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Late 2004 Boxster Base Tiptronic with 45,000 miles
I have racked up 15,000 miles over the last 3 years of ownership. The coolant was flushed about a year prior to purchase. I think it's time to flush the coolant. I plan to buy the Airlift tool - it's a time vs cost issue, time wins.
I know from searching that JFP has recommended to others to replace the water pump as preventative maintenance on a car this age. Fair enough. Porsche pump, clean the mating surfaces carefully and:
1. Use gasket sealant or no sealant?
2. Should I replace the coolant reservoir even though I cannot find anything wrong with it?
I'll replace the thermostat at the same time.
3. Should it be the 160 degree thermostat?
3a. I notice that the car runs between 190 - 210 degrees (using Scangauge) most of the time in warm weather, so will the 160 stat be a benefit?
4. Which hoses should be replaced?
5. Anything else?
Since the start of ownership I've done mostly preventative and general maintenance with very few actual failures of any kind. With that being said, I think mileage is beginning to expose some common failures cropping up like what happened yesterday - the turn signal stalk won't hold in-place, so now I need to replace it but at least getting the 4-stalk version will give me the OBC functions.
Turbo/Turbo S (maybe even GTS) thermostats are not the typical looking reverse poppet design I've come to know an love (hate?) over the years. The "standard" design is pretty obvious - a hole opens up in the middle against the flow of water.
On the Turbo/Turbo S it seems to be a balanced sleeve (am I correct?), which allows pressurized coolant to circulate around all of its moving parts. Sounds great, but I don't understand how it restricts the flow. Upon 1st impression it would seem to me coolant can pass right through it unrestricted, regardless of the position of the internals. I do realize the water pump sits in front of the thermostat and that the inlet(s) coming from the engine and the outlet tubes exit out just over the water pump both are both behind the thermostat. This must have something to do with it but in my mind, having both inlet and the outlet on the other side of the thermostat means the water pump isn't doing anything but churning coolant. See diagram on page 89 of this parts diagram: https://www.porsche.com/all/media/pdf/originalparts/en/E_9PA1_KATALOG.pdf
Does somebody know how this all works? Your knowledge is appreciated!
2005 C2S ~52k miles
For the record, for multiple months prior to these maintenance procedures, I noted an oil temperature of about 205 deg F, whether the ambient temperature was warm or cold. I could get the temp to go up by keeping the RPMs above 3000 for an extended time. Most of the time the needle just stayed pretty steady at 205.
The one day, saw leaking coolant from underneath the water pump. Decided to change the water pump and thermostat myself. I also changed some of the hoses that touch other about-to-be-changed-out parts. I changed the reservoir cap. The new thermostat was labelled as "71" and marked Motorad. I have no history of whether any prior coolant system work had been done by others.
When initially draining the coolant, I used the AirLift three additional times to pull fluid to the back end of the car to get a more empty system. Then I did the parts change out. Put everything back together. The system held its vacuum for at least five minutes. I then refilled with straight distilled water, intending to "flush" out the old, yellow-ish coolant since my new coolant was Audi G12 anti-gel "red". I took it for a 15 minute spin to mix up, and heat up, everything. I drained the diluted coolant three time with AirLifts in between.
It held vacuum again. Proceeded to add 3.3 gallons of straight G12 since that's what I calculated I needed (for appropriately 50/50 against a total capacity of 8.6 gallons). Finished/topped off with distilled water.
To try to get any potentially trapped air pockets out, I turned the heater on HI and fan on high. I'm now getting about 212-215 oil temperature and the needle seems to move (up and down) more often compared to the pre-change state.
I was really hoping for a reduction in oil temperature after the change-out because of the low temperature thermostat. What might explain why the "reduction" seems to have gone the other way?
Thanks for any insights you might provide.
PS: The bright side - there's no more leaking coolant. [Although I didn't hear much noise from the old water pump - when I had it on the bench I could tell the bearing was shot.]