Installed water pump and 160 thermostat today

[stephen wilson]

I think the part you are missing is that a thermostat does not just run fully open, it's the device that actually controls your coolant flow and engine temperature. Otherwise, in winter our engines would never get up to operating temperature. If they operated as you state, with the heat input and cooling capacity in equilibrium, the temps. would be all over the place with varying engine load (heat input), and ambient temperature (cooling capacity). If a car wasn't designed with excess cooling capacity, it would overheat any time conditions aren't ideal.

[teleski]

This is absolutely right. The thermostat controls the lower temperature of the engine when the radiator cooling capacity is sufficient to keep it there. What I didn't quite appreciate is that the steady state temperature is about 15degs higher than the marked stat temp, which means it is already starting to close at 15-20 deg above marked, and regulating the flow. What no one is pointing out here is that the high temperature of the engine is regulated by the cycling of the cooling fans when the air flow is not sufficient.

For me, I am often not driving at a steady fast clip, LA traffic, city streets etc, so I would only really see the benefit of a lowT stat when cruising on the highway. I assume this situation to be true for many folks.

Out of curiosity, when pushing one of these cars on a track, > 100mph, (never done it) do you see elevated temperatures, or is there enough airflow to keep it pegged at the stat determined temperature?

[shadrach74]

Originally Posted by teleski

This is absolutely right. The thermostat controls the lower temperature of the engine when the radiator cooling capacity is sufficient to keep it there. What I didn't quite appreciate is that the steady state temperature is about 15degs higher than the marked stat temp, which means it is already starting to close at 15-20 deg above marked, and regulating the flow. What no one is pointing out here is that the high temperature of the engine is regulated by the cycling of the cooling fans when the air flow is not sufficient.

For me, I am often not driving at a steady fast clip, LA traffic, city streets etc, so I would only really see the benefit of a lowT stat when cruising on the highway. I assume this situation to be true for many folks.

Out of curiosity, when pushing one of these cars on a track, > 100mph, (never done it) do you see elevated temperatures, or is there enough airflow to keep it pegged at the stat determined temperature?

You make my point with the comment "The thermostat controls the lower temperature of the engine." That is its exact function. Most cars normal operating temp is slight above that of the factory installed thermostat. Meaning that it is open under normal driving conditions additional cooling beyond is provided by air over the radiators whether it be from forward motion, or the fans.

If anyone here is suggesting that my stock thermostat does not run wide open during the spring and summer then please tell my fans to stop coming on to cool all the hot water running through the radiator.

High temp thermos are common snake oil sold to the ricer crowd as well. The whole point of the thermo is to minimize warm up time. Lowering the temp that the thermostat opens is counter to that objective. And Homeboy while I truly admire your enthusiasm, you are deluding yourself if you believe it gives you even an inkling of additional power. It will do jack $hit to cool incoming air and have no effect on the combustion event. Do not believe everything that people market to you.

I'll submit it again if anyone can provide instrumented data showing that a stock porsche thermo remains closed while the there is water in the system that is well above 186df, then by all means produce it.

If in fact the steady state temps are in the 215 to 220 range for this vehicle then the issue is with the capacity of the system and no thermostat is going to change that.

A fool and his money...

[JFP in PA]

Originally Posted by shadrach74

I'll submit it again if anyone can provide instrumented data showing that a stock porsche thermo remains closed while the there is water in the system that is well above 186df, then by all means produce it.

If in fact the steady state temps are in the 215 to 220 range for this vehicle then the issue is with the capacity of the system and no thermostat is going to change that.

The OEM stat is rated to start to open at 186F; you can prove it for your self, just take an OEM stat and suspend it in a beaker of water with a thermometer in it, apply heat, and watch what temp it starts to opens at (186F), and what temp it is fully open at, which is much higher.............

The 215F+ running temps are real, try hooking a scanner with PID capability up to the car and take it for a ride, you just might be surprised at how hot it gets....... Then repeat the same test on a car with the 160F stat and see what you get; the "proof is in the pudding"..........

[teleski]

I believe we are all in complete agreement. When running the car on a hot day in traffic with the fans cycling, both stats have got to be wide open making no difference. I would like to see how much lower mine would be in that intermediate range when the temps are not bottoming out like on the highway, but not high enough for the fans to be needed. It sounds like the low T stat in that case would be providing more coolant flow.

What I would really like to see is a curve of flow rate vs temperature for the two stats. That would settle it for me!

[teleski]

Here they claim that engine wear is worse at low temperature, hence a low T stat could be detrimental for cool low load highway runs.

Low Temp Thermostats: What’s the Advantage? | Tuner University

I have no basis for an opinion on this matter. JFP, it sounds like you do. Whats the tradeoff here?

[shadrach74]

Started a new thread with a poll to continue the discussion in tech. Sorry for the hijack Kashmir!

[JFP in PA]

Originally Posted by teleski

Here they claim that engine wear is worse at low temperature, hence a low T stat could be detrimental for cool low load highway runs.

Low Temp Thermostats: What’s the Advantage? | Tuner University

I have no basis for an opinion on this matter. JFP, it sounds like you do. Whats the tradeoff here?

The biggest "trade off" in that article is that it assumes (incorrectly) that the car is going to take longer to warm up leading to additional engine wear, which simply isn't true. Cold starts in a situation where oil takes forever to circulate can result in some level of increased component wear, but the assumption is that the oil is not going to be able to do its job, which would only be the case if high single weight non synthetic oils are involved, or if there were some organic issue with the car's oiling system.

If you step back and think about it, when an engine running 5W-40 oil lights off on a 30F morning, which thermostat is in it is irrelevant as neither would be circulating the coolant at that moment, and the component wear rates are a function of the oil, not the thermostat. As the car with the 160F stat reaches 160F coolant temp, the coolant starts circulation to the heater and the oil cooler, where it warms the oil, helping it to do its job more effectively (take a look at the recent thread about which is more important in an engine, oil temp or coolant temp) . Because the 160F stat is open sooner, the common owner comment is that the car warms up quicker, which is more of a perception that a real fact due to movement of the temp gauge and more cabin heat sooner. In reality, up to the point where the 160F stat opens, both a 160 stat car and a 186 stat car were warming up at the exact same rates, so there is no actual difference in component wear. But because the 160 car is now warming the oil up to operating temperatures, the oil should be circulating more easily and warming up the critical lubricated components.

We have a lot of customers running the 160F stats under all kinds of climatic conditions; I have had the privilege to see the insides of several of these engines and have not seen any evidence of increased wear, sludge build up, high levels of fuel contamination in the oil, or any of the legion of other low temp stat related bugaboos that some people claim result for using them. And as we offer customers UOA's as part of their regular service, I have seen a lot of test results confirming that the oil is happier when the 160F stat is in the engine.

Probably one of the most telling points on the 160F stats is that Porsche uses them as the OEM stat in their max effort engines (Turbo, GT2, GT3). It is also interesting to note that the very late model Boxster and Caymans run a new "thermal management system" in place of a conventional thermostat that keeps the engines cooking at over 225F until you put your foot down, then the system switches to try to quickly lower the coolant to around 185F for as long as you keep your foot in it; then when you lift, the system takes the coolant back up to 225+F. You can read all about this new system in Porsche's own literature on the late model cars.

[shadrach74]

So as I asked in my poll thread. Porsche designed a new water called engine in the 90s and did not separate the heater circuit from the radiator circuit (thermostat)?

[BruceH]

Thanks for the great explanations Jeff. Makes perfect sense to me.

[ohhh my]

Possibly, I would also replace all your hoses and clamps too.

[pedot99boxster]

Thanks I'll do that, i took off the belt and moved the pump wheel and there's a movement and rattle
i'll order the parts tomorrow at pelican. and prep it for replacement i'll just leave the engine mount. I think I can replace it like that.

[ohhh my]

While you're in there, you should replace the engine mount. I haven't done mine yet, but wished I did when I recently did my water pump. The engine mount is about $130 i think or you can just buy the rubber insert which I think is $35 and press the old one out and new one in. I hear it's a good maintenance item to do.

Also, not to take away from Pelican, but I called Sunset Porsche up in Oregon and I got the pump for about $269, gasket for $7, and coolant for about $18 each. My prices may be 1-2 dollars off, but they are much cheaper than any dealer i've seen. Oh and no tax.

[pedot99boxster]

Thanks for the info i'll check into it.

[clickman]

When you get the pump out check the plastic vanes. If pieces are missing, pray they're not stuck in the small passages in the heads, creating hot spots and potential for cracking.

This is why I've proactively changed out my WP.

[pedot99boxster]

Thank you Clickman, i just ordered the parts that i need and should be here tomorrow.

[pedot99boxster]

finished installing new water pump and thermostat, changed the belt, oil and flushed the coolant. everything went smooth everything is working great. ordered parts from pelican water pump $256 and thermostat $54. Thanks to Wayne Dempsey 101 projects for the Boxster, and to Pedro's Garage and thanks to everybody for the tips

[thstone]

Sure, you don't have to do the center rad to get the benefits of the low temp t-stat and the larger S oil cooler. Do them in any order you like.

[AKnowles]

Bryan, I'm in the process of doing just what you have described. I've already replaced the water pump & hoses and have assembled all the center radiator parts (minus one bracket and the actual hoses & clamps). I plan to finish the upgrade itn eh fall when the temperatures drop. Right now the average day here is 100+ degrees. Too hot to work on the car for any length of time.

[howe]

Take both stats and put them in H20 @ 186F measure the net area, forget about warm up duration its not that important what is important, are they the same net area for the same temp?