Just had my valves set at 17000 miles on my 2004 Silverado last week and went for a ride Saturday just a little over 500 miles in 100 degree heat. The wrench said they were too tight and it was a good thing I brought it in. Well I had it in to another shop at 15000 miles and wanted them set and he said they are hydraulic valves and shouldn't need adjusting. Went out Sunday to go fill it with gas and noticed a pretty good rattle,rode it around for around 10 minutes and it got quieter but did not go away completely. I am wondering what the second guy meant when he said it was a good thing I brought it in. Since they were out of spec too tight did I do some permanent damage?

You'll have to ask the mech why he said that.

If they are rattling, then I supect they are now too loose. It's possible the second mech did not know what he was doing.

The first mech is correct. The lifters are hydraulic and take up the slack in the system. They cannot, however, compensate if the valves are not adjusted correctly.

Two intake or exhaust valves work from the same lifter so they need to be spec'd correctly or they rattle as the lifter cannot take the slack out between the two lifters.

Doc

Thanks Doc but does it hurt to ride it like this or should I get it looked at ASAP. It does get silent after about 3 miles.

I tought, and I could be wrong, that Roadies had self adjusting valves.

Musky wrote:
I tought, and I could be wrong, that Roadies had self adjusting valves.

It's the lifter that makes the valves "self adjusting".

Simply put, there's two types of lifters .... solid and hydraulic. With solid lifters, you need to ajust the slack in the valve train that appears over time due to wear and tear within the system. With hydralic lifters, the lifter compensates for this wear.

On the other hand, the R* has two valves per lifter. If the valves are not adjusted properly relative to each other, then you get a ticking sound. The lifter cannot adjust between the valves as they are contolled by one lifter.

Hope I've explained it well enough.

Doc

Flatpockets wrote:
Thanks Doc but does it hurt to ride it like this or should I get it looked at ASAP. It does get silent after about 3 miles.

I would have the valves adusted, especially if it's a "pretty good rattle".

If the valves are too tight, they stay open a bit on the compression stroke. Not good but if they were too tight in the first place you would have noticed it long before.

Why did you have them adjusted by the second shop?

Doc

Roadies do have self-adjusting valves, but like Doc said, there is a caveat. There are two intake and two exhaust valves per cylinder, but each pair of valves is actuated by a single hydraulic lifter. As long as the rocker arms on both valves of each pair are in perfect sync, (meaning that the valve lash is EXACTLY the same for both intake valves for example) the hydraulic lifter will take care of any slack for both valves. However, if the rocker arms are not in sync, then the hydraulic lifter will be able to adjust the lash on only one valve, and the other valve will rattle.

There is a pretty good explaination of how to adjust the valves and how the pairing works in the tech tips section on this website. Since your valves didn't use to rattle, and do now, I suspect that the second mechanic adjusted your rockers out of sync so that now one of each pair is rattling. It would be worth it to ask him what he meant by "too tight" and what adjusting he did. Valves aren't something to ignore--although rattling valves won't necessarily destroy your engine, they will wear at an accelerated rate and the longer you wait to address them, the more expensive it will be to fix.

Hope that helps!

-Akela

Doc I had them adjusted at the second shop because they were making noise and I could not get the first shop to do anything about it. Bought the bike at the first shop along with 36 month YES extended plan.Every time I take it in there I think they rush through it because the already have my money. Took it there twice specifically to get the valves adjusted because the owners manual says to,and they did nothing with the valves. I really don't know what to do now.

Yup. Explained well.

Thanks

Here is the article I was talking about:
http://roadstarclinic.com/content/view/39/104/

Sorry for duplicating your info Doc, I was writing it as you were posting