Highway cruising & Balance Shaft

[blaz]

Some of us think that highway rather than city driving will give us a bit more time before the BHW's balance shaft chain tensioners fall apart.

Well, no.

My passat has been driven 99% on the highway, and except for the occasional "Italian Tune-up", I drive it to minimize fuel consumption. Very gradual acceleration, and so on.

So I thought I would be pretty safe waiting for the 160K km (100K mile) timing belt change to do the geared BS change-over. But as it turns out, I was just lucky.

Brandon and his mechanic (DCB Auto Repair, Toronto) found large plastic pieces of the tensioner broken off and metal shavings all over the place. The metal portion of the tensioner was almost completely worn away. It was one of the worst they've seen.

Brandon immediately identified the increased chain noise when I first brought it into the shop, which really surprised me as I had no clue. Maybe you just get used to it, and probably my old ears just can't pick up those high frequencies anymore. It does sound a bit less noisy now, but not hugely so.

Anyway, knowing what I know now, I would take it in earlier and get it done.

 

[dhuddleson]

Good news that you got the upgrade done, perhaps JUST in time....

I know OilHammer has said that 100k mile Timing Belt change interval seems fine, but VW did reduce the Passat Timing Belt replacement to 80K miles (about 120k KM) a couple of years ago.

 

[oilhammer]

And this is why I keep telling people to quit kidding themselves into thinking "it won't happen to me". They ALL are junk. Upgrade them and no worries.

blaz, you DID get very lucky, your chain was probably very close (possibly 100 miles) away from chucking off and stopping the oil pump. Just think of all the poor saps that STILL don't know about this very serious problem!

And I have a car here from a dealer that swore the BHW had no balance shafts when the owner went in and complained about increased noise and vibration!!

Anyways, kudos to Brandon and the gang for getting another one saved.

 

[blaz]

Here's a couple of photos of the biggest bits they found:
http://picasaweb.google.ca/lh/photo/11bybR4YdD5Ahd1Lhgz0qQ?feat=directlink
and here:
http://picasaweb.google.ca/lh/photo/QJshWObkSgXe1KSswY5rTw?feat=directlink

The shiny metal bit is actually quite purty. Brandon says one of his customer's put one on a necklace chain and gave it to his wife when he couldn't afford anything else for her birthday after the upgrade.

 

[pgoes]

Interesting info about highway vs. city miles. My car has probably 70% city miles: short trips, stop &go,etc. Just what is not ideal for a diesel. But at 88K the tensioner showed little wear when I unchained. I've been very anal about oil changes; I wonder if that or driving style has a greater influence on wear & tear?

 

[thundershorts]

after looking at mine apart, the thing that looks to me that could be why some fail earlier than others is that all engines are slightly different in their manufacture. when the sprocket is installed at factory, its not same on all engines, it could be half a tooth either way, hence the adjustment slot on the ballance shaft sprocket. mine was at extreme of adjustment so it couldn't go any further. differences in individual engines as far as smoothness, or harmonics, probably could account for why some get chewed up faster than others. I agree it was a crappy way to accomplish what they were trying to acheive, a relatively low vibration engine, automatic trans only, to appeal to buyers in North America.

 

[blaz]

All our oil changes were done right at 16K km (10K miles) with 505.01, once or twice with 506, so I don't think that's a factor.

It's a mystery to me as well. Thundershorts' suggestion is as good as any AFAIK.

 

[BIGJDADDY]

I have 260k on my 05 passat tdi and have not had the chain break yet. But it must be very close. I just dropped it of at oilhammer's shop tonight. He is gonna find out what is causing a miss and bad vibration in the engine on heavy acceleration. I just don't understand what is making it smoke so much It just started bellowing out black smoke. It idles smooth but when u bring the rpm's up around 2000 it puts of a vibration. I just hope it is nothing major.

 

[oilhammer]

I have 260k on my 05 passat tdi and have not had the chain break yet. But it must be very close. I just dropped it of at oilhammer's shop tonight. He is gonna find out what is causing a miss and bad vibration in the engine on heavy acceleration. I just don't understand what is making it smoke so much It just started bellowing out black smoke. It idles smooth but when u bring the rpm's up around 2000 it puts of a vibration. I just hope it is nothing major.

Yeah, that engine does NOT sound good. I think most of the cam lobes have left the building, too.

 

[BIGJDADDY]

Well I am curious to see what is causing all my problems. I feel better that it is in good hands now. I just want a good running car and have read nothing but great things about u oilhammer. My first mistake was taking it to the dealer. I will be waiting for your phone call today. Thanks http://www.google.com/url?sa=t&source=web&cd=2&ved=0CCMQFjAB&url=http%3A%2F%2Feast.merriamwebster.com%2Fdictionary%2Fcurious&rct=j&q=courious&ei=LfK-TP_8CIK8lQeEwJniBw&usg=AFQjCNHbogyylMkyfHH7pf4i0vbwIgGjPA&sig2=SPRPoyq2pgBFd0m5zPEJXQ&cad=rja

 

[oilhammer]

Just got the valve cover off, one of the cam lobes is pretty much GONE. Jon will be calling shortly.

Your air cleaner is also broken too.

 

[johnboy00]

What did the dealer say besides: "How the &%$% did you get a VW to last this long"

I'm guessing they said new engine $10K.

 

[BIGJDADDY]

Yeah, that engine does NOT sound good. I think most of the cam lobes have left the building, too.

Yeah I hope not. But I fear u are right. I used Rotella T6. Not sure if that oil is safe or not. I just couldn't find any oil with 505.01 found some 505.00 after i started having problems. It had 113k when I got the car now has 265,xxx miles and want to get alot more out of it.

 

[BIGJDADDY]

Just got the valve cover off, one of the cam lobes is pretty much GONE. Jon will be calling shortly.

Your air cleaner is also broken too.

Dealer broke it and I tried to fix it with no luck.

 

[BIGJDADDY]

What did the dealer say besides: "How the &%$% did you get a VW to last this long"

I'm guessing they said new engine $10K.

No they wanted to keep guessing at it with my money. But check this out there lead tech said he checked the cam and looked good. They are stupid I hate suntrup.

 

[BIGJDADDY]

Well leaving for work just call me whenever I drive all day. Anytime is a good time to call. Thanks oilhammer

 

[Brian's96TDIPASSAT]

so I guess there is hope that mine will last till 200K when I do the next t-belt I've heard 04's and 05's that sound like JUNK at 80K, mine sounds great compared to those. Just about to turn 150K.

 

[thundershorts]

while cleaning up shop after all the work and trashing all the junk, I took a good look at the chain tensioner with 60k miles on it, the passive side had cracked at the point where the casting was open webbed, its almost like they designed it with perferations so it would break easily, there wasn't any chain slop or noise, but its obvious if it hadn't been for this forum, I would have assumed I had a good engine. glad the tensioner is now in the trash can. thanks to all of you.

 

[oilhammer]

I have two of these in the shop now.... one getting a new crank, the other a new engine.

PLEASE get that chain out of your engine if you haven't already!!!!

 

[thundershorts]

what I had felt before, that the tensioner's bad design/quality sets off the chain (pun intended) reaction. tensioner fails, then wear slop in the chain, then chain failure. if the tensioner had been design corrected, then been recalled and replaced, we wouldn't have all been boned.

 

[MattS]

I have two of these in the shop now.... one getting a new crank, the other a new engine.

Yeah... one of those two is mine! Like others I've read all the forums on this. In my opinion there seemed to be a lot of people with noisy chains but not as many with completely failed chains. I bought the car at just under 150K miles. I had listened to posted videos of others with really bad chain noise. Mine wasn't nearly that bad. The car was driven on the highway; I changed the oil on schedule; and the previous owner showed me a stack of dealer receipts for oil changes. I was pretty comfortable waiting for the second timing belt change (due in just 9K miles). It was a calculated risk and it didn't pay off. The chain snapped as my wife was headed to work about 65 miles from home. Luckily she had been warned about this possibility and shut the car down right away to save the engine. I loaded it up on a trailer and towed it around the corner (250 miles) to oilhammer. Hindsight is always 20/20 -- it would have been better to change the timing belt early and take care of the balance shaft module. I'd recommend this to anyone regardless of highway miles, frequent oil changes, or lack of noise.

 

[oilhammer]

Actually, Matt, your chain tensioner was broken when you bought it... without a doubt. It just took that much longer for it to wear completely through and throw itself to pieces out the side of the engine. The whole mess is now in about 100 pieces laying in a pile on the workbench.

Your crankshaft showed up yesterday afternoon, I got the transmission out last night, working on it all day today. I just hope I can get the new gear BACK off the old crank without messing it up. I have another gear here though in case I messed it up trying.

 

[MattS]

Yeah, I believe you that the tensioner was bad -- I wasn't questioning that.

My point was more that I attempted to make a rational, informed decision to just wait until the timing belt change and it didn't really pay off -- maybe I was just being delusional. Hopefully others won't do the same thing.

There are many plausible arguments for putting off such an expensive preventative maintenance item. Such as before you spend the money to repair, your car will be totaled, making the costly repair unnecessary. Or maybe other things begin to fail first that lead one question whether this repair is also worthwhile. It might be easy to think the problem isn't as bad as it seems, since typically only the ones experiencing failures (like myself) are speaking up. I tried to get a solid estimate of the probability of a failure since that is the real number that is needed to make a good decision, but that is hard to figure out from the discussion on this board.

People should just be aware that they are assuming some real risk for very costly repairs. It is also risk that you cannot easily buy insurance for -- the value of your car can instantly drop by at least half and you have no option but to salvage it at a big loss or pay for an expensive repair.

 

[oilhammer]

All done!

 

[Brian's96TDIPASSAT]

Why do these engines end up needing cranks if the engine is shut off as soon as your low pressure light comes on? I"m wondering if both of those engines were run for a few minutes "until the next exit" before shutting down.

 

[leicaman]

I have two of these in the shop now.... one getting a new crank, the other a new engine.
PLEASE get that chain out of your engine if you haven't already!!!!

Brian is so absolutely right.
Just for giggles the other day I was looking at Passat tdi cars on eBay. So there was a wagon there that was so clearly overpriced ($14,999), I just had to ask if the balance shaft was converted to a gear driven unit. The idiot came back with a ultra-snarky response that the balance shaft situation is merely a ploy by some to make profit by replacing these. He also had the balls to say the chain costs a mere $12.00 to replace. What a maroon. If you look at a used passat you must assume it has not been replaced unless you are an expert at knowing which is which with the dipstick test. I know I couldn't tell. Maybe MoGOLF is the only one who can.
Those of us who have owned these cars from day one, know this is not BS. My car vibrated like all billy heck when the A/C would be on while standing still in a traffic jam. My car also made a strange noise when you would be going 70mph that sounded like a chain whipping around (at least that is how I interpreted that noise. My car also made a really obvious noise that most anybody could interpret. I drove my car to a job today on the freeway and it is just so dang quiet, I swear I own a Rolls Royce.
Again do not believe the naysayers. This problem is real, particularly when you own one of these beyond 75k. The big problem is that it is like dealing a deck of cards, you never know when the joker will come up. With cards that is a 1 in 52 odds. Those are incredibly good odds that something will go bad.

 

[s4phillips]

Why do these engines end up needing cranks if the engine is shut off as soon as your low pressure light comes on? I"m wondering if both of those engines were run for a few minutes "until the next exit" before shutting down.

I don't think anyone could recognize the situation and react quickly enough to get the ignition shut off in time if you are driving when the chain decides to go to lunch. There could also be the safety issue that forces you to delay shutting the engine off while driving. Why risk trashing a crank or an engine by continuing to run a doomed chain driven BSM?

 

[MattS]

Oilhammer can elaborate on this more since he saw the insides...

In our case the engine was shut down right away, probably within 5 seconds. The car was being driven at a low speed and RPM on a two lane road and was immediately stopped on the shoulder, shut off, and towed/trailered over to St. Louis without ever being started again.

Apparently when the chain broke it bound up and somehow caused the driving sprocket to spin on the crank. The damage made it impossible to put the new gear on the crank. This is particularly frustrating since the lower end wasn't run out of oil and (according to OH) all bearings were just fine. The lesson: even if you are prepared to stop immediately and do not run the engine without oil pressure, it is possible that the cost of the repair could still well exceed the cost of just doing the replacement in advance depending on how (un)lucky you get when the chain breaks.

 

[oilhammer]

Why do these engines end up needing cranks if the engine is shut off as soon as your low pressure light comes on? I"m wondering if both of those engines were run for a few minutes "until the next exit" before shutting down.

Because the sprocket gets yanked around and mangles the snout of the crank, and so you cannot slide the new gear on. Has nothing to do with how fast you shut the engine off, the damage is already done. That is why I keep preaching about getting this taken care of proactively. I take no pleasure in telling people their car needs $6000+ in engine repairs.

This is actually the THIRD one that has failed in this same manner, and ended up needing a new crankshaft. Snood's failure pounded out the hex drive in the oil pump before the broken chain was able to finish sawing itself through the broken tensioner, BUT in his case, the engine was allowed to run just a little longer and it galded up the bearings. Luckily we were able to R&R the crank, have it polished, I put it back in with new bearings, and sent him on his way. But that sprocket remained intact on the end of the crank.

The other failure mode is the chain shears the teeth of the sprocket, and just slips past it but continues to remain whole.

In every case, the broken tensioner is the root cause. The damage inflicted depends on how long you drive with a broken tensioner and how catastrophic it breaks apart when the chain finally stops doing its job. I have a PILE of broken tensioners, many people did not even know that it was broken. Again, PLEASE, get this taken care of BEFORE it breaks!!!

 

[anoldbaldman]

u wanna come out to Oregon for awhile?