrader: (5)
 
Net Seven's Avatar
 
Join Date: Apr 2002
Location: Mesa, AZ
Posts: 1,374
Thanked 0 Times in 0 Posts
Originally Posted by DaleClark View Post
Also, you really only want to use Mazda thermostats. I have (and have had friends) burned by aftermarket thermostats - either sticking open or sticking closed.

Stock thermostat is 82 deg. C if memory serves. No reason to get a thermostat with a different heat range. There are some aftermarket ones that are colder or whatever but it won't do you any favors.

Dale
You're preaching to the choir. I bought the car with that thermostat installed and replaced it with an OEM one. I added some more info in the post just above. The seller confirmed it never got above 150F and it was tuned to 26PSI on a EFR 9174 turbo, so it was never properly warmed up while running 26PSI. What damage could the engine have because of it?
Net Seven is offline  
Old 01-23-19, 09:05 PM
  #12  
RX-7 Bad Ass
iTrader: (52)
 
DaleClark's Avatar
 
Join Date: Jan 2002
Location: Pensacola, FL
Posts: 11,016
Thanked 231 Times in 200 Posts
I doubt you've necessarily hurt anything running colder at full boost. It's generally a good idea to wait until the car is warmed up but I doubt anything has been harmed.

That said, I don't think anyone has ever truly caused lasting engine damage by boosting a cold engine.

Dale
DaleClark is online now  
The Following User Says Thank You to DaleClark For This Useful Post:
Net Seven (01-23-19)
Old 01-23-19, 09:40 PM
  #13  
Built Not Bought
iTrader: (13)
 
TwinCharged RX7's Avatar
 
Join Date: May 2008
Location: Stamford, CT
Posts: 2,566
Thanks: 0
Thanked 33 Times in 30 Posts
As long as it's hot enough for the coolant to flow (thermostat open) so it doesn't develop hot spots, there really shouldn't be a difference to the longevity of the engine (assuming a good tune) whether it operates at 160 - 180 - 200 - 220 degrees. Unless there is some kind of proof I'm unaware of that shows the housings or seals will wear faster when cold. At 150 degrees F, the oil is already warm enough to do its job.

Above 220 then I'd start worrying about coolant seals.
TwinCharged RX7 is offline  
Old 01-23-19, 09:52 PM
  #14  
Rotary Enthusiast
Thread Starter
iTrader: (5)
 
Net Seven's Avatar
 
Join Date: Apr 2002
Location: Mesa, AZ
Posts: 1,374
Thanked 0 Times in 0 Posts
Originally Posted by TwinCharged RX7 View Post
As long as it's hot enough for the coolant to flow (thermostat open) so it doesn't develop hot spots, there really shouldn't be a difference to the longevity of the engine (assuming a good tune) whether it operates at 160 - 180 - 200 - 220 degrees. Unless there is some kind of proof I'm unaware of that shows the housings or seals will wear faster when cold. At 150 degrees F, the oil is already warm enough to do its job.

Above 220 then I'd start worrying about coolant seals.
Fair enough. Just a few hours ago I drove it to a tire shop and it stayed around 145-150F during the 30min freeway drive (No idle warm up time !!!! . While waiting for my wheel to get checked out, I spoke to Heath at Sakebomb. He thinks maybe the huge oil coolers might be too big for street application? They come with a 180F thermostat that always flows some but starts to open earlier. On the way back, I was in some stop and go traffic and the temps climbed towards 180F, if I'm on the freeway it drops to 145F. I'm going to get a 200F oil cooler thermostat from Heath and see if it fixes the problem. BTW, it was about 60F outside in sunny AZ today, so not very cold.
Net Seven is offline  
Old 01-23-19, 11:04 PM
  #15  
Built Not Bought
iTrader: (13)
 
TwinCharged RX7's Avatar
 
Join Date: May 2008
Location: Stamford, CT
Posts: 2,566
Thanks: 0
Thanked 33 Times in 30 Posts
Are you monitoring both oil and water temps? Hard to talk about oil cooler thermostat requirements by using water temp as a guideline.
TwinCharged RX7 is offline  
Old 01-23-19, 11:05 PM
  #16  
Built Not Bought
iTrader: (13)
 
TwinCharged RX7's Avatar
 
Join Date: May 2008
Location: Stamford, CT
Posts: 2,566
Thanks: 0
Thanked 33 Times in 30 Posts
If your thermostats are all opening and fans occasionally come on, I would double check your sensors before doing anything significant.
TwinCharged RX7 is offline  
Old 01-24-19, 12:08 AM
  #17  
Time or Money, Pick one
iTrader: (31)
 
silverTRD's Avatar
 
Join Date: Oct 2005
Location: Torrance, ca.
Posts: 2,691
Thanks: 0
Thanked 13 Times in 13 Posts
My cars oil temps stay low when in the freeway, pick back up when Im boost and Iím traffic, but Iím planning to swap the thermostat as well. I donít like cold oil temps. I donít have the issue with the coolant temps however. Have you thought of just putting a cardboard shield to temporarily cover half the radiator and monitor the temps? Iíve covered one oil cooler and successfully raised my oil temps.
silverTRD is offline  
Old 01-24-19, 12:28 AM
  #18  
Lives on the Forum
iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 7,044
Thanked 141 Times in 125 Posts
The behavior your FD exhibits is normal for a street rotary with a track oriented cooling system in my experience.

The coolant thermostat has a bypass and cruising down the freeway just that much bleed through into the very well cooling radiator drops the coolant temps below the thermostat opening.
Sucks in the winter when you crank the heater and barely warm air comes out.

On my FC for 15 years I had a giant Griffin radiator and horizontal mount IC and even ran the less thermally conductive 100% PG coolant and it did this. I actually switched up from a 160deg F racing T-stat to a 180deg F T-stat and it helped a bit.

On my FD when I just switched to Koyo Z flow triple pass radiator with stock mount IC it also started exhibiting this same behavior.
That Z flow is crazy for how small it is (stock fit). It can be blazing hot on the inlet side and cold by the outlet side.

As long as your coolant temps are above ~ 120F and come up normally as you boost you are fine in my experience.

The only problem with running the rotary marginally cold is gas mileage won't be as good and it doesn't run as smooth- as long as your fuel map is properly compensated and not just tuned to run right at t-stat temps

The oiling system is a whole different ball of wax as viscosity matters and you will need an oil temp gauge/sender to know what is going on.
BLUE TII is offline  
Old 01-24-19, 08:09 AM
  #19  
rotorhead
iTrader: (3)
 
arghx's Avatar
 
Join Date: Aug 2004
Location: cold
Posts: 15,603
Thanked 47 Times in 47 Posts
I have a theory that the oil squirter thermostat delete mod (delete the thermostat for the rotor cooling jets, save $70 instead of buying a new one) hurts engine warm up, including coolant warm up. Yeah I know they fail, but seriously, the original one lasted for years and years, and you can still get a new one from Mazda last I checked, so why delete it???? Audi uses an ECU controlled piston squirter thermostat. Now that's gotta be expensive.

Somebody un-delete theirs and report back. I've always had cars with the delete or without, but never did a before-after comparison.


Last edited by arghx; 01-24-19 at 08:14 AM.
arghx is offline  
Old 01-24-19, 12:33 PM
  #20  
It Just Feels Right
iTrader: (10)
 
TomU's Avatar
 
Join Date: Feb 2014
Location: Arlington, VA
Posts: 1,516
Thanked 38 Times in 37 Posts
Best solution for large oil coolers is running them in parallel vs series with a T-stat for each cooler. That way you could have different rates of opening.

I'd recomend a lighter oil (10-50) if you have low oil temps

Also, never thought about carbon build up from idling. Learn something new on this site all the time
TomU is offline  
Old 01-29-19, 03:18 PM
  #21  
Junior Member
 
Darkning's Avatar
 
Join Date: Feb 2012
Location: Charlotte, NC
Posts: 40
Thanked 2 Times in 2 Posts
Originally Posted by TomU View Post

Also, never thought about carbon build up from idling. Learn something new on this site all the time
Same here - I'd assume that same fresh carbon would be coming off in short order as long as you're redlining and boosting frequently enough. Like they say, a redline a day keeps the mechanic away. That's generally been true for my rotary ownership haha.
Darkning is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Texas_Ace
2nd Generation Specific (1986-1992)
8
10-18-08 09:03 PM
j_tso
1st Generation Specific (1979-1985)
10
02-19-07 03:10 PM
RX187
Megasquirt Forum
3
09-14-06 09:38 PM


Thread Tools
Search this Thread
Quick Reply: Not fully warming up


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.