1Qu1ck1

Well, I just bought the car (2005 w/ 31K miles) a few weeks ago and I notice what seems to be what sounds like lifter noise (tapping?) coming from the engine on cold starts. What I've noticed is that the noise seems to go away, or lessen to the point of barely being audible when the oil hits 140-160 Deg.F. Is this normal valve-train startup noise?

I didn't notice this when I bought the car...but you know how it goes, I might be in the "start hearing every strange noise possible" phase. Its my wifes daily driver, and we both get it on the weekends. This afternoon we went out and I started up the car and shut off the radio and A/C so I could try to get a grasp of the sound. My wife (who's usually blasting the radio) of course said she never heard that before and commented on how noticeable it was.

I tried searching and it seems I did find a few old posts regarding cold startup noises, but they seemed to be deleted.

Any ideas? Theres nothing worse sitting here thinking that I might have a serious engine issue here.

Thanks!

Tony

HuskerBullet

Some engines will have a tappet noise for a few seconds upon start up until the lifters pump up with oil....again, it's only a few seconds and then they should be quiet (unless you have a solid-lift cam, which I doubt).

In your case, if they are noisy until the engine reaches 140 or so, then you either have a couple of bad tappets where the plunger inside is sticking, or they need to be readjusted. In either case, IMO you have a problem and will slowly get worse....have them checked if you can't do it yourself.

Ben Diss

What kind of adjustment is there?

calemasters

I think what you are hearing is normal for the LS2. Also, valve lash is net build, so there is no valve adjustment is required on the LS2.

You can always have your dealer listen to the valve train noise, but this may be a normal condition.

calemasters

1Qu1ck1

Ok, this morning I hopped in for my Saturday morning (or should I say weekly ) stint to the gym. I started it up in the garage and there was no tapping noise at all. Brought the Rev.'s up to 2 or 3 grand and the engine sounded great. I thought "Whatever it was must have loosened up".

That was until I pulled out of the garage and put it in gear (A4). As soon as I placed a load on it, the tapping was there as usual...increasing with RPM's. What I noticed is that when I was coasting, if I put it in neutral and brought the RPM's up, there was no noise.

Now, typically, this would point towards a tranny issue to me, but the sound is definitely coming from the front.

Any ideas?

Sparo2

1) Does the noise accelerate when you bring the RPMS up while in N or P or does it just do it when you're in D driving taking off?

2) Does it do it while you're standing still but the car is in D?

My opinion:
If it does it when you're only in N or P accelerating the enigne, then it's coming from the engine. GM was known for having piston slap on Gen III engines. The pistons would dance around in the bores until the engine came up to operating temp. Then the pistons would expand and seal up the bores. Kinda hard to tell without hearing it in person though.

If it does it when you're taking off or driving then it's something in the driveline.

1Qu1ck1

It only does it with the car in D and is proportionate with increasing RPM.

I just sold an '01 Yukon Denali that had the piston slap. It had it from the day I bought it and 130,000 miles later the truck ran just as good as new (Mobile 1 every 3,000 miles).

This sound is definitely different from the piston slap that I'm used to. With the Tranny in the rear, what could be on the driveline towards the front of the car that would make a tapping noise that increases with RPM, yet goes away upon getting warmed up?

Ben Diss

HuskerBullet

Oops, you're right about that, my mind was on the engines of the past....no adjustment here, but he could still have a couple bad lifters.

tmak26b

Use qualtiy synthetic oil, problem should lessen. Also the engine might be full of sludge (might have been oil by a waxer. If you keep your oil fresh and run it hard at the track, you should be all set.

Zig

when was the last oil change done?

tmak26b

Lifters were a problem for me in my old Miata, 350Z and Q45. Even the Corvette up a certain point since my commute is 1 mile. Problem usually go away after a track day or fresh QUALITY synthetic oil. The problem will definitely more noticeable as everything ages

JRHAWK9

yeah, that's not good for any car.

tmak26b

That's why I ride the bike or moped whenever I can....

1Qu1ck1

I actually just changed it myself 3 weeks ago when I had the front wheels off for a pad change. The oil was only at "49%" but I decided to take advantage of the situation while the filter and drain plug were giving me that look like "Hey dummy over here".

I put Mobile 1 in with a Fram 'Tough Guard' filter that uses a silicone anti-drainback valve. What do you guys recommend?

1Qu1ck1

Would there be sludge buildup after 31,000 miles? I believe the previous owner had GM do all of the previous service to the car. So, I'm hoping that they would have used Mobile 1??

I do have to admit that I've been babying the heck out of the car since I've got it. I think its only seen 6500 RPM once since I've had it for the last month. Maybe I need to ring it out a little to loosen things up. .

What still confuses me is the fact that sounds perfect while in park and revving. The tapping sound only comes while in D and during acceleration. Would the lifters have a different sound if there's a load placed on the engine?

tmak26b

Of course it can, stock change level is around 10K miles. Most Corvette owners drive slower than my mom in her minivan, sludge can build up very easily.

Zig

i always use the mobile 1 filter.

any new news?

since you bought her used, did you do the 'all fluids change/flush' project?

EuroRod

The LS generations of engines are notorisously noisey. The coil covers are not there to make the engine purdy, they are acoustic baffels designed to reduce engine noise.