Squeal at 2500 - 3000 rpm

I just got back from a 1000 mi trip to Porsche's on the Mac. The car ran great, however I am noticing that there is a squeal when I run between 2500 and 3000 rpm in any gear. I don't know if squeal is the right word, as it's hard to describe. It starts lower pitched at 2500 rpm and higher at 3000 rpm where it goes away. It's not loud as my wife can't really hear it and only happens when the car is fully up to temp. It's a 2001 and has 30k mi on it. I bought it a yr ago with 25K mi and had the IMS done this spring. This afternoon I pulled the airbox and serp belt. The idlers were good, and the belt was good. Also the alternator felt fine. I get the noise with or without the ac on. The water pump at first had no movement until I turned the pully 30 degrees, checked, turned again 30 degrees, checked etc. In one orientation I had a bit of movement. 1/16" maybe? 1/32" maybe, but I could definitely feel it. It's looks like the original pump. Is that my problem? Or am I barking up the wrong trree? Who has replaced theirs and how hard was it to do? Myron

Hard to say...Stand at the engine and have your wife bring up the rpms slowly and listen for it. Pelican parts has great tech articles... https://www.pelicanparts.com/techart...eplacement.htm Also, get yourself the Bentley Service Manual (every DIY'r should have it)

If by movement you mean side to side play, there should not be any at all. The pump is not difficult to replace, I would say about a 4 out of 10 difficulty. It entails supporting the engine while moving the rear mounting plate back far enough to get the pump out. great time to go for a low temp thermostat and nice fresh coolant as well.

the main thing when removing the water pump is that 7 screws hold it in place. They are of different lengths. Make sure that you replace them in the correct order. 72 thousand is about the right time for a pump change. Mine went at the same mileage.

I'm definitely not the expert here, but I do know that if it's the original water pump, then more than likely it's time for a new replacement. The Porsche pumps have plastic impellers that over time tend to deteriorate and break off. This could turn into a major problem for the engine if not caught soon. The squealing noise is a common telltale sign of a worn out pump. Hope you find the solution.

I have decided that I will replace the water pump. I should have done it when I had the IMS done but the bill was adding up fast.

I would get the car good and warm so that you can reproduce the noise. Then take the serp belt off. See if it makes the noise with the belt off. You might need to replace the water pump, but what if the noise is still there? You will have to make another repair in that case.

1. There should be zero play in the water pump. 2. It should spin easily without making any sound at all. 3. A 17 year old water pump should be replaced immediately even if it seems fine. A water pump failure could cost you an engine. 4. If you have a 17 year old water pump it is likely that your coolant and thermostat are also 17 years old. Experts recommend changing the water pump and thermostat every 4 years. Get a low temp (160F) thermostat, an OEM (Pierburg) water pump, an OEM metal gasket (don't use any sealant), and Porsche coolant. It's not an easy job but it is doable with the right tools, some patience, and a go to list of swear words. Even if this isn't the source of the noise it needs to be done.

Murrphyslaw: Sounds like a good idea. Bill: Wahler thermostat 160F and Pierburg Pump with gasket are on order.

I am now ready to get to the water pump replacement. I got the car good and hot today. I can hear it beginning to make a squeal (or howl) at 2500 rpm. As the rpms go up the pitch goes up. It quits at 3000. Happens while driving or just racing the engine. Happens with the ac on or off. It does not happen with the serp belt off. Is there a way to individually run each pully up to speed with the serp belt off and the engine off? In my opinion the only thing besides the water pump that is suspect may be the top idler pulley. It spins a bit longer than the other 2 pulley when given a twirl. any ideas?

Here is my opinion. Waterpump and belt idle bearings and bels are maintenance items, to be changed at 60K miles. Don't wait for them to fail because they won't fail at home in your garage. Don't guess which ones, just change them. Yes, that is pricy, but you bought a Porsche. It comes with the territory.

My friend and I used compressed air (from a compressor) aimed at the pulley and got it to spins fast enough to hear the bearing noise. We were able to identify my tension-er pulley was on its way out this way.