Are all timing chain guides really necessary?

[supton]

So this evening I thought it'd be "fun" to take the valve cover off our K24 with its failing exhaust cam, to gauge how things are going. Am guessing I did it not favors with whatever dirt fell into the engine, but whatever. I'm not sure how I got the valve cover off the first time but it was quite a bear this time; am not sure if I can just unbolt the high pressure power steering line as that is in the way? was guessing that has some sort of one time use washer or something else to make me regret touching it.

Anyhow, upon installation, the valve cover gasket caught this upper guide and snapped it off. The other piece fell off too. It's this piece at the top. In this pic, the part on the left was taken off after this; the other half that should be on the right side... well it's not there anymore.

Got all the pieces.

Very little wear.

If not clear, it's this top piece (not a picture of my engine, but rather some one else's that I found on google):

I didn't hear any new noises when I started it, and rev'd it, so I'm guessing it's just like all the other bolts and bits that get left over after working on cars. Something like that. [Probably only important at the rev's that this car doesn't see.]

In other news, I was able to verify that 3 lobes are failing, but only in the early stages. The one that is worse doesn't seem to be wearing that fast. 5k OCI's with 5W30 has helped. Maybe I should drop to 3k.

 

[fantastic]

Need to keep the chains "Snug" went they are rotating around. Possibly decrease chain wear too via less movement/vibration?

 

[supton]

Need to keep the chains "Snug" went they are rotating around. Possibly decrease chain wear too via less movement/vibration?

The chain felt snug when I first looked it over; after that piece came out, it wasn't quite as snug. There is faint wear on it, so I think it's there to prevent slapping around. Am guessing that it might be an easy piece to replace--once I figure out how to better remove/install the valve cover!

 

[fantastic]

The chain felt snug when I first looked it over; after that piece came out, it wasn't quite as snug. There is faint wear on it, so I think it's there to prevent slapping around. Am guessing that it might be an easy piece to replace--once I figure out how to better remove/install the valve cover!

Take my old 97 Nissan D21 as an example. They were notorious for guides wearing out & the chain slap at startup was quite noticeable when it started (perhaps hitting to worn guide). Or if the chain stretches out a bit it may make more noise/vibration? Interesting to ponder & probably a good idea to replace it if you need to. At the very least I'd think it would provide longevity for the chain & gears due to less vibration/movement.

 

[supton]

Take my old 97 Nissan D21 as an example. They were notorious for guides wearing out & the chain slap at startup was quite noticeable when it started (perhaps hitting to worn guide). Or if the chain stretches out a bit it may make more noise/vibration? Interesting to ponder & probably a good idea to replace it if you need to. At the very least I'd think it would provide longevity for the chain & gears due to less vibration/movement.

True. If I can find that piece, and figure out how what to do about the PS line in my way, it'd be on my to do list.

 

[fantastic]

True. If I can find that piece, and figure out how what to do about the PS line in my way, it'd be on my to do list.

I'm sure it's a tight area. Fun!
Yeah, that cam lob looks awful. Is this your older Honda you've previously mentioned the cams were bad & needing to be replaced but wanted to keep it around town in the meantime?

 

[supton]

I'm sure it's a tight area. Fun!
Yeah, that cam lob looks awful. Is this your older Honda you've previously mentioned the cams were bad & needing to be replaced but wanted to keep it around town in the meantime?

Yes. Our 2003 CRV, has about 204k on the clock now. MIL owned it for the first 160k--but lived a mile from work. Transmission seems just fine but lots of short trips. When she handed it down, she said it was using oil but it does not seem to be using much, I might add half quart or a full quart over a 5k OCI (but I bumped it to 5W30 from the prior 5W20). It's not too rusty and I think has a few years left. But if my son gets a better job I do have a temptation to have it replaced. Or we'll have to come up with a plan to fix its known issues (exhaust cam, one airbag, and whatever breaks between now and then).

 

[oldhp]

I couldn't live with myself knowing the cam looks like that. I'd install a new guide and new cams. But that is me. Maybe step up to 5W40?

 

[supton]

It bugs me too but if I dug into it and bricked it, then what? I need 3 cars on the road. I haven’t replaced the fourth one that we lost, but can’t justify a fourth car at the moment.

Local garage wanted to swap the whole head. Seems unwise—maybe best to swap whole motor, find something with low miles?

 

[oil pan 4]

If it's a simple timing chain like an ohv engine, no.

 

[SC Maintenance]

Nissan VQ's had similar problems with the tips of the primary guides breaking after they get worn.

The short answer is yes - they are required or you will get some chain slap, or it will be more likely to jump when it gets worn. OEM's won't spend one penny if not needed.

Of course there are caveats. The engine was designed for 6500RPM or whatever. If you drive like me and never get half way there, you likely have a lot more leeway and it may last a long time without all of them functioning.

 

[supton]

looks like I can get that guide piece easily enough. I see some videos on how to move that PS hose differently, not sure how I missed that (or I didn’t push hard enough).

 

[The Critic]

looks like I can get that guide piece easily enough. I see some videos on how to move that PS hose differently, not sure how I missed that (or I didn’t push hard enough).

O-ring on that line can sometimes be reused once or twice. I usually unbolt the hose.

 

[supton]

O-ring on that line can sometimes be reused once or twice. I usually unbolt the hose.

Any fluid loss?

 

[The Critic]

Any fluid loss?

Not much. I just wrap a towel around the hose and suction out what's in the opening of the pump. Usually need to top off an ounce or two.

 

[Exhaustgases]

"ARE ALL TIMING CHAIN GUIDES REALLY NECESSARY ?" To quote the title of this thread.

Naaa, engineering and the factory just put them all there just for something fun to do.
Pretty simple to answer question, right?

 

[Oliveoil2]

Looks like the cam wear after the lobe shows a tight valve. When were the valves adjusted?

 

[supton]

Naaa, engineering and the factory just put them all there just for something fun to do.
Pretty simple to answer question, right?

I just figured they were some CAFE or EPA requirement, like smog pumps and cats. I did order the guide and hopefully it doesn’t elect to jump time in the meantime.

Looks like the cam wear after the lobe shows a tight valve. When were the valves adjusted?

I should check, there’s a lot that I’ve deferred without thinking about it. Three of the lobes could be adjusted, am guessing the fourth is now automatically adjusting.