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

When to let your turbos idle and cool off.

Thread Tools
 
Search this Thread
 
Old 01-21-07, 10:28 AM
  #51  
Magnet Boy

 
rxcited2's Avatar
 
Join Date: Jan 2007
Location: NorCal
Posts: 251
Likes: 0
Received 1 Like on 1 Post
Originally Posted by dgeesaman
Well if you watch your water temps, you might find that they get hotter during idle. So idling can actually leave the engine bay a lot hotter than if you simply shut it off when the car comes to a stop. Idling makes my engine much hotter. So a turbo timer would create worse heat soaking than none, in my case.
I can respond to this point. I find typically, even with normal driving (some boost), that if I just park it and turn it off, the cooling fan comes on and I can hear the coolant bubbling in the radiator. This goes on for some time. If however, I let it idle until the fan comes on (highest temperature) and then continue to let it idle until it just goes off (lowest temperature), it does do this. Apparentlly idling DOES leave my engine cooler than when I just pull in to park, provided the period is not excessive.
rxcited2 is offline  
Old 01-21-07, 10:49 AM
  #52  
Racecar - Formula 2000

 
DaveW's Avatar
 
Join Date: Sep 2002
Location: Bath, OH
Posts: 3,861
Received 281 Likes on 201 Posts
Letting the engine run at no load either idling or at a slightly higher RPM after it's gotten very warm is a long-used method for stabilizing temperatures in the engine and cooling system. This no-load running reduces the temperatures at any hot spots, at least partially reducing the tendency of coolant temperature (and pressure in the system) to rise after shut-off. Letting the fan cycle once, as mentioned above assures that things have at least partially stabilized, so that's good.

VERY gentle driving just before shut-off accomplishes most of the same things.

Dave - veteran of driving overheating British sports cars in the '60's.
DaveW is offline  
Old 01-21-07, 11:00 AM
  #53  
Cheap Bastard

iTrader: (2)
 
adam c's Avatar
 
Join Date: Sep 2002
Location: San Luis Obispo, Ca
Posts: 8,370
Received 50 Likes on 42 Posts
Originally Posted by rxcited2
I can respond to this point. I find typically, even with normal driving (some boost), that if I just park it and turn it off, the cooling fan comes on and I can hear the coolant bubbling in the radiator. This goes on for some time. If however, I let it idle until the fan comes on (highest temperature) and then continue to let it idle until it just goes off (lowest temperature), it does do this. Apparentlly idling DOES leave my engine cooler than when I just pull in to park, provided the period is not excessive.
I do not agree with this procedure. Letting the car sit at idle until it reaches 220 degrees (stock point at which fans come on) seems really stupid. However, doing this makes it even more foolish to own a turbo timer, as it will not follow your procedure.
adam c is offline  
Old 01-21-07, 11:14 AM
  #54  
Racecar - Formula 2000

 
DaveW's Avatar
 
Join Date: Sep 2002
Location: Bath, OH
Posts: 3,861
Received 281 Likes on 201 Posts
Originally Posted by adam c
I do not agree with this procedure. Letting the car sit at idle until it reaches 220 degrees (stock point at which fans come on) seems really stupid. However, doing this makes it even more foolish to own a turbo timer, as it will not follow your procedure.
You're correct, adam c, that letting it go to 220F if it was not already close to that, is dumb.

I should have added in my last post, that I have a Miata thermoswitch, which, IIRC, makes the fans come on at ~205F.

Dave
DaveW is offline  
Old 01-21-07, 11:25 AM
  #55  
Super Snuggles

 
jimlab's Avatar
 
Join Date: Feb 2001
Location: Redmond, WA
Posts: 10,091
Received 32 Likes on 17 Posts
Originally Posted by rxcited2
I am suggesting that a modest cool down period is appropriate when shutting the car off suddenly after some hard driving.
Why would you shut the car off suddenly immediately after hard driving?

A. Professional thieves robbed the local branch of the Big City bank and you assisted the police in the resulting high speed chase which ended in a shoot-out, leaving you no time to cool down the car because you immediately had to take cover behind it. You then had to rush across town to save kids in a burning orphanage, shutting your car off just before before heading into the flames...

B. A serial killer took a young girl hostage and led you from phone booth to phone booth across town to see if you were bringing followed while delivering the ransom money. The only way to make it to the next phone on time was to keep the pedal to the floor and then immediately shut the car off so you could actually hear his next instructions...

C. The only brain surgeon in Smallville, U.S.A. was in a terrible car accident and the only way to save the governor's life was for you to beat your car all the way across town to scrub in on the surgery with only minutes to spare before lack of oxygen to the brain left him a drooling vegetable...

D. You don't have the maturity or self control to keep from flooring it all the way through your neighborhood just to show everyone how special you and your rotary exhaust note really are...

There's no excuse for not being able to drive sanely for a few minutes prior to arriving at your destination. Doing so eliminates the need to allow the car to cool down and absolutely eliminates the need for a turbo timer.
jimlab is offline  
Old 01-21-07, 11:34 AM
  #56  
HDP
A Fistfull of Dollars!

iTrader: (2)
 
HDP's Avatar
 
Join Date: Nov 2002
Location: HuntsVEGAS, AL
Posts: 5,321
Received 3 Likes on 3 Posts
Originally Posted by dubulup
second that.

I have a turbo timer...and it's great for one thing; telling me system voltage.
And also for allowing the car to warm up on cold mornings (or cool the cabin in summer heat). Go outside, start the car, turn on heater (or A/C in the summer), set the timer for maximum time (mine is 10 min.), shut the car off, lock the car and go back inside.
HDP is offline  
Old 01-21-07, 11:39 AM
  #57  
HDP
A Fistfull of Dollars!

iTrader: (2)
 
HDP's Avatar
 
Join Date: Nov 2002
Location: HuntsVEGAS, AL
Posts: 5,321
Received 3 Likes on 3 Posts
Originally Posted by adam c
The truth is spoken!
Only by men with narrow vision...
HDP is offline  
Old 01-21-07, 12:35 PM
  #58  
Moderator

iTrader: (7)
 
dgeesaman's Avatar
 
Join Date: May 2002
Location: Fort Kickass
Posts: 12,302
Received 16 Likes on 15 Posts
Originally Posted by rxcited2
I can respond to this point. I find typically, even with normal driving (some boost), that if I just park it and turn it off, the cooling fan comes on and I can hear the coolant bubbling in the radiator. This goes on for some time. If however, I let it idle until the fan comes on (highest temperature) and then continue to let it idle until it just goes off (lowest temperature), it does do this. Apparentlly idling DOES leave my engine cooler than when I just pull in to park, provided the period is not excessive.
Yes, if you wait for the fans to bring down the coolant temps, you will be better off than just shutting down the engine anytime. And like DaveW said, it will dissipate heat from the hottest spots while idling.

But turbo timers don't do that, they just run for a specified period of time. So if the fans had just cycled off, and you park it, the timer could just as easily have let the coolant temps reach the threshold right before the fans kick on, making the situation worse.

Dave
dgeesaman is offline  
Old 01-21-07, 12:55 PM
  #59  
Cheap Bastard

iTrader: (2)
 
adam c's Avatar
 
Join Date: Sep 2002
Location: San Luis Obispo, Ca
Posts: 8,370
Received 50 Likes on 42 Posts
Originally Posted by HDP
Only by men with narrow vision...
Narrow vision can provide great detail, while wide vision provides specifics of nothing
adam c is offline  
Old 01-21-07, 01:03 PM
  #60  
Rotary Enthusiast

 
web777's Avatar
 
Join Date: Mar 2003
Location: LOS ANGELES
Posts: 1,228
Likes: 0
Received 0 Likes on 0 Posts
So are you guys saying that you should not shut off the car after immediately driving hard?
web777 is offline  
Old 01-21-07, 02:50 PM
  #61  
Super Snuggles

 
jimlab's Avatar
 
Join Date: Feb 2001
Location: Redmond, WA
Posts: 10,091
Received 32 Likes on 17 Posts
Originally Posted by HDP
Only by men with narrow vision...
Someone who doesn't move his car when his neighbors have been cutting down a tree next door could be accused of having narrow vision... among other things...
jimlab is offline  
Old 01-21-07, 02:51 PM
  #62  
HDP
A Fistfull of Dollars!

iTrader: (2)
 
HDP's Avatar
 
Join Date: Nov 2002
Location: HuntsVEGAS, AL
Posts: 5,321
Received 3 Likes on 3 Posts
Originally Posted by adam c
Narrow vision can provide great detail, while wide vision provides specifics of nothing
Only in the eye of the beholder... like I said, I use my timer for other purposes as well. We all agree since the 7 is a bit tempermental, it should be warmed to operating temps before spirited driving. I don't know how you drive your car, but for me this is not an Oldsmobile, so everytime I get in mine, I engage in spirited driving. How long do you sit and wait for your 7 to warm to operating temps? In the cold of winter? In the middle of summer? Me... no wait at all. Using my timer to run my car and shut off after a set time, when I decide to leave, I just hop in and go, nice and warm in the winter, cool and comfortable in the summer.
HDP is offline  
Old 01-21-07, 02:54 PM
  #63  
HDP
A Fistfull of Dollars!

iTrader: (2)
 
HDP's Avatar
 
Join Date: Nov 2002
Location: HuntsVEGAS, AL
Posts: 5,321
Received 3 Likes on 3 Posts
Originally Posted by jimlab
Someone who doesn't move his car when his neighbors have been cutting down a tree next door could be accused of having narrow vision... among other things...
You stuck in a time warp... or maybe your life in worthy of nothing, so all you have is the past to hold on to.
HDP is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
Kyo
2nd Generation Specific (1986-1992)
6
04-13-19 09:24 AM
smikels
Rtek Forum
4
05-12-16 12:34 AM
pzr2
General Rotary Tech Support
1
08-15-15 08:29 PM



Quick Reply: When to let your turbos idle and cool off.



All times are GMT -5. The time now is 06:40 PM.