11 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHIs Coolant Ever Too Cool?
Leading reported evidence
Adjust timing and fuel
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
The effect of running too cool, will mean the ECU will adjust timing and fuel to match the fuel and ignition mix that Porsche mapped into the CPU.
Leading evidence: 'Adjust timing and fuel' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'gauge, sender, sensor, etc' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Adjust timing and fuel' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suspected cause
If it is in the normal range then maybe suspect the gauge, sender, sensor, etc.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suspected cause
If the coolant is actually too cool, then suspect the thermostat, as that is really the only thing it could be - maybe the cooling fans stuck on high all the time and not turning off - I guess that could be another possibility ...
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Shoot it at your engine cooling hoses or at the thermostat housing, or at a radiator and check the actual temp reading.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
For sure, flush the coolant, make sure your water pump is relatively new, check your rubber and plastic cooling parts, clean your radiators, etc in prep for the summer months
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
For sure, flush the coolant, make sure your water pump is relatively new, check your rubber and plastic cooling parts, clean your radiators, etc in prep for the summer months
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
For sure, flush the coolant, make sure your water pump is relatively new, check your rubber and plastic cooling parts, clean your radiators, etc in prep for the summer months
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suspected cause
If the coolant is actually too cool, then suspect the thermostat, as that is really the only thing it could be - maybe the cooling fans stuck on high all the time and not turning off - I guess that could be another possibility ...
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
I don't know why but I tried a lot of things before throwing a new one in, and that solved it.
On longer drives this winter, I've noticed that my coolant temp
drops
to have the needle in-line with the "1" of the "180" mark. In normal around-town driving, it's typically right between the 8 and the 0. Stop-and-go traffic in the heat of the summer it will go a little bit past the zero. My commute this winter is about 90 minutes on wide-open highway at (outdoor air) temperatures of 20 - 40 degrees.
I've noticed that the car warms up as usual to just above the "8", but then after some time on the highway, it drifts down to be in-line with the "1". Once I get to my destination and have a mile or two of in-town driving, it bounces back to 180.
I did replace the heater core and the foam on the door in October, but otherwise haven't done anything that I think could have impacted this.
But ultimately...is this a feature or a bug? Sign of a sticky thermostat? Something else?
Car is a 2004 cab with 130,000 miles.
Probably fine.
Every vehicle I've ever owned and gotten to know well, has run cooler in sub freezing temps. The colder it is out side the cooler engine runs, to a point.
The oem t-stat opens at 180� so temps should not get much lower than the 1 in the 180. Exception, if you're in <10� temps then even with t-stat partially closed its so cold out the engine will run cold. Thats more or less normal...
Hows the heat work..?
Whats more important is your oil temps. What is your oil temps.?
If t-stat was stuck open the temp gauge probably would stay close to the bottom in very cold weather....
These cars are designed for the Autobahn. 10+ qts of oil (I have the UAOS-Track) and copious radiator area works really well. I have only driven 90 mph for a couple hours continuously in the summer at temps at or above 90F and she runs cool. I installed
@Coopduc
's oil temp gauge and find that I need to lower the spoiler to get the oil temp above 180F.
I have driven the Autobahn, but not in my 996. Montana and the Redenso are a worthy substitute. Montana does a fantastic job with their road construction in the NW region.
@tnj100
, the 996 is a car that in general really doesnt have any major cooling/overheating problems on the street.
But its a 25 year old platform and sensors/parts start to get old and need to be refreshed. Best advice I can give is to find
@Coopduc
thread on his digital oil temp gauge and get one. Its extremely affordable and it will give you another temp indicator to compare that is imho more useful than the water temp gauge.
For sure, flush the coolant, make sure your water pump is relatively new, check your rubber and plastic cooling parts, clean your radiators, etc in prep for the summer months
This sounds normal. When you drive at highway speeds there is enough air flow through the radiators to keep the engine cool and the thermostat is regulating the coolant temperature. When you stop at a light or sit is slow traffic there is not enough air flow through the radiators and temperature will rise unitl the cooling fans come on. Then the temp will cycle between the fan-on temp and the fan-off temp until you get back to higher road speeds.
If it running too cool, or failing to warm up, etc. then it pretty much has to be a thermostat stuck open, or perhaps some sort of sensor signal malfunction, imho.
There is no other way the engine can run too cool - the thermostat is the device that allows coolant to circulate or not.
The effect of running too cool, will mean the ECU will adjust timing and fuel to match the fuel and ignition mix that Porsche mapped into the CPU.
So, if the "choke is on (electronically)" then you will see worse mileage and less performance than you might at the designed warm operating temperature.
An easy test is to grab an infrared temperature gun, the kind that shoots a red dot at whatever you want to measure. Shoot it at your engine cooling hoses or at the thermostat housing, or at a radiator and check the actual temp reading.
If it is in the normal range then maybe suspect the gauge, sender, sensor, etc. if the gauge reads low. If the coolant is actually too cool, then suspect the thermostat, as that is really the only thing it could be - maybe the cooling fans stuck on high all the time and not turning off - I guess that could be another possibility ...
Good luck! Should be straightforward
Just following up on this...it was indeed the thermostat being stuck most of the way open. I don't know why but I tried a lot of things before throwing a new one in, and that solved it.
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