Last post on Dec 14, 2013 at 8:42 AM
You are in the Automotive News & Views
What is this discussion about?
Car Buying, Biodiesel, Diesel, Hybrid Cars, Coupe, Hatchback, SUV
#9630 of 11807 Re: now it's just up to supply and demand [steve_]
Jun 14, 2013 (7:01 am)
Well, I can't say I can tell the difference between a 90's Corolla iding (belt) and a late model (chain). If anything the later model makes more injector clatter than the older car's throttle body injection.
But, I can sorta imagine a belt having the ability to be quieter and contribute fewer parasitic losses. Mainly due to bearings in idler wheel tensioners having less friction resistance than a guide whereby it relies entirely on the surface compound and the oil that lubes it. I guess too, the metal to metal contact must make a slight difference in db potential no matter how exacting the engagement area is. Take metal bottomed frypan and set it gently on a steel work bench. Now take that same frypan and layer some kevlar etc on the bottom and set it down gently..I'm guessing that with db measuring device, it's going to read lower with the kevlar based pan.
You should hear the RACKET! that many bikes make from nothing more than the timing chain tensioner guides..Holy smokes, some of them make more noise than the exhaust note. Honda CX and many of their CBR models come to mind right off.. Now take Honda's ST. The first year and right up to 2002 (inclusive) generation, they used a belt. Then in 03 they did a complete and massive model redesign. The engine grew in displacement, placement in an aluminum frame (vs steel), became stressed in the frame (vs rubber mounted) used a timing chain, and grew a chain driven internal counter-balancer. It is that last little tidbit of info that camouflages the potential extra noise of a timing chain. The balancer uses straight cut gears that whine. And they are loud! Too loud for my liking. And they easily overcome any noise the timing chain may be making over the older belt model. The new generation is an entirely different beast. Incredibly capable in the handling department. The lowering and more forward positioning of the engine in the aluminum frame and stressing it in the frame as a structural member, all contribute to that handling. But that same solid mounting is what necessitated the internal balancer.
Sorry..I was going somewhere with this and now got totally sidetracked
#9631 of 11807 Re: now it's just up to supply and demand [gimmestdtranny]
Jun 14, 2013 (8:43 am)
I think for the purposes of the diesel engine discussion the use of chains and/or T/B or aux belts should NOT be a deal breaker. In many ways, either is TMI. Even the most well built GASSER car (which is pretty rarified distinction (1990's Lexus!) uses chain drives. As I have already delineated the 94/96 TLC's both I 6 GASSERS, use CHAIN drives. So for example in the process of checking and doing the TLC's valves (neither have needed the procedure) the shop took a stern look at both chain drives (AOK!) Of course it is at a more expensive labor charge and cheap parts cost (gasket).
So the key difference is that belt drives normally need a SCHEDULED maintenance cycle: as opposed to a CHAIN drive that is not scheduled but some TBD or unscheduled point, MAY or may not need a rehab to R/R !! As a general rule we are talking something on the order of 200,000 to 300,000 miles that it should the very leas be inspected by a qualified mechanic/shop. As a point of TMI belt drives really allow more precision in design, operation, and cheaper renewal, albeit on a schedule basis vs a TBD UN scheduled basis.
So for example early this morning, I heard the "PEPBOY'S" CEO say the 8.5 to 13 year old car owner is his organization's sweet spot customer. So given the US AVG yearly miles 12,000 to 15,000 miles, the range is between 102,000 miles and 195,000 miles. So by defacto and inference, a car is relatively care free: sub 8.5 years.
This was unsaid but almost any car is really designed to go a min of 100,000 miles with only minimal scheduled maintenance (oil/filter change, brake pads , rotors, tires and alignments if one is a consumption "MONSTER. "
#9632 of 11807 Re: now it's just up to supply and demand [gimmestdtranny]
Jun 14, 2013 (8:52 am)
I don't like the fact that the automakers have a high maintenance element built into the vehicle. Like the timing belt and VW with their 60k mile DSG expensive maintenance. I understand automakers like MB, BMW and Lexus will charge big bucks for normal maintenance. The owner can get it done cheaper. Not sure with some of these built-in failure items. Are companies like Honda and Toyota saying they cannot design an engine that will not destroy itself if a belt breaks? With Toyota 6 cylinder Land Cruiser engines in the 1960s, they decided to use a fiber timing gear rather than a metal one like the Chevy engine they copied. The 3rd time my timing gear went out with less than 25k miles, I had a local mechanic that asked why I did not put in the Chevy timing gear? It was identical in size with the marks one tooth off. He installed it and ended my problem. No more failures. Same for the cheap metal the Japanese used in their valves.
#9633 of 11807 Re: now it's just up to supply and demand [gagrice]
Jun 14, 2013 (9:35 am)
If I am to use the 2004 Honda Civic (gasser) as an example, then I have say yes to your question. It does require both a valve adjust AND timing belt change app the 120,000 miles mark. The procedure takes longer than the VW TDI TB/WP change. But the Indie Honda mechanic took the deliberate tack of taking his time over 2/3 days to do this, with consent of the shop's owner. I just went to the shop over several days and times to look, monitor the progress and get schooled about the innards of this whinny engine. (he was rebuilding others so he demo'ed the process at various levels). For reasons unknown to me, my Honda mechanic is a Honda sponsored racer on his off time.
#9634 of 11807 Re: now it's just up to supply and demand [gagrice]
Jun 14, 2013 (11:04 am)
Yes, I agree on the VW maintenance costs..and no doubt MB. (I just found out they charged my friend with the ML 400+ bucks for its first service. One yr..did an oil change and refilled the adblue..that's it!
A couple years ago, I tallied up the extra costs to just own an auto in a new Jetta or Golf (cuz I plan to finally get an auto due to leg and knee issues:( ) and it was really significant! Seems to me each service was 500-700 or some such ridiculous price. And it happened every ..I forget..still have the pamphlet here somewhere though..50 or 60k km less than 40k miles! As for the timing belt, well, it is pretty much a universal issue of not having enough room at TDC (top dead centre) for the valve to be left hanging from a broken belt, and the piston relentlessly following through with its usual stroke and wham on diesels because of the higher CR's. So the actual combustion area is quite compact. And over the years, this same compact combustion chamber is on lots of gassers too..especially name brands who sell cars with higher performance levels, using premium gas and of course, all saddled with those small combustion chambers. That's why basically all the luxury brand names use premium gas, and all have interference engines. When the belt broke on the Magic Wgn van, an 88, it had the Mitsubishi 3.0 V6 in it. A non interference engine.
Sometimes engine rpm at the time of belt failure can cause the interference to happen or if lucky, not. But this will only happen with CC's that are not really squishing the intake air. So IOW's, if it's a diesel or very high performance type engine, not having a timing failure is crucial.
I believe that that is one of the reasons mfgrs have gone to chains...not just cuz we have voiced annoyance with the ongoing expensive maintenance of belts, but because if a belt happens to have a flaw and fails inside wty, well that costs them..
And chains (even with poorly designed guides and tensioners on certain engines) usually never fail under wty.
#9635 of 11807 Re: now it's just up to supply and demand [steve_]
Jun 14, 2013 (11:10 am)
Had you had a bad experience in the past with this or were you just hedging your bet? Maybe you were partially in there (I'm not real familiar with the boxers) whilst having a head gasket replaced and decided to go ahead and do the belt too?
#9636 of 11807 Re: now it's just up to supply and demand [gimmestdtranny]
by Stever@Edmunds HOST
Jun 14, 2013 (11:36 am)
It's an interference engine and I haul a couple of octogenarians around in the winter so I didn't want the big expense of a ruined engine nor a stranding with them in it. The gaskets seem okay and the main seals aren't leaking much at all, so the engine hasn't been opened (yet).
It was okay stranding my wife this past April when the belt broke in the Quest fifty miles from home. We got towed home pretty fast and the engine didn't get damaged by the belt breaking. And she's pretty tolerant of my foibles.
#9637 of 11807 Re: now it's just up to supply and demand [gimmestdtranny]
Jun 14, 2013 (12:02 pm)
I just found out they charged my friend with the ML 400+ bucks for its first service.
That sort of thing was widely told in the auto rags. $250 AdBlue fill ups. When I get a vehicle with Adblue tank that will be the first thing I do. Locate and keep it filled. If MB wants to rape me on synthetic oil change I will go elsewhere to have it done. There is a long established Mercedes Indie much closer than the dealer. He is right next to my wife's favorite thrift shop and my favorite gun dealer. I would probably use his shop anyway to save 30 extra miles of driving.
Dieter is also an authorized MB warranty shop.
#9638 of 11807 Re: now it's just up to supply and demand [steve_]
Jun 14, 2013 (12:04 pm)
It was okay stranding my wife this past April when the belt broke in the Quest fifty miles from home.
You and your wife are very adventurous. You stay in tents when there are perfectly good motels to stay in.
#9639 of 11807 Re: now it's just up to supply and demand [ruking1]
Jun 14, 2013 (12:44 pm)
I saw this on a " 5th Gear" episode: How about 68.9 mpg? Is there really any question that a lot of good diesels are being withheld / BANNED from the US market?
13 BMW 3 series