I’m with meanjoe on this. If “satisfactorily” means that the car will last as long as the typical new car owner owns the vehicle then IMHO that’s not very good. Most people sell their new cars long before 10 years or 150k miles.
I want to see how well these LONG-OIL-CHANGE-INTERVAL vehicles stand up to 300k or 400k miles. Is there a study on that??
Gm is trying to get the chain wear to last past warranty.
SAE is not GM, though GM engineers belong to it. Technical papers were preented to other engineers at SAE and the work was reviewed by other engineers from different companies. If GMs work was flawed, I;m sure that other manufacturers would have been happy to point it out and make it a sales point. Instead, they all started offering OLMs as well. Refereed publications, the state of California, and probably other large fleet users tested OLMs and found that they work well.
Many 4cyl engines are using one cam to operate 16 valves nowadays. It sure makes timing belt jobs easier I can tell you that.
I consider each link in 5 miles of timing chain “alot of moving parts” As far as me, i like old school “no replacement for displacement” What the big 3 should of done when considering overhead cams is Go the way of toyota and use timing belts. That way they could be serviced easily. Timing chains wear and stretch quickly if not properly lubricated. I learned that when i stretched out 3 chains on my pro mac 555 using drain oil instead of bar and chain oil.
“Exactly” Gm didnt have to stop making the cast iron v6 3.8 liter. They were not selling more cars when that engine was surviving over 400,000 mile of use.
US automakers are as smart as Japanese, they just put money before consumer satisfaction.
Unless you are trying to make the most power out of a given displacement class for racing or taxation purposes, pushrod engines have some advantages over OHC engines especially in V6 or V8 applications.
The OHV engines can be made larger in displacement with the same power and more torque and still fit in the same size or smaller than a lesser displacement DOHC. The OHV is quieter ang generally operates at a lower rpm. Less piston speed = longer life. GM (as much as I dislike their cars) has the best fuel management systems outside of F1.
When owners of those 50s Jags with the beautiful looking DOHC I6 engines found out what it cost to overhaul or replace those engines many owners chose to swap in small block Chevy engines and got a car that was lighter, more powerful, more reliable, and got better gas mileage.
Please come back meanjoe.
The reflash for the OLM maxes the change interval to 7500 miles. I think that is the max interval on all GM OLM as of about 2013 or so.
You revived an 8 year old thread and compare a chain saw chain to a vehicle timing chain , get serious. Many manufactures are going back to timing chains from belts .
I apologize for my stupidity, I am 55 yrs old. I have been a big fan of chevys , all ohv. My first " AND LAST"dohc is a 2008 trailblazer. That didnt have recalls on timing chain yet had a bad cam phaser. I use to do my own engine repairs but not being familiar with cam timing let alone dohc. I brought it in. They told me chain was stretch also and needed replacement. But with oil pump pickup tube location the engine had to be partially removed . Cost over $3000, mostly labor. Then i started reading up on overhead cam engines and it seems like chevy and ford triton dohc had alot of issues. So i will not buy a chained dohc automobile again. Or at least until they can last a long as the 3.8 liter that was dicontinued in 2008.
Maybe not buying one from GM is a better option. Toyota has done it right for decades. My 05 4runner was dohc chain driven. Sold truck with well over 300k miles with original chain. No problem what-so-ever.
Thanks, i will keep that in mind. Have heard alot of good about toyota. I have a habbit of buying from the big 3 chev, dodge and ford.
I WAS a big Chevy fan through the 60’s, 70’s and into the 80’s. Then I saw the light, and haven’t looked back since. Far better quality from Toyota, Honda or Nissan then GM products. But if you only keep your vehicle 100k miles then any brand will do.
The 3.6 vvt from GM has had many issues. They have recalled many of them for timing chain issues, but many issues exist. Their programming was a scheme, as they had skipped years for it. Why would you fix it for a year and go back to the old programming the next year? I asked, they couldn’t answer. These engines are prone to catastrophic failure. Best bet is to avoid any vehicle with it. The programming will not prevent the outcome. It is mechanical issues, not computer related.
There was never a DOHC “triton” engine, they were all SOHC
There are many panther cars and F-150’s with the 2 valve 4.6L that just as many if not more miles than GM’s 3.8L V6.
An engine’s vavletrain design alone doesn’t determine it’s reliability. There are plenty of overhead valve (pushrod) engines with chronic problems, Ford’s Essex V6 was know to have faulty head gaskets. GM’s 3.1/3.4L V6’s were known to have intake manifold gasket problems, and so on.
DOHC,single OHC, when Chain driven will not last over 150000 miles. Toyota made a 3.0 Liter, V6 stopped in 2004. It had a easily serviceable timing belt. they Should of kept making it or that design should of continued. I know a used car dealer that goes to auto auctions and said they are flooded with 8 to 10 year old crossovers, American and import throwing cam timing codes most likely from worn timing chain components. He wont bid on them. If someone (like me) that cant afford a new vehicle, end up buying one, then I get to deal with the problems and service bill. That being said, I will NEVER buy a chained OHC vehicle again. No one can change my mind. Being that chained OHC is all that is on the market, My next vehicle will probably be a full size sport utility or pickup with a OHV V8.
That is absolutely false. I don’t know where you heard that, or what would lead you believe it was true.
The market spoke. Consumers didn’t want to have to spend anywhere from $300 to $1200 every 60k-110k miles to change a timing belt when a timing chain will typically last the life of the car.
I was a new/used/fleet salesman for a few years, and I still keep up with current trends in the industry. I can tell with unequivocal certainty that chain-driven overhead cam engines are just as reliable as anything else. If there were some kind of secret fatal flaw inherent to the design, the entire industry wouldn’t be using it for the majority of their engines.
If you’re buying used, then you’re at the mercy of whomever owned the vehicle previously. If the prior owner didn’t keep up with required maintenance then you’re going to be the one of the hook for it unfortunately. That’s not the fault of the engine design.
Your choices in vehicle will be dramatically reduced in that case
Just so we’re on the same page; You manged to stretch some chains on your chainsaw because you neglected to use the proper lubricant. And then somehow parlay that, along with the word of a used car salesman as definitive proof that overhead-cam engines with timing chains are all faulty designs and are incapable of going 150k miles without failing. That’s my takeaway from what you’ve posted on this subject thus far. To me that’s not a strong argument.
In that case you’re going to be limited to GM or FCA. Ford does have a new big-cube 7.3L gas engine coming out for their Super Duty trucks though.
In fairness, timing chain issues aren’t a rare issue with Ford (5.4 3 valve, first gen ecoboost). Not sure if the issue is the chain stretching because of the length, the design of the variable timing system (cam phasers, etc), or what. Of course if you were to substitute a belt in these engines instead of a chain, the results wouldn’t be better, probably much worse.
I wasn’t aware the GM 3.6 had timing chain issues. We owned one in an 08 Malibu from 18k miles to 108k miles and didn’t have any problems. May be a good thing that we got rid of it if they’re problematic.