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more lack of heat discussion...


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As Loren had pointed out Durametric upgraded their software recently which gave me the ability to see real time values for the automatic AC system. (their software rocks and is well worth the money http://www.durametric.com/)

I have had lack of heat (warm at best) from the system and that is ONLY when I turn the auto/AC (snowflake) off. Additionally I run at 180-190F so I ruled out thermostat, plus the coolant level is correct.

So as was proposed it could be the air mix flap, a failure trend. The Duremtric software shows the full range of motion I would expect for the Mix Flap. 99% for on HI and 1% on LOW an a constant mix in the middle when that temp is selected. Additionally the footwell/defrost flap and central air flap all appear to be working correcty. As far as I can tell the entire automated system is working correctly. No error codes

So today in Ohio it as 32-38F and w/o the wonderful seat heater it would have been a bit cold. I noted on the way home that after a 5-7 minute 25-45mph ride the engine was still on 100-120F and it would be about 10 minutes on the freeway before it got to 180F, so a total of 15-20 minutes before 180F coolant temp was reached. After 30 minutes (I'm home!) I was at 185-190F. After idling in the garage for 15 minutes while I run the software it did finally start to get warmer in the car (which the values show a ECTS of 91C (195F), but again with the AC/Auto off. I did hear the coolant fan cycle, so I know that ECTS temp should be accurate.

So is that rather slow warm up temps on the road in this weather with the 2.5L?

Could I be battling a bad thermostat?

That is the usual issue in the average world of cars but again 180F usually means enough coolant temp for internal heat!

Any other ideas?

Lastly what is ECTS (what does it stand for) listed in the AC Actual Values list, it showed a temp of 91C , best I can tell that is the coolant temp of the system which would be 195.8F

Examples of Durametric output attached:

post-13335-1161641693_thumb.jpgpost-13335-1161641678_thumb.jpgpost-13335-1161641667_thumb.jpg

Edited by rsfeller
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ECTS -- Engine Coolant Temperature Sensor

So, you are correct that is the coolant temperature.

Can you compare the actual values when it is not working to when it is?

(or is that what you did above?)

I guess you could verify the sensors by using a thermometer to check outside temp and inside temp and see if they are close to actual.

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Hi Loren. We'll tonight was the first night ever that it "almost" felt hot (acceptable), but that would have been from idling in the open garage for 15+ minutes!

I do have a thermal sensor gun that I will check in detail tomorrow to compare to the actuals as you state. Since I don't think quick "on the fly" with celcius I really didn't digest all the temperature values while outside. Since I'm now inside and converted them to fahrenheit I do see a couple of odd (to me), things:

1. Inside Temp 31C (87.8F) with windows rolled down in 50F outside temp while ACC was at 82-84F

2. Outlet Temp 49C (120.2F) also seems high, but I don' t know where the outlet sensor is to consider its reading. A thermal will NOT get a similar reading at the vent.

When the ACC is set by me to 84F the mix flap is at 99% as expected yet the INSIDE TEMP claims 87.8F which should move the mix flap somewhere between 1-75% to start lowering the temp. I do note if I set the ACC to 74F then yes the mix does go to 20-30%.

A couple of questions:

  • What is the OUTSIDE TEMPERATURE (A/C REGULATOR) all about? I'm guessing this is a engine area temp sensor maybe on the compessor? And how this varible figure into the system?
  • What do you think of my thermostat theory? Are the 2.5L in fact this cold blooded?

I note my Saab V6 (3.0L) is warm in 4-5 minutes and putting out considerable heat in 5-7minutes after leaving home. It's also up to drive temp in that time period. I understand the Boxster has longer runs to the radiator but even my Vanagon (nothing has longer runs then a Vw Vanagon!) was warm in 5-7 minutes!

The thermostat should be cheap so I should order it and take that posiblity out of my head. I've got a pit at work and it looks easy to do on the Boxster.

EDIT UPDATE:

OK, I couldn't stand the wait so I went back out and got the car warmed up. I waited for the fan to kick in and then took some "real readings" and compared them to Durametrics ACTUAL VALUES.

At this time it appears I have heat. Either:

1. The software reset something and now the mix flap works (doubt that's it)

2. The thermostat is stuck open and I an only get heat while at idle. Motion causes the stuck open thermostat to keep the coolant temp to low while in motion as the radiator does its job to the open system. Tomorrow I'm going to take the laptop on the road and drive to work. I'll pull over quickly 1/2 way and check the ECTS temp to see how cool I really am (or not) at 60mph speeds.

Why do I think it may be the thermostat even knowing the dash gauge temp seems ok?

at 195.8F ECTS (coolant temp) I show the following computer values:

95F inside temp

125.6F outlet temp

while my thermal gun shows temps up to 138.5F inside the center vent, 128F at the drivers side vent and a old school chef's thermometer stuck in the vent shows 110F. I would guess those temps are acceptable enough to see the heat is working (at the moment).

To get comparison I went and fired up the Saab and ran to the video store. After that run and 5 minutes of idle in the drive I took the following readings at the center vent:

Highest temp inside vent with thermal-gun was 124F

Highest temp at dash around event was 98F

Outside temp 34F

Chef's thermometer in vent 110F

therefor these temps after a sustained warm up period are not even as high as some of the porsche valus!

Lastly, my Dad is laughing at me. I told him on the phone tonight my project with this. He thinks its funny with all my electronic gimzos on the car and my software I'm over looking what was obviously a bad thermostat to him! He drives a 1986 Chevy truck with a 305 V8!

Edited by rsfeller
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Lastly, my Dad is laughing at me. I told him on the phone tonight my project with this. He thinks its funny with all my electronic gimzos on the car and my software I'm over looking what was obviously a bad thermostat to him! He drives a 1986 Chevy truck with a 305 V8!

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Don't laugh when your dad is right.

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Lastly, my Dad is laughing at me. I told him on the phone tonight my project with this. He thinks its funny with all my electronic gimzos on the car and my software I'm over looking what was obviously a bad thermostat to him! He drives a 1986 Chevy truck with a 305 V8!

[/b][/color]

Don't laugh when your dad is right.

Hopefully he is correct! That would be the cheap and easy route for sure!

Again he agrees that a temp gauge showing full temp is not normal (usually a they are noticably low) for a failed thermostat and many people on this board and others have suggested the often failed mix flap!

We'll see...

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