Secondary air pumps whines when engine cold

[pterfloth]

C2 996 2000 Cabrio. The secondary air pump whines when the engine is cold and first started up. After 20-30 sec the air pump stops, revs drop and the whine ceases. It would seem to be a bearing.

Has anyone rebuilt one of these or have any suggestions? I'd like to nip any problems in the bud.

Thanks

[wvicary]

No way to rebuild them that I know of. Search for a replacement unit at a breakers yard.

[Loren]

You do know the air pump is supposed to stop after 30 seconds to 2 minutes?

[pterfloth]

You do know the air pump is supposed to stop after 30 seconds to 2 minutes?

I thought so, thanks for the confirmation. The whine it is making is very high pitched and not normal. If I can stop it from failing I'd like to. I may just pull it apart to have a look if I can do anything.

Is the only time this pump runs when the engine is cold or does it supplement air flow at other times too?

This forum is a tremendous resource and I appreciate everyone's input.

Edited August 27, 2010 by pterfloth

[Loren]

Sometimes it comes on when you come off the freeway and idle at a stop light. In those cases it is usually just a few seconds.

I agree with wvicary - you might want to find a used one somewhere as the MSRP is $1453.32 :eek: Although I am sure the folks at Sunset Porsche (Porsche Parts at Dealer Cost) can do better.

Make sure you get a 996.605.104.00 for MY00 and newer.

[Dharn55]

First both Loren and the folks at Sunset are the best. Unfortunately Sunset does not have an on-line parts/price look up. Porscheoemparts.com has this and will show fitments, superseded part numbers, list prices and discounted prices (that are usually about what Sunset charges) which can be very helpful. For the part number that Loren has provided the Mechanical catalog shows a fitment for 996 2000-2004, GT3 2004-2005, Turbo 2001-2005, the Collusion catalog 996 200-2005. Lots of useful information on line there. The discounted price is $982.73. Give Jeff at Sunset a call, I bet this is about their price too.

A used one should be readily available at a much better price. Also, I think a squeal from these pumps is not uncommon. And for $1,000 a squeal on start up is not so bad IMHO.

[Johnny-5]

Sometimes it comes on when you come off the freeway and idle at a stop light. In those cases it is usually just a few seconds.

I agree with wvicary - you might want to find a used one somewhere as the MSRP is $1453.32 :eek: Although I am sure the folks at Sunset Porsche (Porsche Parts at Dealer Cost) can do better.

Make sure you get a 996.605.104.00 for MY00 and newer.

Loren,

Is that modual near the upper front passenger side somewhere? I have the same whinning sound and I hear it mostly when at idle at a stop light during normal operating temp. I actually had a friend drive and was sitting in the passenger seat and heard it and it appears to be coming from the front, am I wrong? It eventually goes away and all is good again. But mainly when I notice it is when in traffic or at a street light, etc.

Thanks,

Johnny

[Loren]

Sometimes it comes on when you come off the freeway and idle at a stop light. In those cases it is usually just a few seconds.

I agree with wvicary - you might want to find a used one somewhere as the MSRP is $1453.32 :eek: Although I am sure the folks at Sunset Porsche (Porsche Parts at Dealer Cost) can do better.

Make sure you get a 996.605.104.00 for MY00 and newer.

Loren,

Is that modual near the upper front passenger side somewhere? I have the same whinning sound and I hear it mostly when at idle at a stop light during normal operating temp. I actually had a friend drive and was sitting in the passenger seat and heard it and it appears to be coming from the front, am I wrong? It eventually goes away and all is good again. But mainly when I notice it is when in traffic or at a street light, etc.

Thanks,

Johnny

No, the air pump is near the left rear in the engine compartment.

You are likely hearing either the HVAC fan or the fuel pump. The HVAC fan can be turned off for troubleshooting by hitting the down arrow until it says "oFF".

[Johnny-5]

Sometimes it comes on when you come off the freeway and idle at a stop light. In those cases it is usually just a few seconds.

I agree with wvicary - you might want to find a used one somewhere as the MSRP is $1453.32 :eek: Although I am sure the folks at Sunset Porsche (Porsche Parts at Dealer Cost) can do better.

Make sure you get a 996.605.104.00 for MY00 and newer.

Loren,

Is that modual near the upper front passenger side somewhere? I have the same whinning sound and I hear it mostly when at idle at a stop light during normal operating temp. I actually had a friend drive and was sitting in the passenger seat and heard it and it appears to be coming from the front, am I wrong? It eventually goes away and all is good again. But mainly when I notice it is when in traffic or at a street light, etc.

Thanks,

Johnny

No, the air pump is near the left rear in the engine compartment.

You are likely hearing either the HVAC fan or the fuel pump. The HVAC fan can be turned off for troubleshooting by hitting the down arrow until it says "oFF".

Ok thanks for that clarifications. Ill have to drive it around and see if it does it again and jump out right than and there (hopefully not at a street light or in traffic :unsure: ) and try to narrow down the noise. Once again I was just hearing it from the the passenger side window so I never really narrowed it down. But if it is the HVAC fan or the fuel pump where would those be located? And also what is the HVAC? And last but not least where would I go to toggle through to turn it off? I dont think it would be the fuel pump would it? Also in the passenger front there is a smaller radiator right would that fan maybe going bad?

[Loren]

HVAC = Heater/Ventilation/Air Conditioner

The fan is in the dash right in front of the right seat.

Fuel pump is in the gas tank under the battery.

The radiator fans don't run all the time unless the AC is on. Then they run fast.

When AC is off they only turn on (low speed) when needed.

[PILFILR]

I hate these pumps! I had a VW and went through 3 pumps ($650 each). On most set-ups...there is a crankcase valve that diverts flow to the crankcase from the sec-air pump. My valve froze (would not completely close) and allowed moisture to accumulate in the sec-air pump... When this water added up over time the pump started to whine as you mentioned. The pump finally stop working when it was full of water. I pulled the pump and shook all the water out and it worked another 6 months. It was after 2 pumps we discovered the valve was the reason for the premature pump failure. It was a very frustrating problem. The dealer would get the sec-air system malfunction codes and think it was a failing pump. YES, the pump was failing to pump out the water and it whined like crazy... You might pull the pump and shake it out to see if you find water...

[Johnny-5]

HVAC = Heater/Ventilation/Air Conditioner

The fan is in the dash right in front of the right seat.

Fuel pump is in the gas tank under the battery.

The radiator fans don't run all the time unless the AC is on. Then they run fast.

When AC is off they only turn on (low speed) when needed.

Thanks Loren for the clarifications on things. Im pretty sure its not coming from the inside of the car as its really distinctive outside the car on the passenger front side but once again cant confirm that. The weather here in Cali has been pretty decently warm so the AC is usually on. Do you think the radiator fan could be going bad or maybe just needs cleaning? But if it was going bad wouldnt it be happening everytime it kicks on? In my case it happens in spurts. There will be times Ill step outside to the passenger side and can hear the fan running but no whinning noise?

[Johnny-5]

I hate these pumps! I had a VW and went through 3 pumps ($650 each). On most set-ups...there is a crankcase valve that diverts flow to the crankcase from the sec-air pump. My valve froze (would not completely close) and allowed moisture to accumulate in the sec-air pump... When this water added up over time the pump started to whine as you mentioned. The pump finally stop working when it was full of water. I pulled the pump and shook all the water out and it worked another 6 months. It was after 2 pumps we discovered the valve was the reason for the premature pump failure. It was a very frustrating problem. The dealer would get the sec-air system malfunction codes and think it was a failing pump. YES, the pump was failing to pump out the water and it whined like crazy... You might pull the pump and shake it out to see if you find water...

Did you get any type of check engine while it was whining? Where exactly is this pump that pumps out water? Gee's theres more to these motors than I thought! :cursing:

[PILFILR]

I hate these pumps! I had a VW and went through 3 pumps ($650 each). On most set-ups...there is a crankcase valve that diverts flow to the crankcase from the sec-air pump. My valve froze (would not completely close) and allowed moisture to accumulate in the sec-air pump... When this water added up over time the pump started to whine as you mentioned. The pump finally stop working when it was full of water. I pulled the pump and shook all the water out and it worked another 6 months. It was after 2 pumps we discovered the valve was the reason for the premature pump failure. It was a very frustrating problem. The dealer would get the sec-air system malfunction codes and think it was a failing pump. YES, the pump was failing to pump out the water and it whined like crazy... You might pull the pump and shake it out to see if you find water...

Did you get any type of check engine while it was whining? Where exactly is this pump that pumps out water? Gee's theres more to these motors than I thought! :cursing:

The CEL's occured and were ... Secondary air system incorrect flow? The dealer assumed this meant the pump was bad. So they replaced the pump 2 times. The problem was the crank-case valve. The valve was frozen and allowed moisture back up the pipe to the sec-air pump. The moisture should never be there. Moisture in your pump = a pump that will fail soon. In my case it took 3 pumps to determine why the pumps were failing. The CEL codes told us what was happening...(the air flow was moving the wrong direction)...BUT, it did not tell us why... I had to figure this out. I was sick and tired of paying the dealership to not properly fix the problem..

[PILFILR]

I hate these pumps! I had a VW and went through 3 pumps ($650 each). On most set-ups...there is a crankcase valve that diverts flow to the crankcase from the sec-air pump. My valve froze (would not completely close) and allowed moisture to accumulate in the sec-air pump... When this water added up over time the pump started to whine as you mentioned. The pump finally stop working when it was full of water. I pulled the pump and shook all the water out and it worked another 6 months. It was after 2 pumps we discovered the valve was the reason for the premature pump failure. It was a very frustrating problem. The dealer would get the sec-air system malfunction codes and think it was a failing pump. YES, the pump was failing to pump out the water and it whined like crazy... You might pull the pump and shake it out to see if you find water...

Where exactly is this pump that pumps out water? Gee's theres more to these motors than I thought! :cursing:

There is not another pump... Moisture builds up in the engine and accumulates in the oil. As you drive the car the moisture burns off (if you drive it long enough). Most of the moisture goes out the tailpipe... in my case some of it went to the secondary air pump and condensed into a "pond" that killed my sec-air pump.

[wvicary]

The problem with VW's is the combi valve and this does not happen in P-cars as the secondary pump is higher up and water doesn't collect in it over time as in the VW. Porsche combi valves do fail but often in the closed position. As to the noise described by Johnny-5 I would also check the fuel tank vent valve which can cause an intermittent whistle sound.

[EastBay]

My air pump was doing the same thing, nasty squeal when cold. I took it apart and found it chock full of brake dust. I blew it out with compressed air, cleaned it all up and oiled the bearings and it has been quiet for over one year now. Super easy fix.

[pterfloth]

My air pump was doing the same thing, nasty squeal when cold. I took it apart and found it chock full of brake dust. I blew it out with compressed air, cleaned it all up and oiled the bearings and it has been quiet for over one year now. Super easy fix.

Thanks EastBay! I have been working too much lately to get at a look at this but hope to in the coming week. I suspected a bit of service like you've described was all it would take. It only happens every once in a while but I like to address any symptoms as soon as possible. I'll post my findings once I get it out and have a peek.

Much appreciate your input!

[SpawnyWhippet]

In my recently bought 2004 C4S, I am getting a high pitched whining from the engine bay (when hot), that changes frequency with engine revs. Any ideas what this could be?

[Ahsai]

You may want to remove the serpentine belt, hand spin each pulley and see if they have any free play and noise. Can also run the engine briefly and see if the noise is from the engine.

[DK570]

In my recently bought 2004 C4S, I am getting a high pitched whining from the engine bay (when hot), that changes frequency with engine revs. Any ideas what this could be?

If it changes with revs, I doubt it's the SAI pump. 

 

However, while we are on the subject of SAI, I have codes p0491, and p0492 that reoccur.  These are secondary air injection bank 1 and bank 2.  I'm thinking about replacing every hose + the reservoir.  Looks like you can access all of that if you remove the intake plenums?  Any other ideas?  

 

It's strange in that I only get the codes when it's above freezing.  I've been able to clear the codes, and not have them come back until the temp reaches about 34º on a few different occasions, so I don't think it's a coincidence.   

[Ahsai]

 

In my recently bought 2004 C4S, I am getting a high pitched whining from the engine bay (when hot), that changes frequency with engine revs. Any ideas what this could be?

If it changes with revs, I doubt it's the SAI pump. 

 

However, while we are on the subject of SAI, I have codes p0491, and p0492 that reoccur.  These are secondary air injection bank 1 and bank 2.  I'm thinking about replacing every hose + the reservoir.  Looks like you can access all of that if you remove the intake plenums?  Any other ideas?  

 

It's strange in that I only get the codes when it's above freezing.  I've been able to clear the codes, and not have them come back until the temp reaches about 34º on a few different occasions, so I don't think it's a coincidence.   

 

If you can read O2 sensor voltage from the scanner, you may want to try some diagnostic here 

 

http://www.renntech.org/forums/topic/47862-help-diagnosing-possible-sai-problem/?p=263337

 

It will be a lot easier to diagnose if you can see what the DME sees (hence complains about). I suspect your SAI changeover valve is bad or you have a vacuum leak somewhere.

 

To overhaul those vacuum components, check out my thread here http://rennlist.com/forums/996-forum/849770-mkii-996-vacuum-line-routing-and-related-components.html

 

You only need to remove the alternator and the rear (rear of the car) intake plenum.

[Ahsai]

BTW, your observation of 34F (with some margin) is correct since the pre-conditions for those diagnostic codes are:

• Intake air temperature 4.5 - 60 ° C

• Engine temperature 4.5 - 102 °C

[DK570]

I really want to try and fix this problem now.  I started the car, and recorded until the RPM dropped & the SAI shut off.  I'm looking for opinions on what you see.  To me, the O2 voltage ahead of cat bank 1 looks funky.  Anyone agree or disagree?  What should my next action be?  Thanks!

Copy of 2015_05_25_12_00_21.pdf

[SpawnyWhippet]

I replaced the water pump and the variable pitched whining disappeared. However the SAI motor bearings were also noisy at engine startup, so I stripped it down and greased them. No strange noises from the engine bay now.

 

 

In my recently bought 2004 C4S, I am getting a high pitched whining from the engine bay (when hot), that changes frequency with engine revs. Any ideas what this could be?

If it changes with revs, I doubt it's the SAI pump.