E46 Fanatics Forum banner
41 - 60 of 93 Posts

· Registered
2003 330ci
Joined
·
2,370 Posts
Post number two in this thread states:

"The hose will hold just over an ounce of Seafoam. Reconnect the hose and run the car 5 seconds so the air pump blows the Seafoam into the exhaust port. Repeat this fill and restart 3 more times only running the engine 5 seconds so the secondary air pump runs for the 3 fills. "
 

· Registered
Joined
·
20,764 Posts
Good thread, I just bought an OEM air box thinking that it would solve my check engine light. Returning P1421 and 1423 codes brought me here.

My light was intermittent at first, it would literally go on and off randomly for days/weeks/months at a time, until recently, it hasn't turned off in a month or so now.

Going to try Seafoam first
 

· Registered
Joined
·
2,794 Posts
The primary issue with the SAP is caused by two things:
- the check valve in the vacuum system needs to be replaced occasionally
- the solenoid that controls the air flow to the SAP valve needs to be removed, and cleaned with electronic parts cleaner
These two items are the source of the issue in most cases. The solenoid actuates the valve to open it. When it deactivates, the vacuum in the line needs to bleed off rapidly, to close the valve. The check valve in the vacuum line to the solenoid is what causes the vacuum to bleed off. If the SAP valve does not close immediately, because the vacuum is not bleeding off, the valve stays open, and exhaust gasses blow through the valve, and into the pump. This will kill the pump eventually.
This Seafoam procedure does not address the root cause. It simply cleans out the valve, and the cycle starts again. If you pull off the hose from the pump to the valve, look inside the hole, and see soot from engine exhaust blowing past the valve, then you need to replace the check valve, and clean the solenoid. Replace the rubber hoses as well. If the system is working normally, you should see a nice, clean valve when you look inside there. Anything else is a sign of a larger problem that will eventually kill your SAP.
Another sign of a failure of the vacuum actuation is if your hose from the SAP to the valve is degrading. It should be firm, and hard to compress. Check the large vacuum line from your brake booster for reference. They should feel the same. If it is degrading, it is because of exhaust gasses blowing by a SAP valve that is not closing in time to prevent exhaust gasses from back flowing into the pump. I have seen many people advise replacement of the hose, but a degraded hose is a symptom of another problem.
The fix is fairly cheap, but a bit labor intensive, due to the location of the solenoid and the check valve. If you want to save your $400 SAP pump, I would advise dealing with the problem, rather than treating a symptom (dirty SAP valve).
Also, it is much easier to just remove the valve, and clean it with brake cleaner, rather than pouring Seafoam in your engine. You can also access the port in the head with the valve off, and clean it as well. BUT, you need to deal with the root cause of the problem, in addition to cleaning the valve.
 

· Registered
Joined
·
520 Posts
Secondary Air Pump & Valve

I used to get secondary injection codes now Iam getting post car too rich codes. Is the rich code from lack of oxygen from the pump? Only happens when it's really cold


Sent from BimmerApp mobile app
 

· Premium Member
Joined
·
28,968 Posts
You are not likely getting Rich codes, you probably have Lean codes. If you are using a BMW type of specific software, it probably says something like fuel control at Rich deviation, this reference means the engine is running lean and the fuel control cannot compensate for the massive lean condition.

SAP not working does not cause fuel management issues other than slower O2 sensor and catalytic converter warm up.
 

· Registered
Joined
·
520 Posts
Secondary Air Pump & Valve

You are not likely getting Rich codes, you probably have Lean codes. If you are using a BMW type of specific software, it probably says something like fuel control at Rich deviation, this reference means the engine is running lean and the fuel control cannot compensate for the massive lean condition.

SAP not working does not cause fuel management issues other than slower O2 sensor and catalytic converter warm up.
The code I was getting was post cat too rich. And used to get injection codes at like 40 degree but now being so cold I only rich


Sent from BimmerApp mobile app
 

· Premium Member
Joined
·
28,968 Posts
Please provide the exact code and description.
 

· Registered
Joined
·
5 Posts
ive been getting the same codes and confirmed my air pump is dead - getting 12 volts to it on startup, but its not running. So i spend the $500 in parts to replace the pump and valve. Seems like a very easy job.

i was just wondering though - i don't notice a difference in the way the car runs. Whats the risks if i don't replace them, and leave it as is? Am i causing damage to the motor?
 

· Registered
Joined
·
56 Posts
After using the Seafoam trick I think it breathed new life into the hose around the Secondary Air Pump. It's been several weeks now and there has been no occurrence of the check engine light or code P0492. I highly recommend this if you aren't sure if the SAP is the culprit or if it's simply a hose and air flow issue.

Edit 2015: It's been over a year and based on my experience Sea-Foam is hardly the solution. The real culprit was that after either sitting for a few days or when the temperature drops the SAP would throw the P codes during a cold start and then would settle down back to normal with no problem. Seems like it's a temperamental issue with the SAP that can come and go but is not always because it is failing. In my case the SAP has continued working with no problem. If you can still hear it pumping when you first start it, it's not necessarily the SAP going bad.
 

· Premium Member
Joined
·
28,968 Posts

· Registered
Joined
·
1,102 Posts
P0491 and P0492. Everything I've read anywhere indicates that this is a problem somehwere in my secondary air system. I believe I've verified that all the components between the pump and the manifold are in proper working order.

I dont have freeze frame data, but if this problem persists I'll have to obtain it.
 

· Premium Member
Joined
·
28,968 Posts
What everyone needs to understand is on the older SAP systems without the input air MAF, the O2 sensors confirm the SAP is operating properly.

If the O2 sensors are lazy, the there is no way for them to confirm the SAP is operating.

So the issue MAY be related to lazy O2 sensors, but it could also be something more basic.

The SAP Readiness Monitors should clear on the first cold start. This is not something that takes multiple starts.

Not sure what OBDII tool you are using, if it is a very cheap one, they do not support Freeze Frame.

Also Freeze Frame is ONLY available while the SES/CEL/MIL is still lit, once you clear the codes the Freeze Frame info is cleared until the next instanace of the SES/CEL/MIL coming on.

Do not put a lot of hope for "Mechanic In A Can" to resolve your problem.

You could graph the O2 sensors from cold start if you had the right OBDII tool, or if the sensors are orignal on an E46, the Pre-cat sensors are likely due for a refresh anyway.
 

· Registered
Joined
·
1,102 Posts
What everyone needs to understand is on the older SAP systems without the input air MAF, the O2 sensors confirm the SAP is operating properly.

If the O2 sensors are lazy, the there is no way for them to confirm the SAP is operating.

So the issue MAY be related to lazy O2 sensors, but it could also be something more basic.

The SAP Readiness Monitors should clear on the first cold start. This is not something that takes multiple starts.

Not sure what OBDII tool you are using, if it is a very cheap one, they do not support Freeze Frame.

Also Freeze Frame is ONLY available while the SES/CEL/MIL is still lit, once you clear the codes the Freeze Frame info is cleared until the next instanace of the SES/CEL/MIL coming on.

Do not put a lot of hope for "Mechanic In A Can" to resolve your problem.

You could graph the O2 sensors from cold start if you had the right OBDII tool, or if the sensors are orignal on an E46, the Pre-cat sensors are likely due for a refresh anyway.
I'm not 100% clear on how you're describing they system.

But I do know that the "mechanic in a can" is a quick and easy way to attempt to resolve the problem before I go digging any further. It's also cheap, so no harm there. If it doesn't work then I may have to put more time into the car. Time is at a premium for me these days, so its worth a shot.

BTW, I don't have a code reader. I just go to AZ to get the codes read. If I have to, I'll set up PASoft so I can get more information when this stuff happens.

My car has 175k miles, so I'm guessing I'll be seeing more and more SES lights as the car reaches and surpasses 200k. So if I want to keep it on the road that may be a sound investment. I already have the software I just need the interface. PASoft will provide all the info I need, correct?

Is it only the pre-cat o2 sensors that might be the problem? Cuz the postcat sensors are a PITA and probably even worse on an XI. I'm guessing you need more info to really know.
Reading through your other thread, sounds like this could be a real PITA. May just be time to trade the car in if replacement pre-cat o2 sensors dont solve he problem.
 
41 - 60 of 93 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top