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1999 986 Coolant Vacuum Problem Uview Airlift 550000 HELP
Hello everyone!
New to the Rennlist membership as this is my first post but I've been lurking from the outside for sometime and know its a great source for fellow Porsche enthusiasts!
Anyways, I'm having a problem drawing a vacuum on my coolant system on my 1999 Porsche 986 Boxster Base 2.5L.
I've confirmed there are no air leaks and the system is airtight. I cant seem to get the vacuum to go over 17-18 on the Uview Airlift 550000.
All of the coolant is drained to make sure I get a proper fill on the system, I've went underneath and removed the plug, and 3 coolant hoses near the plug and leveled the car to make sure it is all out.
Please if anyone could chime in and help me with this Id be forever grateful, this has been a headache Ive been working on for literally days.. And I'm just about at my throwing the wrenches point...
Here is a link to the video i made concerning this problem.
Hard to tell what adapter you are using on the valve body. Looks like you verified that there are no leaks in the system. I just filled my ‘02 base yesterday using the airlift system with no issues.
Here is a picture of the adapter I used -
You need to screw the valve body down pretty good within the coolant tank opening to make a good seal.
Thanks for the welcome!
I tried using the plug adapter along with the cone adapter with the same results. In the video I just used the cone adapter for the sake of time.
I only wish I had the same outcome as you..
Hard to tell what adapter you are using on the valve body. Looks like you verified that there are no leaks in the system. I just filled my ‘02 base yesterday using the airlift system with no issues.
Here is a picture of the adapter I used -
You need to screw the valve body down pretty good within the coolant tank opening to make a good seal.
Sorry I don't know if the post needs to be quoted in order for you to see my reply, but I replied to your comment with my previous post!
You sure about no leaks? It is not unknown for a coolant tank to have a split along its bottom seam that can retain fluid and up to a point pressure tight but under enough pressure or in this case vacuum leak.
Do you have a reliable source of oil free/water free shop air at 90psi and enough volume to work the Airlift system?
After I posted I watched the video. Guess you got shop air handled.
Still could be a coolant tank split leak. My Boxster tank leaked but only when I shut off the engine with the coolant hot enough to cause the radiator fans to run. After things cooled down I was able to refill the cooling system with distilled water and start the engine and drive the car a couple of miles to the dealer with no coolant leaking.
My point is the leak self seals when pressure/vacuum drops/rises below/above a certain threshold.
One thing you can do is try to rig up another vacuum gauge and confirm the lift system gauge is accurate.
A sign the gauge may not be accurate is do the hoses collapse?
After I posted I watched the video. Guess you got shop air handled.
Still could be a coolant tank split leak. My Boxster tank leaked but only when I shut off the engine with the coolant hot enough to cause the radiator fans to run. After things cooled down I was able to refill the cooling system with distilled water and start the engine and drive the car a couple of miles to the dealer with no coolant leaking.
My point is the leak self seals when pressure/vacuum drops/rises below/above a certain threshold.
One thing you can do is try to rig up another vacuum gauge and confirm the lift system gauge is accurate.
A sign the gauge may not be accurate is do the hoses collapse?
First off thank you, I am very grateful for all your valid points received.
I failed to mention that the Airlift system I have is used and I got it off ebay for around $60, and the gauge top plastic protective window is missing, so I can physically touch the gauge needle.
I did stop at my local TSC to see if I could find a vacuum gauge to test this theory but they did not have any, only in PSI.
And yes, the hoses are collapsing under the vacuum.
The other valid point you made is a leak at the above stated vacuum, I thought of this problem also, that its only leaking when it gets to a certain pressure and or vacuum.
I have not noticed any coolant leaking during normal driving conditions, before the airlift I simply did the rev & add method once I changed my water pump & T-stat.
My T-stat is a 160 degree and when I ran it, it would always sit in the 190 range which worried me that the system was not fully filled.
Is there any method that you'd recommend on finding the leak at this vacuum pressure if this is the case?
Again, thanks a million for your input on this.
I'm about to the point of posting a reward for anyone figuring out the solution to this haha.
After I posted I watched the video. Guess you got shop air handled.
Still could be a coolant tank split leak. My Boxster tank leaked but only when I shut off the engine with the coolant hot enough to cause the radiator fans to run. After things cooled down I was able to refill the cooling system with distilled water and start the engine and drive the car a couple of miles to the dealer with no coolant leaking.
My point is the leak self seals when pressure/vacuum drops/rises below/above a certain threshold.
One thing you can do is try to rig up another vacuum gauge and confirm the lift system gauge is accurate.
A sign the gauge may not be accurate is do the hoses collapse?
Update from my last post I sent you,
I vacuumed the system again just for s**ts and giggles and went inside to grab a bite to eat after I disconnected the shop air and closed the valve.
I came back about 20mins later and the pressure/vacuum dropped from 18-17 to near 7-6 vacuum.
Now this is a sure sign there is a leak somewhere correct? Or is it normal in that time frame for it to drop like this?
Hopefully Im onto something here!
Thanks again for all the help!
The “Airlift” instructions only require the system to hold vacuum for 20 seconds. I’ve let it sit for up to 5 min. and the system still held vacuum. It appears that since the glass is missing off of the top of the unit it was mishandled at some point in the past and is not providing accurate readings.
FWIW - my ‘02 base with a 160 degree t-stat installed will rise to between the 8 and the 0 of the 180 degree mark (approx. 190 degrees) in certain conditions, ie. city driving or stop and go hwy driving. My ‘04 “S” never goes above 180.
Thanks for the welcome!
I tried using the plug adapter along with the cone adapter with the same results. In the video I just used the cone adapter for the sake of time.
I only wish I had the same outcome as you..
Unless the coolant tank openings on the ‘98’s are a different size than the ‘02’s you don’t even need the cone adapter.
Here is a picture of the airlift assy. on my coolant tank. Notice how the knurl **** is screwed down a good bit. This ensures a good seal.
The “Airlift” instructions only require the system to hold vacuum for 20 seconds. I’ve let it sit for up to 5 min. and the system still held vacuum. It appears that since the glass is missing off of the top of the unit it was mishandled at some point in the past and is not providing accurate readings.
FWIW - my ‘02 base with a 160 degree t-stat installed will rise to between the 8 and the 0 of the 180 degree mark (approx. 190 degrees) in certain conditions, ie. city driving or stop and go hwy driving. My ‘04 “S” never goes above 180.
Thanks again for your input, and honestly it may be the life saving input I needed.
The highest it has ever gone would be between the 8 & the 0, almost exactly vertical if you will.
I believe the needle assembly/correctness may be off on the gauge so i ordered a new vacuum gauge on eBay literally seconds ago to test if it is bad. (I tried to pick one up around here but I live in BFE)
I was under the impression that a 160 T-stat would stay at exactly 160 degrees.
Now Im contemplating if the system was filled fully all along and the gauge itself has caused me literally weeks of headache..
I believe our tank housings are the same, I just used the cone so I could press down to ensure it was sealing.
I was just worried that when the water pump went out that something along the coolant system went bad because it just about got to the red zone with heat.(never fully reached red)
Nevertheless thank you so much for all of your time and effort spent helping me with this, i believe I may be close to the solution!
Cheers!
I was under the impression that a 160 T-stat would stay at exactly 160 degrees.
Incorrect. I, too, installed the 160 thermo, but only so that the thermo would open at 160 provisioning that water/coolant to delicate parts sooner than that of the ~180/whatever thermo. The engine still has to rise to operating temperature... with is that mark between the 8/0.
The 160 thermo doesn't limit how hot the coolant temp gets... but allows it to begin circulating around the engine... sooner.
Well here is the verdict, after SC-986 suggested that the gauge may not be reading correctly I went ahead and bought a cheap-o $6 vacuum gauge off eBay.
And to my absolute surprise the vacuum went straight up to 25 inHG with absolutely no problems!
This thrills me to no end because:
1) I dont have to replace the expansion tank like I intended to
2) I dont have to worry every time I take my car out that the coolant is not filled all the way
3) The complete headache of not knowing where the problem lies
So I'd like to thank everyone personally that was involved and helped me with this.
-SC-986
-Starter986
-Macster
Thank you all very much, being my first thread Ive learned Rennlist is a wonderful place for Porsche owners and knowledge alike.
Thanks again everyone.
Happy driving!
Well here is the verdict, after SC-986 suggested that the gauge may not be reading correctly I went ahead and bought a cheap-o $6 vacuum gauge off eBay.
And to my absolute surprise the vacuum went straight up to 25 inHG with absolutely no problems!
This thrills me to no end because:
1) I dont have to replace the expansion tank like I intended to
2) I dont have to worry every time I take my car out that the coolant is not filled all the way
3) The complete headache of not knowing where the problem lies
So I'd like to thank everyone personally that was involved and helped me with this.
-SC-986
-Starter986
-Macster
Thank you all very much, being my first thread Ive learned Rennlist is a wonderful place for Porsche owners and knowledge alike.
Thanks again everyone.
Happy driving!
Case CLOSED!
Awesome! Always nice to find out it's something relatively simple. Cheers!
One potential vacuum leak source is the coolant bleeder valve aka burp valve. Make sure the bail is not in the up. position. This valve is sometimes used to burp the system when vacuum equipment is not available.
02-12-2019, 05:33 PM
1999 986 Coolant Vacuum Problem Uview Airlift 550000 HELP
