Originally Posted By: tsduke
UOA is "used oil analysis". Take a sample of your oil and send it to a lab.
What lab?
UOA is "used oil analysis". Take a sample of your oil and send it to a lab.
What lab?
Silverado engine problem
- Thread starter markhait
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The problem is with the AFM(Active Fuel Management), It is causing major oil related issues with these trucks. Go over to GM-TRUCKS.COM and there is a ton of stuff on this problem.
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Originally Posted By: markhait
I had a GMC Sierra truck before my Silverado and I kept it till I had some 140k miles on it. I did that exact same oil changes on it too. 1 year or just under 25k miles. I NEVER had any problems related to the engine. In fact, its still running as my parents bought it off me and they have almost 200k on it. Why would Amsoil work on it, but not on a Silverado? I drive the EXACT distance now as I did then. Please explain?
PT Barnum also said "There are many freaks, but not enough circuses"!
As Pablo and others has suggested their might be a underlying engine problem. I would not just come out and throw AMSOIL under the bus just yet must get a used oil analysis or every thing els is just guessing.
I had a GMC Sierra truck before my Silverado and I kept it till I had some 140k miles on it. I did that exact same oil changes on it too. 1 year or just under 25k miles. I NEVER had any problems related to the engine. In fact, its still running as my parents bought it off me and they have almost 200k on it. Why would Amsoil work on it, but not on a Silverado? I drive the EXACT distance now as I did then. Please explain?
PT Barnum also said "There are many freaks, but not enough circuses"!
As Pablo and others has suggested their might be a underlying engine problem. I would not just come out and throw AMSOIL under the bus just yet must get a used oil analysis or every thing els is just guessing.
Not every vehicle is a candidate for extended drains. People should ease into them, and get UOA confirmation. Otherwise take the oil bottle label with a grain of salt. The engine could have underlying problems that reared their ugly head as a result of the extended drain intervals. I'm willing to bet if that's the case the engine would have gone longer following the suggested OCI. Something we'll never know in this case.
Originally Posted By: markhait
Originally Posted By: tsduke
UOA is "used oil analysis". Take a sample of your oil and send it to a lab.
What lab?
Many here like Blackstone, but others may suggest different options. They will send you a free kit for sending the sample to them.
http://www.blackstone-labs.com/
Originally Posted By: tsduke
UOA is "used oil analysis". Take a sample of your oil and send it to a lab.
What lab?
Many here like Blackstone, but others may suggest different options. They will send you a free kit for sending the sample to them.
http://www.blackstone-labs.com/
we all know people who do 25k oci on cheapest oil (and rarely check the 2qts of crud in motor) they can find or the "just add oil" routine and engines keep running for 200k but really it is playing with fire esp w/ snake oil like amsoil...just kidding haha...i would go with 10k oci in warm weather and 8k in cold from now on...i rarely go over 7k oci even w/ syn
I'm guessing maybe you had the 5.7 in your GMC? And the newer one is a 5.3? Maybe something to do with design differences. Anyways I would never go 25K on an oil change.
Originally Posted By: tsduke
Originally Posted By: markhait
Originally Posted By: tsduke
UOA is "used oil analysis". Take a sample of your oil and send it to a lab.
What lab?
Many here like Blackstone, but others may suggest different options. They will send you a free kit for sending the sample to them.
http://www.blackstone-labs.com/
Thank you....just went there and sent for kit.
Originally Posted By: markhait
Originally Posted By: tsduke
UOA is "used oil analysis". Take a sample of your oil and send it to a lab.
What lab?
Many here like Blackstone, but others may suggest different options. They will send you a free kit for sending the sample to them.
http://www.blackstone-labs.com/
Thank you....just went there and sent for kit.
Originally Posted By: SigShooter
I'm guessing maybe you had the 5.7 in your GMC? And the newer one is a 5.3? Maybe something to do with design differences. Anyways I would never go 25K on an oil change.
That could be....I don't remember what size engine was on the Sierra. Anyway...I'm getting the feeling that I shouldn't have done the 25k mile thing without at least a used oil analysis. Never heard of a used oil analysis until today. Just sent for a kit from Blackstone and I'll send in a sample as soon as I get it. Now I'm anxious and nervous at the same time. I still want to know about Amsoil and so if everything checks ok, I'm going to try it again, but this time at around 5k miles I'll send them a sample and see if their claim is hype or not. I'm definitely second guessing everything now!
I'm guessing maybe you had the 5.7 in your GMC? And the newer one is a 5.3? Maybe something to do with design differences. Anyways I would never go 25K on an oil change.
That could be....I don't remember what size engine was on the Sierra. Anyway...I'm getting the feeling that I shouldn't have done the 25k mile thing without at least a used oil analysis. Never heard of a used oil analysis until today. Just sent for a kit from Blackstone and I'll send in a sample as soon as I get it. Now I'm anxious and nervous at the same time. I still want to know about Amsoil and so if everything checks ok, I'm going to try it again, but this time at around 5k miles I'll send them a sample and see if their claim is hype or not. I'm definitely second guessing everything now!
I just want to say thanks to everyone here! And I hope you all have a GREAT and happy New Years!!!! Thanks again everyone!
Originally Posted By: dave1251
Originally Posted By: Jehartley
Originally Posted By: blsnelling
GM fixed the piston slap problems in model years 2004-2005.
No, they didn't.
Really? By checking your signature are you having problems with your 4.8? This is something that I have not heard about.
Yup. It's starting slowly, but it still a problem all the way around. Go check out the Silverado/Sierra forums...still an issue.
Originally Posted By: Jehartley
Originally Posted By: blsnelling
GM fixed the piston slap problems in model years 2004-2005.
No, they didn't.
Really? By checking your signature are you having problems with your 4.8? This is something that I have not heard about.
Yup. It's starting slowly, but it still a problem all the way around. Go check out the Silverado/Sierra forums...still an issue.
Originally Posted By: SigShooter
I don't care about Amsoil oil or their website. Maybe you should contact them to get them to reimburse GM for your engine problems. After all they guarantee it for 25000 miles. PT Barnum said their is a sucker born every minute.
That's a bit rough. The OP thought he was doing the right thing. It appears he may have made a mistake. We all have made mistakes. Cut him some slack.
While I'm not an Amsoil fan, the oil may be fine. If sludge exists at all, it may be due to the PCV system or a coolant leak, as others have said.
OP: when you get your report back from Blackstone, make sure to post it. If you do have sludge, others will jump in to help as well. The folks here are generally really cool.
I don't care about Amsoil oil or their website. Maybe you should contact them to get them to reimburse GM for your engine problems. After all they guarantee it for 25000 miles. PT Barnum said their is a sucker born every minute.
That's a bit rough. The OP thought he was doing the right thing. It appears he may have made a mistake. We all have made mistakes. Cut him some slack.
While I'm not an Amsoil fan, the oil may be fine. If sludge exists at all, it may be due to the PCV system or a coolant leak, as others have said.
OP: when you get your report back from Blackstone, make sure to post it. If you do have sludge, others will jump in to help as well. The folks here are generally really cool.
Originally Posted By: markhait
Originally Posted By: SigShooter
I'm guessing maybe you had the 5.7 in your GMC? And the newer one is a 5.3? Maybe something to do with design differences. Anyways I would never go 25K on an oil change.
That could be....I don't remember what size engine was on the Sierra. Anyway...I'm getting the feeling that I shouldn't have done the 25k mile thing without at least a used oil analysis. Never heard of a used oil analysis until today. Just sent for a kit from Blackstone and I'll send in a sample as soon as I get it. Now I'm anxious and nervous at the same time. I still want to know about Amsoil and so if everything checks ok, I'm going to try it again, but this time at around 5k miles I'll send them a sample and see if their claim is hype or not. I'm definitely second guessing everything now!
See what the used oil analysis report shows. You might have a bad head gasket, or a fuel dilution problem. First rule those things out. If you plan on using Amsoil again I would suggest taking their recommended OCI and cut it in half. At that point take a sample of the oil and send it to a lab and decide based on that if you can go longer or not. You can buy a tool for taking an oil sample w/o having to drain the oil. Amsoil should easily make 5000 miles and taking a sample at that point might be a little to soon. JMO
Originally Posted By: SigShooter
I'm guessing maybe you had the 5.7 in your GMC? And the newer one is a 5.3? Maybe something to do with design differences. Anyways I would never go 25K on an oil change.
That could be....I don't remember what size engine was on the Sierra. Anyway...I'm getting the feeling that I shouldn't have done the 25k mile thing without at least a used oil analysis. Never heard of a used oil analysis until today. Just sent for a kit from Blackstone and I'll send in a sample as soon as I get it. Now I'm anxious and nervous at the same time. I still want to know about Amsoil and so if everything checks ok, I'm going to try it again, but this time at around 5k miles I'll send them a sample and see if their claim is hype or not. I'm definitely second guessing everything now!
See what the used oil analysis report shows. You might have a bad head gasket, or a fuel dilution problem. First rule those things out. If you plan on using Amsoil again I would suggest taking their recommended OCI and cut it in half. At that point take a sample of the oil and send it to a lab and decide based on that if you can go longer or not. You can buy a tool for taking an oil sample w/o having to drain the oil. Amsoil should easily make 5000 miles and taking a sample at that point might be a little to soon. JMO
I doubt that the UOA will find a coolant leak, or anything else, at this point. If this was related to a failure of the original design, materials or assembly, GM had a chance to find it and deal with it without incurring negative publicity. I'd take this as an opportunity to start over with a clean slate. Start with the OLM as a guide and use UOA to see if it is worth extending the drain intervals.
My '06 Sierra with a 5.3 sees mostly rural (55 mph) miles and will only go about 4-7k miles before the OLM reaches 0%. I've done 2 used oil analysis (both at a little over 4k miles) and both came back with higher than desirable fuel dilution, so I don't consider my truck driven under my conditions a good candidate for extended drains. I currently run dino with 3 changes per year, which is about 4k miles. Two changes a year would be about 6k miles and I can't make it that far according to the OLM (at least in the colder Ohio months).
I have considered going to twice-a-year/6k with synthetic (extending the drain intervals a little). But quite frankly, I don't consider most of the readily available “synthetics” that much better than SM dino for my application. Although the more readily available “synthetics” do meet a few more stringent specs, from what I understand those specs don't really address an oil's performance in the presence of fuel dilution.
Some of the 5.3s had issues with head gaskets, not sure about the 2007s. Many also tend to fuel dilute the oil like mine. Given all that, I would never consider extending the drain intervals for my truck beyond 10-12k on any oil, even one recommended for 15, 25, or even 35k (but no more than a year). And I wouldn't even try going beyond 8k without a used oil analysis.
Although you drive more highway miles, I'd be surprised if any oil wouldn't be well spent before 15k miles in your truck. With your driving, I'm guessing your OLM reaches 0% at somewhere around 8-9k miles.
Since you had an engine “failure” and possible sludging, get a used oil analysis done at about 4-5k miles and look at the fuel and glycol levels. If both of those are good (fuel under 0.5% and no glycol/antifreeze) you may want to consider resuming extended drains with Amsoil (but not without supporting used oil analysis at 5k intervals [starting at 10k] up to the 1 year point) to establish a safe oil change interval.
I have considered going to twice-a-year/6k with synthetic (extending the drain intervals a little). But quite frankly, I don't consider most of the readily available “synthetics” that much better than SM dino for my application. Although the more readily available “synthetics” do meet a few more stringent specs, from what I understand those specs don't really address an oil's performance in the presence of fuel dilution.
Some of the 5.3s had issues with head gaskets, not sure about the 2007s. Many also tend to fuel dilute the oil like mine. Given all that, I would never consider extending the drain intervals for my truck beyond 10-12k on any oil, even one recommended for 15, 25, or even 35k (but no more than a year). And I wouldn't even try going beyond 8k without a used oil analysis.
Although you drive more highway miles, I'd be surprised if any oil wouldn't be well spent before 15k miles in your truck. With your driving, I'm guessing your OLM reaches 0% at somewhere around 8-9k miles.
Since you had an engine “failure” and possible sludging, get a used oil analysis done at about 4-5k miles and look at the fuel and glycol levels. If both of those are good (fuel under 0.5% and no glycol/antifreeze) you may want to consider resuming extended drains with Amsoil (but not without supporting used oil analysis at 5k intervals [starting at 10k] up to the 1 year point) to establish a safe oil change interval.
Originally Posted By: demarpaint
Originally Posted By: markhait
Originally Posted By: SigShooter
I'm guessing maybe you had the 5.7 in your GMC? And the newer one is a 5.3? Maybe something to do with design differences. Anyways I would never go 25K on an oil change.
That could be....I don't remember what size engine was on the Sierra. Anyway...I'm getting the feeling that I shouldn't have done the 25k mile thing without at least a used oil analysis. Never heard of a used oil analysis until today. Just sent for a kit from Blackstone and I'll send in a sample as soon as I get it. Now I'm anxious and nervous at the same time. I still want to know about Amsoil and so if everything checks ok, I'm going to try it again, but this time at around 5k miles I'll send them a sample and see if their claim is hype or not. I'm definitely second guessing everything now!
See what the used oil analysis report shows. You might have a bad head gasket, or a fuel dilution problem. First rule those things out. If you plan on using Amsoil again I would suggest taking their recommended OCI and cut it in half. At that point take a sample of the oil and send it to a lab and decide based on that if you can go longer or not. You can buy a tool for taking an oil sample w/o having to drain the oil. Amsoil should easily make 5000 miles and taking a sample at that point might be a little to soon. JMO
Whats this tool that I can use? I want it as I plan on sending oil samples to Blackstone until I can figure this out.
Originally Posted By: markhait
Originally Posted By: SigShooter
I'm guessing maybe you had the 5.7 in your GMC? And the newer one is a 5.3? Maybe something to do with design differences. Anyways I would never go 25K on an oil change.
That could be....I don't remember what size engine was on the Sierra. Anyway...I'm getting the feeling that I shouldn't have done the 25k mile thing without at least a used oil analysis. Never heard of a used oil analysis until today. Just sent for a kit from Blackstone and I'll send in a sample as soon as I get it. Now I'm anxious and nervous at the same time. I still want to know about Amsoil and so if everything checks ok, I'm going to try it again, but this time at around 5k miles I'll send them a sample and see if their claim is hype or not. I'm definitely second guessing everything now!
See what the used oil analysis report shows. You might have a bad head gasket, or a fuel dilution problem. First rule those things out. If you plan on using Amsoil again I would suggest taking their recommended OCI and cut it in half. At that point take a sample of the oil and send it to a lab and decide based on that if you can go longer or not. You can buy a tool for taking an oil sample w/o having to drain the oil. Amsoil should easily make 5000 miles and taking a sample at that point might be a little to soon. JMO
Whats this tool that I can use? I want it as I plan on sending oil samples to Blackstone until I can figure this out.
Originally Posted By: Jehartley
Originally Posted By: dave1251
Originally Posted By: Jehartley
Originally Posted By: blsnelling
GM fixed the piston slap problems in model years 2004-2005.
No, they didn't.
Really? By checking your signature are you having problems with your 4.8? This is something that I have not heard about.
Yup. It's starting slowly, but it still a problem all the way around. Go check out the Silverado/Sierra forums...still an issue.
It's definitely still an issue, just less prevalent now.
Though that video could be of a wrist pin or bearing noise.
Originally Posted By: dave1251
Originally Posted By: Jehartley
Originally Posted By: blsnelling
GM fixed the piston slap problems in model years 2004-2005.
No, they didn't.
Really? By checking your signature are you having problems with your 4.8? This is something that I have not heard about.
Yup. It's starting slowly, but it still a problem all the way around. Go check out the Silverado/Sierra forums...still an issue.
It's definitely still an issue, just less prevalent now.
Though that video could be of a wrist pin or bearing noise.
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Originally Posted By: INDYMAC
Exactly how do you check this "fixed orifice"? Where is it? My daughter's 2008 Avalanche 5.3L apparently doesn't have a PCV valve either.
Originally Posted By: OVERK1LL
Originally Posted By: tsduke
On my 05 5.3 the pcv isn't even replaceable or doesn't have one. I've asked 2 GM parts depts and looked online at the major parts stores...nothing. Is it replaceable on the 07?
IIRC, it should have the "fixed orifice" PCV assembly. Which should still be checked to make sure it is free of build-up.
Supposed to be on the very back of one of the valve covers. Looks like a tube.
Exactly how do you check this "fixed orifice"? Where is it? My daughter's 2008 Avalanche 5.3L apparently doesn't have a PCV valve either.
Originally Posted By: OVERK1LL
Originally Posted By: tsduke
On my 05 5.3 the pcv isn't even replaceable or doesn't have one. I've asked 2 GM parts depts and looked online at the major parts stores...nothing. Is it replaceable on the 07?
IIRC, it should have the "fixed orifice" PCV assembly. Which should still be checked to make sure it is free of build-up.
Supposed to be on the very back of one of the valve covers. Looks like a tube.
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