Engines requiring periodic valve adjustment ???
- Thread starter Bamaro
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From what I understand most newer engines that use shims for adjustment should hold their settings for a long time, possibly the life of the car. I've heard this specifically about the V8 Toyotas, in particular.
Older cars often had screw-and-locknut adjusters that needed looking at every 10-20k, but it was an easier, quicker job.
Having adjustable valves has some advantages as there are no hydraulics needed to keep the clearances set. The hydraulics have their own problems. "Collapsed lifters," or "ticking lifters" seems to be one of the most common maladies for just about any American V8 engine as far as I can tell. I know little about those engines, I just see it being talked about a lot.
Older cars often had screw-and-locknut adjusters that needed looking at every 10-20k, but it was an easier, quicker job.
Having adjustable valves has some advantages as there are no hydraulics needed to keep the clearances set. The hydraulics have their own problems. "Collapsed lifters," or "ticking lifters" seems to be one of the most common maladies for just about any American V8 engine as far as I can tell. I know little about those engines, I just see it being talked about a lot.
It's because the lifters get clogged up with crud due to lack of oil changes.
My 1988 Mustang GT has not had a problem with ticking lifters...and it has 184K on it.
My 1988 Mustang GT has not had a problem with ticking lifters...and it has 184K on it.
Kestas
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When I was involved with camshaft design the engineers told me the specified one-time 40K valve adjustment was not so much the adjustment as it was an inspection to weed out the infancy wear failures of the cam/followers. Apparently, break-in was crucial to the cam/followers. If they made it to 40K, they were effectively good for life.
Originally Posted By: Bamaro
I recently heard the Astra 1.8 Ecotec requires periodic valve adjustment. Is this becoming common or is this an exception? What other engines require this, how often and what is a reasonable cost?
This is the only Ecotec with mechanical tappets and a timing belt. The other Ecotecs have hydraulic lash adjusters and a chain. Don't know if the 1.8L has lock-nuts or shim & buckets for lash adjustment. Either this engine was cheap, or GM just wants the service bucks associated with the lash adjustment and T-belt changeout! Most manufacturers went away from belts and lash adjustments (Toyota, Honda, Hyundai, etc..) The trend was/is away from this. The 3.5L V6 in my 2008 uses a T-belt and lock-nut adjustments. Not often though.
I recently heard the Astra 1.8 Ecotec requires periodic valve adjustment. Is this becoming common or is this an exception? What other engines require this, how often and what is a reasonable cost?
This is the only Ecotec with mechanical tappets and a timing belt. The other Ecotecs have hydraulic lash adjusters and a chain. Don't know if the 1.8L has lock-nuts or shim & buckets for lash adjustment. Either this engine was cheap, or GM just wants the service bucks associated with the lash adjustment and T-belt changeout! Most manufacturers went away from belts and lash adjustments (Toyota, Honda, Hyundai, etc..) The trend was/is away from this. The 3.5L V6 in my 2008 uses a T-belt and lock-nut adjustments. Not often though.
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That's an awesome picture.
The current Civic's 1.8 liter engine also has mechanical lash adjustment (although it has a timing chain thankfully). IIRC the current Sentra's engine and possibly the MZR20/Duratec20 from the Mazda3 and Ford Focus also lack hydraulic lifters. I think it's pretty common on economy car engines for whatever reason.
The current Civic's 1.8 liter engine also has mechanical lash adjustment (although it has a timing chain thankfully). IIRC the current Sentra's engine and possibly the MZR20/Duratec20 from the Mazda3 and Ford Focus also lack hydraulic lifters. I think it's pretty common on economy car engines for whatever reason.
The 2007 DOHC 2.7 V-6 in our Suzuki Grand Vitara uses a shim and bucket design. The engine used to employ hydraulic lifters but for some reason that was changed sometime around 2004 or 2005. The manual says to adjust every 22.5K miles. But Suzuki recently issued a TSB extending the adjustment period to 30K miles.
I've heard the adjustments are painstaking and expensive. Upwards of $900. And specialized tools are required which effectively shuts out a DIY'er from doing it. Not sure what I'm going to do when the time comes. Luckily the engine does use a timing chain rather than a belt.
I've heard the adjustments are painstaking and expensive. Upwards of $900. And specialized tools are required which effectively shuts out a DIY'er from doing it. Not sure what I'm going to do when the time comes. Luckily the engine does use a timing chain rather than a belt.
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Not that it is "hard" to adjust but poor design, some designs need the cam removed . It is a screw the consumer design and smart buyers will research and avoid the added expense of labor intensive maintenance designs. Some shim and bucket designs are really simple if the cam doesn't have to be removed . Measure the lash then usually there is a chart in the svs manual that with the measurement of the old shim plus the lash will list the correct new shim to install. A pain compared to the adjustment on the rocker or hydraulic adjuster
Originally Posted By: rationull
That's an awesome picture.
Yeah it is, thanks for posting it. Worth a thousand words.
That's an awesome picture.
Yeah it is, thanks for posting it. Worth a thousand words.
I just did the locknut valve clearance on our 1998 Honda CRV. Not too hard at all, my very 1st time because I am used to Euro cars w/hydrolics.
http://www.bobistheoilguy.com/forums/ubb...rue#Post1084556
btw- how often do you think these engines with $900 adjustments actually get done on typical used car lots?
http://www.bobistheoilguy.com/forums/ubb...rue#Post1084556
btw- how often do you think these engines with $900 adjustments actually get done on typical used car lots?
My Euro has screw/nut adjusters (E30 325i). So did my M30 E34 535i.
Didn't even know the CR-V had them. I like the 1st gen CR-V very much. Among newer (to me anything post-'90 is "newer") Hondas it's the only one that appeals to me on the same simplicity/efficiency basis that earlier Hondas did.
Didn't even know the CR-V had them. I like the 1st gen CR-V very much. Among newer (to me anything post-'90 is "newer") Hondas it's the only one that appeals to me on the same simplicity/efficiency basis that earlier Hondas did.
Originally Posted By: Axe Man
...The manual says to adjust every 22.5K miles. But Suzuki recently issued a TSB extending the adjustment period to 30K miles.
That is an absolutely insane manufacturer recommendation!! There's really nothing to adjust on a shim and bucket system. Normal recommendation would be to "check if noisy". You either replace the original shims with thicker ones, or I've heard of some engines where you can just flip over the "bucket" (washer type thing) to the untouched flat side. Typically you wind up having to buy an entire OEM shim kit that includes a bunch of different sizes since individual shims usually can't be purchased. I wouldn't even consider going through this every 30K miles!! 150Kmi? yes.
Joel
...The manual says to adjust every 22.5K miles. But Suzuki recently issued a TSB extending the adjustment period to 30K miles.
That is an absolutely insane manufacturer recommendation!! There's really nothing to adjust on a shim and bucket system. Normal recommendation would be to "check if noisy". You either replace the original shims with thicker ones, or I've heard of some engines where you can just flip over the "bucket" (washer type thing) to the untouched flat side. Typically you wind up having to buy an entire OEM shim kit that includes a bunch of different sizes since individual shims usually can't be purchased. I wouldn't even consider going through this every 30K miles!! 150Kmi? yes.
Joel
The reality with a lot of these shim systems is that you might want to check them occasionally, but there will very likely be no valves out of spec. So the actual need to replace a shim might occur every 150k or even less.
Having said that I don't think there's any good excuse for individual shims not being made available.
Having said that I don't think there's any good excuse for individual shims not being made available.
Originally Posted By: badtlc
I thought Hyundai also requires periodic valve adjustment.
That's true, but I talked to a Hyundai tech who recently attended a Hyundai training class. He said the instructor said that as long as the engine is not displaying any signs of problems, there's no need to check/adjust the valve clearance at all. He also added that there's a 06 Sonata V6 at work with over 140k miles that has not experienced any problems and has not had an adjustment. The key is on-time oil changes.
I thought Hyundai also requires periodic valve adjustment.
That's true, but I talked to a Hyundai tech who recently attended a Hyundai training class. He said the instructor said that as long as the engine is not displaying any signs of problems, there's no need to check/adjust the valve clearance at all. He also added that there's a 06 Sonata V6 at work with over 140k miles that has not experienced any problems and has not had an adjustment. The key is on-time oil changes.
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