zojirushi

Recently picked up a 2017 991.2 Base 911 with 14k miles. I negotiated to add the CPO warranty to the purchase. During the CPO inspection, they found that the drive belt wasn't in CPO condition and we agreed to have it replaced at a later date. A week after the service, I noticed a dried light colored residue underneath the engine. I'm certain this was not here before because I did an inspection of it prior to the belt service. The car is going in for service this upcoming Tuesday for an unrelated issue and I will ask them to look at it. I wanted to ask if this looks like a coolant leak? Does replacing the drive belt involve removing any cooling system parts that could leak some coolant in the process? Thanks!

subshooter

Looks to me like road splatter of something. Notice that there is residue on the bottom of that bar.....but no dripping residue to create it.

PacificGerman

That is dried up coolant, leaking from the water pump.

I have seen some dealers call this normal leakage from the weep hole on the pump.. Keep an eye on it, though if it were my car I'd have it replaced.

LexVan

Strange that the drive belt would need replacement at on 14,000 miles.

I had mine done during the 40K service, at 42,000 miles, and it looked perfect.

To get to the belt, the rear bumper was off, and the air box removed.

zojirushi

I thought so as well but the general manager explained that the belt has some threading coming out the side and didn't meet CPO standards. I met the service manager after the sale and he said that the old belt was still perfectly fine and that i could "Drive from New Jersey to California and everything would be fine."

LexVan

Great job them catching it!

wareaglescott

Is it possible it was just residue from them servicing and not an active leak?
Check for signs of it currently leaking after you park it.

Class5Kayaker

My. $.02 worth

I'd say clean that part off and then drive around for a while and see if it reappears. If not, it's probably not a leak and something you either picked up on the road or something that got on there when they were replacing the belt.

zojirushi

I've been informed by my dealership that the water pump will be replaced. I've seen several instances of 991.2 requiring water pump replacements on this forum. Best to keep an eye out for potential leaks.

Mr. Big

I had the same residue under my car. The dealer replaced the water pump too.

dflowerz

Had my water pump replaced on my 991.2 when I took it in for a chirping sound.

zojirushi

I was reading your thread earlier before the dealership called me and noted the similarity between the symptoms of our cars. I reported earlier to the dealership that I noticed a high pitched rattling sound around the engine compartment that would dissipate when the engine was above idle speeds. I had my suspicions that it was the water pump after reading your post and noticing the light residue. Sure enough, the dealership confirmed that suspicion.

Rocket_boy

Agree,...although if it is going in for service, might as well have them take a look.

One thing older Porsche's are notorious for is after the belt is replaced that drives the water pump, there is decent chance the water pump bearing may fail with the "new" belt tension.
Not nearly as common today as tensioners are much better, but a new belt could exploit a water pump on the edge.

wisky

Around how many miles on your car when you noticed this?

dflowerz

6500 miles. I never noticed any water pump issues. The chirping sound was a strut mount unrelated to the water pump. They noticed the water pump was seeping when they had the car apart looking for the noise.