My 97-528 SAP is kind of loud compares to my 02-530.
It's a fast loud thumping sound.
I think the air passage may have been clogged, but then again this maybe normal for 528.
How's every 528 SAP sound in the morning? Thanks for the feed back.
I can't speak from experience with a 528 but a SAP should not have a "fast thumping sound". It should be very similar to your 530, where you can hear it if you are listening to it but it is strictly background noise. Your check valve could be failing or your pump could be failing. I would check both.
It's definitely louder than my 530
The pump and air valve were replaced at the same time about a year ago
The sound exist before replacement of both valve and pump
Reason to replace was CEL
Car has no CEL at themoment.
I think the orifice inside the exhaust manifold is partial clogged.
I think I need to find a way to clean the carbon build up inside the exhaust manifold.
But here is my plan to diagnose.
Disconnect the output hose to the pump and turn it on and see if the noise still there or not. And depends on the outcome of this test, I will have a better idea.
I think I just had my SAP issue figured out. I was getting codes for low air for secondary pump and it was very loud. I replaced the tube that goes from the pump to the valve, issue persisted. I then replaced the vacuum hose connected to the valve which got baked since it was routed above the exhaust manifold. Whoever designed that should be shot. I also replaced the salmon colored relay in the E-box. It's the 3rd day and the code has not come back.
The pump is sooooo much quieter now. I have a feeling that between the vacuum leak and the relay ( not opening the valve), the pump was having to work much harder. I used to be able to hear it over the motor and possibly the next neighborhood over.
Yes, it's under the cabin filter housing(driver side) which easily comes off. It's the only salmon color relay and P/N 1263742690 ($14 from dealer).
The pump is sooooo much quieter now. I have a feeling that between the vacuum leak and the relay ( not opening the valve), the pump was having to work much harder. I used to be able to hear it over the motor and possibly the next neighborhood over.
Yes, it's under the cabin filter housing(driver side) which easily comes off. It's the only salmon color relay and P/N 1263742690 ($14 from dealer).
Thank you BentValve for getting back with me on this info.
Yeh! my SAP is really loud, I'm hoping to find a clogged vacuum line to the air valve, this would explain the fast thumping (whooshing, chu chu train) sound.
If the above doesn't then I will look into the relay. Thanks again.
Yeah check the little things first. Your pump should be fine if it still turns on, chances are the valve is fine too. The vacuum hose that goes from the valve to the electric air valve is more than likely rotted. Replacing that was the hardest because the electric air valve is under the intake manifold. I basically just had to feel around there to put the new hose on.
In my case, I'm not sure if it was the vacuum hose or the relay, I replaced both to be on the safe side. I still have the relay which may or may not work if you want it.
I don't think your vacuum line would be clogged but it may be cracked, leading to a leak, which could then result in insufficient pressure to fully open the check valve. The backpressure against the pump could be that sound you are hearing. I would check the section of the vacuum line between the thin plastic pipe that runs parallel to the engine and the check valve. That section of hose is prone to fracture due to the exhaust manifold heat. The rear section between the plastic line and the pump is usually fine as it is away from any major heat source.
Yeah that vacuum line was toast on my car. I tugged on it just a little (I'm not Hercules) and it crumbled. I routed the new one under the intake manifold now. It's not pretty but functional.
Since this car is a 97 M52, the vacuum control line is ran around the front, and then under the intake manifold. I remember replaced all the hoses about a year and half ago during the CCV R/R.
- All hoses appeared to be in good shape
- Checked item 11 electric valve functions, it toggled when 12V DC is applied.
- Checked item 14 one-way valve for correct position and blow test passed.
I'm back to square one
1/ Air valve partial clogged
2/ Exhaust passage partial clogged
3/ Pump has water
Tomorrow morning when the engine is cold I will disconnect the inlet hose to the air valve and see if the loud noise changes.
- Just dis-connect the big hose goes to the air valve inlet, started the car, no chu chu train nor fast thumping noise, I can feel the powerful air out of this hose. So, the pump itself is fine.
- I also checked the for vacuum during this time from the vacuum line, and yes I felt vacuum.
Now, with the above have been checked and verified.
The remainders are more likely suspect.
- Half clogged air valve
- Partial clogged exhaust passage.
I plan to to take Seaform to this thing. Stay tune.
Before you do that seafoam madness, try removing the valve, and let it soak in WD-40 overnight. If the valve is partially sticking mechanically, this soaking will free things up.
If the valve isn't opening up due to other issues, like a diaphragm malfunction, then most likely a replacement is what's needed. :dunno:
FYI, the BMW TIS recommends that whenever you suspect a bad air valve, the following in that circuit needs to be replaced to avoid further troubleshooting:
1. Air Valve (average life is 100-120K)
2. Vacuum hose to Air Valve and to the Electric Valve.
3. Electric Valve (under Intake Manifold), here is a pic of the Electric Valve:
Good idea on soaking the airvalve :thumbup:. I may try that tonight.
I would replace the air valve in a heart beat if I know for sure it will solve my chu chu train noise problem. The last time I checked for price was 110 buckaroos, that's a lot of money to throw away.
Good idea on soaking the airvalve :thumbup:. I may try that tonight.
I would replace the air valve in a heart beat if I know for sure it will solve my chu chu train noise problem. The last time I checked for price was 110 buckaroos, that's a lot of money to throw away.
Don't worry I won't go the brake booster route.
I will probably go via the air valve inlet.
Even if it doesn't fix your problem, consider valve replacement as preventive maintenance. They can and do fail. I had one fail at around 35k miles under warranty. When I hit 120k I went ahead and had a new one installed.
Interesting about your results with Seafoam. It is supposed to reduce intake deposits on valves and such. I run a can of Lubro Moly "Ventil Sauber" in my gas tank every 5k miles or so. When I had my valley pan gaskets replaced the tech said my intake system and the ports into the intake valves looked really good.
So, I have been hitting my SAP with Seafoam about a 1/4 of the bottle each time early in the morning to ensure the SAP will kicking.
Start the car up, nice cloud of white smoke out of the tail pipe and a whip of stinky diesel aroma, off I went for a ride to burn up the seafoam while bring the cats to temperature.
It has been three times and 3/4 of the Seafoam bottle later and here is my impressions
- The audible chu chu train sound of the SAP has definitely improved.
- The exhaust out of the tail pipe is not as smelly as it used to be. I considered this is a bonus since I didn't expect any thing.
I will probably get another bottle once this one run out.
So what do you think folks?
Not sure what exactly the Seafoam is doing to what but if it works, what the heck! FWIW, I had multiple (3 total over 4 years) SAP failures in my previous e39. This one has no issues over 2 years. :dunno:
The Seafoam thing is supposedly remove carbon deposits wherever it touches, there's ton of people out there really believe in them. I'm one of those that is reluctant, but what the heck! is the correct term for me too.
If this ever turned out to be the fix for my chu chu train sound! I will make seafoam as a part of my SAP passage routine maintenance.
This morning the ambient temperature is about 25 degree F.
Started the car. No more chu chu train or fast thumping sound. After all these years it's finally fixed.
The credit goes to E46Fanatics though! Here is picture I got from them.
DHoang,
Make sure the engine is cold early in the morning to ensure the secondary air pump will kick in.
Just pour about a 1/4 of the seafoam or less then re-attch the hose.
Start the car, let it idle for 15 minutes, go for a ride to burn off.
Yes, when you pour the seafoam it would go down to the motor, but no big deal once the motor kicks in, all will be evacuated into the air valve, exhaust passage, and some will go to the intake manifold via the smaller vacuum hose.
I will be doing this to all my cars as a preventive maintenance. You wouldn't believe how quiet my SAP now :thumbup:
I noticed my pump a few times (many months ago) to be quite noisy on -some- occasions, not always (more of a loud electrical buzz than a choo-choo), but in recent months I've heard nothing from it. Maybe it is dead...
My car starts fine, runs fine, no CELs, nothing ... but the silence is worrisome. Time to diagnose but wanted to get some clarification with the Seafoam.
If you are running Seafoam through the valve, does it go straight into the cats (ex. manifold) and out the exhaust? Or into the cylinders/valvetrain at all?
I noticed my pump a few times (many months ago) to be quite noisy on -some- occasions, not always (more of a loud electrical buzz than a choo-choo), but in recent months I've heard nothing from it. Maybe it is dead...
My car starts fine, runs fine, no CELs, nothing ... but the silence is worrisome. Time to diagnose but wanted to get some clarification with the Seafoam.
If you are running Seafoam through the valve, does it go straight into the cats (ex. manifold) and out the exhaust? Or into the cylinders/valvetrain at all?
I just went out and unplugged the fat plastic hose between the SAP and the valve. It has no major residue.
I will test the relay with a 12v source, and may try to clean the checkvalve (possible?) and dissect the pump. I have a new bearing that I bought sometime ago, time to go read CN90's rebuild thread again ....
This morning it was about as cold as it usually can get here in wintertime, just below freezing. I unplugged the pump hose from the diverter valve and cranked the car.
The flow from the pump is very strong and steady but the pump itself I cannot hear over the engine.
The diverter valve inlet has vacuum, but it is not anywhere as strong as the air blowing out the pump hose.
I suppose this means time to replace the valve. Thing sure looks clean and shiny but it's probably 12.5 years old.
My other car wants a battery.... I'm about ready to join a monastery, too much material controlling my life.
Pete, sounds to me your SAP is working orderly. The diverter valve's vacuum just enough to open the valve to let the air into the engine. I would not do a thing to it..
I believe there is a spring inside the valve. The vacuum simply overcomes the spring tension and opens the valve. When the vacuum ends, the spring closes the valve. Pretty simple. I believe the problem is with carbon buildup in the valve. It is exposed to the constant exhaust stream on one side, which is full of contaminants. These build up over time and eventually cause the diaphram to jam in the open position. This then allows hot exhaust gas into the pump, which condenses into water, drips down into the pump and kills it. That is why periodic (every 8-10 years) replacement of the check valve is good preventative maintenance. The pump only runs for a minute or so every cold start so it should last the life of the car. Only when the check valve fails does the pump fail.
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