: What is Normal Valve Train Noise?



dkozloski
05-09-09, 08:03 PM
I have an '06 STS4 V-8 with 25,000 miles and the valve train is noisey as hell. At an idle it's quiet but at 1200RPM on up it sounds like a '49 Olds with 100K miles. You could hear them coming from a block away. It's the same hot or cold. It seems to me that it's getting louder and louder as time goes by. Inside the car you can hear the valve clatter over the radio. I asked the service advisor about it and he started into some story about no drain back valve in the oil filter in aftermarket filters so at startup it can be noisey. It's not at startup; it's all the time. I asked them to start somebody elses car up so we could compare and they wouldn't do it. I don't even know anybody else with a RWD Northstar so there's no help there. It seems to me that the noise is not distributed evenly across the engine like you would suspect it would be if all the valve train elements were the same. Some valves are louder than others and predominantly on the right side. It doesn't sound like stuck lash adjusters as much as it sounds like a 350 Chevy with some flat cam lobes. I know that electronic fuel injection nozzles can make noise but I don't think they are this noisey.

I guess I'm asking if valve noise is noticeable inside the car when your driving down the road to the extent that it can be heard over the radio set at a normal level for easy listening.

Many years ago I overhauled a '54 Caddy for a guy. He stopped by the shop to see how the work was going and asked me when I thought I'd get it running. We were standing alongside the car and the hood was up. I told him, "It's running right now". He looked over at the engine and was shocked to see the fan going around and he'd never noticed it because it was nearly silent. I realize that a NorthStar has a much higher parts count in the valve train but I wouldn't expect it to clatter either.

Krashed989
05-09-09, 10:09 PM
I had a question like this on my ASE test I took last week. It's not the oil filter because there is a bypass valve that would not allow that to happen. The only plausible answer that was given on the test was a restriction on the oil screen on the oil pickup tube. The question is, what's causing the restriction? Did anyone replace a gasket on there and use excessive RTV sealant?

You might want to hook up an oil pressure gauge to it. You might be getting enough to idle quietly, but not enough pressure at higher rpms.

dkozloski
05-09-09, 11:47 PM
I had a question like this on my ASE test I took last week. It's not the oil filter because there is a bypass valve that would not allow that to happen. The only plausible answer that was given on the test was a restriction on the oil screen on the oil pickup tube. The question is, what's causing the restriction? Did anyone replace a gasket on there and use excessive RTV sealant?

You might want to hook up an oil pressure gauge to it. You might be getting enough to idle quietly, but not enough pressure at higher rpms.
It doesn't sound like low oil pressure. It sounds like worn out parts. It seemed to get worse, fast, with a lot of cold starts last winter.

Eldo1953
05-10-09, 03:17 AM
What type of oil have you been using?

dkozloski
05-10-09, 04:16 AM
What type of oil have you been using?
5W-30 Mobil 1, just like the factory put in it and is listed in the owner's manual.

32vmonte
05-12-09, 10:09 PM
I would say do the oil press. test, and if that passes pull a valve cover. That would be the only way I could see to find out if its lifter noise. It sounds to me like it's extremely loud if you can hear it over the radio. There is something wrong.

Raze
05-13-09, 08:11 AM
I was also going to suggest pulling the valve covers and taking a peek, see if there's any worn lobes on your cams. If you can hear it over the radio, yeah, you have a problem. Is it a 'chatter' sound, similar to a worn out OHV engine?

dkozloski
05-13-09, 12:50 PM
I was also going to suggest pulling the valve covers and taking a peek, see if there's any worn lobes on your cams. If you can hear it over the radio, yeah, you have a problem. Is it a 'chatter' sound, similar to a worn out OHV engine?
It's still under warranty but the dealer claims it's normal. It sounds like a 350 Chevy with a cam with worn lobes. It's quiet at an idle but from about 1200RPM on up it's NOISEY.

Raze
05-13-09, 01:49 PM
This newer N* iteration has VVT right? If so you may get some weird valve noise under light to moderate accel load for a few seconds, I know on every 4 banger w/VVT I've ever driven/ridden (Toyota, Nissan, Honda) in I was shocked to hear the valve clatter upon light throttle accel, but it would usually go away after a second or two. The funny part is my wife's Camry 4banger sounds like my 3.0L V6 in my Ranger when I lug it under light/part throttle at low speeds...

dkozloski
05-13-09, 02:00 PM
This noise is continuous and some valves are much louder than others. The right bank is much louder than the left. I guess I'll just have to wait until something fails before I'll be able to get the dealer to move on it. The next closest dealer is about 360 miles away and they are even less accommodating.

Raze
05-13-09, 11:31 PM
you can take your VC off w/o voiding a warranty unless there's a 'sealed' sticker on it like a PC ;)

Submariner409
05-14-09, 08:52 AM
If the engine IS VVT, I wonder if something has gone haywire in that control system ??? Can you pull trouble codes in your car like the earlier models ??

dkozloski
05-14-09, 07:27 PM
If the engine IS VVT, I wonder if something has gone haywire in that control system ??? Can you pull trouble codes in your car like the earlier models ??
You can't pull trouble codes like on the oldtimers but I have a PC based scanner that is pretty comprehensive. There are no codes present. I think I'll have another run at complaining to the dealership and make them show me another NorthStar that is as noisey as mine.