2002 8.1 liter engine oil burn

Messages
17
Location
VancouverBC Canada
2002 Chevy Avalanche 8.1 liter engine 5w30 dino oil first 6000 miles no burn. Switched to castrol Syntech 5w50--burned 1 qt /300 miles Switched to 10w30 Castrol Syntech--burned 1 qt /600 miles. Walmart tech tech 2000 Syn-10w30-burned 1qt/800 miles Now on oil watch with GM with 5w30 Dino again--so far in 1000 miles no burn--what gives?? The engine now has 16000 miles on it and it appears that Synthetic oil and this engine don't mix?? Yes, there is piston slap and my neighbour thinks I have a diesel for the first 1 minute of ops--the same for all the oils tried --no appearent difference. Any ideas--should we try 15w40 mobil in temps above 0 deg C ??Would like to use a synthetic oil as it must be better over a greater operating range of temps and trailer towing. Clare
 
Messages
319
Location
N. Florida, USA
the 8.1 is an oil burner, it will get worse as it ages, the thinner the oil the more it burns, I tried GC 0-30 on the last oci in 6k it burned close to a full sumps worth [Mad] change you spark plugs often the get pretty fouled there is a TSB to tighten the intake bolts supposedly some of the oil burnt is being drawn from the valley area, we are fortunate that our intake is dry (no coolant passages) or we would be in the same boat as all the other Chevy's with coolant in the oil, I have been wanting to try tightening the intake and see if it helps never have gotten to it I think a good portion is getting in past the rings not much that can be done about that
 
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2,569
Location
College Dorm...
First, make sure you have no easily-fixable (as in not tearing the engine down to a bare block and starting over!) mechanical issues that would be causing consumption. I strongly suggest using a 40-weight oil in these engines to begin with. Yes, without a doubt, if temperatures are high enough, then a HDEO 15w-40, either Delo, Delvac, or Long-Life would be a great choice. Personally, I'd start with a 15w-40 as soon as the spring temperatures come around and continue with the 15w-40's until fall/winter when temps start constantly dropping below freezing again. I know I say this alot as well, but use a good, high-quality oil filter as well. The only problem with this is given the temperatures you operate in up there, a 15w-40 will not be an acceptable year-round oil. I'd suggest that you first switch to Rotella-T 5w-40 and determine what consumption is with this oil. If acceptable, continue on and you'll have a great year-round oil. If not, switch to something like Pennzoil Long-Life in the warmer months (spring thorough fall) and see how consumption does. If good (and I believe it will be), use Long-Life in the warmer months and a 5w-40 in winter. [ February 19, 2004, 03:04 AM: Message edited by: Jelly ]
 
Messages
526
Location
Manitoba Canada
The Vortec 8.1 V8 does appear to have a problem, mostly oil past rings, and most folks have reported the motor also appears sensitive to what brand of oil you use. Have you checked out the GM Trucks forum? The HD forum there has numerous posts on problems and quick fixes: Oil Consumption topic on GM forum Some folks who have had oil burning problems tried Mobil 1 15W-50 and substantially reduced or eliminated the oil burning. This should only be tried in temps over -18 C or 0 F. Using the dino oil you created excessive deposits in the Ring Land area of the pistons: IOW you quickly filled the groves with carbon/varnish/sludge. The rings stuck but the deposits kept the rings reasonably tight. Switching to a synthetic partially cleaned out the ring groves, but now the rings are floating and you're using oil. Do what some Vortec 8.1 owners have done and try an Auto RX flush. You may have to do this several times. Those that ran synthetic from new appeared to have the fewest problems. Especially those running Mobil 1 15W-50: 1 quart every 7,000-8,000 miles. FWIW I tried Mobil 1 15W-50 once in my Vortec 5.3. There was no difference in fuel economy and the motor was SILENT. However, I was Dum and went back to Mobil 1 10W-30, as the manual warns engine damage may result. What a crock of s***. When I found out the Holden's in Australlia run 15W-40 and 20W-50 in their LS1's, I'm no longer afraid of running a thick oil in summer in the Vortec motor. Hope this helps. Jerry [ February 19, 2004, 12:09 PM: Message edited by: rugerman1 ]
 
Messages
526
Location
Manitoba Canada
As a follow-up: Using that much oil, you will have massive deposits on the Crown Land of the pistons, massive Squish area deposits, probably intake valve and even fuel injector deposits. Once you get the Auto RX flushes out of the way, I'm sure you can find a good shop in Vancouver that offers the MotorVac injection and intake cleaning service. The MotorVac will get the injectors, intake valves, Crown Land, and combustion Squish area spotless. Be prepared to change the oil a few more times to get that washed gunk out. Your O2 sensors and catalytic convertors will also be plugged, as excessive oil burning coats everything in metallic ash. This can be $$$ to replace if the dealer refuses to do it. Jerry
 
Messages
526
Location
Manitoba Canada
quote:
Originally posted by C T Puchniak: Thanks for the replies fellas Sounds like we have our hands full with GM BS over the period of the oil watch.Just cannot wait till they hand me the statement--acceptable oil burn is 1qt / 100 gallons of gas---this is what others are getting.Complete joke!!! Otherwise it is great vehicle. Clare
Sorry, did you say 1 QUART every 100 GALLONS of gas?? [freaknout] Geez, that isn't a 2-cycle outboard motor! I agree, if that is what GM is claiming, you may be on your own. Yikes. The O2 sensors and cats are really $$$ to replace too. Jerry
 

C T Puchniak

Thread starter
Messages
17
Location
VancouverBC Canada
Thanks for the replies fellas Sounds like we have our hands full with GM BS over the period of the oil watch.Just cannot wait till they hand me the statement--acceptable oil burn is 1qt / 100 gallons of gas---this is what others are getting.Complete joke!!! Otherwise it is great vehicle. Clare
 
Messages
509
Location
Las Vegas, NV
quote:
Using the dino oil you created excessive deposits in the Ring Land area of the pistons: IOW you quickly filled the groves with carbon/varnish/sludge. The rings stuck but the deposits kept the rings reasonably tight. Switching to a synthetic partially cleaned out the ring groves, but now the rings are floating and you're using oil. Do what some Vortec 8.1 owners have done and try an Auto RX flush. You may have to do this several times. Those that ran synthetic from new appeared to have the fewest problems. Especially those running Mobil 1 15W-50: 1 quart every 7,000-8,000 miles.
I agree with all of Heyjay's comments. The oil consumption that you had with Castrol Syntec is crazy. It must be caused by a mechanical problem (rings). I am amazed at the number of problems GM is having with their V8 and V6 engines!
 

C T Puchniak

Thread starter
Messages
17
Location
VancouverBC Canada
YES WE CHECKED THE PLUGS! The plugs are loaded with a black deposit on one side of the ceramic insulator,almost shorting the center electrode to the sidewall--approx 12 to 15 thous of deposit--it can be scraped off fairly easily---wonder what GM will say to this when we send them the pictures?? The frustrating part we have gone 1500 miles on the oil watch using 5w30 dino and no oil burn at all. Just think--this is their latest design--will they ever get it correct?? Clare
 
Messages
526
Location
Manitoba Canada
quote:
Originally posted by C T Puchniak: YES WE CHECKED THE PLUGS! The plugs are loaded with a black deposit on one side of the ceramic insulator,almost shorting the center electrode to the sidewall--approx 12 to 15 thous of deposit--it can be scraped off fairly easily---wonder what GM will say to this when we send them the pictures?? The frustrating part we have gone 1500 miles on the oil watch using 5w30 dino and no oil burn at all. Just think--this is their latest design--will they ever get it correct?? Clare
Clare: If you check out the GM Trucks forum, the folks with oil burning have the problem whether they run a "regular" 5W-30 or a synthetic 5W-30. They have been able to substantially reduce the oil use by running a heavier oil. This makes no sense whatsoever that going back to a regular 5W-30 would have stopped the oil consumption. Unless the synthetic managed to knock out enough deposits that the regular 5W-30 works well. Weird. The viscosity and HTHS rating all appear to make a difference too. Although many Vortec truck owners would KILL to have my oil consumption results, here is what my 2000 GMC Sierra 1500 with Vortec 5.3 V8 burns (Converted to U.S. quarts and miles): Mobil 1 0W-30 1 quart every 4,200 miles Mobil 1 5W-30 1 quart every 4,400 miles Mobil 1 10W-30 1 quart every 6,800 miles Mobil 1 15W-50 0 over 7,000 miles Note: I used Mobil 1 15W-50 in 2001 from May to September, and put on almost 7,000 highway miles. The oil level remained at Full. Despite the fact that Mobil 1 0W-30, M1 5W-30, and M1 10W-30 are all "supposed" to be xW-30 oils, there is a substantial difference in oil use, especially when using the 10W-30. I used Mobil 1 10W-30 in summer of 2002 and in summer of 2003. I have never used Castrol Syntec and cannot comment on its performance. There have been oil burning issues when folks have switched from dino oil to a synthetic with VERY high detergent/dispersant levels. Usually, a short OCI using Auto RX safely cleans everything out, then you can use synthetic without oil use worries. So what is your next step? Keep on the dino 5W-30 and hope for the best? Hope the O2 sensors and cat's hold out?? This is a mystery. Jerry
 

C T Puchniak

Thread starter
Messages
17
Location
VancouverBC Canada
Thanks Heyjay Yep, it is very frustrating--but I am leaning to the heavier oil 15w 40 Mobil 1. As we changed to the higher viscosity/weight oil the burn went down considerably--3/1 ratio. I think the comments regards the scavanging/cleaning action of the synthetic oil is well taken -- it certainly seems as though the engine should require the cleaning action to preform over a longer period of time.I can't imagine this engine with over 100,000 miles,if the deposits continue! I might pull the O2 sensors and see what they look like!Should be interesting---like to know before it goes out of warrantee. The GM reps are all but useless in analysis so far. Great forum fellas--let's keep the true info available!! Clare
 
Messages
526
Location
Manitoba Canada
Hello Clare: Do you mean the "new" Mobil 1 Truck & SUV 5W-40? Or Mobil Delvac 1300 15W-40? I'm not sure if the "new" Mobil 1 T&S will even be available in Canada. Though you should be able to find Mobil Delvac 1 5W-40 at Wally World. Vancouver BC rarely gets to -15 C, though this winter you folks sure had the cold spells and nasty snow. If you want to consider a good HDEO (Heavy Duty Engine Oil), look for an Esso Bulk distributor. I'd consider Esso XD-3 15W-40 year round, or if too thick in winter, Esso XD-3 0W-40. Both oils are proven in HD diesel motors. They substantially reduce deposits. The XD-3 15W-40 is priced around $2.25 a litre. Mobil Delvac 1 5W-40 would most likely be fine year round in Vancouver. Delvac 1 claims to reduce oil consumption 40% compared to the "reference" 15W-40 oil. Yeah, I bet your O2 sensors are plugged, along with the catalytic convertors. I'd check if NAPA or Canadian Tire carry the O2 sensors for your truck, as they will be a fraction of the price of dealer. Remember you have 4 O2 sensors: for each cylinder bank you have an O2 sensor before the catalytic convertor, and an O2 sensor AFTER the catalytic convertor. As far as the catalytic convertors, I shudder to even think about it. I have no idea what they cost. I do think these Vortec motors have an oil consumption issue. I'm not used to getting only 1 litre every 7,000 km. My 1984 Ford F-150 with 302 V8 that I bought new ran its whole life on Delvac 1 changed every year or two. Its average oil consumption was 1 litre every 15,000km. It now has around 515,000km on it. I've heard that folks with the new Dodge Ram Hemi are burning oil too, and some Ford F-150's and some 1 ton V10's guzzle oil too. Jerry
 
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2,569
Location
College Dorm...
quote:
Originally posted by heyjay: Delvac 1 claims to reduce oil consumption 40% compared to the "reference" 15W-40 oil
I can't figure out how it'd be possible that Delvac1 will reduce consumption 40% in comparison to a brand-name HDEO 15w-40, be it Delo, Delvac, or Long-Life...it just doesn't make any sense!
 
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3,542
Location
Colorado
Just to chime in I have a 2003 Silverado with the 5.3 Vortec and I broke it in with Valvoline dino 5w30 changed at 500 miles, 1,500, and 2,800 miles and then started to use Mobil 1 10w30 year round. So far at 15,000 miles the engine has burned 0 oil! This last run has been 5,000 miles and 0 qts have been burned. I wonder if it is the piston and ring change for the 2003 model year??? I really hope the 8.1 is fixed this year as I was concidering an Avalanch with the 8.1. That engine is a MONSTER, I think it is the most powerful gaser made and gives these diesels a run for their money! Good luck with it and I hope you get it fixed! Also I have a 2002 LS1 Camaro that burned oil and slapped so GM rebuilt it under warranty and now it burns no oil but it still make some slapping noises to a point. Maybe if you talk to GM you can get them to rebuild the engine if they have come up with a fix for the 8.1 like new rings or something???
 

C T Puchniak

Thread starter
Messages
17
Location
VancouverBC Canada
Thanks for the info guys We will put the AUTOTAP on the vehicle and see the readings we get around the O2 sensors. We have done readings every 5000 KMs and should be able to compare them. The engine certainly runs well--no misses or oil burning evidence.The exhaust tailpipe is virtually clean.The only evidence is on plugs--one side (180 Deg--is heavily deposited.The other 180 Deg is absolutely clean as one would expect)I have never seen a plug deposited that way! Possibly the manifold is the problem--we did retorque the manifold bolts at 3000 Kms and found them below spec--At that time the engine burned no oil at all---it only started burning oil when we went castrol 5w50 at 6000 KMs. The Mobil 1 was the 15w40 that Cantire was selling.I am not familiar with the delvac Mobil 1. Will look into the various oils. Thanks Clare
 
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2,569
Location
College Dorm...
"Delvac 1 is not as volitile as regular HDEO 15W-40. To meet CI-4 specs the maximum volitility is around 15%, where Delvac 1 claims 3% at extended 700 F testing." Not blaming you here, but how can an oil protect and claim a 3% max volitility when the oils flash point is at 439F? In terms of high-temperature protection...wanna hear something interesting? Delvac 1300 actually has a HIGHER flash point, at 446F in comparison to the Delvac 1 5w-40's flash point of 439F. "So in a motor in good mechanical condition and properly broken in, the primary cause for oil consumption is using too light an oil with excessive volitility." I do agree, but there are also other points to ponder... For example, in older engines I've used it in, Pennzoil Long-Life 15w-40 has reduced consumption a great deal over Delo 400 or Delvac 1300, which are the same viscosity, same HT/HS rating, etc, etc... [ February 23, 2004, 09:34 PM: Message edited by: Jelly ]
 
Messages
526
Location
Manitoba Canada
quote:
Originally posted by Jelly:
quote:
Originally posted by heyjay: Delvac 1 claims to reduce oil consumption 40% compared to the "reference" 15W-40 oil
I can't figure out how it'd be possible that Delvac1 will reduce consumption 40% in comparison to a brand-name HDEO 15w-40, be it Delo, Delvac, or Long-Life...it just doesn't make any sense!

Delvac 1 is not as volitile as regular HDEO 15W-40. To meet CI-4 specs the maximum volitility is around 15%, where Delvac 1 claims 3% at extended 700 F testing. This is in contrast to PCEO's that are "allowed" 25% volitility. That's why folks who run even regular HDEO 15W-40 report much lower oil use. I'll quote from an older Delvac 1 PDS: "Because synthetics have higher boiling points than conventional oils, Mobil Delvac 1 does not evaporate as readily in the high-temperature piston ring area of turbo-charged diesel engines." "Mobil Delvac 1 is capable of providing fuel economy benefits of up to 3% and more in heavy duty diesel engines, with as much as a 40% reduction in oil make-up in over-the-road service." European oils rated ACEA A3, A5, B4-02, etc, also have strict limits on oil volitility that in many cases are less than half the humourous North American "Starburst" rating. Scary fact: at one time API/SAE oils could boil off +40%! So in a motor in good mechanical condition and properly broken in, the primary cause for oil consumption is using too light an oil with excessive volitility. Jerry
 
Messages
526
Location
Manitoba Canada
quote:
Originally posted by Jelly: "Delvac 1 is not as volitile as regular HDEO 15W-40. To meet CI-4 specs the maximum volitility is around 15%, where Delvac 1 claims 3% at extended 700 F testing." Not blaming you here, but how can an oil protect and claim a 3% max volitility when the oils flash point is at 439F? In terms of high-temperature protection...wanna hear something interesting? Delvac 1300 actually has a HIGHER flash point, at 446F in comparison to the Delvac 1 5w-40's flash point of 439F. "So in a motor in good mechanical condition and properly broken in, the primary cause for oil consumption is using too light an oil with excessive volitility." I do agree, but there are also other points to ponder... For example, in older engines I've used it in, Pennzoil Long-Life 15w-40 has reduced consumption a great deal over Delo 400 or Delvac 1300, which are the same viscosity, same HT/HS rating, etc, etc...
First of all, I'm directly quoting Mobil's own ad copy. That IS what they claim. Their "reference oil" is Delvac 1300 15W-40. In my Cummins ISX motors, once off the factory 15W-40 for break-in, using Delvac 1 lowered the oil consumption to less than half. Average of 1 litre every 5,400km, which is NOT bad for a HD diesel motor. In most HD diesel motors, Delvac 1300 Super 15W-40 has a higher oil consumption rate than Mobil Delvac 1 5W-40. The basestocks are completely different and the additive packages are completely different. Most reefer makers (Refrigerated trailer compressors) recomend Delvac 1 for extended OCI but do NOT recommend Delvac 1300 Super for extended OCI. This is severe service, those little diesel motors really work hard. All oils appear to behave somewhat differently. Like when folks here compare the results especially of different 5W-30 PCEO's, they prove just how different the additive packages and base stocks really are. Doesn't Penzoil LL have extra additives for seal conditioning? That might explain your lowered oil consumption. It can be quite a brew with those extra additives. Seal conditioners are prohibited by most HD diesel engine makers as they usually cause excessive Top Grove Fill, or turbocharger bearing problems. Most folks have excellent results with Delvac 1, so I imagine the new Mobil 1 Truck & SUV should keep up that reputation. Jerry
 
Messages
2,794
Location
NM
quote:
Originally posted by C T Puchniak: Thanks for the replies fellas Sounds like we have our hands full with GM BS over the period of the oil watch.Just cannot wait till they hand me the statement--acceptable oil burn is 1qt / 100 gallons of gas---this is what others are getting.Complete joke!!! Otherwise it is great vehicle. Clare
I feel for you, my fellow GM owner. I just had the pistons in my 02 Z28 replaced due to HEAVY knocking. The engine burned no oil whatsoever in 4k miles, but the noise was embarrassing, to say the least. As a loyal GM fan, I am extremely disappointed in the way GM has turned a good engine design into a pile or crap by their lack of quality control and the use of inferior materials. Chevy now advertises as "A new revolution"......I think it's more like Armageddon. Anyway, I would pursue a fix from GM immediately and do not let them talk you into the usual "It's normal" crap.......that much oil being burned in such little time is beyond excessive. Rick
 
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