Last post on May 27, 2011 at 4:22 PM
You are in the Buick LaCrosse
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Buick LaCrosse, Sedan
#104 of 134 Re: Reply: dexos [gberpa]
Mar 17, 2011 (11:56 am)
I had my 2011 CVS in to the dealer today for a complimentary (birthday month!) wash and wax and discussed Banto's comments re: the EnclaveTSB. I also noted to him, after my recent oil change, the sticker the tech put on windshield which said to bring it back in 3K miles. I questioned whether he changed his view of a recommended oil change interval of 5-6k miles on the LaCrosse. On the last point, he said he hadn't changed his view but a lot of long-term customers might get uncomfortable seeing a longer interval. He is going to shift the techs to sticker a longer interval. There is no OLM TSB for the LaCrosse.
The issue, as he explains it, for the Enclave was that a lot of folks were following the extended change interval per the OLM AND they were not monitoring oil level during the longer intervals (stupid, I'd say). As there could be a loss of maybe 1 qt/5,000 miles, and say 2-3 qts over 10-15k miles for those following the OLM exactly, that low oil level and oil flow surges could/did result in timing chain stretching for some. So, Buick decided to change the OLM programming for the Enclave.
My oil level didn't budge over the first 4100 miles but your results may vary. So, for those pushing the OLM projections to the limit- check you oil levels. Also, E-net rider posting here found high gasoline/light ends levels in his 5800 mile old oil which he sent in for analysis. This means the effective resistance to wear (viscosity) could be even lower for our engines at longer change intervals.
#105 of 134 Re: Reply: dexos [gberpa]
Mar 17, 2011 (5:16 pm)
Totally agree with checking your own oil level periodically IN ADDITION to watching the OLM per prior posts. If the oil is down 2 quarts out of 5.5 and the OLM says 60% oil life remains, you have a major engine protection problem IMO if you do not add or change oil.. Also newer DI engines dump more gas into oil, as previously posted, for various reasons, resulting in need for sooner changes due to dilution- oil level may not go down but viscosity does, as you comment on. Dealer putting on a sticker with 3000 mile oil change supports both of the preceding comments; 1) don't rely on the OLM soley for oil change interval and 2) change the oil on your own schedule prior to gas dilution or loss of viscosity resulting in timing chain or other mechanical failure. $30 to protect your $5-$8000 engine is a no brainer decision for the dealer and should be for the owner!
#106 of 134 Re: Reply: dexos [gberpa]
Mar 18, 2011 (4:36 am)
Thank you for the quote from dealership. That is a definite "Aha!" moment.
The part about oil surges and timing chain.
The loud steel to steel bang upon start coincides with what I have been wondering, believing to be from oil drain down between runs.
If it made the loud bang, shutting down and restarting never repeated the sound. Thus it would take time for the oil to drain down again and as I posted some time ago, my factory PF48 was missing its anti-drain back valve.
If you have a vehicle that has not yet had oil changed, I'd definitely be concerned and save that filter. There is no knowing how often one of these slips by.
As to those who had problem fixed by changing exhaust, you may have had a different problem. What I was hearing, at no point did the sound make sense as coming from something in the exhaust. It was too loud and too defined as something heavy, steel against steel. Like maybe a 3 to 5 # engineers hammer against a large anvil.
BTW, I do get a sound in the exhaust upon start occasionally. It is the sort of sound I would expect from exhaust pipes, catalytic convertor, etc.
#107 of 134 Re: Reply: dexos [crankeee]
Mar 18, 2011 (6:43 am)
Book suggests checking oil level at every fill of gas. That seems a bit of overkill to the point that they should have included a low-level sensor as they did with some others.
You might check it 50 times showing no use, then something catastropic happens and it loses all oil on one tank.
I can't help wondering if dexos contains some secret ingredient to deal with excess gasoline?
There is a consensus that this engine with DI & VVT has been showing high gasoline content in UOA. And possibly tied to timing chain issues. I have not explored the siblings of this engine or any other that employ both DI & VVT, so I do not know how widespread the issue is or if issues are related to these technologies.
Because of results of UOA, many high readings with the lab calling attention to high gasoline, I will continue to test and monitor, probably avoid going below 25% or more than 5-6K miles between changes. To date I have seen absolutely no oil use, period! Even though GM is tying low oil to timing chain issues, it may extend to not using any oil but being diluted by gasoline. How bad is gasoline? My Dad runs many engines on the farm. Older ones often being more rebuildable than some newer ones and not as fussy as those with newer technologies. One thing he has used over the years are John Deere Gators. His biggest problem was because he did a lot of short runs, not allowing engine to be thoroughly warmed and burn off fuel, the gasoline engines all failed quickly and in one case right at one year. He never had issue with the diesel version because the fuel is like a very fine grade of oil. One of my sisters had 79 T-Bird w/400M that only lasted 27K because of gasoline issues. Most days it went less than 2 miles one way to work, school, or grocery. Under such extremes she probably should have been changing every 500miles or 2 months and for my Dad every 10 hours on gasoline Gator.
A sure killer of a motor if not caught in short time was the failing of mechanical fuel pump diaphram. They often leaked into the engine without external clues. A couple of basic rules for gasoline, never use as a solvent because of danger, and certainly never use on bearings because it will start rust which destroys the bearing, eventually. Sound like you want it in your motor oil? It will cause your bearings to wear out and destroy seals. It will also gum up lifters, valve seals, and rings.
I think GM owes us the truth about the gasoline, timing chains, etc. Do we need to change oil every 2K/2mo. for a long lasting engine? Or is that overkill? These bits and pieces, rumors, are not satisfactory. I do not like the idea of being the 1 in 1000, or whatever numbers game they may be using, that results in a bad vehicle.
#108 of 134 Reply: dexos [e_net_rider]
Mar 18, 2011 (9:54 am)
I also lean towards more frequent oil changes - 5000 miles max until the gasoline issue is clearer. Also the issue of added ethanol is coming up more. Damage to rubber and synthetic fuel lines so who knows?
Small engines appear to be obviously affected and Stihl, Toro, Honda warn against ethanol damaging engines. The latest proposal by the feds to increase ethanol to 20% caused a reaction by car makers (FINALLY!).
Timing chains on DOHC engines is a pretty new subject since the domestics lagged the offshore makers by 20 years on that technology IMO. The Japanese used belts rather than chains for 20+ years but replacement was VERY important and expensive. We will see if the long term durability of the newer GM, Ford engines lives up to the old Honda- Toyota engines that had VVT,DI and DOHC years ago.
Good luck to us all.
#109 of 134 Re: Reply: dexos [crankeee]
Mar 19, 2011 (2:09 am)
I don't believe there has been issues with DOHC. GM has had the Aurora/Northstar for a lot of years. I'm thinking the Mercury built Vette engine is also. Ford has the 4.6L which started in Town Cars and spread to trucks and 'Stangs.
Automakers have made statements about E85, high alcohol content, claiming they can't make engines last using it. I find this a bit strange since alcohol burns cleaner than gasoline. Is it Brazil that has been using it in lieu of gasoline for probably close to 50 years?
#110 of 134 Re: Reply: dexos [crankeee]
Mar 19, 2011 (3:57 am)
Call me compulsive but I change my oil 4 times a year at the beginning of each season: spring, summer, winter and fall. Since I do mostly city/suburban driving I believe these are considered extreme driving conditions and therefore require more frequent oil changes. This prescription has served me well over the years and I've never had an oil related problem, even driving the sludge-prone Avalon.
#111 of 134 Re: Reply: dexos [bwia]
Mar 19, 2011 (5:02 am)
Frequent (3000 mile) changes seems to be an abundance of caution, but that is what we have done for 40+ years. GM has used overhead valve engines for years but dual overhead cam all aluminum is a more recent model. The engineering for these "lighter" and "cheaper to make" engines may or may not allow for extended oil change intervals- only time will tell. We had a '90 300ZX that needed that schedule due to increased gas dumping into the oil, esp. when the cold start valve acted up (like the old choke) and incresed the mixture and idle speed. Your plan seems cheap relative to the downside of major engine problem!
#112 of 134 Re: Engine Rough [e_net_rider]
Apr 15, 2011 (4:06 am)
The subject of engine shaking around 1500RPM, plus & minus a couple of hundred RPM is resurfacing it appears.
I have not received a satisfactory answer as to why, just that other new ones do it also.
GM must think we are stupid and can't understand a real explanation.
For me it is of concern in many ways but in part because that range is so close to cruise RPM at a number of lower speeds. Unless they are actually shutting fuel off to some cylinders, it would be indicative of a poor burn.
BTW, I'm now seeing a long hesitation when I need to suddenly accelerate.
#113 of 134 Re: Engine Rough [e_net_rider]
Apr 15, 2011 (10:01 am)
Rider: Is shaking happening at idle or on the road under load? The DOHC higher revving engines DO NOT like to be lugged or loaded at relatively low RPM's. couple that with the newer 6-speed being programmed with a preference for economy (quick to upshift - slow to downshift) and it is easy to lug the engine. The old GM aluminum 4.1L in Cadillacs was famous for this since it was grossly underpowered relative to the vehicles obesity and was very easy to lug. Higher revs keeps the family happy in one man's opinion.