Sorry guys this is my first post, i had no idea where to post this. Anyway, we have a 2005 Uplander with the 3.5 v6, and it just crossed 100K miles...we do oil changes at a local shop every 3000 miles with regular dyno oil. I think its castrol gtx...anyway, ONLY AFTER then car heats up to operating temp and you are accelerating right around 2500-3000 rpm (thats where the greatest load is on the engine) it starts to ping (that marbles in a tin can sound) yes we started to use premium 93 octaine gas, yes we have done a carbon clean out and used seafoam and techron multiple times. had the coolant changed too. new spark plugs and wires also. NO check engine lights ever. had it scanned, nothing. Is this damaging the engine? Ive heard pinging is bad for an engine. Its been going on for about a year and a half. it doesnt happen during the winter months though. we live in florida so the winter months are very few. SO most months it is pinging, and in the summer when its hot out it pings VERY bad. Any idea? is there bad damage being done? or is she going to be ok? we want to keep the van for a while longer, just had the transmission rebuilt and two new tires put on the front as well as a rear brake job.
Chevy Uplander pinging problemsSorry guys this is
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How much does a new knock sensor cost? Maybe that isn't functioning correctly and isn't retarding the ignition as it should?
Did this problem begin all at once?? The first place to look would be the knock sensor...there may be more than one. This transducer detects ping and sends a signal to the computer to retard the timing enough to end the pinging. It may have failed, or a wire/connection may have failed.
No, it will not set a fault code, as no pinging is being detected.
Nearly all of our newer cars have both high compression and lots of spark advance in search of gas mileage....but are dependent upon the knock sensors and circuitry to protect the motor from the ravages of severe spark knock.
Most competent garages should be all over this problem. The ones that recommended additives, new wires, etc are not the places to return to.
No, it will not set a fault code, as no pinging is being detected.
Nearly all of our newer cars have both high compression and lots of spark advance in search of gas mileage....but are dependent upon the knock sensors and circuitry to protect the motor from the ravages of severe spark knock.
Most competent garages should be all over this problem. The ones that recommended additives, new wires, etc are not the places to return to.
You can idle it and rap on the motor with a big wrench or small ball peen hammer. Pick something solid like a motor lifting eye hook. Try and bang 2x a second for 5 seconds. Something in the sound of the idle should change, that would be the knock retard kicking in.
isn't the knock sensor monitored by the car computer? if it weren't within spec, the CEL light would surely have lit up with the knock sensor code?
I have an 06 Relay, same engine and I'm at 83k. I use cheap costco gas usually and I haven't changed plugs or anything else yet.
You mentioned you changed spark plugs on it..
what brand? AND was the gap set to .060" (which is the factory spec)?
That engine comes with Iridium tipped plugs, and I'd run the AC Delco's, nothing less, and make sure the gap is set correctly.
There is no such thing as a pre-gapped plug.
I have an 06 Relay, same engine and I'm at 83k. I use cheap costco gas usually and I haven't changed plugs or anything else yet.
You mentioned you changed spark plugs on it..
what brand? AND was the gap set to .060" (which is the factory spec)?
That engine comes with Iridium tipped plugs, and I'd run the AC Delco's, nothing less, and make sure the gap is set correctly.
There is no such thing as a pre-gapped plug.
Originally Posted By: EricF
isn't the knock sensor monitored by the car computer? if it weren't within spec, the CEL light would surely have lit up with the knock sensor code?
I have an 06 Relay, same engine and I'm at 83k. I use cheap costco gas usually and I haven't changed plugs or anything else yet.
You mentioned you changed spark plugs on it..
what brand? AND was the gap set to .060" (which is the factory spec)?
That engine comes with Iridium tipped plugs, and I'd run the AC Delco's, nothing less, and make sure the gap is set correctly.
There is no such thing as a pre-gapped plug.
i dont know. had it done at the local shop. They were iridium tipped whatever whatever they were. either way it pinged before and after the spark plug change. they said the plugs were clean and were barely out of spec gap wise. wires were changed too. like you said, i would think that the cel would come on if the knock sensor went out but no cel =/ anyway, is it doing damage???
isn't the knock sensor monitored by the car computer? if it weren't within spec, the CEL light would surely have lit up with the knock sensor code?
I have an 06 Relay, same engine and I'm at 83k. I use cheap costco gas usually and I haven't changed plugs or anything else yet.
You mentioned you changed spark plugs on it..
what brand? AND was the gap set to .060" (which is the factory spec)?
That engine comes with Iridium tipped plugs, and I'd run the AC Delco's, nothing less, and make sure the gap is set correctly.
There is no such thing as a pre-gapped plug.
i dont know. had it done at the local shop. They were iridium tipped whatever whatever they were. either way it pinged before and after the spark plug change. they said the plugs were clean and were barely out of spec gap wise. wires were changed too. like you said, i would think that the cel would come on if the knock sensor went out but no cel =/ anyway, is it doing damage???
IME a knock sensor is a pretty simple piece of equipment. Two wires. Power goes in, if it senses knock it completes the circuit. I don't see how the computer could monitor one, if it never went off the assumption would just be that there is no knock. There is no diagnostic mode. You can bench test them with a 12v source and a test light. But why would you...
Out of boredom at work/curiosity I had to know what one would cost for the Uplander. RockAuto. AcDelco. Four dollars, seventy six cents. Seriously. Don't search for complex hail mary fixes. Your car is knocking. Why would you not R&R a part called a "Knock sensor" for four dollars?
Out of boredom at work/curiosity I had to know what one would cost for the Uplander. RockAuto. AcDelco. Four dollars, seventy six cents. Seriously. Don't search for complex hail mary fixes. Your car is knocking. Why would you not R&R a part called a "Knock sensor" for four dollars?
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Pinging, especially signficant pinging, is very bad for the tops of the pistons.
Was the shop told about this problem?
You have two separate issues
1) It should not be knocking in the first place
2) If it is knocking, the computer should retard the timing to eliminate the knock
First could be happening because the engine is full of carbon or something is causing the timing to be wildly off
Second means that either computer is not hearing the knock aka non-working knock sensor or timing is still off after the computer has retarded it as much as it is programmed to do so. However, if it were the later case, it will (should?) throw check engine light.
A good shop would have looked at the timing using the scanner and using old fashioned timing light. It would have also checked the knock sensor manually as eljefino suggested. It would have also performed the carbon clean service if it found timing withing specification and working knock sensor.
You have two separate issues
1) It should not be knocking in the first place
2) If it is knocking, the computer should retard the timing to eliminate the knock
First could be happening because the engine is full of carbon or something is causing the timing to be wildly off
Second means that either computer is not hearing the knock aka non-working knock sensor or timing is still off after the computer has retarded it as much as it is programmed to do so. However, if it were the later case, it will (should?) throw check engine light.
A good shop would have looked at the timing using the scanner and using old fashioned timing light. It would have also checked the knock sensor manually as eljefino suggested. It would have also performed the carbon clean service if it found timing withing specification and working knock sensor.
Are your non standard plugs too hot?
How about an odd bad water pump impeller?
Could be a coolant temp sensor [not the gauge sensor.
How about an odd bad water pump impeller?
Could be a coolant temp sensor [not the gauge sensor.
Originally Posted By: EricF
isn't the knock sensor monitored by the car computer? if it weren't within spec, the CEL light would surely have lit up with the knock sensor code?
Nope. On my car there was an issue with the knock sensor where the wires would chafe and short it occasionally. No CEL and the only indication I had was occasional hard pinging and pulsating at highway speeds (trailer hitching). Wasn't till the tech saw the car "knocking" at idle did they narrow it to the sensor.
isn't the knock sensor monitored by the car computer? if it weren't within spec, the CEL light would surely have lit up with the knock sensor code?
Nope. On my car there was an issue with the knock sensor where the wires would chafe and short it occasionally. No CEL and the only indication I had was occasional hard pinging and pulsating at highway speeds (trailer hitching). Wasn't till the tech saw the car "knocking" at idle did they narrow it to the sensor.
AFAIK knock sensors return "some" voltage to the computer even when they're sitting there, and a voltage with a frequency on top of it if they're knocking. So an open circuit would be detected.
If the knock sensor fell apart insides, or separated itself from the engine block so it didn't feel vibrations, I can see it failing w/o code.
If the knock sensor fell apart insides, or separated itself from the engine block so it didn't feel vibrations, I can see it failing w/o code.
Originally Posted By: bepperb
Out of boredom at work/curiosity I had to know what one would cost for the Uplander. RockAuto. AcDelco. Four dollars, seventy six cents. Seriously. Don't search for complex hail mary fixes. Your car is knocking. Why would you not R&R a part called a "Knock sensor" for four dollars?
There you go, trying to spend other people's money. It's easy to just jump right out there and offer up some other guy's $4, but if it were your pinging problem would you be so ready to just open up your own wallet and buy something that could possibly be unnecessary?
Out of boredom at work/curiosity I had to know what one would cost for the Uplander. RockAuto. AcDelco. Four dollars, seventy six cents. Seriously. Don't search for complex hail mary fixes. Your car is knocking. Why would you not R&R a part called a "Knock sensor" for four dollars?
There you go, trying to spend other people's money. It's easy to just jump right out there and offer up some other guy's $4, but if it were your pinging problem would you be so ready to just open up your own wallet and buy something that could possibly be unnecessary?
Originally Posted By: yonyon
There you go, trying to spend other people's money. It's easy to just jump right out there and offer up some other guy's $4, but if it were your pinging problem would you be so ready to just open up your own wallet and buy something that could possibly be unnecessary?
4 dollars and 76 cents....
There you go, trying to spend other people's money. It's easy to just jump right out there and offer up some other guy's $4, but if it were your pinging problem would you be so ready to just open up your own wallet and buy something that could possibly be unnecessary?
4 dollars and 76 cents....
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A knock sensor is a peizoelectric device that generates electricity in the presence of knock. It can be grounded to the block and have a single signal wire or have two wires. The ecu measures the ohms of the sensor and will trigger a trouble code and possibly a CEL.
That five bucks is almost three days of lunches for one of my kids at school. No need to replace parts that aren't known to be broke, yet.
Five bucks is five bucks can get wasteful fast.
Five bucks is five bucks can get wasteful fast.
Just a data point:
On my 97 Maxima, a bad knock sensor didn't trigger a CEL but did set a code. Since OBD -II is a standard, I would expect all the OBD-II cars behave the same.
$4.76 is not a lot of money, but I'll bet replacing the part is a PITA.
On my 97 Maxima, a bad knock sensor didn't trigger a CEL but did set a code. Since OBD -II is a standard, I would expect all the OBD-II cars behave the same.
$4.76 is not a lot of money, but I'll bet replacing the part is a PITA.
a guy told me that knock censer will activate if there is a bolt or something else lose on the engine. just a thought.
Originally Posted By: toeout
On my 97 Maxima, a bad knock sensor didn't trigger a CEL but did set a code. Since OBD -II is a standard, I would expect all the OBD-II cars behave the same.
It doesn't quite work that way. If the detected fault (in this case a faulty knock sensor) can be expected to increase emissions to the limit the vehicle is certified for + 50% it turns the light on. If not, then you get a stored DTC with no light. This varies from model to model and can even vary within one model depending on where the car is first sold as new.
On my 97 Maxima, a bad knock sensor didn't trigger a CEL but did set a code. Since OBD -II is a standard, I would expect all the OBD-II cars behave the same.
It doesn't quite work that way. If the detected fault (in this case a faulty knock sensor) can be expected to increase emissions to the limit the vehicle is certified for + 50% it turns the light on. If not, then you get a stored DTC with no light. This varies from model to model and can even vary within one model depending on where the car is first sold as new.
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