Afm Knocking/pinging

cpirch · November 2, 2007

When my yukon switches into v4 mode I hear some pinging/knocking going on.

Does anyone else hear this. Dealer called GM Tech line and they said it was considered normal??

The manual of course calls for 87 octane fuel, but when I run 93 octane the noise is virtually eliminated.

xThanks

2007silveradonbs · November 2, 2007

If I used Citgo gas, I get pinging. I learned my lesson. You should try a better quality gas.

C & A s Dad · November 2, 2007

Charles, I am a beiever of 93 octane fuel in late model 5.3s and 6.0s but I would have to disagree with what your dealer has told you. I firmly believe the Computer system in your truck will take advantage of higher octane fuels by increasing the timing, thus providing more power. However, in no way should it be pinging on 87 octane fuel. The Knock Sensors are there to take care of this by sending a message to the computer so it can retard the timing to remove the ping.

Seeing that your truck is a 2007, if you try another brand of 87 fuel and it continues to ping, you need to see your Svc Mgr. IMO, this would not be acceptable.

cpirch · November 2, 2007

The shop foreman called the gm techline and was informed that because of the way the lifters work in the transition between v8 to v4 mode, that noise is considered withen spec.

I also questioned him about the knock sensor, and he told me that in his opinion if the knock sensor was malfucioning, I would have a check engine light on and when the tech 2 system was hooked up everything showed to be normal.??

He did complete a field service report, so hopefully, they will figure something out, if not I may try another dealer.

I personally believe that if it was normal, it would have made the noise from the beginning and not started at about 10000 miles.

Norseman · November 2, 2007

There is a TSB for this. # 06-06-05-001A.

Ive up loaded a copy as an attachment. You should be able to down load it.

TSB_06_06_05_001A.pdf

cpirch · November 2, 2007

Thank you for the information

NathanL · November 2, 2007

I guess if enough people complain about something to GM they don't change/fix it - they just issue a bulletin saying "It's normal"......not a big fan of that.

If that many people complain then they have a problem and need to fix it even if it won't hurt the truck mechanically. It's not a normal sound in a truck that's why people complain lol.

Norseman · November 2, 2007

I guess if enough people complain about something to GM they don't change/fix it - they just issue a bulletin saying "It's normal"......not a big fan of that.

If that many people complain then they have a problem and need to fix it even if it won't hurt the truck mechanically. It's not a normal sound in a truck that's why people complain lol.

What ever man. Just because GM issues a TSB covering a topic does not mean they are covering anything up or fix. When those engines switch modes that's a major change of course there are gonna be a few changes in the sound of engine when it happens.

When anti-lock brakes activate they make a sound that is out of the norm and IIRC GM issued TSB's about these noises early on stating the noise was normal durring anti-lock activation. But, according to you that would be GM just trying to get out of fixing something.

redvett · November 2, 2007

I guess if enough people complain about something to GM they don't change/fix it - they just issue a bulletin saying "It's normal"......not a big fan of that.

If that many people complain then they have a problem and need to fix it even if it won't hurt the truck mechanically. It's not a normal sound in a truck that's why people complain lol.

Thats why i have always said that you need to go in and have the problem written up to document it and that is a complaint to the MFR's. Fixing it your self isnt the solution. You bought the new vehicle and they provide a warranty. If GM or any other MFR thought there would never be a problem they wouldn't need a warranty.

hotwheels57 · November 2, 2007

There is a TSB for this. # 06-06-05-001A.

Ive up loaded a copy as an attachment. You should be able to down load it.

Isn't there a brand new GM TSB out now covering "Some GM truck owners will complain about almost everything"...?

NathanL · November 2, 2007

I haven't complained about this but yes I've complained a LOT about my new GM truck....

Let's see I should be putting 100-200 miles at a minimum per day on my work truck. So far in a little over a month I'm still at 1250 miles.

It's been in the shop 4 times and is scheduled for a 5th soon as I can get it in.

It's stranded me twice. Once the transmission went out and required a brand new transmission, because I was not on the highway but "off road" I had to pay for the wrecker out of my own pocket as roadside assitance doesn't cover dirt roads even if they are county maintained. The tow truck Chevy sent got to within .5 mile of me and then called and told me if I could push my truck that .5 mile down a 2 lane dirt road he could pick it up....

The second time at the house in the morning it would crank but you couldn't give it any gas. Soon as I cranked it it threw a code. Back to the dealer. Couldn't drive it to the dealer at idle - so another tow truck ride.

The passanger side window fell down in the door.

The TPMS has had to go in twice now. Once for a defective sending unit (which I'm not sure was the problem) and the second to reprogram (or flash whatever they call it) the computer to fix it. It's still not fixed.

The cruise had to be replaced/repgrommed or whatever they do because you could only set cruise under certain conditions and it would never accelerate to keep the cruise speed up. It would wait till it bogged down hard enough to downshift but never give gas. They fixed this.

So yeah I complain a good bit about my truck.

Norseman · November 2, 2007

I haven't complained about this but yes I've complained a LOT about my new GM truck....

Let's see I should be putting 100-200 miles at a minimum per day on my work truck. So far in a little over a month I'm still at 1250 miles.

It's been in the shop 4 times and is scheduled for a 5th soon as I can get it in.

It's stranded me twice. Once the transmission went out and required a brand new transmission, because I was not on the highway but "off road" I had to pay for the wrecker out of my own pocket as roadside assitance doesn't cover dirt roads even if they are county maintained. The tow truck Chevy sent got to within .5 mile of me and then called and told me if I could push my truck that .5 mile down a 2 lane dirt road he could pick it up....

The second time at the house in the morning it would crank but you couldn't give it any gas. Soon as I cranked it it threw a code. Back to the dealer. Couldn't drive it to the dealer at idle - so another tow truck ride.

The passanger side window fell down in the door.

The TPMS has had to go in twice now. Once for a defective sending unit (which I'm not sure was the problem) and the second to reprogram (or flash whatever they call it) the computer to fix it. It's still not fixed.

The cruise had to be replaced/repgrommed or whatever they do because you could only set cruise under certain conditions and it would never accelerate to keep the cruise speed up. It would wait till it bogged down hard enough to downshift but never give gas. They fixed this.

So yeah I complain a good bit about my truck.

Man, you should sell it and go buy a toyota so you can be happy.

NathanL · November 2, 2007

And of course you wouldn't complain if you bought a truck soley for work and so far in a little over a month I've had it - it's been to work 3 days now?

I mean I guess I nitpick when you get stranded twice, truck sits in the shop for 6 days waiting for GM to ship a transmission etc...

Where did Toyota come from? I expect whoever makes the vehicle I buy for it to work. Period. I'm restricted to buying a Ford, Dodge or a GM product for work.

The company that gives me the allowance for the vehicle has offered to buy it at my cost and scrap it all together and make it an office queen or something - but it has to get running to get it to them first.

Norseman · November 2, 2007

And of course you wouldn't complain if you bought a truck soley for work and so far in a little over a month I've had it - it's been to work 3 days now?

I mean I guess I nitpick when you get stranded twice, truck sits in the shop for 6 days waiting for GM to ship a transmission etc...

Where did Toyota come from? I expect whoever makes the vehicle I buy for it to work. Period. I'm restricted to buying a Ford, Dodge or a GM product for work.

The company that gives me the allowance for the vehicle has offered to buy it at my cost and scrap it all together and make it an office queen or something - but it has to get running to get it to them first.

Yea, I'd get rid of it. Get something else. Sorry you are having probs, but when you said:

I guess if enough people complain about something to GM they don't change/fix it - they just issue a bulletin saying "It's normal"......not a big fan of that.

If that many people complain then they have a problem and need to fix it even if it won't hurt the truck mechanically. It's not a normal sound in a truck that's why people complain lol.

That was BS and wasn't helping pirch one bit!!

hotwheels57 · November 3, 2007

Does your state have a "lemon law"? That might be a remedy. Have you tried talking to the dealer/area GM representative about the issues?

I made general light of people complaining about their GM trucks. It wasn't specifically directed towards you. It wasn't intentional. Complaining about everything GM has become a regular topic. It gets old, at least to me. This is the first time we've owned all GM vehicles in our household. We've usually had a Ford daily driver and GM weekend "toys". We've had very few issues with any of our vehicles, GM or Ford.

I'd be upset if my new truck had caused me the same problems as yours has, especially a work vehicle. The deal your company offered sounds generous. I hope it works out that way so you can find what you need.