Still Pinging

nme904 · October 19, 2008

I posted here a few weeks ago about my truck that has pinging when the engine is under load. The dealer did an induction service on the engine which may have improved it slightly. Someone posted on here that I should try letting the engine soak in engine cleaner overnight. I pulled the spark plugs and sprayed a can of GM engine cleaner down each bank and let then I let it soak overnight. I'm still getting pinging though.

I am considering having the knock sensors changed but that is something I will have to pay someone to do. I hate to do it if that isn't the likely problem. Anyone have a guess about what is the most likely next cause after carbon build up being ruled out? Thanks for any help you all can provide.

merlin5577 · October 19, 2008

I posted here a few weeks ago about my truck that has pinging when the engine is under load. The dealer did an induction service on the engine which may have improved it slightly. Someone posted on here that I should try letting the engine soak in engine cleaner overnight. I pulled the spark plugs and sprayed a can of GM engine cleaner down each bank and let then I let it soak overnight. I'm still getting pinging though.

I am considering having the knock sensors changed but that is something I will have to pay someone to do. I hate to do it if that isn't the likely problem. Anyone have a guess about what is the most likely next cause after carbon build up being ruled out? Thanks for any help you all can provide.

Check the EGR valve. If its sticking/inoperative it would contribute to pinging. Is the truck throwing any codes?

nme904 · October 19, 2008

I posted here a few weeks ago about my truck that has pinging when the engine is under load. The dealer did an induction service on the engine which may have improved it slightly. Someone posted on here that I should try letting the engine soak in engine cleaner overnight. I pulled the spark plugs and sprayed a can of GM engine cleaner down each bank and let then I let it soak overnight. I'm still getting pinging though.

I am considering having the knock sensors changed but that is something I will have to pay someone to do. I hate to do it if that isn't the likely problem. Anyone have a guess about what is the most likely next cause after carbon build up being ruled out? Thanks for any help you all can provide.

Check the EGR valve. If its sticking/inoperative it would contribute to pinging. Is the truck throwing any codes?

No its not throwing any codes. Where is the EGR and how would I check it? I also forgot to mention its an '02 silverado with the 5.3.

merlin5577 · October 19, 2008

I posted here a few weeks ago about my truck that has pinging when the engine is under load. The dealer did an induction service on the engine which may have improved it slightly. Someone posted on here that I should try letting the engine soak in engine cleaner overnight. I pulled the spark plugs and sprayed a can of GM engine cleaner down each bank and let then I let it soak overnight. I'm still getting pinging though.

I am considering having the knock sensors changed but that is something I will have to pay someone to do. I hate to do it if that isn't the likely problem. Anyone have a guess about what is the most likely next cause after carbon build up being ruled out? Thanks for any help you all can provide.

Check the EGR valve. If its sticking/inoperative it would contribute to pinging. Is the truck throwing any codes?

No its not throwing any codes. Where is the EGR and how would I check it? I also forgot to mention its an '02 silverado with the 5.3.

No codes....hmmm.... Now that is interesting.

I couldnt find a picture of a 5.3L egr valve but here is a picture of the one on my Suburban. Just look for a mushroom looking thing on the top side of the engine. It should be held on by 2-3 bolts and pry tab electrical connector.

Once you get it off there should be two openings on the bottom with flaps covering one or both. Using a pen or similar small object push on the flaps gently. If they open easily it is working fine. If it resists you or doesnt open at all you found your problem. Good luck.

bossier62guy · October 19, 2008

I posted here a few weeks ago about my truck that has pinging when the engine is under load. The dealer did an induction service on the engine which may have improved it slightly. Someone posted on here that I should try letting the engine soak in engine cleaner overnight. I pulled the spark plugs and sprayed a can of GM engine cleaner down each bank and let then I let it soak overnight. I'm still getting pinging though.

I am considering having the knock sensors changed but that is something I will have to pay someone to do. I hate to do it if that isn't the likely problem. Anyone have a guess about what is the most likely next cause after carbon build up being ruled out? Thanks for any help you all can provide.

Check the EGR valve. If its sticking/inoperative it would contribute to pinging. Is the truck throwing any codes?

No its not throwing any codes. Where is the EGR and how would I check it? I also forgot to mention its an '02 silverado with the 5.3.

No codes....hmmm.... Now that is interesting.

I couldnt find a picture of a 5.3L egr valve but here is a picture of the one on my Suburban. Just look for a mushroom looking thing on the top side of the engine. It should be held on by 2-3 bolts and pry tab electrical connector.

Once you get it off there should be two openings on the bottom with flaps covering one or both. Using a pen or similar small object push on the flaps gently. If they open easily it is working fine. If it resists you or doesnt open at all you found your problem. Good luck.

My 02, 5.3L doesn't have an EGR valve so you might be looking for something that isn't there.

merlin5577 · October 19, 2008

I posted here a few weeks ago about my truck that has pinging when the engine is under load. The dealer did an induction service on the engine which may have improved it slightly. Someone posted on here that I should try letting the engine soak in engine cleaner overnight. I pulled the spark plugs and sprayed a can of GM engine cleaner down each bank and let then I let it soak overnight. I'm still getting pinging though.

I am considering having the knock sensors changed but that is something I will have to pay someone to do. I hate to do it if that isn't the likely problem. Anyone have a guess about what is the most likely next cause after carbon build up being ruled out? Thanks for any help you all can provide.

Check the EGR valve. If its sticking/inoperative it would contribute to pinging. Is the truck throwing any codes?

No its not throwing any codes. Where is the EGR and how would I check it? I also forgot to mention its an '02 silverado with the 5.3.

No codes....hmmm.... Now that is interesting.

I couldnt find a picture of a 5.3L egr valve but here is a picture of the one on my Suburban. Just look for a mushroom looking thing on the top side of the engine. It should be held on by 2-3 bolts and pry tab electrical connector.

Once you get it off there should be two openings on the bottom with flaps covering one or both. Using a pen or similar small object push on the flaps gently. If they open easily it is working fine. If it resists you or doesnt open at all you found your problem. Good luck.

My 02, 5.3L doesn't have an EGR valve so you might be looking for something that isn't there.

I though of that as well. But I know different trucks sold in different states got different equipment. I searched google and found a few sites selling EGR valves for an 02' 5.3 so its worth a look.

minibike132 · October 19, 2008

If you have one it should be to the front of the right cylinder head, just infront of the oil fill.

Also in addition to the valve stick a coat hanger down the tube to make sure it isn't plugged up. If the valve opens but there is no place for the exhaust to go it isn't going to work either.

nme904 · October 19, 2008

If you have one it should be to the front of the right cylinder head, just infront of the oil fill.

Also in addition to the valve stick a coat hanger down the tube to make sure it isn't plugged up. If the valve opens but there is no place for the exhaust to go it isn't going to work either.

I took a look under the hood in front of the right cylinder head but there is nothing there. The only thing in that general area is the water pump. So I'm guessing my truck must not have one.

I am kind of frustrated with this whole pinging issue. Any ideas about what I should check or do? The TSB out about knock sensors makes me think that may be it. I have never washed the engine bay or gotten water in there though, and I don't have any codes.

Other than the pinging the truck seems to run as well as it always has.

merlin5577 · October 20, 2008

Does anyone know if his year truck has an EGR valve?

nme, if you run premium fuel through the truck does the pinging go away?

nme904 · October 20, 2008

Does anyone know if his year truck has an EGR valve?

nme, if you run premium fuel through the truck does the pinging go away?

It is substantially lessened by using premium. It is still there though. Does anyone know if there is a way to check the knock sensors without pulling the intake?

merlin5577 · October 20, 2008

It is substantially lessened by using premium. It is still there though. Does anyone know if there is a way to check the knock sensors without pulling the intake?

Ok, I am now stumped. Hopefully someone else can chime in and help you out.

I am pretty sure you can just unscrew the knock sensor and it will come right out.

nme904 · October 20, 2008

It is substantially lessened by using premium. It is still there though. Does anyone know if there is a way to check the knock sensors without pulling the intake?

Ok, I am now stumped. Hopefully someone else can chime in and help you out.

I am pretty sure you can just unscrew the knock sensor and it will come right out.

From what I understand the whole intake on top of the block has to come off to get to them though. I think there may be a way to just check the sensors without actually getting to them though. I have read that there is some way to just check the wiring to see if it is working.

merlin5577 · October 20, 2008

Alright, I did some digging, if your truck has the california/massachusetts emission set up it does have an egr vavle and it looks like this;

merlin5577 · October 20, 2008

From what I found on autozone.com your truck should have 2 knock sensors, 1 on each side of the engine screwed into the block or cylinder head and they look like this;

bossier62guy · October 20, 2008

From what I found on autozone.com your truck should have 2 knock sensors, 1 on each side of the engine screwed into the block or cylinder head and they look like this;

But they are under the intake just like he stated.