engine running hot but not overheating - thermostat? - Rennlist Discussion Forums
Rennlist Discussion Forums   classifieds | membership | rennlist | photo album    
sponsors | upload photo | chat    
 

Go Back   Rennlist Discussion Forums > Water Cooled Technical Discussion Areas > 924/931/944/951/968 Forum
Log In 
Search


engine running hot but not overheating - thermostat?

Reply
 
Thread Tools Search this Thread
Old 09-24-2008, 11:12 PM   #1
knfeparty
Addict
Rennlist Member
 
knfeparty's Avatar
 
Join Date: Sep 2006
Location: Jacksonville, FL Duval County
Posts: 3,354
UHAD2POINT
Default engine running hot but not overheating - thermostat?

My engine runs hot when I drive it hard. By hard I mean blasting down a back road through 3rd and a bit into 4th but nothing like 100mph or anything. As you drive more legally, however, the temp comes down. Pull up to a stoplight or let it sit still and idle and the fans will never cut off and the car can't cool itself off. It won't overheat, it just won't get any cooler. Stepping on the gas to raise the idle speed will make the gauge go down a bit but then it immediately goes back up when you let off.

The car has a new (rebuilt) waterpump about 14k miles ago, has had 2 thermostats since then, a new radiator, new hoses, and a new expansion tank.

I'm thinking thermostat failure or blockage. When I installed the new expansion tank, I made the mistake of not being able to get it all the way clean. It was a clear tank but I could never get all of some gunk out of it (it was from a wrecked car and the gunk might have been oil or something now that I think about it )

So the expansion tank is a bit filmy looking, but if you look at the coolant itself it's pretty clean.

Paging marky522....ready to do another thermostat?
__________________
GT Silver 2004 911 40th Jahre edition PCM2, heated memory comfort seats, 030, 220, x51 Power Package, IMS bearing upgrade
Titanium Silver 2004 Cayenne Turbo w/ sport technos and CF interior trim
Past (and sorely missed!): E Stock Alpine White on Blue 1989 944 NA 2.7L 8v. Options: 030 (Sport Chassis) 220 (LSD), short 5th, driver sport seat cloth. Sold to JohnTorg 03/2010.
knfeparty is offline   Reply With Quote
Old 09-25-2008, 08:22 AM   #2
dillon410021
Addict
Rennlist Member
 
dillon410021's Avatar
 
Join Date: Dec 2007
Location: Valparaiso, Indiana (46385)
Posts: 3,769
Default

mine does that
__________________
Dillon
06 Lancer Evo 9 MR, intake, exhaust, tune @23psi, 310awhp.
86 944 Turbo-Sold 9-20-13
86 944 Turbo-"The Garage Queen" Autothority chips/ MAF, SMT-6, SFR full 3" SS exhaust, SFR stage I turbo, wastegate dump, TR Motorsport F2 wheels, momo mod 7 steering wheel, bilstein turbo cup rear coilovers, adj koni coilovers up front.
88 944 Turbo Sold 11-1-13, gonna miss it.
,
dillon410021 is offline   Reply With Quote
Old 09-25-2008, 08:27 AM   #3
theedge
Addict
Rennlist Member
 
theedge's Avatar
 
Join Date: Aug 2003
Location: Canada, Eh?
Posts: 14,222
Send a message via MSN to theedge
Default

How high on the gauge does it get?

Before you do another thermostat, bleed it again. Park facing uphill to do it if you can. Could be air in your cooling system.
__________________
Brian - Winner of "Best Bent Rod"
Smokey - 1986 951 That is being rebuilt again.... Even betterer....
Breadbox - 1993 VW Passat

"I got kicked out of Barnes and Noble for moving all the Bibles to the Fiction section."
"The first 50% of the project takes 90% of the time... The rest of the project takes the other 90% of the time."
"Remember, if you can't fix it with a hammer, you've got an electrical problem."
theedge is online now   Reply With Quote
Old 09-25-2008, 08:29 AM   #4
knfeparty
Addict
Rennlist Member
 
knfeparty's Avatar
 
Join Date: Sep 2006
Location: Jacksonville, FL Duval County
Posts: 3,354
UHAD2POINT
Default

It never gets over the upper white mark, which technically is "acceptable" depending on how much you trust the owner's manual. I figured air, too, especially because I have a very slight heater core leak (although the HCV has been closed for a long time now). Also it was being a bit jumpy. As I am the master of coolant system bleeding from when I used to have a radiator leak, I did that already and it helped stabilize the problem but it still heats up.
It's mainly the fact that it can't cool itself down by idling that worries me. 20 minutes after I had run it hard it was still pretty hot.
__________________
GT Silver 2004 911 40th Jahre edition PCM2, heated memory comfort seats, 030, 220, x51 Power Package, IMS bearing upgrade
Titanium Silver 2004 Cayenne Turbo w/ sport technos and CF interior trim
Past (and sorely missed!): E Stock Alpine White on Blue 1989 944 NA 2.7L 8v. Options: 030 (Sport Chassis) 220 (LSD), short 5th, driver sport seat cloth. Sold to JohnTorg 03/2010.
knfeparty is offline   Reply With Quote
Old 09-25-2008, 08:37 AM   #5
roman944
Super User
 
roman944's Avatar
 
Join Date: Oct 2007
Location: Rochester, NY
Posts: 2,377
Default

with fans on, right now, mine gets between 1/2 and 3/4

never past that

and I am happy

still going to do a full tune up on it this winter though
roman944 is offline   Reply With Quote
Old 09-25-2008, 11:54 AM   #6
hardtail15
Addict
Rennlist Member
 
hardtail15's Avatar
 
Join Date: Oct 2007
Location: Pennsylvania
Posts: 352
Send a message via AIM to hardtail15
Default

mine does this also
__________________
-Chad


1986 Blue El Camino - 383 stroker
1985.5 Black Porsche 944 - stock
2003 Chili Red MINI Cooper S - Totaled
2003 Silver Saturn ION - DD
hardtail15 is offline   Reply With Quote
Old 09-25-2008, 02:11 PM   #7
flashgordon
User
 
Join Date: Jan 2007
Location: Washington, NJ
Posts: 209
Default

I had the same issue with my car and fixed the problem by cleaning the grounds. The thing that got me thinking was the gauge moving up and down when I stepped off and on the gas. The grounds on the bellhousing by the back of the engine were dirty and once they were clean the temp gauge operated right and the crazy temp swings were gone.
flashgordon is offline   Reply With Quote
Old 09-25-2008, 02:44 PM   #8
knfeparty
Addict
Rennlist Member
 
knfeparty's Avatar
 
Join Date: Sep 2006
Location: Jacksonville, FL Duval County
Posts: 3,354
UHAD2POINT
Default

definitely will give that a try. the headlights affect the gauge right now
__________________
GT Silver 2004 911 40th Jahre edition PCM2, heated memory comfort seats, 030, 220, x51 Power Package, IMS bearing upgrade
Titanium Silver 2004 Cayenne Turbo w/ sport technos and CF interior trim
Past (and sorely missed!): E Stock Alpine White on Blue 1989 944 NA 2.7L 8v. Options: 030 (Sport Chassis) 220 (LSD), short 5th, driver sport seat cloth. Sold to JohnTorg 03/2010.
knfeparty is offline   Reply With Quote
Old 09-25-2008, 02:49 PM   #9
Z-man
Super User
 
Z-man's Avatar
 
Join Date: Jan 2002
Location: North NJ, USA
Posts: 10,166
Default

On the track, my 944S2 will climb up to just under the red hash mark. Do audible signs of air in the system, but I suspect a bleeding of my system may help. I have used water wetter but it doesn't help a whole lot.

What has helped was running with the defrost on. Brings the temps down immediately. But it sure gets hot in the passenger area!

My h2o pump is fairly new, as is the thermostat and other related stuff...

-Z-man.
Z-man is offline   Reply With Quote
Old 09-25-2008, 03:58 PM   #10
knfeparty
Addict
Rennlist Member
 
knfeparty's Avatar
 
Join Date: Sep 2006
Location: Jacksonville, FL Duval County
Posts: 3,354
UHAD2POINT
Default

I dont run the heat because it puts air in the system due to the heater core leak. i will go clean some grounds and go from there
knfeparty is offline   Reply With Quote
Old 09-25-2008, 03:58 PM
Rennlist



Paid Advertisement
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Draining coolant with Mityvac Plus? Mark-87-951 944 Turbo and Turbo-S Forum 8 02-21-2010 10:28 PM
928 Overheating ! kassim 928 Forum 19 11-15-2009 03:38 AM
Coolant leaking? Could be your coolant expansion tank... Dan@SharkWerks 996 Forum 10 05-23-2009 08:55 AM
Oil Change Procedure DIY wsybert 964 Forum 13 04-02-2007 09:19 PM
Air lock after thermostat install?? Jeff928S4 928 Forum 29 01-19-2006 07:16 PM


Tags
03, 27, 944, car, engine, failure, heating, hot, overheating, passat, red, running, termosthat, thermostat, thermoste

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

 

All times are GMT -3. The time now is 06:26 PM.


Powered by vBulletin® Version 3.8.7 AC2
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Copyright ę 1998 - 2007 Rennlist.com