Water Pump Replacement - How Often?

[Latitude48]

So, the 951 is in the shop for clutch master & slave replacement and I was going to have them change the belts, rollers, and tensioners since I have all the new Porsche parts. However, the shop thinks the water pump should also be replaced.

History of pump replacement:
July 1998 at 57,313 miles
May 2011 at 114,345 miles

The pump was only replaced in May 2011 because the belts were replaced, and the shop is thinking the same now. The 951 has 139,626 miles so this pump (and belts) only have 25,281 miles... but they are 11 years old now; in the past 3 years the car has not been driven, just started now and then.

So, the belts, etc. are overdue because of age, but what about the pump, and is there any difference between Laso, Geba and Porsche other than price? I'm thinking of doing this job myself since I've done it on the S2 in the past and have all the tools, and don't want to drop another $2K or more for the shop to do it.

Thanks for any feedback.

[Tom]

So, the 951 is in the shop for clutch master & slave replacement and I was going to have them change the belts, rollers, and tensioners since I have all the new Porsche parts. However, the shop thinks the water pump should also be replaced.

History of pump replacement:
July 1998 at 57,313 miles
May 2011 at 114,345 miles

The pump was only replaced in May 2011 because the belts were replaced, and the shop is thinking the same now. The 951 has 139,626 miles so this pump (and belts) only have 25,281 miles... but they are 11 years old now; in the past 3 years the car has not been driven, just started now and then.

So, the belts, etc. are overdue because of age, but what about the pump, and is there any difference between Laso, Geba and Porsche other than price? I'm thinking of doing this job myself since I've done it on the S2 in the past and have all the tools, and don't want to drop another $2K or more for the shop to do it.

Thanks for any feedback.

On my '86, the original pump lasted about 15 years (2001) and about 40k miles, and then started leaking out the weep hole. I replaced that with a LASO and it was good for another 32k miles until I pulled the motor out for the 3 liter in 2008. The LASO pump on the 3 liter was fine for about 12 years and 35k miles, but since I was doing all the belts and rollers myself, I went ahead and changed it in 2020 as a 'while you're in there' precaution. On the advice of long-gone gurus back in the day, I've always gone with LASO pumps and have never had one fail.

[stitch2k1]

I used a Laso on my 89na (2.7) and I did so on my S2 (3.0), but the one I got for the S2 had metal shavings in it from a bad casting, which I inspected for per Tim Comeau's (CRE) recommendation to look out for it. A Laso I have laying around NIB for a 2.5 motor does not have casting issues. Never used a Geba, I plan to try a Geba next. My 2c is leave that pump. It's not gonna suddenly fail. Might as well make the most of your $.

*2.7 and 3.0 pumps are 77mm impeller, different than the 67mm of the 2.5L motors

Also fun fact: My S2 had an original pump on it still. If I had known that, I would have left it on and just replaced a belt. I think it was perfectly fine. I don't think it needed to be replaced. Pumps last longer than you think.

As for a replacement interval, I run with the factory 45k for belts, I translate to "Start planning on a replacement when they are 4 years old, and get it done before they're 5 years old" and I normally say a water pump every other time. But I think at this point I might quit recommending it so religiously if it's been done within 15 years or not driven much since. I don't think it's always necessary at this point. Which is contrary to a previous opinion I held.

[Latitude48]

The 951 currently has a Laso pump. Part of the issue is the shop says the engine needs a front reseal (and also the balance shaft housings, but that can wait as that involves a whole lot more work on a turbo... I'll do it when I change the turbo), so to do the front reseal you need to pull the rear cover, so the pump is exposed and accessible. Of course, changing it is more work and expense, so I'm inclined to leave it, and may not do the reseal now either if oil isn't getting on the belts.

[AudiSport]

If you're doing the belts, do the pump too. Be silly to not do it. I've had a water pump lock up on me before.

[Cruise98]

I would not recommend a GEBA pump. The Laso and factory pumps have performed perfectly for me. Zim's has a good reputation for rebuilt units, but I have never used one.

If the car was stored with coolant in it, and current pump is not leaking, I would inspect the bearing. Grab the pulley and try to discern if there is any play up/down or in/out. If so, replace it. The pulley should rotate freely, but not "freewheel", and it should be smooth throughout the entire rotation. If it passes these tests, personally I would leave it alone. But, I do my own work and am not paying a shop to do the labor, so paying for a new pump is kind of like insurance. Do replace all of the belt rollers, seals/races. The rollers I have seen lately are crap and never last as long as the belts.

Don't you love all of the different advice!

[Latitude48]

Don't you love all of the different advice!

Uh... yes, I do. Everyone has different experiences.

As of today, I'm leaning towards doing all the work myself since I've done it in the past. Unfortunately, for the last 15 years my garage hasn't had enough room to work on either of the Porsches because it was full of remodeling appliances, wood, etc., etc. Now that I can finally work on the cars again, I think I'll go that route as I'm tired of paying for shop labor. Since I usually supply my own genuine Porsche parts I think I might be getting hit with more labor to make up for the parts profit. I have records on both the S2 and 951 going back 25 years and the amount of labor to do a belt and roller/tensioner job keeps going up. Since both the S2 and 951 are "play toys" I can take as much time as needed to complete the job.

Edit: for those that have resealed the front of the balance shafts... how difficult a job is that? Per the PET it looks like I'd need 1-seal, 2-O-rings, and 1-spacer sleeve per shaft. The lower one is obviously a bit more work to remove the housing.

[AudiSport]

Have you scanned through the Clark's garage procedure ?

http://www.clarks-garage.com/shop-manual/eng-14.htm