Dropping Coolant While Driving

[Philip Adler]

Well I was driving yesterday when the coolant light began to flash, temp hit 200, so I went home and filled the coolant, which was really low. When looking through the fill, there wasn't any coolant all the way down. I put in about 3 quarts [ capacity 2.5 gal.] which was a lot of loss. But There wasn't any leaking. [?] The level stayed steady at the 1/2 min-max mark.

 

Driving today, about 10 miles back and forth, not only did the light come on but the temperature shot up. I pulled into the driveway just as it hit 250. 

No check engine light, no other diagnostic light, just the flashing coolant light.
[meter/check codes?]

 

When I got out of the car, I could hear a loud whine from the trunk. 

Opened it to find that the coolant cap was venting hot coolant steam, and of course the loud and unnerving hissing-whine, from the cap.

After a few moments it stopped. Waited till it all cooled down and slowly and carefully removed the cap. Same issue as above.

No visible coolant in fill. I again put about 2 quarts, level hit between min-max.

No leaks under car, coolant level hold steady.

 

The mix is  1 gal. Porsche coolant [bought though Pelican], and 1 gal. distilled water.
Shaken, not stirred to mix. Let sit. Yes, nice and pink when poured.

The coolant tank is brand new, perhaps has a thousand miles on it. Cap came with the tank. Porsche, not OEM. Put on by a reputable shop which specializes in German cars. I screwed that cap down properly, real tight.

 

No overflow. No leaks.  I'm loosing coolant when driving, only.

Any ideas?

 

Obviously I can't drive it. Next steps is to load it on a flatbed, and drop it off at the shop.

{Poor Boxie} ?

 

Thanks, as always!
 

[wizard]

Are the last 2 digits on the coolant reservoir cap '04'?

 

Do you see any signs of fluid 'splat' around the area of your water pump?

Edited June 29, 2018 by wizard
Additional question

[White987S]

Any coolant under the rear trunk carpet?

[Philip Adler]

Thanks for the quick replies .

The coolant cap does have the 04 digits. It's the black Blau cap, Part 996-1106-447-04-M8 in the Pelican catalog.

As for the water pump, I'll have to take the car apart to answer that.

 

There is no coolant in the trunk. I went through that experience 2 years ago.

Had to replace the reservoir. Still have the bruised knuckles. 

 

Failed to mentioned that after I filled the tank for the first incident above, I ran the engine for 30 minutes, without an issue.

[wizard]

On my 2003 Boxster, it was relatively easy to check out the water pump by removing the panel beneath the carpeting behind the seats. If it appears to be a water pump problem, that then gives you access for serpentine belt removal to check for any play on the pump bearing.

 

Were any/all fans running at full speed at the overheating stage?

[Philip Adler]

Thanks Wizard, I'll get back to you on the water pump. Sorry I can't remember a.about the fans.

Could all this be a air pocket and/or pressure issue. Bleeder or faulty cap?

Sent from my VS987 using Tapatalk

[wizard]

Do you have any history on the car i.e. if the water pump has ever been changed?

 

Provided the car has the correct level of coolant, opening the burp valve whilst idling it shouldn't do any harm. You will, of course, need to monitor the temperature and coolant level. That valve is under the rubber cover and adjacent to the coolant fill cap.

 

As the cap itself is Porsche and '04', it should be OK.

[White987S]

45 minutes ago, Philip Adler said:

Could all this be a air pocket and/or pressure issue. Bleeder or faulty cap?

Sent from my VS987 using Tapatalk
 

I thought about this, but you've driven about 1,000 miles. Hard to believe the car would still have an air pocket after all of that. Your cap sounds good-to-go.

[Philip Adler]

Here's what I did this morning.

I opened the trunk, took off the bleeder cover, added some more coolant to top it to proper measure, and turned on the car.

Ran it, checked the temperature, coolant level, bleeder valve, cap.

After 15 minutes everything OK, checked around and under car for leakage, especially around the overflow tube.

Nothing.

After 30 minutes, I saw the needle just go over 180, at that point turned off the car.

No leakage, boil-over, etc.

 

HOWEVER

 

The fans never went on.

Soooo???

[wizard]

I believe that the engine would need to be hotter than that for the fans to activate.

 

Have you checked to see if there has been any drop in the coolant level after the engine has cooled down again?

 

In my case (water pump), there was no readily visible evidence to suggest a leak other than some coolant loss judged from viewing the level in the reservoir ... and powdery sort of deposits in the vicinity of the water pump.

Edited June 30, 2018 by wizard

[Philip Adler]

Hmmm,

 

I remember that usually the fans come on after 10 minutes of idling, no matter what the temperature is.

There really is no discernable drop in coolant level, nor excess coolant anywhere.

 

I would think that if something so faulty as a water pump or fan issue that the check engine light would come on or some DTC's 

codes would come up. Neither is the case with this.

 

I've been on other forums and of course going through the manuals.

Would a stuck or broken thermostat cause issues like these?

 

If it cools down here I'll start to take the car apart, i.e.  water pump, belt condition, etc.

We're having some 100 +/- days here in PA, so working in the driveway is really unbearable.

 

Thanks for all the help! Much appreciated!

[JFP in PA]

41 minutes ago, Philip Adler said:

Hmmm,

 

I remember that usually the fans come on after 10 minutes of idling, no matter what the temperature is.

There really is no discernable drop in coolant level, nor excess coolant anywhere.

 

I would think that if something so faulty as a water pump or fan issue that the check engine light would come on or some DTC's 

codes would come up. Neither is the case with this.

 

I've been on other forums and of course going through the manuals.

Would a stuck or broken thermostat cause issues like these?

 

If it cools down here I'll start to take the car apart, i.e.  water pump, belt condition, etc.

We're having some 100 +/- days here in PA, so working in the driveway is really unbearable.

 

Thanks for all the help! Much appreciated!

 

If you have access to either a PST II, PIWIS, or Durametric; you can command trigger the fans to make sure they are working correctly.  If you had a stuck thermostat, the car would very quickly overheat.

[White987S]

3 hours ago, JFP in PA said:

 

 If you had a stuck thermostat, the car would very quickly overheat.

Only if it were stuck closed.

[JFP in PA]

3 hours ago, White987S said:

Only if it were stuck closed.

 

They only very rarely fail open, failing closed is the most common mode.