Happy hump day!
Thanks in advance for the assist here.
Background:
About a month into my new to me ownership of this 2006 C4. Purchased in Dallas last month at around 129k. PPIs done at both Nine Eleven and K3S motors right there in Dallas - clear bore scope from the latter. Verified strong service history from Porsche of Dallas. All told, an excellent car with a regular track history (and upgrades/maintenance to show).
I saw evidence from the PPI of a past coolant leak, but the guys a K3S assured me it passed pressure test.

Issue: About 3,500 miles later, she’s leaking pretty good from what appears to be the water pump.


Worth mentioning I sheared an idler pulley about 350 miles ago. I’ve not had that happen on any of my cars before. Thinking perhaps a previous coolant leak compromised it.
Water pump and thermostat are both pretty straightforward services. Car is already up in the air with parts on the way.
Anything else I should be looking at while in there?

 

The pump has most likely been replaced at least once, before. 131K miles: definitely time to replace it. Usually every 60-70K miles, you will need a new pump.

I would also replace the engine mounts, they seem pretty beat up....

Yves

 

Thanks! Those mounts actually look relatively new when clean - with stickers in great shape and all. Engine bay is filthy (kinda how I like it) from the long drive home, and some dirt roads.

 

Check the coolant reservoir and cap for leaks and clean that engine bay for god sakes looks worse than my kids bedrooms...

 

Give a once over on your coolant tank, right near the lower middle, engine side. Cracks start to form there. My 997.1 had a crack that started leaking, my 997.2 had a stress mark, but no leaking.

 

I would suggest that you also replace the serpentine belt and the three idler pulleys while the water pump is being replaced, if they haven't been done recently.
FYI, the water pumps seem to last about 60-75K miles.

 

Thanks!
Belt and associated idler was done couple weeks ago after idler failed. Tensioner is still VERY strong.
Pretty clear to me (both in person and in the photos I provided) it’s coming from the water pump. I’ve got the parts on the way tonight or tomorrow. Will see how it goes. Looks like a two-beer job - vs. Audi, which is a kegger! 😂

 

Well, it is more than a two beer job..... You will need a device to create vacuum inside your coolant system. I used to have a complete and detailed DIY guide for the pump, but did not keep it online.
Check this forum as there are probably other threads covering that task.

Yves

 

I just closed door to boys rooms rather than stress over it. When done with repairs close the engine lid and don’t worry about it lol!

 

Based on the looks of the engine bay, I'd change your air filter too. If the 3 chain tensioners have never been replaced, you're well past due on those as a preventative measure. The bank 1 and IMS chain are easy (but you'll need the cam lock tool and replacement plugs). The Bank 2 one requires removal of the A/C compressor, but if you already have the belt off for the water pump....

Only install water pumps with composite impellers and install the 160 degree low temp thermostat, not a regular 180 degree one.

 

Guessing you guys don't take your cars on or near dirt roads ... Haha!
Finally got a chance to get everything inspected a little closer, cleaned and buttoned up last night. Filled with coolant and took her for a good rip. Much clearer picture with wet coolant. Seemed pretty clear to me before that it was coming from behind the water pump pulley. Visited Porsche of Syracuse (Driver's Village) today and they confirmed that's the most common failure point for the water pumps. Great folks, BTW!
Thanks for the heads up on the poly impellers (also recommended by Porsche). I spoke w/ LNE a couple days ago RE: 160-degree thermostat. I've got the opposite of the problem it solves.
This is a year-round car in upstate NY. Between cold (often well below zero) startup temps and having a third radiator, I want that engine to heat up as fast as possible.
Anywho - I've got the new water pump. Out with the old and in w/ the new, later today. First oil change, too.
Worry not about my sense in oil. I'm running some 10W-30 I found on sale at Advance Auto last week and reusing the oil filter. Got a YouTube vid on how to clean out w/ brake fluid!
Rennlist FTW

 

Actually you don't. The problem the LTT solves is allowing the engine to come up to temperature more gradually and has nothing to do with ultimate running temperature. One of the major contributors to bore scoring is that the regular thermostat doesn't start opening until 180 F and isn't fully open until more like 212. The problem is cylinders 5 and 6 don't get a gradual warmup and the piston expands faster than the cylinder so you're putting a larger round peg into the same sized hole.

 

Thanks! Car had a lot of the right mods. Very reasonable chance it’s already got the LTT. Any way to identify (i.e. warming time, variance between oil and coolant temps, product markings, etc ...)?

Next step is probably casting the RL net and finding out who owned this car last. I’d bet a thermostat they’re on here.

 

Yes, there is a way to tell. If you take the thermostat housing off, you will see a temp marking (in Celsius) and date code on the thermostat. Or at least I think it is a date code. But once you've gotten that far, you've done all the hard work to replace the thermostat, so might as well just put a new one in.

 

Congrats on the purchase!