I'm getting an P04011 Code on the Trailblazer and figure it's a bad air pump since I can't hear it running. I've read that they get water in them and quit working and a solution is to drill a small hole in it to release the water. So the question is. Will drilling a hole in it make it work again or is the pump toast?
Bad Air Pump?
- Thread starter Warstud
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if its stopped its probably got water in it and rusted it up and its done. The trailblazer uses a pierburg pump same as my Audi, its not a cheap piece to replace, does your trailblazer have the pump in the engine bay or is it under the truck on the drivers frame rail?
I wouldn't drill a small hole in it, they get water in them because the combination valve is bad allowing hot exhaust to condense in the line. I'm not sure how fussy the trailblazers are but all my euro cars with SAI throw a light at the slightest SAI leak which drilling a hole would cause.
I wouldn't drill a small hole in it, they get water in them because the combination valve is bad allowing hot exhaust to condense in the line. I'm not sure how fussy the trailblazers are but all my euro cars with SAI throw a light at the slightest SAI leak which drilling a hole would cause.
Originally Posted By: Warstud
I'm getting an P04011 Code on the Trailblazer and figure it's a bad air pump since I can't hear it running. I've read that they get water in them and quit working and a solution is to drill a small hole in it to release the water. So the question is. Will drilling a hole in it make it work again or is the pump toast?
Before you go tossing it, the pump might be frozen. This is also on common on VW/Audi when the kombi valve fails in the middle of winter and it does throw a P4011.
Take it off or heat it with a hair dryer for a while, it could have a lot of ice in it so its not happening in a few min, the under hood ones tend to melt with engine heat and blow a huge vapor cloud out the exhaust when it gets free but yours has no heat source do its going to stay frozen.
If its free you need to find the culprit which is usually the kombi valve. 15min job on a VW/Audi 4 cyl yours I have no idea.
I'm getting an P04011 Code on the Trailblazer and figure it's a bad air pump since I can't hear it running. I've read that they get water in them and quit working and a solution is to drill a small hole in it to release the water. So the question is. Will drilling a hole in it make it work again or is the pump toast?
Before you go tossing it, the pump might be frozen. This is also on common on VW/Audi when the kombi valve fails in the middle of winter and it does throw a P4011.
Take it off or heat it with a hair dryer for a while, it could have a lot of ice in it so its not happening in a few min, the under hood ones tend to melt with engine heat and blow a huge vapor cloud out the exhaust when it gets free but yours has no heat source do its going to stay frozen.
If its free you need to find the culprit which is usually the kombi valve. 15min job on a VW/Audi 4 cyl yours I have no idea.
I don't do it but I know people that have drilled a small hole without issue, I don't know what size hole was drilled. Worst case if it throws a code due to leakage you plug/cover the hole with a cut down real short (not long enough to hit something in there) sheet metal screw.
Put 12v test lead to it and see if it spins up good, if so your problem is probably somewhere else. If not the motor is probably shot and needs to be replaced.
Is there a fuse or fusible link for this? I don't have a manual for this vehicle handy but I can look on Monday.
Is there a fuse or fusible link for this? I don't have a manual for this vehicle handy but I can look on Monday.
Worth a shot for sure, if it doesn't work the motor is probably getting weak but give it a chance. did the code code come back?
Strange even turning slow I would think some air would come out, is there any sort of valve that may be vacuum operated that could be closed?
I have had some luck with spraying a good blast of WD40 down them then running them on test leads for about 3-5 min, a few of them have come back (and stayed okay) some didn't.
I have had some luck with spraying a good blast of WD40 down them then running them on test leads for about 3-5 min, a few of them have come back (and stayed okay) some didn't.
Keep in mind that the air pump will only run during what the computer deems a cold start.
Also, if the pump runs on the bench but not on the truck, then maybe a relay issue? When you ran it on the bench, did it spool up quickly and move some serious air?
Also, if the pump runs on the bench but not on the truck, then maybe a relay issue? When you ran it on the bench, did it spool up quickly and move some serious air?
Do you hear the pump running when you start it cold? I am not familiar with this vehicles system, I would think the kombi valve could cause it to throw a code depending on the position it failed in but I don't know for sure how this one is set up.
gathermewool
Site Donor 2023
Are there separate codes for pump and control valve(s)?I was lucky enough to have one of the two control valves freeze up just before my warranty expired. They replaced both, even though the recurrent and then solid fault code called for the one.
Did you check the fuse?
These have a "maxi" large fuse.
These have a "maxi" large fuse.
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