samurai_k

Hello engine experts, I need your help to diagnose this problem.

This morning my car is making this weird whining noise when the motor is running. It sounds like it is coming from the right side (passenger side) cylinder bank. At first I thought it was the AC compressor, but it sounds like it is coming deeper in the engine bay. The engine will start and idle roughly and obviously make the whining sound like a supercharger blower.




https://photos.app.goo.gl/NL97Bft2OTbPxg9n1

Update-> Look at post #15 for solution.

pp000830

Power steering pump or belt? If your steering is working properly it could simply be the belt rubbing against the belt housing.

nine9six

Hmm, sounds metallic to me, like the fan blade rubbing on the housing; so maybe I spent alternator bearing?

Could also be compressor clutch bearing.

It would be more helpful if you could definitively isolate the location of the sound.

samurai_k

Hi Andy,

Looking at the bentley manual, I really hope it is not the power steering belt pump, as that is way back in the right side of the engine? Does the belt or pump just fail? Or would it be caused by the steering rack to fail which puts pressure in the power steering system thereby straining the system?

samurai_k

The alternator was just replaced with a new unit right before me buying the car.

I just loosened the AC compressor and removed the AC belt. Fired up the engine and it the noise is definitely coming from the right side (passenger side) deep in the engine bay, which to Andy's suspicions may be the power steering pump/belt area of the engine... ugh.

I am going to get her on jack stands to look at what is going on in front area now.

Power steering was flushed right before I bought the car...

pp000830

A skilled technician can service the belt and maybe the housing and pump w/o removing the engine from the car. Rack failures have more to do with leaking not load on the pump. Your issue may just be an old belt rubbing against the belt housing, not a failed pump.

mpruden

Verify you're not low on PS fluid. A dry pump will make that noise.

P-daddy

+1

samurai_k

Thanks guys. Looks like the fluid is at the first notch... Done with wrenching tonight. Will do some further analysis tomorrow now the air box cover is out and I can see the PS pump and can hopefully hear clearly it is from that area.

Churchill

Ignore the suggestion about the PS belt. No way it can make that sound. It also can't "rub on the housing." It's a toothed belt that rides inside the pulleys.

AOW162435

Low on PS fluid or wrong fluid was used when recently replaced. That sounds a bit worrisome...




Andreas

pp000830

FYI - The power steering reservoir has a filter in the bottom of it that is not serviceable. If you end up servicing the pump I would replace the reservoir as it is inexpensive and a replacement has a fresh filter in it. If it has not been replaced before you will need to cut off a hose clamp to one of the hoses on it and reuse the hose with an aftermarket clamp. It is easy to replace. I emptied mine out with a Turkey baster and then stuffed lots of rags around it when lifting it out to catch the power steering fluid drips that can't be avoided.

95_993

You may want to check out this thread...."Scraping noise from PS"

https://rennlist.com/forums/964-foru...-pulley-3.html

BlackSnake99

Clearly I'm no Porsche expert, but why would any abnormality with the PS pump cause the rough idle mentioned in the original post?

There appears to be a bit of smoke in the video.... is that exhaust? Seems excessive to this n00b, unless that is the first start after sitting for a couple of weeks.

samurai_k

Thanks @95_993. You found the problem. I got a tip to use an automotive stesescope which easily isolated the location. Great $20 investment from napa auto.

One of the bolts that secures the ps belt cover on top got loose and fell into the area under the airbox just like the 964 owner that @95_993 shared... Eventually the bolt made it's way through the gap in the engine bay rubber gasket and unfortunately fell into the ps belt cover opening and chewed up my ps belt. Why it got loose is beyond me, but I guess the last mechanic who touched it didn't tighten it enough as the one next to it came off easily too. Sure this could have easily been avoided by inspecting those bolts. Those that are paranoid about this it is simple if you just remove the airbox...


Luckily the damage was to the ps belt and minor scratches to the lower cog. Not enough to warrant replacement as that would have meant an engine out procedure.

Did some research on the topic to do an engine in ps belt replacement and it was not as bad as everyone claims it to be.

[url]https://rennlist.com/forums/993-foru...-pump-diy.html

[url]https://rennlist.com/forums/993-foru...ring-belt.html

[url]https://rennlist.com/forums/993-foru...ed-advice.html

[url]https://rennlist.com/forums/993-foru...t-replace.html

In the end it came down to having the right tool and my car being a newer one where the bolts that secure the pump to the housing were hex head instead of pan heads (PET says they are pan head bolts). I am certain it would have been tough to loosen a pan head bolt as I tried to replace the old grade 8 hardware to grade 12 hardware first with pan heads and could not get the same ratchet I used to loosen the hex heads with. I ended upgrading the old zinc grade 8 hex head hardware with some steel grade 12 as I notice the hex heads always get wear and sometimes marred on these lower grade bolts when you try to loosen a tight bolt in suboptimal locations.

The procedure to replace the belt is straight forward per all of the advice in the threads above. I'll write a detailed diy on this but here are the highlights...

1. Remove all of the stuff that blocks direct access to the belt cover. Right muffler, rear ARB, fender well covers, and the aluminum pipe that connects the airbox to the engine (I think is the SAI inport), and airbox. Eventually you can remove the ps belt cover. I found the rubber engine bay gasket keeps it in place so if you fold it up makes removing the cover easier from the top (engine bay).

2. Remove the rear bracket from the ps pump so the ps pump can separate from the housing. Details are in the bentley service manual.

3. Use the right tool to get to the hex head bolts buried in the housing below the ps pump and loosen it from the top (engine bay). I used a small Craftsman fine tooth 1/4" drive ratchet and a 6mm socket from a Neiko metric short hex head set sold on Amazon. This tool perfectly fits between the housing, belt, and engine bay as it is really tight. I tired to use an Allen key and that was too hard to get it to loosen the bolts as they are pretty tight. Using the ratchet they came off easy.

Using your touch and left/right hand index/middle fingers you can feel the ratchet into the housing and get the ratchet to engage a solid connection to loosen both the left and right hex heads. Once loose, the pump easily slides out and you can remove the belt.

5. Installing the belt is the opposite where you slide the new belt in from the bottom, loop it around the lower cog and then with the ps pump slightly out you slide it in the housing again and the belt slides easily on to the pump upper cog if you just adjust the upper cog to align the teeth of the belt. Tighten the lower hex head bolt on the right (closer to the wheel well) first and then the lower left one, then install the upper bolts. Everything else is the reverse of above.

Engine purrs again like she should