Water Pump

[cvhs18472]

My 98 Boxster is very quickly reaching 60K and I would like to replace the water pump this winter. Is it worth paying the vast difference to get the pump from a dealer, or has anyone had good luck with an EBay seller. Thanks in advance for you thoughts. Ed

[JFP in PA]

Considering the amount of work you are going to have to do to replace it, why not give Sunset Porsche a call (they are the lowest cost dealer out there) and get the correct one. Would also be a good time to swap out your T-stat with a 160 F unit……………….

[23109VC]

what is the benefit of doing hte 160 degree thermostat?

does it make the car run faster by making the car run cooler? i've heard of guys claiming that on other cars.... but h aven't heard any definitive proof that it does that...

if the car runs better/faster/more efficieintly/etc on a 160 thermo why didn't Porsche put one in from the factory?

[JFP in PA]

Originally Posted by 23109VC

what is the benefit of doing hte 160 degree thermostat?

does it make the car run faster by making the car run cooler? i've heard of guys claiming that on other cars.... but h aven't heard any definitive proof that it does that...

if the car runs better/faster/more efficieintly/etc on a 160 thermo why didn't Porsche put one in from the factory?

Besides potentially saving your engine by keeping it cooler, as well as substantially lowering oil temps ( a HUGE plus); yes is makes slightly more power by improving volumetric efficiency to the tune of picking up 5 HP. LN Engineering, who developed the 160 F stat in conjunction with Jake Raby, has data from dyno pulls on their website……………..

And Porsche does use lower temp stats in their "performance" engined cars such as the GT2, GT3, and Turbo cars................

[jmatta]

I have the 160 LN stat in my Box S, so I'm biased. This has been debated many times on this and other forums, but the bottom line is the car's coolant temp is reduced by some 20+ degrees, thereby reducing oil temps at the same time.

As for why Porsche didn't design this like the GT3s, turbos, etc?
I think the answer lies in that the typical use of a US Boxster driver is shorter trips as a daily driver vehicle. The higher temps help burn off containiments in the oil, at the cost of higher heat, oil breakdown and engine wear. JFP, Raby and Navarro have dissected these engines and know their faults and weaknesses...I trust their judgement in the "everyday" real world.

I want my engine to last a long time (I'm approaching 16k miles). I change my oil at least annually (3k miles) and use only high quality synthetic and OEM Porsche coolant.

If I were changing my water pump, it wouldn't be with some knock-off.

[Franco]

Hi, I replaced the crappy OEM pump with one bought on ebay, it has been 2 years since and haven't had any problems.

I paid about $125.00 shipped.

[Lil bastard]

I have to disagree with those urging oem replacement.

While I usually always go oem, the waterpump is simply inferior to several of the remans or aftermarket ones out there using a metal impeller instead of the oem plastic one.

Not only is coolant flow reduced and debris forced through the system (possibly clogging it) as the impeller degrades, but it also throws the shaft out of balance shortening the life of the bearing, seal, and the pump itself.

The pumps with metal impellers don't cost any more, in fact, they're usually less than oem.

[cnavarro]

Originally Posted by JFP in PA

Considering the amount of work you are going to have to do to replace it, why not give Sunset Porsche a call (they are the lowest cost dealer out there) and get the correct one. Would also be a good time to swap out your T-stat with a 160 F unit……………….

If you call Suncoast, they carry the low temp thermostat as well. One stop shop if you did want to go that route.

[gschotland]

I recently purchased an OEM pump from Suncoast for about $200 delivered. A good enough price to make me not think much about the $70-80 "savings" buying one from an iffy seller on eBay.

[Lil bastard]

Originally Posted by gschotland

I recently purchased an OEM pump from Suncoast for about $200 delivered. A good enough price to make me not think much about the $70-80 "savings" buying one from an iffy seller on eBay.

Sorry, but IMHO, the 'iffy' part is the oem replacement.

[pk2]

Originally Posted by JFP in PA

... Would also be a good time to swap out your T-stat with a 160 F unit……………….

------------------------------------------------------------------------------------------
I always thought tolerances in an engine were optimized to operate best at a specific, predetermined temp. Motors are made of lots of different alloys any metals. They all expand at different rates. In this case, the state of the alloys at 180 degrees is where the engineering is done and optimized.

Just in a piston and rod assembly, you have 5,6...10 (?) different alloys all expanding at different rates and amounts as they heat up. The engineers decided 180 was nice and designed the parts, taking into account they're expansion, to fit best when they are all at 180. At 160, your goung to have different tolerances. Maybe the rings have expanded but the cylinder hasn't caught up, more compression, more hp, what ever. But harder on other stuff that's not fitting right. Of course far to be it from me preaching tips for longevity, I've disregarded all common sense pushing mine towards a D-chunk.

I could be totally wrong, after all you don't really have to warm up a car any more. But, justifying this change because a GT runs at 140 is apples and oranges for the reasons above. The engineers liked 140, for whatever reason, and designed everything to fit best at that temp and the accompanying degree of expansion of the various alloys etc.

Aside from that, the GT and Turbos are entirely different engines. Water cooled flat sixes yes, but I believe they were derived from the 959 which was based loosely on the old bullet-proof, air cooled 963(?).

I'm not saying don't do it, with a good explanation, I might even do it myself when the time comes. I'm only saying I doubt that the 180# was an arbitrary # for this motor. Probably very minuscule, but I don't think you do it without some long term consequences.

Coffee's gone, Saturday sermons over.

Regards, PK

[jmatta]

Jake and Charles have shown that the M96 engine actually operates at around 210*, not 180*. The factory t-stat doesn't even open until 185* and isn't fully open until around 205*. The LN stat opens at 160* and is fully open by 180*...cooler coolant and cooler oil; makes your engine last longer.

As far as the water pump; if I ever have to replace mine, I will compare the options and purchase the best replacement part regardless of cost.

[pk2]

jmatta

In all sincerity, why would Porsche knowingly put a thermostat in that they must know (if you do) is much hotter and is therefore going shorten the engines life ?( As if the motor wasn't a bit of a disaster as it was.) And if it's running at 210, why not say so instead off consciously papering over the dash gauge to read 180?.

Do you think they play the same hi-jinx with the GT and turbos that, as is stated in this thread , are supposedly running at 140?

Also , cooler oil sounds nice (especially on a hot day (grin)) but what difference dose it make...it breaks down sooner and might be harder on rubber seals but what else that isn't compensated for? These things have a pretty aggressive oil change regiment which should mitigate any oil degradation, and rubber seals arn't your fathers

This isn't rhetorical and I'm not being a smart a__, I'm truly curious.

Regards, PK

[Lil bastard]

Originally Posted by pk2

jmatta

In all sincerity, why would Porsche knowingly put a thermostat in that they must know (if you do) is much hotter and is therefore going shorten the engines life ?( As if the motor wasn't a bit of a disaster as it was.) And if it's running at 210, why not say so instead off consciously papering over the dash gauge to read 180?.

Do you think they play the same hi-jinx with the GT and turbos that, as is stated in this thread , are supposedly running at 140?

Also , cooler oil sounds nice (especially on a hot day (grin)) but what difference dose it make...it breaks down sooner and might be harder on rubber seals but what else that isn't compensated for? These things have a pretty aggressive oil change regiment which should mitigate any oil degradation, and rubber seals arn't your fathers

This isn't rhetorical and I'm not being a smart a__, I'm truly curious.

Regards, PK

Well, 60% of the heat produced in the engine (and some of the most critical heat, think bearings) is carried away by the oil, not the coolant.

In the Boxster, the heat exchanger transfers much of that heat from the oil to the coolant which dispels it from the radiators.

So, if the coolant runs lower temps, it does a better job of aiding the oil in shedding the heat.