JCGMS

Ok peanut gallery.....
2006 997.1. 95K miles, no issues, diligently maintained. Presumably larger bearing given build date / VIN / Engine #. Water pump replaced 40K miles ago. No leaks.

Got in car (to go to dentist of all places) and heard this rattle. Seems to be coming from drivers side of engine bay. Increases in speed with RPM. Gonna flatbed to Indy tomorrow. Ideas?

Buddhamonk

is it rev dependent?

JCGMS

Yup

semicycler

Remove the serpentine belt. Rotate all the pulleys to see if any are loose or noisy. Start the engine briefly with the belt off and see if the noise returns. This test will isolate the noise to one of the accessories driven by the belt or to the engine itself.

JCGMS

Thanks. Definitely a logical way to go about it. My DIY doesn't really extend past oil and brakes/rotors and the car is in the parking lot at work. However if I had the time and it was at home would definitely try that route.

Waiting for flatbed to tow to indy, not gonna take any chances. I'm thinking it's gonna be the water pump.

OKB

bearing or clutch in alt or comp or some pump

JCGMS

It was the water pump. Bearing loose. Impeller intact. They also replaced the tensioner and idler pulleys. Not a pretty bill.

I'm now on my fourth water pump. 1st one failed (leak) at 57K miles. Second one started leaking a week after installation and was replaced right away. #3 (this one) lasted just shy of 40K miles. I don't know if play in the other pulleys exacerbated the failure.

semicycler

Honestly that's good news. My first instinct was a bank two cylinder issue with the noise coming out the driver's side exhaust. That would have been an expensive engine repair!

JCGMS

Yup, at least it's something I knew would need replacing at some point in the next few years.

German888

Maybe rethink the brand of water pump your purchasing...

JCGMS

They've all been OEM. What are the alternatives?

Petza914

4 water pumps in 100k miles is an impressive record - like double the norm. Hoping this one sees you through for the next 40k-50k miles. Did you verify that they installed one with a plastic impeller and not a metal one?

JCGMS

If you ignore the second one, which only lasted a week, that's 2 pumps lasting 95K miles and 11 years of service, so I think maybe par for the course. The pumps have all been OEM so plastic.

Petza914

Yes, that's true, and you're right 40-45k miles is what I consider the PM service interval on them.

Lvt19672

Is it a 3.6 or 3.8?