What do you think this engine noise is?

[Gasbuggy]

This is my well maintained 98 Cavalier 2.2L with 270,000 miles. Original engine. I'm just now noticing this sound, though it has probably existed for a while. My girlfriend uses is for commuting. The car had a noisy accessory bearing under the hood for a very long time, just loud enough to cover this up, not loud enough to make me worry about chasing it down and fixing it. I did finally fix it recently. Tonight I started the car in a parking garage, got out for something, and heard this light tap. I drove the car to my house (1/4 mile) and took the video in the driveway. It's more audible under the engine where I placed my phone to record. It is perhaps a bit more defined hearing it in person.

My guess is a little piston slap.

Currently running QSUD 5w30/PureOne (recently changed, usually run PZHM)

 

[FowVay]

Piston slap, water pump chatter, belt pulley chatter, etc. Many noises show themselves on high mileage engines.

Piston slap will usually go away once the engine gets hot so pay attention and see if you notice it smooth out after a good warm-up.

Water pumps just chatter until they start to leak. You'll notice that.

Let us know if you find anything obvious.

 

[Merkava_4]

Originally Posted By: Shark
Currently running QSUD 5w30/PureOne (recently changed, usually run PZHM)


That could do it right there: QSUD 5W-30 acts like a very thin oil; thinner than what the label says, while PZHM 5W-30 acts like a thicker oil that lubricates very well and causes engines to run quiet. You never mentioned whether the noise was there while running PZHM. That's one variable, the other variable is that PureOne oil filter; they are known for being very restrictive to oil flow. You gotta eliminate those lubrication variables before moving onto mechanical suspects. And another thing: being at 270,000 miles, it's probably ready for a 40 weight.

 

[Gasbuggy]

Originally Posted By: Merkava_4
Originally Posted By: Shark
Currently running QSUD 5w30/PureOne (recently changed, usually run PZHM)


That could do it right there: QSUD 5W-30 acts like a very thin oil; thinner than what the label says, while PZHM 5W-30 acts like a thicker oil that lubricates very well and causes engines to run quiet. You never mentioned whether the noise was there while running PZHM. That's one variable, the other variable is that PureOne oil filter; they are known for being very restrictive to oil flow. You gotta eliminate those lubrication variables before moving onto mechanical suspects. And another thing: being at 270,000 miles, it's probably ready for a 40 weight.



Thanks, that's why I included that bit of information about the oil and filter. I could toss in 1/2 quart of straight 30 weight and spin a delco filter onto it. I hadn't considered going up a weight but I am not opposed to it on the next change.

My girlfriend is the primary driver, I am almost never the first cold start of the day. Actual cold mornings are just arriving, creating another variable.

Also, like I said in the first post, I had another noise that would have been overriding this one for quite some time. It was a worn out idler pulley bearing. I ran the car with and without the belt when I was working on it, I did not remember hearing a difference like this between fixed and without the belt. That was just prior to the oil change.

I'll eliminate some possibilities today.

 

[Astro14]

Sounds like valve train noise - bad/collapsed lifter (or hydraulic adjuster).

But often, what sounds like a valve tap is actually an exhaust manifold leak. You'll hear it only when the engine is cold, the heat of expansion closes the gap as the manifold warms. And the manifold warms quickly, like 30 seconds.

A stethoscope is a great help in diagnosing...

 

[aquariuscsm]

I'm with Merk. Oil is cheap and you mentioned it showed up after the oil change. Go back with Pennzoil HM. I'd use 10W30 for a slightly thicker oil. It's also been said here that Fram TG filters have excellent flow and are good for ticky engines.

 

[skyactiv]

A co-worker had a high mileage OHV Cavalier which broke a valve spring. He fixed it.

 

[Andrew1972]

Sounds fine to me for vehicle/age. Drive on.

 

[Cressida]

Originally Posted By: madRiver
Sounds fine to me for vehicle/age. Drive on.


I am thinking the same thing. Give it some time and something else will show up that demands more attention.

 

[javacontour]

Sounds like almost every S10 pickup I've heard. Actually, it sounds better than most, so carry on.

 

[Trav]

Listen to it with a hammer handle on the oil pan, if its piston slap you will hear it make a knocking sound which is much louder cold than warm. This sounds more in the top end.

 

[Gasbuggy]

Originally Posted By: Astro14
Sounds like valve train noise - bad/collapsed lifter (or hydraulic adjuster).

But often, what sounds like a valve tap is actually an exhaust manifold leak. You'll hear it only when the engine is cold, the heat of expansion closes the gap as the manifold warms. And the manifold warms quickly, like 30 seconds.

A stethoscope is a great help in diagnosing...



I believe it is some type of an exhaust noise, as you increase the rpm slightly the sound fades out. I listened through a warm up cycle, idling it started to fade and then rather suddenly disappeared. Maybe right as the engine switch from open to closed loop. I did see some people elsewhere online chasing this same noise on their 2.2. Some were paying mechanics, changing water pumps, timing chains. No one eliminated the sound.

 

[Gasbuggy]

Originally Posted By: javacontour
Sounds like almost every S10 pickup I've heard. Actually, it sounds better than most, so carry on.


This Cavalier has been really solid. My dad bought it new in 98 and ran Mobil 1 synthetic for around the first 90,000 miles, in intervals which I'm sure were too short. Then he switched to PYB. He did the transmission fluid changes with Mobil 1 atf too. In 2011 he gave me the car after dealers would not take it on trade in. I've run a number of different oils, mainly PP/PZHM, and put another 100,000 miles on it.

 

[artificialist]

I suggest first getting an automotive stethoscope and touching it to different parts of the engine and to all the items driven off the serpentine belt.

Anyway, sometimes the timing chain wears out or the chain tensioner fails in high mileage 2.2 OHV engines. Test it with the scope.

If it is a worn chain, I don't know how much time you have before it fails. I worked with a guy who repaired numerous 2.2 OHV engines, and he never saw valve interference when a chain broke.