Interesting Valve Train Noise?

[turbotroy]

Hey all! In what seems the never ending search for my random KR issues, I put a new knock sensor on it today. Still showing knock
Anyway I started it up and let it get warmed up and the only way I can describe this sound is it is in time with the valve train and sounds like a valve thats out of adjustment.
It's not much louder then the valve train, it will "tap" for about 6-8 times and then you won't hear it for 10-15 seconds and then you can hear it again. It does this at regular intervals at idle and the only thing I can come up with is it's like a lifter thats bleeding down and then pumping up again, but to be honest, I've never heard of such a thing, and not at a regular interval.
I have used a screwdriver and a piece of heater hose as a stethescope all over the engine, accessories, etc and I can't hear anything abnormal, and I called my brother and his girlfriend over to verify that I was hearing what I thought. Any ideas?

 

[earlbrown]

I would verify you don't have a broken rocker shaft as that's easy to check (and the rocker buttons too)

A harder check would be to make sure you don't have timing gear teeth in the oil pickup.
Sounds like you need to hook up an oil pressure gauge and watch what it's doing at idle.

Are your running a quality biggie filter or at least a long stocker?

 

[turbotroy]

Hey Earl, I've got the big wix on it, 60psi cold and 25 hot at idle. Pulling the valve covers just to see what I could see was my thought also, but this noise is random, kinda like my kr issues. Thanks for the reply.

 

[earlbrown]

I'd check those rocker buttons then. Might not be a bad idea to roll the pushrods on something flat too.

 

[fuzzyGN]

I had the same thing and it turned out to be an extremely badly worn lifter. It obviously killed the cam too. The liter was worn uneven so as it rotated it would have excess then no clearance. Weird but that was it. It was quiet, then noisy for a few seconds, then quiet again. Don't even remember how I found it.

 

[CGASTON]

Hey all! In what seems the never ending search for my random KR issues, I put a new knock sensor on it today. Still showing knock
Anyway I started it up and let it get warmed up and the only way I can describe this sound is it is in time with the valve train and sounds like a valve thats out of adjustment.
It's not much louder then the valve train, it will "tap" for about 6-8 times and then you won't hear it for 10-15 seconds and then you can hear it again. It does this at regular intervals at idle and the only thing I can come up with is it's like a lifter thats bleeding down and then pumping up again, but to be honest, I've never heard of such a thing, and not at a regular interval.
I have used a screwdriver and a piece of heater hose as a stethescope all over the engine, accessories, etc and I can't hear anything abnormal, and I called my brother and his girlfriend over to verify that I was hearing what I thought. Any ideas?

Troy,

Your car only has like 70,000ish miles correct? Here is what I would do....... I would go get some marvel mystery oil and add a bottle to your oil. Let it run for a while. While I do agree that it could be a nylon hold down button on one of your rockers, it would be a constant rattle. If the rocker arm shaft is broke like it was suggested earlier, then you would be hating life. Trust me on this. I have broken two of them over the years. It always seems to be over #6. And if it were broke it would sound like a little rod knock. SCARY!!!

So why do I mention mystery oil...... Well at 70,000ish....... your lifters or one lifter may have collapsed a little and trapped a piece of dirt in it or gummed up from lake of oil changes. Not saying you, but the previous owner probably didn't take car of the car as I know you are. So now the Karma has kicked in and your feeling the pain of someone that was an idiot.......

That Kenne Bell car that I had last summer only had 67,000 miles on it and it had gummed up lifters. When I bought the car, the oil was black as black. So after I gave it some TLC, I had the same noise that would come and go.

As we talked, I believe your KR is from something else. I believe and will almost bet you that it is physical, not mechanical. I am going to be working on my car this weekend and dealing with the same issue. So if your up for a road trip, give me a call. I will try and help you out on yours. 4 EYES ARE BETTER THAN TWO..... PLUS SAVE SOME MONEY IN YOUR POCKET EXCEPT FOR GAS. And benefit of it all is the site seeing and cold beer.

Clint

 

[phil_jordan]

Hmmm, might ship my car to where you are. Lol. J/k.

 

[CGASTON]

Hmmm, might ship my car to where you are. Lol. J/k.

Where you located?

 

[turbotroy]

Hey all, thanks for the replies. These wonderfully weird finicky Buicks require an infinite amount of patients to diagnose, and I'm SO glad we have this forum to bounce ideas around, if for nothing else then to let me know I'm not going crazy! I have been reading on this site daily since July and have found lots of answers to my questions. The search button has been my best friend, but experience is king and only gotten one way.

Clint, thanks for the idea on Marvel Mystery Oil, forgot all about that one but always use to keep it in the toolbox, even use to put a couple ounces in my planes fuel tank just for good measure. I will dump in a can. I'm currently waiting on a phone call for an out of state job, if I get it the Buick will go back to sleep until next time, but if not I'll drive out this weekend. It's a nice ride down that way!

Phil, I think that would be an excellent idea! I figure about the easiest thing to do is if your going to own one of these cars, you may as well own two of them. That way you can swap parts around and not have to order EVERYTHING just to see if it's the fixes the problem, plus, hey, you get two seperate headaches.

Troy

 

[phil_jordan]

Infinite patience is extremely accurate. Im trying to maintain my sanity, because I've found the most simple repairs and gadgets all add up. A Buick money pit so far for me. I have to admit that it's worth it when it's all going the way it's suppose to. Maybe I'll post a vid of the sound I'm hearing. It's almost familiar to what you describe.

 

[turbotroy]

Hey Phil, post on up. Like CGASTON said, four eyes (or ears) are better then two. On the patience front, started mine this morning and sounded like a slight miss/ vacuum leak. BL's are 128 but wideband is off the charts lean. I hit the test button on the alky and engine smooths out. Get out the trusty carb cleaner and start spraying and the leak seems to be at the gasket below the tb where the IAC is. Call several parts houses, NAPA can get one out of VA. Only $1.93 for gasket set but I'm in AZ. All I can do is laugh...and ponder getting a larger ported tb and plenum while I'm there

 

[phil_jordan]

Lol. Nice. I definitely will post up. This will be the time that my car makes an a** out of me and don't do it.

 

[CGASTON]

Hey Phil, post on up. Like CGASTON said, four eyes (or ears) are better then two. On the patience front, started mine this morning and sounded like a slight miss/ vacuum leak. BL's are 128 but wideband is off the charts lean. I hit the test button on the alky and engine smooths out. Get out the trusty carb cleaner and start spraying and the leak seems to be at the gasket below the tb where the IAC is. Call several parts houses, NAPA can get one out of VA. Only $1.93 for gasket set but I'm in AZ. All I can do is laugh...and ponder getting a larger ported tb and plenum while I'm there

Troy, A larger throttle body is a waste of money. It is capable and has been proven that the stock throttle body is more than capable of putting the car into the 9's...... Ask Red Armstrong.......

And on the vacuum leak.... Congrats..... Seems to be many problems. Now once you have changed the plenum gasket you will have to rest your TPS and IAC..... I suggest that you turn out the idle screw then back in 2.5 turns. That will set you about perfect on your IAC Counts and the TPS should be almost there. Remember, you adjust one the other needs adjusted.....

Have fun.....

 

[turbotroy]

Troy, A larger throttle body is a waste of money. It is capable and has been proven that the stock throttle body is more than capable of putting the car into the 9's...... Ask Red Armstrong.......

And on the vacuum leak.... Congrats..... Seems to be many problems. Now once you have changed the plenum gasket you will have to rest your TPS and IAC..... I suggest that you turn out the idle screw then back in 2.5 turns. That will set you about perfect on your IAC Counts and the TPS should be almost there. Remember, you adjust one the other needs adjusted.....

Have fun.....

I'm holding off on ordering that gasket because I may not be here to get it... but I'll take Buick parts for $1.93 + shipping any day. I remember one of my first patience learning experiences with the car; setting the tps properly Meanwhile...there's a post in cars wanted for an 87 rosewood with the chrome trim package...hmmm, naw that would make my life to easy just to sell it Thanks again for the input, Clint!

Troy

 

[BADDGUY6]

Did you fix the "tapping"? Check the headers for cracks. Or leaking Header gaskets/loose header bolts?

 

[bison]

There is no way to diagnose this without inspection. Covers, then intake, then lifters one at a time. Lifters are a simple device and can be opened up and inspected/cleaned very easily. If the cam is worn I've been able to see it in the past with the oil pan off. Done a few rear seal jobs that turned into cam replacement jobs.

 

[3.8L V-8 eater]

Bison, can a roller lifter ruin a cam if it doesn't pump up properly or just flat tappet??

 

[king kong]

Did you fix the "tapping"? Check the headers for cracks. Or leaking Header gaskets/loose header bolts?

x2 I had a leak in my header on my WH1 and it sounded like a very light valve tap

 

[bison]

Bison, can a roller lifter ruin a cam if it doesn't pump up properly or just flat tappet??

If it it pumps up you will hit valves and bend pushrods/break rocker shafts. I've seen weak valve springs cause roller cam failure also

 

[turbotroy]

Hey all! I'm going to get to the car this morning. First off, see if I can make a gasket or permatex repair my vacuum leak and make the car driveable. I'm scared of "lean"
The headers are tight and no cracks, etc. Listening with my "stethescope" everything was quiet on that front.

Bison, I hear ya on the only way to diagnose is get in there and tear it down and look. The engine in this car is about 6 years old and has sat for most of that time, I have put a few thousand miles on it. I know back in the day the builder was good at what he did, but he's passed on so the build on this car is a bit of an unknown.

I have been going through the car as time and money would allow so I would know what the car actually has in it. I had Nick Micale build the tranny because it had issues and I know that this is backwards way of doing it, but now I KNOW that I have a solid trans with a 3000 stall lu converter. If I tear apart the top end to check lifters, I'm going to be mighty tempted to just put another cam in it that compliments the torque converter. And then...what about my unknown turbo?

Back from my hotrod days, I know that cam and converter needs to match, sooo, what cam and turbo would you match my 3000 stall lu converter with? My goal would be mid to low 11 second street car that I can play with at the track, that doesn't have to pass emissions. Thanks for all the replies!

Troy