Thinking of doing a valve adjustment at 79K

[BuickGN]

I know it's early, recommended is 105K but here's the story.

Around 40K, the car developed a weird noise from the exhaust from time to time. Anyone remember what it sounds like when you have a bad exhaust valve? It sounds like a random pop or suck through the exhaust? The TL started doing this but it was closer to a regular rhythm than random. Now I have a very slight valvetrain clatter that goes mostly away when hot. Car seems to have lost some low end and mpg.

Are there any known valvetrain issues with the J32? I'm also wondering if it may be stuck in vtec on a cylinder or two.

 

[BuickGN]

I didn't describe the sound very well. The engine is silent on a cold start. It's a hot restart when it makes the noise and it takes a minute or so to go away. I rule out piston slap since it does not do it when cold and it doesn't increase with load, only rpm, besides, it sounds nothing like piston slap.

My engine is quieter than most of the other TLs I've heard or driven. If it weren't for the funky exhaust stuff going on I wouldn't try this so soon.

 

[andyd]

mebbe apples and oranges, but on the 99 CRV , the 105k mile valve adjust interval is too long. After it flunked inspection because it was throwing a code for engine mis-fire. I did a compression test to find #4 low. A burnt exhaust valve. I found 3 exhaust valves with no lash when I checked the adjustment. BTW, noisy valves dont burn, quiet ones often do.

 

[XJ1100]

Originally Posted By: andyd
BTW, noisy valves dont burn, quiet ones often do.


"Tappy valves are happy valves"

I would go ahead and give them an adjustment. That first adjustment is the most important as it will get your clearance back in spec. after the valves have seated into the head - as I am sure you already know. My Honda (I know, completely different valve train) wanted an adjustment at 30k miles and then never again. I checked them at 196k when I was doing the timing belt and a few were loose - I am sure this is just from valvetrain wear.

I am assuming this does it with different oil/filter combinations?...just to rule that out. How about length of time since last start? 1-2 hours or 15 minutes?

 

[BuickGN]

Originally Posted By: XJ1100
Originally Posted By: andyd
BTW, noisy valves dont burn, quiet ones often do.


"Tappy valves are happy valves"

I would go ahead and give them an adjustment. That first adjustment is the most important as it will get your clearance back in spec. after the valves have seated into the head - as I am sure you already know. My Honda (I know, completely different valve train) wanted an adjustment at 30k miles and then never again. I checked them at 196k when I was doing the timing belt and a few were loose - I am sure this is just from valvetrain wear.

I am assuming this does it with different oil/filter combinations?...just to rule that out. How about length of time since last start? 1-2 hours or 15 minutes?


Length of time is no more than an hour or it doesn't do it. I ran the same Amsoil from new to 77K and now it's on Redline. No change in the noise. Also went from an EAO filter to RP, no change.

It makes sense that there is a little break-in and that's why the first interval may be much shorter than the rest.


This car has seen lots of extended highway driving, going to Vegas nearly every weekend for a while with no stops along the way, 4 hours at a time. Also drove it the 8 hours to Phoenix without stopping at all the whole way. I'm worried I may already have a burned exhaust valve. Luckily no check engine light for misfires.

 

[BuickGN]

Originally Posted By: andyd
mebbe apples and oranges, but on the 99 CRV , the 105k mile valve adjust interval is too long. After it flunked inspection because it was throwing a code for engine mis-fire. I did a compression test to find #4 low. A burnt exhaust valve. I found 3 exhaust valves with no lash when I checked the adjustment. BTW, noisy valves dont burn, quiet ones often do.


That's a very good point about the noisy valves not causing burned exhaust valves. I'm worried right now that I may have one that's potentially getting too tight when fully hot. It's good to hear others that have needed a valve adjustment sooner than the 105K so I know I may be on the right track here.

 

[mechtech2]

Modern valves and seats don't burn like they used to.
Really rare.
But getting the lash in spec is always good. All cylinders will behave the same - nice and smooth.
If this does not fix the problem, so what? You did a good thing and can go on .

 

[BuickGN]

Originally Posted By: mechtech2
Modern valves and seats don't burn like they used to.
Really rare.
But getting the lash in spec is always good. All cylinders will behave the same - nice and smooth.
If this does not fix the problem, so what? You did a good thing and can go on .


That's a good way of thinking about it. What harm could it possibly do... Though I'm so broke right now I'll have to wait a couple weeks to buy the intake and valvecover gaskets.

I was thinking about this and I wonder how close to out of spec the valves are after the break-in process. It almost seems like they may spend the first part of their lives nearly out of spec.

I guess we'll have some more valvetrain pictures to look at soon.

FWIW, I listened to the exhaust, the rythmic "thumping" noise is not coming out of the tailpipes. I may pay more attention to the conditions that make it happen. I'm worried I may be chasing nothing. I wonder what the odds are of it being some idle emissions thing such as retarding the timing to ensure the cats stay hot enough. It would almost be in perfect time if it did every cylinder on every other power stroke. Then again I would think the guys that throw aftermarket exhausts on these cars would've noticed by now.

 

[BuickGN]

Just one more question... I'm thinking of doing the timing belt and water pump early since I'm going to be this far into it. The car has seen a few 110+ degree summers but on the flip side, very easy low rpm usage for most daily driving. It will be right at 80K when I get around to doing it. I don't want to throw money away but at the same time, I've got the entire day free...

 

[mechtech2]

How about spending even more money and get new pulleys with that timing belt?
It really is a good idea if you are keeping the car.
A kit should be available with everything.

However, the newer round toothed belts can last a long time. 80-180,000 miles. It's your judgment call.

 

[BuickGN]

If you point me in the right direction, I'll do it. Are you talking about the cam pulleys? I plan on driving this thing until the wheels fall off so anything within reason I'll do.

I have talked to more people with these cars, some living in Vegas and they seem to go 120,000 on the belt with no problems. I want to be reasonable here, not wasting money but not tempting fate. I know it's practically impossible but I've always been afraid of getting a bad replacement belt. People at work call me Murphy. If it can go wrong, it will.

 

[oily boyd]

Mechtech2 is referring to idler and/or tensioner pulley(s) for the timing belt.

Parts counterperson will know what to give you.

 

[mechtech2]

The gears should be just fine [crank and cam. But clean them dinner plate clean!
I was referring to the little wheel turning idler and tensioner pullies.
If you have time, online has the best prices. An auto parts store will have a kit or can get it for you in a few days.

 

[BuickGN]

Thank you guys. I must've been having a bad day when I asked about the pullies. I'll be sure to post pics of everything even though it won't mean much for the oil I'm using with only 80K.

 

[andyd]

I always replace the tensioner pulley when I do a TB. most are fine when replaced ,but a couple have been real growly. It is an interference engine, so the extra 15$ is peanuts.

 

[BuickGN]

I figure pulleys, tensioner, water pump, belt, valve adjustment, plugs (these have 30K but they're one step colder, I want to take a look, air filter, and oil and filter change.

I'm thinking about installing one of the lightweight non underdrive crank pulleys since I'm going to be in there anyway. Only thing is their reliability has been questionable. This would be the first engine mod and I'm scared it will end up an obsession like the GN.

 

[chrome]

Any issues with the lightweight crank pulley not having a rubber harmonic damper? There seems to be 2 camps when it comes to these pulleys. Advocates will claim the pulleys are perfectly balances, hence no need for the harmonic damper. But the other camp claims the harmonics come from the crank and firing pulses, and had nothing to do with the pulley balance.