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Showing results for tags 'knock'.
Found 8 results
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I've had this issue for two months but it has been minimal until recently. While going anywhere above 30mph, at around 1200rpm if I give it about quarter throttle to half throttle i will hear a clanking/knocking noise. I have recorded it with my phone but you are unable to hear it at all. The other day while merging on the highway it made the noise much worse than it ever has. I am wondering if anyone has had this before, I know some of the 3.0 DuraMax guys have had it, but has anyone with the 6.2 had an issue similar to this. I will be taking it to the dealership tomorrow. -
So, I've had this truck about 15 months. I bought it used from Carmax and ran 87 octane for the first year or so. I noticed that I got a good bit of engine pinging. It's would get worse under load or in hot weather. And during that year I always felt like the truck was a bit of a dog. In January, I'd had enough and bumped up to 91 octane for a couple months. It got much better but didn't quite go away. About 3 or 4 tanks ago, I switched to 93 octane (premium, in my area) and I don't think I've heard it ping once. The mileage hasn't changed (unsurprisingly), but the truck just feels "peppy." The throttle response is massively improved and it's a much better driving vehicle. I think the best way I can describe it is that it's no longer lazy. I mean, it's not a sports car, but it no longer needs a few seconds to get it to accelerate. I know the instant response to that is "it's all in your head" but my wife who has no idea (read: doesn't care) what's been going on commented the other day that I haven't complained about the truck's performance lately. I'm not excited about having to feed this beast premium, but if I don't I'm afraid it's going to tear itself up. Also, I haven't changed gas stations through this time and the ones I use are busy, top-tier locations so I'm not thinking the quality of the gas is involved. I'm thinking the truck was tuned by the previous owner. I'm going to ask about that at my next service visit, but I don't expect they'll tell me anything. Is there a way I can verify if the truck is on the stock tune? Also, has anyone else had a similar experience? -
Hi community, I have a 2014 Sierra 2500 4x4 with the 6.0 Gas. I've read and watched some videos about known issues with older GM transfer cases have pump knock that leads to a hole in the case. Is this an issue with 2014 2500s? Thanks for insights. Edit: I should note, have not had an issue with my transfer case at this point. Just want to know because I'm going to be taking apart the drivetran to upgrade the diffs and might as well bullet proof the transfer case if I'm doing the diff work. I've done some more digging and found that GM switched to a new transfer case 07/08, MP1226XHD. My rig has a corresponding RPO code of NQF. Does this transfer case have the issue the older NP cases have? Not alot out there about them.
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Ok so here is my problem! I'm new here so hopefully I can get this rite lol!! I have a 2004 suburban 5.3 vortec 2wheel drive! 170,XXX miles on it. I've owned it for about a year now. Always took care of it. Truck is very nice and well kept up! So here is my issue. I was sitting in my buddy's driveway last nite talking for a min when I noticed a knock coming about! I mentioned it to him but we thought maybe it was just the AC compressor or something.( Noise was light at this time) so we think nothing of it continue to talk and I noticed it getting louder! So I get out and I swear it was a rod knock from in pan so I leave go home (about a mile away) shut it off stop for the night and tow it to my shop this morning... I drop the pan pulled all rod caps and checked the bearings then pulled all the main caps and checked those as well!! THEY LOOK GREAT! so now I go to the oil that I drained out of it prior to dropping the pan there is gold flakes of metal in my oil! So I keep looking to find that looking up between the crank I can see the cam shaft and I can see a lobe is shot!! So now I'm gonna put lifters and a new cam.... Now here is my question where did the gold flakes come from? As far as I know gold flakes are from a bad bearing correct???? But I don't have a bad bearing I have a bad lobe on my cam and a bad lifter!!! Would the bad cam lead to a bad cam bearing?? HELP ME PLEASEEEE
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If it is a lifter, what kind of lifters should I get for a 05 GMC 2500 HD with a 6.0 vortec? This video shows whats goin on. More to come as the information becomes available.
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Hi guys. Was wondering if anyone had a easy way to keep a check on fuel octane levels? I saw this Russian made device OKTIS-2 http://www.ebay.com/itm/PORTABLE-FUEL-OCTANE-NUMBER-ANALYZER-TESTER-METER-OKTIS-2-NEW-/161886552305 looked like it would be useful for keeping an eye on octane levels and it is cheap (under 100 bones). looks like you just stick it in the tank and then pump some fuel through it, seems rather ingenious but not sure how accurate the thing would be? The reason I am looking is that I recently installed a canned tune from a hand held programmer for premium fuel 91 plus octane in my 16 Denali 6.2 I buy Shell 93 octane and the truck has run great for the first week after that premium fuel tune install but after I filled back up with Shell 93 octane last Thursday the next morning on the way to work I got the "reduced engine power" warning on my dash anytime the engine was over 3000rpm. I suspect that the fuel was BAD from my local Shell station but have no way to prove that...... I went back to stock tune friday afternoon and the issue is gone but now I do not want to use the premium tune without verifying that I am actually getting 91 octane or better fuel. Note: Gas line was busted in AL a couple of weeks back and Middle TN has suffered from spotty shortages of fuel (most notably premium fuel) I suspect that my local Shell had regular fuel loaded into their premium tank. (could have been a mistake) my plan is to run this tank all the way down to just a few gallons and then hopefully have a tester in hand and fill back up with REAL premium 91 plus octane fuel. Anyone got one or have something else that they use?
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Hey guys, Recently my 2011 silverado with the 5.3L has begun pinging under load at around 2000rpm. Here is a list of things I have done already: 3 bottles of Lucas Oil Deep Clean though fuel tanks(3 tank fulls) 1 bottle of Chevron Techtron concentrate (half tank full) new air filter cleaned MAF sensor cleaned throttle body Used AutoCal to read spark advance during pinging event; minimum advance was 18* during pinging (pinging does not stop unless I change throttle position) Note; I have a Blackbear tune. I now believe it is a faulty knock sensor since the pinging does not stop after a few seconds. This started happening after I had a low oil pressure sensor voltage DTC. I brought it to the dealer and they replaced the oil and oil filter with a UPF48 claiming the PF48 already installed on the truck was faulty. It seems to have fixed the low oil pressure issue. I would like your opinions before I decide to take it back to the dealer. Thanks
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Hello all, Recently (couple weeks ago) I replaced both knock sensors when my MIL came on and threw code P0332 (knock sensor bank 2 low voltage input IIRC). I knew that only one sensor was affected by the code but I replaced both just because. I did however notice that the bank 2 sensor connection was easier to come off than bank 1, which I think may come into play later on in this story. Of course, both knock sensors were submerged in water, which I cleaned out. I did NOT do the silicon-dam method, as I discovered this after I was done with the job. I did not replace the wiring harness either. The MIL was off for at least a week before it came back, P0332 again. Yesterday I did some diagnosis to try and figure out what is going on with this. Bank 1 and bank 2 sensor (ohmed out at the harness plug on intake) both show a resistance of 99-100 kOhm (or Ohm, can't remember) with the engine off. I then checked the response of each sensor. Bank 1 and bank 2 sensors both showed a change in voltage when tapping on the block with a hammer, which is good. I then started the engine up and measured the voltage change with RPM change for each sensor, and here is where it gets interesting Bank 1 sensor fluctuated from approximately 50 mV to 150 mV with a quick RPM sweep (friend stabbed the gas pedal quick to change the sensor output) Using the same technique, Bank 2 sensor fluctuated from approximately 50 mV to 100 mV, which was significantly different than the bank 1 sensor. Bank 1 and bank 2 pins from the connection on the intake manifold to the PCM show very similar resitances between them, signifying that there should be no short between the PCM and knock sensors themselves (unless the sensor harness is bad) That completes all of the diagnostic trouble-tree steps I have taken via AllData. The next steps are PCM replacement, which I do not want to do. I realize that the sensors may be designed to pick up specific frequencies and as such, different responses under the same conditons, but the sensors have the same P/N if I am not mistaken, so that must be the characteristics of the mounting location, right? The fact that the bank 2 sensor electrical connection seemed to be loose compared to bank 1 has me wondering about the sensor wiring harness and the fact that the connection may be poor/intermittent. I am going to order one and replace it because it's a relatively quick and inexpensive job to do, but I was wondering if there is anything else that would make sense? Thanks in advance!
