joe-1972

The biggest problem that you "might" face is the small coolant passages in the heads... if any air is stuck in them you WILL create a hot spot and that will cause some damage that eventually will lead to a cracked head or worse.
95+ times out of 100 you will never need to worry about this happening.... but with the cost of the damage verses the cheap cost of the tool its definitely worth it!

PS two radiator car is about 5 gallons of mix... three radiator cars come in at 6 gallons of mix!

PSS if you are in the Chicago land area send me a PM and ill give you my address... we can flush and refill your car in no time since I have the tool!

rolex11

No hijack here, but OP says he's replacing thermostat when doing water pump. Is this necessary or recommended? Do they wear or fail often? Doing my WP tomorrow and not replacing thermostat and this post got me to rethinking it. Was going to but I'm not going with the low temp version, sticking with stock.

Thanks.

tekkie

Mbren1979

HIGHLY RECOMMENDED. The thermostat goes thru thousand of cycles through out the years and it can get stuck open or closed. It's cheap insurance to replace at the same time. Not to mention the time, money and aggravation to do it at a later time in the event it fails soon after water pump replacement. Normally as a tech i would agree to go with the OE temp stat. However Porsche has had and does have issues with certain spots in the engine potentially getting hotter than expected before the OE temp stat opens which can cause severe damage. The low temp stat does not in effect keep the engine colder. It just opens earlier preventing the hot spots from forming. My car has the low temp LN Engineering t-stat. It only runs a few degrees cooler on the highway and normal temps in traffic. The question shouldn't be why should i change the t-stat, rather why not?

rolex11

I did the 3-step coolant flush today. Only got 5 & a quarter gallons out, no spills. So I decided to refill (used the Uview) with just distilled water to flush again. Once filled, I ran the car for 15 minutes to get the thermostat to open and mix the distilled water thru. Right at 15 minutes the temp flight started flashing and the digital temp gauge (in the hidden menu) read 97 celsius. Shut it down immediately.

Wondering why the light started flashing?

Tonight I'm draining the distilled water (let it cool down) and replacing the water pump & thermostat and refilling.

WonByOne

Quick follow-up. Water pump has taken longer than expected due to fabspeed x exhaust in the way. I had to remove the cats and the bolts were rusted so badly I broke everyone on the clamps. The bolts holding the cat to the exhaust manifold some broke (desired outcome) while others stripped and I had to cut them off. My cutting tool is slow and the angle was disastrous, so it took a very long time. Anyway, water pump is finally out and getting ready to out in the new one. Question on the most difficult bolt to the lower right (from rear looking to front), that took me forever to get out. Wasn't difficult but could only manage 1/8 turn. I got it out from the top of engine but not sure the best way putting it back in. Any suggestions? I wonder if it would help to loosen the two mounting bolts from underneath and just lower the engine so that bolt can be reached easier from under the car rather than above?

WonByOne

Water pump back on but I did NOT replace thermostat, need to order the part first. However, it should be an easy job in the future since 95% of my time was dealing with the exhaust. For those who have the fabspeed x exhaust: on mine, there is not enough room between the exhaust mounting bracket BOLT and the pipe from catalytic converter in order to remove the mounting bolts and the exhaust bracket. I had to remove the cats first, then it was easy. All the bolts on my exhaust we're severely rusted and most snapped while the painful others stripped; all were presoaked with PB Blaster for 24hours to no effect (as always). The bolts that stripped you have two options: drill and or cut. I cut them off with a small air-powered cutting tool that takes about 30mn to cut through a small M6-M8 bolt. I had to be careful cutting so you don't also hit other exhaust parts. I replaced all bolts at the hardware store. The ***KEY*** is reassembly. Fabspeed should have provided this and I will call to pet them know: you need to cut half of the threads off the mounting bolts that hold the exhaust bracket to the engine bracket. This will allow just enough room to remove these bolts without having to remove the cats in the future. *KEY*

When the time comes to replace thermostat, other than costing additional coolant (which I want to flush again anyway) it shouldn't take much time at all.
Lastly, regarding the water pump bolt on far-right. If you're having trouble here is the number one tip with these engines. You HAVE to have a 1/4" flat head drive to work on these engines. You might think, well 3/8" is pretty close, but I promise you that unless you have a 1/4" drive along with extensions, you will encounter headache after headache on these engines.