When do you need to adjust valves?

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How would you know it's time for adjustment? What is the reason you need to adjust valves?

Comments appreciated.
 
Ken4, I know that on my Acura, the maintenacne schedule calls for 30,000 mile valve adjustments. Does your onwers manual say anything about this? -Joe

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Man do we have alot of "Kens" on this site. I can't keep up with who is who as far as the "Ken's" are concerned
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-Joe
 
Over the years, For Hondas I've used 15,000 and 30,000 depending on the owner's manual. After the first adjustment, though... they don't drift much.

Last 4 years or so, they have been recommending at 105,000 miles or "when noisy". A small amount CR-V owners may have burnt exhaust valves MAYBE because they let them go too long.

Here's two cars that said wait until 105,000 miles:

1999 CR-V: Adjusted at 30,000 miles and still runs like I just did it at 51,000. This car gets the shakes on acceleration if you don't have good adjustment. (some call it wobble, you feel it in the calves of your legs!) I had this condition for probably 5,000-10,000 miles before the 30K adjustment I did.

2002 S2000: Adjusted at 7,000 miles, had a minor but noticeable improvement on warm idling.

So the first valve adjustment should come at 15,000 miles on the Hondas, even the newer ones based on my experiences. After that you can probably wait 30,000-60,000 miles if you do good mainenance otherwise. Especially if you take your time and get each and every valve exactly where it needs to be and use a torque wrench to set the adjuster lock washer. Don't wait for the valves to get noisy, consider how rough the car's idle is an earlier indicator.

[ February 11, 2003, 10:38 PM: Message edited by: S2000driver ]
 
Im thinking of changing my nick to 'Bob the builder', but then there'd be too many Bob's on this site
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My toyota manual says nothing about valve adjustment interval. It only says Intake (cold) 0.24mm, Exhaust (cold) 0.33mm.

But I have noticed, after 3 years / 59,000km, the vibrations have increased during Idling (as compared to brand new). Is it time for valve adjustment? According to my Haynes Manual, it doesnt look like an easy job. I need a special lifter tool and correct sized replacement shims. Shims = Tappets??
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I was supposed to have my wife's 2000 Civic's valves checked at 30k, but we're at 40k now and I still haven't gotten it done. I wonder if this is the reason for her poor MPG? (typically 21-23!)

Her engine feels strong though, so I don't think the valves could be that far out of whack.
 
adjust the valves only when they make ticking noise. on a good running engine you souldnt even hardly hear the valves. my sisters honda civic has 60K and her valves make zero noise. i wont bother even looking at them because of the lack of noise. me moms crv makes ticking, and has that wobbly thing!!!!!!!!
i never knew thats why it did that! why is that do you know?!>?! its very interesting that lose valves make the car wobble under acceleration. such weird little engines these hondas have, good, but definitly weird.
 
So the ticking sound comes from the Cam Lobe hitting the Tappet? Or comes from the Valve hitting the top of the Cylinder Head?
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I've found that most Toyota and Honda engines don't need their valves adjusted nearly as often as the maintenance schedules say. My '93 Camry's 5S-FE 4 cylinder has 156,000 miles on it and the valves are still in spec, I've NEVER adjusted them. Car still runs perfectly. It's a pain to adjust these bucket tappets with the shims and all, but it's pretty easy to check the clearances. My suggestion is to check the valves, but not to necessarily adjust them (unless they really are out of spec). I had a '90 Accord with 150,000 miles and the valves were still in spec when I sold it without ever being adjusted.
 
One other point, the valves may still be out of spec even if they're not tapping. Generally they'll tap if the clearance is too large as crypokid states. But, the real big problem comes when the clearances are too tight, that's when the valves can burn up. And you probably aren't gonna hear tapping in this case. You have to get out the feeler guages and check them directly.
 
Valves can wear "loose" or "tight". If the wear is related to lobe wear, or valve stem wear, the valves will be "loose" and identifiable by the characteristic valvetrain "clicking" sound. This is a relatively benign condition, though it will affect intake uptake or exhaust extraction since the valve is opening late and closing early. Not dangerous and the affected valve will not burn in this situation, but power and mileage may suffer. However if the valve clearance becomes "tight" due to valve seat recession, LOOK OUT! The valve is not closing properly and is opening too soon. There will be NO telltale clicking. In addition to idling/driveabilty problems, this is a valve RIPE for burning since it never closes fully against the seat so that its heat can be adequately drawn off. When you adjust valves, better to err on the side of excessive clearance than inadequate clearance. (I'm not a mechanic, but I did stay at a Holiday Inn Express last night.)
 
The valve adjustment on the Hondas is so freakin easy I see no reason not to do it. No shims to mess with like Toyota.

You don't have to buy anything once you have the right tools, and it's fun going in and inspecting the top end of the car.

Hondas give off lots of valvetrain noise anyway, especially in the cold. What normal person is going to know the difference between normal noise and a valve starting to need adjusment?
 
this is one time that i really like my jeep 4.0 inline 6- none of this valve adjustment crap... thing will run forever.. only negative is it sounds like a diesel and leaks oil... O well


i am interested in the final verdict though because im planning on getting a honda v-6 accord for college. Does the owners manual call for adjustment?
 
quote:

Originally posted by higney85:
i am interested in the final verdict though because im planning on getting a honda v-6 accord for college. Does the owners manual call for adjustment?

No. Honda V6 motors have hydraulic lash adjusters - the way God intended internal combustion motors to be built.

[ February 13, 2003, 01:03 PM: Message edited by: Ray H ]
 
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