ecrouse

I've Googled myself in to a corner so now I ask for help.

First off, first post so hi. That out of the way:
I have a new to me 2000 C5 and driving home it popped a CEL. Pulled codes, got p0410 and p0411. Dug in and found the secondary air pump wasn't pumping so I took it out. Bench test showed bad motor, got replacement and installed, now it blows nicely. Cleared codes, drove around, pending p0410.

Checked bypass valve with Mityvac and valve opens under vacuum. Checked vacuum line to bypass, no vacuum. Google says this is likely due to a leaky battery eating the vacuum line under the bat tray but may also be a problem at MAP sensor which requires pulling intake.

Before I start disassembling my motor I though I might do a sanity check here.

Is there an interim step between "no vacuum at secondary air bypass" and "remove intake manifold" that I should be doing? Do I need to remove the battery and battery tray to get to the vacuum lines underneath or is there a better way? I have found conflicting information as it seems there was a change in the 2001's and possibly an access panel behind the passenger tire that gets me in to the area under the battery tray.

Asking you guys before I start taking stuff apart so I can find the shortest path to success.

Thanks in advance.

Pounder

taking the battery out and checking for acid damage would not be a waste of time, and I would do that for piece of mind considering the damage a leaking batt. can cause. I know you are saying no vacuum but did you check your gas cap for tightness?

Pounder

don't know what info you have but here is some more.

ecrouse

Thanks for the info, I think my current problem is summed up in the first sentence "A P0410 code is very common on the 2000 and 99% of the time it is caused by a vacuum leak."

With no vacuum to the bypass valve it never opens so till I get that cleared up it is my only problem
Question is, next steps. I need to find the other end of that vacuum line and see if there is a leak somewhere but I don't know where it is. Under the battery tray? Behind the intake manifold? Behind an access panel in the passenger wheel well?

I suppose I could just pull the wheel and see what's back there, just trying to save myself some effort.

ecrouse

Just went and pulled the battery. Current battery isn't leaking, there is a bit of rust in the well under the battery tray but nothing that says massive corrosion to me. I'll let you guys judge.





Still, there is a mess of stuff under there. Is that where I look for the other end of this vacuum line?

I did see that there was an access panel in the passenger wheel well.

Pounder

take the batt tray out and check some more and the access panel will give you a better view of the vacuum tank and such, can check for vacuum there also.

ecrouse

Heh, that was my plan of attack for this morning, removing the access plate and seeing what was there. Then I realized some idiot pulled my battery and removed my intake tube and MAF sensor before they put the car on the 2x12 so I can't get my jack under it to remove the tire. If I catch that guy...

eleonb

I had this problem a few years back. Between the pump and the vac. tank, the rubber hose was broke, i put a hose connector in it and solved the problem. A few months later it happened again so I ran a new line all the way through. If u have a air compressor with blower nozzle or canned air, u can blow from the pump side and hear where the leak is, a friend would be very helpful here while u listen for air. Hope this helps. You can finish jacking car up from frt under cross member lol

ecrouse

Good idea with the air, thanks. I just ended up pushing it on to the board. Love how light these things are.

ecrouse

Well, compressed air did it, it was within three inches of the pump elbow :/

Something melted the plastic just enough to to leak.

The other end of this thing ends up in a manifold or solenoid that is mounted on the top of the inner fender liner so I'd have to remove the fender to access it. Hopefully it doesn't come to that. From there it goes to the tee on the vacuum reservoir which also seems inaccessible without removing the fender or the computer.

Does this seem correct or am I making it harder than it needs to be?

don37

There is a vacuum switch behind the fender. remove the front fender. i would also remove the intake plenum.

ecrouse

All fixed! Thanks for the tips, everybody. I picked this car up as a fun project car, it has many needs but the price was right. Right now I'm just trying to get through inspection so I can transfer the title but I need to replace the drivers fender due to damage so I'll probably pull the passenger fender too and clean up the rust I found there.

I probably ought to pick up a service manual too...

Pounder

huesmann

I had the exact same problem with my P0410 code. The plastic hard line between the AIR pump and the vacuum manifold behind the fender had cracked somewhere where it travels inside the wrapped-up wiring harness. I wasn't about to unwrap the harness just find where it was broken, so I just ran rubber vacuum tube the entire length from the pump to the vacuum manifold.