sauceman

Folks, you may want to plan on replacing your timing chain around 250,000 to 300,000 km (150,000 to 175,000 miles) on your odometer.

At 314,000 km a few weeks ago, my chain had become pretty loose, and upon shutting the engine down, it kicked back for half a turn as it will happen for any engine once in a while. But since the chain is binded only one way and it was stretched by 1/4", the cams didn't follow the crank.

Result: intake cam was -90 degrees and exhaust cam was -180 degrees.

We could still fire up the engine, which worked on 2 cylinders, thanks to variable cam. So we didn't figure out right away it was a timing problem, so the engine did a few thousand revs before they got to work on it.

Apparently though, variable cam also makes it that the valves didn't touch the pistons when on low cam profile, and the engine just wouldn't rev past low cam profile.

So lucky me, the engine revs absolutely smoothly over a month and 6000km after the incident.

It took the ECU about a week to relearn the specs after having reset it. The car then ran smoothly, but on limp mode, with a dramatic dip in power below 6200rpm. Car felt like a GSR.

Since then all seems well, and I don't seem to hear any hurt valve on a cold start, so I'm pretty optimistic this was a close call. Nevertheless, a CEL came on for 1200km last week, but went back off, so I'll have it looked at Wednesday and hopefully it's just a minor thingy.

So all in all, if you want to be sure, keep an eye on the chain, even if they don't mention it in the maintenance schedule. Aside from that, car runs okay.

jmathew34

i knew it'd have to be replaced at some time!

thanks for the info!

CarbonGray Earl

Good to know Sauceman. As our cars age, I'd really hope that guys with higher mileage keep us up to date on what's ahead.

curls

Hey sauceman (and other!)...

Sorry to hear about the incident, but I was wondering if you've ever had the timing chain tensioner replaced or even looked at? I remember when I got the new engine put in from Camco Acura, the head tech mentioned that the timing chain tensioner is somewhat common to eventually go out of spec and cause the chain to jump, both on the TSX and the CR-V and and other K-series engine. Luckily I got a new tensioner, I think(?), when I got the new shortblock.

I think his story makes sense though, since the tensioner, if working properly, can account for almost all of the slack a chain can develop through stretching.

Once you get the CEL sorted out let us know what it says. Also, did you manually go in there yourself and change the timing back to proper specs, or did you see the dealer for this work?

TSX 3Pedal

I guess I better keep an eye on that timing belt since I'm at about 135,000 Miles

Mokos23

thanks sauceman, i'm only still at 56,300 miles myself, not even sure if i would keep the TSX that long. i'm still going to get the rear axle leak fixed tomorrow.

sauceman, how many times have you:

1. changed the tires and batteries?
2. has your a/c compressor broke?
3. how many times have you changed the xenon bulbs?
4. think your TSX can make it up to 350,000 miles?

lcrazyaznl

iTrader: (1)

05 here just hit 90k, sounds scary to think what else is going to possibly be chaotic for this car.

moda_way

Well, I've been hearing a "rattling" coming from the timing chain cover and was going to pull the tensioner check cover off. Might as well just get the new parts and suck up to do the service. At my 04 is at 82k miles....

sauceman

No problem!

Thought this might be useful for you guys.

sauceman

Hi Eric!

Yeah the techs did change the tensionner while they were at it. They obviously also changed the chain and put the cams back at the right timing with the crank.

I'll keep you updated with the CEL.

sauceman

Tires: I believe I'm on my 4th set of all-seasons (Nokian WR)
Battery: Changed my first battery about a month and half ago. Went with a Trans-Canada battery. Much better than OEM.
A/C Compressor: Broke once. Replaced at 135,000km on a good will warranty.
Xenon Bulbs: Once each at 240,000 km. Also replaced my sealed beams altogether in December. The old ones I will polish and offer them for sale in Black Market.

The TSX will make it to 350,000miles and beyond, but not with me. I'll stop at 300,000 miles. By experience I can tell you that further than that and your maintenance expenses are gonna jump exponentially.

sauceman

I wonder if having a new tensionner might prolong the life of the chain?

curls

That's what I was trying to get at. I think the tensioner would be the thing I'd place 95% of the blame on. The other 5% would be on the chain. I think the chain can only physicaly stretch so far and that's it, and the tensioner is supposed to keep it taught until beyond that point. But knowing the tensioner on the K-series engines can be problematic at higher mileage (or sooner than stated in any official print), it seems to me that the tensioner lets the chain get slack and skip, causing the problem you experienced.

Any idea how hard it would be to get this information from Acura? I'm thinking that the tensioner replacement could become routine maintenance, kind of like the regular change intervals for timing belts on other engines, as a preventative measure.

dom

Great to have the sauceman back!


Any oil burning? leaking?

I have what looks to be a slow leak in the intake gasket.

Fox137

Hmm me too... How many miles on your car dom? I have 81k on mine... it's a very slow leak though (for now anyway)

godfather2

i had my auto tensioner replace just before i hit the 30,000 mile mark under warranty. fyi, i started to hear a strange whistling sound from under the hood and went str8 to the dealer

Mokos23

Wow, the Acura service people must like you!

dom

121,000 km's or 75K miles.

I was told its a $200 repair. Although it wasn't confirmed as being from the intake gasket.

peterjedi

What's your city/highway ratio?

Do you V-Tec often?

What's your RPM range?

Basically car driving habits increase or decrease the tensionner/timing chain?

Thanks,

Peter

moda_way

It is definitely the week point, only issue I have is, they haven't changed the P/N for it, which means Accords (K24) and us should all be seeing the issue and frankly, I've not heard a word about it as I have an insider at Honda. So makes me the think the added torque of our motor could be another contributing factor. As you can probably guess, all of our cam drive parts are shared in the K24 series (chain, guides, tensioner, etc).

925tsx

The tensioner on my 04 went, and took my engine with it.

Now i have the 08 and will have that tensioner checked when i reach the higher miles.

moda_way

More info plz. Mileage, what happened, etc etc

LukeaTron

More likely it's the variable cam timing. I imagine that it causes a bit of bounce in the slack when the timing shifts. Does any one know what the failure mode of the tensioner is? I suspect it has to be one of two things, the bearing or the spring. Probably the spring.

moda_way

I've only see a picture of it and it isn't like any tensioner I've ever seen, so I can't even describe it. All I know is, I hear something "rattling" in the chain cover. Went to go check the tensioner view a cover down by the crank. Looked like a PITA to get off since I didn't have the right socket to get my crank pulley off.

LukeaTron

Got any links to schematics or anything?

I get a rattling but only when I'm way up in the revs. I plan on poking around a bit when the weather gets better. For the mean time I just don't go up there very frequently.

moda_way

I'll look around, but I get a rattling from the case at cold startup only. Once warm, no rattling and it is most definitely against the chain case and not internal, which would probably just be the end valves being starved of oil at startup and wouldn't sound like a rubbing noise. I've already started the process to have someone look at my chain and tensioner. If I can, I'll take pics whenever it happens.

curls

I just called my dealership back and asked them to double-check whether my timing chain and tensioner were replaced when the new shortblock was put in. Short answer: No, the short block is the block and everything inside it, but not the tensioner, chain, etc...

So, my chain + tensioner now have about 126,000km on them. Not a lot, but I'm considering replacing the tensioner while I am in there installing the underdrive crank pulley in a few weeks.

The service advisor said that he's seen some K24 engines come in for a new tensioner, and the going rate is about 3hrs labour + about $100 for the part. He says the trend is for people who drive the car harder, to be the ones that need a new tensioner. I guess that makes sense.

I didn't ask if the chain itself should be replaced, but judging by his quote of ~$100 for parts, I'm guessing they do not replace the chain.
http://www.acuraoemparts.com/delray/...All&vinsrch=no

Chain: List price $93.97 USD
Tensioner Assy: $65.88 USD
Arm, cam chain tensioner: $85.75 USD.

I'm guessing that being a Canadian dealership, they probably charge about $100 for the tensioner assembly. Going by the diagram, it's a small little part that pushes on the arm, which tensions the chain. Very bizarre setup as compared to a typical tensioner pulley!

925tsx

Mileage was 105K.

Dealership said that the tensioner failed, which caused the timing chain to jump off the cam gears.
Basically they said the valves hit the pistons and went kabam.

They wanted 13grand for a new engine, and wouldnt fix the old one.
I made a thread on here when it happened.

PACman

I was thinking along the same lines. What about folks with Hondata Reflash since they change cams earlier thank stock RPM?

925tsx

schematic of the tensioner/ oil pump
http://www.acuraoemparts.com/delray/...All&vinsrch=no

curls

My question would be "How the heck can someone inspect the timing chain tensioner before it's too late???"

I'd like to check mine before I get to work on the underdrive pulleys, so if I need to, I can change the tensioner the same day without having to wait for parts to be ordered, etc...

curls

I am 99% sure that you linked to the BALANCER CHAIN, not the timing chain. My link a few posts back, had the timing chain. Here's my link again: http://www.acuraoemparts.com/delray/...All&vinsrch=no

I guess this also answers the question of "Are our engines internally balanced", and the answer would be "yes, they are, they have a front and rear balancer, both driven from the balancer chain".

925tsx

Your right, i linked the wrong thing. thanks for the clarification

LukeaTron

This kind of tensioner is frequently used in motorcycle engines (or at least I've run into a couple times on motorcycle engines). There are three ways they wear out. By far the most common is the spring just wears out.

I can't tell from the picture but the motorcycle ones are usually ratcheting, meaning that the tensioner can only get tighter. Sometimes the little catch will get broken or the spring that keeps it against the teeth will break or get weak. I've heard of this happening but never seen it. I suspect the TSX tensioner has a ratcheting mechanism or else the centrifugal force of the chain at high RPM would overpower the tensioner spring.

Lastly, the plastic chain guide can get worn down. I've never heard of this happening on a bike but they usually have wet chain. The dry chain on the TSX might present more problems.

So as far as checking it goes, make sure the spring is up to snuff (I don't know how you would check without some sort of specialty tool) and that the ratcheting mechanism is working correctly. Also check the chain guide for signs of excessive wear. Alternatively and I might say preferably, you would just replace it while you have easy access.

gr8ness97

iTrader: (5)

Wow...I have a squeak under my hood like its a belt or something


Mine is an 04 with 93K

curls

Guys, I just checked the Helm's manual, and the procedure to change the auto-tensioner is SIMPLE.

- No need to remove crank pulley
- Just get down by the crank pulley, remove 3 bolts to remove a small portion of the chain case cover, turn crank pulley counterclockwise to compress auto-tensioner, stick a lock pin into the tensioner, remove the 2 bolts holding the tensioner in, remove tensioner, transfer lock pin into new tensioner, install new tensioner (2 bolts), apply liquid gasket to small cover you removed, reinstall, voila.
- There's a bit of detail around the pin thing but it's simple, really. I can scan the pages if anyone wants to see them - just PM me!

I think I might pick up a new tensioner and install it when I'm putting my underdrive pulleys in a few weeks from now. Unless I can find a way to test the existing one... ??

jfrank1845

Hey guys, I have an 04 with 90k Miles on it.... and i've already done much of this stuff.. as a side note I bought the car used a little less than a year ago with about 74k miles on it so I only know a short history on it... Anyway here is my history.

When I got it I had to do:
Timing chain, tensioner, arm, gasket set, o-ring [ timing chain was stretched dtc p0341]

also had a burnt out front headlight w/ ignitor, which I wish I could go back and do again... as I bought a bulb from the dealer.. $188 and it wasn't quite the same color temp as the other... bothered the hell out of me until I bought an after market set which matched.

Nonetheless, since then i've had no issues except the other ignitor went out as well just last weekend :-( ... there goes another $170, other than that it runs beautifully. Only had to get new tires because ended up getting nails in 2 of them.. in a parking lot at the mall at night ... pissed about that...

All in all, I spent $1500 on repairs when I got it.. including 10 oil changes.. which my dealer only charged 169 for.. so $17 an oil change.. and a free car wash... not a bad deal if you ask me.

Some might say that is a rediculous amount of work to have done on the car, but I will note that I got it from a dealer auction for only about 12.5k so hell of a deal if you ask me.. list at the time was right around $21k for normal miles.. which yeah I'm high, but not that high. Other than that, i've noticed some rattling in the steering wheel/collumn area which is driving me crazy.. i've read on here that some say it is an airbag issue.. I will possibly take it in to the dealer and see if they can guess what it is from a quick test drive... it only mainly does it in specific temperatures.. I'll let you know if I end up with a verdict on that.. Other than that i'm In love with my car :-)

lcrazyaznl

iTrader: (1)

Guys what kind of whistling sound are you getting?

I get this loud sound but thought it was tapping from the valves. Asked the dealer about valve adjustment and they said it wouldn't do much but reduce the noise?

Are you guys getting a sound away from the valves? its like a ticking sound as the pulleys spin.

LukeaTron

Yeah, that sounds like what I've got. Initially I thought it was oil getting thrown off the chain and hitting the valve cover but then I realized that it's a dry chain. The best way I can describe it is a very solid and mechanical rattle. From what I can tell, it's coming from the right side of the engine.

sauceman

Hey Dom!!

Yeah, oil burning? Car needs it's regular litre of oil every 1000-1500km. No leek though.

And as long as I feed it with oil, it runs smooth and happy.

I do too, as long as the Habs win a hard-fought battle against the Bruins..