Go Back  Rennlist - Porsche Discussion Forums > Water Cooled Technical Discussion Areas > 996 Forum
Reload this Page >

Technical Question - Blinking overheat light when temperature is normal

Notices
996 Forum
Sponsored by:
Sponsored by: LN Engineering

Technical Question - Blinking overheat light when temperature is normal

 
Old 07-11-2007, 12:53 AM
  #1  
dimnslow
User
Thread Starter
 
dimnslow's Avatar
 
Join Date: Sep 2006
Location: San Francisco, Ca
Posts: 75
Likes: 0
Received 0 Likes on 0 Posts
Default Technical Question - Blinking overheat light when temperature is normal

So I have this problem I am hoping some had before or knows the solution to. This has happened to me twice so far.

Sometimes when I drive my car the red light on the 'hot' end of the temperature gauge (right side) start blinking even though the needle on the temperature gauge shows that the car's internal coolent temperature is only around 190 degrees or so, which based on the meter is the middle 3rd of the temperature gauge - well within normal.

When I park the car and get out the fan in front sounds like it's on full blast.

I can't figure out what the problem is... any suggestions? Thanks!
dimnslow is offline  
Old 07-11-2007, 12:54 AM
  #2  
RobynC
Addict
Rennlist Member
 
RobynC's Avatar
 
Join Date: Nov 2002
Location: Manteca, Calif.
Posts: 506
Likes: 0
Received 0 Likes on 0 Posts
Default

low coolant
RobynC is offline  
Old 07-11-2007, 12:56 AM
  #3  
dimnslow
User
Thread Starter
 
dimnslow's Avatar
 
Join Date: Sep 2006
Location: San Francisco, Ca
Posts: 75
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks Robyn C - so there's no gauge or light that comes on to say low coolant, just the blinking lights? What type of coolant should I buy?
dimnslow is offline  
Old 07-11-2007, 12:57 AM
  #4  
redridge
Super User
 
redridge's Avatar
 
Join Date: Oct 2006
Posts: 7,259
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by RobynC
low coolant
+1
redridge is offline  
Old 07-11-2007, 01:46 AM
  #5  
RobynC
Addict
Rennlist Member
 
RobynC's Avatar
 
Join Date: Nov 2002
Location: Manteca, Calif.
Posts: 506
Likes: 0
Received 0 Likes on 0 Posts
Default

Porsche has it's own coolant...so you could pop by a dealer and pick some up.

I have heard Pentosin...but I don't know much about it.
RobynC is offline  
Old 07-11-2007, 02:06 AM
  #6  
BlackCab996
User
 
BlackCab996's Avatar
 
Join Date: Oct 2005
Location: San Marino, CA
Posts: 718
Likes: 0
Received 0 Likes on 0 Posts
Default

Beware - you could have a leak or you could potentially have oil + coolant intermix - this is what my car did and led and looking into the cause helped me to discover my needing a new engine. Check your oil and pray that you see normal looking oil. If it is foamy and frothy, sit dow and take a deep breath. Then get the car to a garage pronto.
BlackCab996 is offline  
Old 07-14-2007, 12:56 AM
  #7  
bzalforno
User
 
Join Date: Aug 2006
Location: Deep River, CT
Posts: 47
Likes: 0
Received 0 Likes on 0 Posts
Default

low coolant. just had the same thing, had a leaking overflow tank. unfortunately over$ 300 for the tank. but it solved the problem.
you could also check your coolant level regularly while the engine is cool, in unpressurized mode and keep a gallon of coolant in the trunk. much cheaper, but temporary fix.
bob
bzalforno is offline  
Old 07-14-2007, 06:24 PM
  #8  
michael.s.under
Addict
Rennlist Member
 
michael.s.under's Avatar
 
Join Date: Jan 2007
Location: Peoria, AZ
Posts: 1,258
Likes: 0
Received 0 Likes on 0 Posts
Default

There are many threads on this, it can be low coolant ore hight temps in the engine compartment as well. Unless you do a coolant system flush only use porsche coolant as an additive. BTW there is also a fan mod to automatically run your fans at will. 996s fans come on late in the game, especially if you live in a high temperature climate.
michael.s.under is offline  
Old 07-14-2007, 08:06 PM
  #9  
ScottArizona
Addict
Rennlist Member
 
ScottArizona's Avatar
 
Join Date: Jan 2007
Location: Phoenix-area, Arizona
Posts: 1,098
Likes: 0
Received 0 Likes on 0 Posts
Default

I have also had this problem, even though the coolant temperature was not too hot, and not other coolant leaks. My mechanic advised to check the engine compartment sensor located on the passenger side, top of the engine, between the first and second intake manifold ducts. It can slip out of its gromet, causing it to actually rest on the engine, which will cause the computer to think engine compartment temps are too high. good luck.
ScottArizona is offline  
Old 04-03-2019, 01:58 PM
  #10  
aeichmiller
User
 
aeichmiller's Avatar
 
Join Date: Aug 2016
Location: MD
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
Default

Bringing back a very old thread from the dead. On hot days I sometimes get the slow blinking light. Coolant is at the correct level, and I do not see any signs of leaks around the expansion tank or cap. So that means it is the engine compartment blower fan not coming on. Which makes sense, because I can't recall ever hearing it run in the 3 years I have owned the car.

What is the fix for this? Is there a relay that is bad? Does the entire blower need to be replaced? Could the temp sensor be the culprit? Most of my research around the temp sensor says that it usually falls onto the engine and reads too hot and fan runs too often. I seem to have the opposite problem.

BTW car is a 99 C2 coupe.

Thanks in advance for the help,
Alex
aeichmiller is offline  
Old 04-03-2019, 02:15 PM
  #11  
808Bill
Super User
 
808Bill's Avatar
 
Join Date: Dec 2016
Location: Kauai
Posts: 4,780
Received 16 Likes on 9 Posts
Default

Originally Posted by aeichmiller View Post
Bringing back a very old thread from the dead. On hot days I sometimes get the slow blinking light. Coolant is at the correct level, and I do not see any signs of leaks around the expansion tank or cap. So that means it is the engine compartment blower fan not coming on. Which makes sense, because I can't recall ever hearing it run in the 3 years I have owned the car.

What is the fix for this? Is there a relay that is bad? Does the entire blower need to be replaced? Could the temp sensor be the culprit? Most of my research around the temp sensor says that it usually falls onto the engine and reads too hot and fan runs too often. I seem to have the opposite problem.

BTW car is a 99 C2 coupe.

Thanks in advance for the help,
Alex
Check your fuses/relays for the fan. I hear mine click on after I park the car.
808Bill is offline  
Old 04-03-2019, 03:41 PM
  #12  
DBJoe996
Addict
Rennlist Member
 
DBJoe996's Avatar
 
Join Date: Apr 2010
Location: Ormond Beach, FL
Posts: 3,373
Likes: 0
Received 3 Likes on 1 Post
Default

The coolant gauge light blinks for different things. I will look it up and post.
DBJoe996 is offline  
Old 04-03-2019, 03:45 PM
  #13  
DBJoe996
Addict
Rennlist Member
 
DBJoe996's Avatar
 
Join Date: Apr 2010
Location: Ormond Beach, FL
Posts: 3,373
Likes: 0
Received 3 Likes on 1 Post
Default

Four functions of the coolant warning light:
1. Engine coolant level too low; light flashes slowly (0.5 Hz)
2. Engine compartment temperature too high; light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)
3. Engine coolant temperature too high; light is lit; pointer on the right
4. Temperature sensor at water outlet faulty; light flashes rapidly (1 Hz); pointer on the right
Note
The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously
(1Hz = 1 flash per second. 0.5Hz = 2 seconds per flash).
DBJoe996 is offline  
Old 04-03-2019, 03:45 PM
  #14  
aeichmiller
User
 
aeichmiller's Avatar
 
Join Date: Aug 2016
Location: MD
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by DBJoe996 View Post
The coolant gauge light blinks for different things. I will look it up and post.
Correct. Slow blinking is attributed to either low coolant or engine compartment temp too high. Fast blinking is temp sensor at water outlet faulty and the light constant on is the coolant temp too high.

Mine is showing the slow blinking that seems to be more frequently attributed to low coolant level or a leaking expansion tank. I have ruled both of those out so I believe the issue is with the engine compartment temp. I don't recall ever hearing that fan run so I am looking to figure out the next steps.
aeichmiller is offline  
Old 04-03-2019, 09:44 PM
  #15  
aeichmiller
User
 
aeichmiller's Avatar
 
Join Date: Aug 2016
Location: MD
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by 808Bill View Post
Check your fuses/relays for the fan. I hear mine click on after I park the car.
Checked the fuses and they are fine. I didn't see a relay on the fuse box diagram. Is there one somewhere other than the fusebox?
aeichmiller is offline  

Thread Tools
Search this Thread
Quick Reply: Technical Question - Blinking overheat light when temperature is normal


Contact Us - About Us - 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.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: