did i damage my motor when changing the oil?

[Tonglebeak]

I finally got around to changing my oil today (14 months/5k). After changing it and starting the car, the engine made a godawful racket (metal on metal) for a few seconds, but then subsided. Is this normal after doing an oil change?

[Duke George V]

Yes. There's very little oil in the heads normally when sitting overnight, and you've just drained it all out and replaced it. It takes a few seconds to pump the new stuff everywhere. It's not a very reassuring sound, but I wouldn't worry about it too much.

[Tonglebeak]

Yes. There's very little oil in the heads normally when sitting overnight, and you've just drained it all out and replaced it. It takes a few seconds to pump the new stuff everywhere. It's not a very reassuring sound, but I wouldn't worry about it too much.

I had actually changed it just a few minutes after driving it :\

[Duke George V]

Same idea though, the oil takes a few to circulate.

[dcjredline]

ummm is this the first time youve ever changed oil at all? On any car.

[Tonglebeak]

Alright thanks.

And this is the 2nd time I've changed the oil. Last time was a few years ago and I remember nothing about the noises. So long as it's normal then that's fine with me.

[Prospeeder]

Its gotta fill the oil filter up is what your hearing.

[CieraSL92]

I usually fill the oil filter up about halfway when I do mine. The oil light lingers for about a second after it starts then goes out. I don't hear any knock if I change it this way. If I put it on dry it sticks around for a few seconds and knocks.

Partially fill your oil filter.

[Prospeeder]

Meh i never have. I use lucas in my 6k so the insidy parts are well lubricated, it doesnt even make noise anymore when it fills the empty filter, lol.

[Pontiac6ksteawd]

Filling your oil filter is all well and good. But that doesnt work on a 4tech with a internal oil filter... I know, he doesnt have one..

I personally have never heard any noise after doing an oil change. You might want to change it a little more frequently..

[turbokinetic]

As everyone said, the engine takes a few moments to pump the filter and other oil passages full. During this time, the engine is lubricated by the film of oil that alwas remains on the parts.

Normally there shouldn't be any noticable excessive noise. If there is wear in the engine's bearings you will hear a rattling or rumbling noise. When the excessive gap in the worn bearings is constantly being filled by oil from the pump, it cushions the looseness. When the excess gap is not filled with a constant stream of oil, the parts have slack and it knocks.

"Good" bearings have such a small gap that there is never more than an oil "film" anyway, so it sounds no different.

Bottom line - there is some wear in the engine. Don't worry about it unless it makes the noise all the time.

David

[Century7667]

The 3100 (don't know about the 3.1) has a filter bypass until the system has pressure. My 2200 does'nt, and there's definitely a difference after the oil change. It takes about a second on the 2200 before the pressure guage shows pressure, but it's a looooonnnng second while waiting with baited breath! My 3100 engines instantly have pressure after the change.

Ken T.

[Jr's3800]

If you hear some bottom end noise when you change the oil, thats an indicator of bottom end clearance issues... But if it only does this when you change the oil and no other time, then keep on going.... If you hear this every morning then its time to get somewhat concerned..

From what was described I would not be too worried..

[turbokinetic]

The 3100 (don't know about the 3.1) has a filter bypass until the system has pressure. ....

Actually..... no. The filter bypass does not bypass the filter during startup.

The filter bypass opens when the pressure DROP across the filter gets too high. This is to allow the engine to receive some lubrication if the filter becomes plugged, or if the oil is too cold to flow through the filter media.

Like most Chevy engines; the oilpump of the 3.1 / 3100 is submerged in the pan so it starts pumping the minute the engine rotates. It should buid pressure very quickly.

David

[Prospeeder]

What Oil filter is everybody usin?
Im Using just Napa 5w30 (Generic Valvoline) And a Wix Gold filter, quiet on engine start up! I used a fram once on my TGP and it made it Tick like crazy with it. Its quiet with a Wix Gold, I run the Napa 10w30 Synthetic (Valvoline Synpower) as my oil cap says

[jeffreyclay]

What Oil filter is everybody usin?
Im Using just Napa 5w30 (Generic Valvoline) And a Wix Gold filter, quiet on engine start up! I used a fram once on my TGP and it made it Tick like crazy with it. Its quiet with a Wix Gold, I run the Napa 10w30 Synthetic (Valvoline Synpower) as my oil cap says
Filters in order of preference,
Donaldson
Wix
Mobil One

I run Mobil One or Valvoline Synpower depending on which is on sale

I have no idea how Fram got the respect & reputation that it has. Marketing I suppose. Cut one open and you'll never buy one again.

[Apollo-Soyuz 1975]

When I changed my oil I picked up an AC-Delco PF47 filter from NAPA. The diagonal oil filter mount on the 3100 complicated things a bit, but I managed to squeeze my hands between the exhaust manifold and the rad to button it up. I filled the filter to about halfway with fresh oil before installing; I don't know if anyone else has observed this, but it looked almost as though the filter medium wicked up some of the oil, just like when milk is poured over Frosted Mini-Wheats cereal. Spillage turned out to be a non-issue.

[Century7667]

Actually..... no. The filter bypass does not bypass the filter during startup.

The filter bypass opens when the pressure DROP across the filter gets too high. This is to allow the engine to receive some lubrication if the filter becomes plugged, or if the oil is too cold to flow through the filter media.

Like most Chevy engines; the oilpump of the 3.1 / 3100 is submerged in the pan so it starts pumping the minute the engine rotates. It should buid pressure very quickly.

David

I knew I wasn't going crazy, so I went back and check the GM Shop Manual...

Actually... We're BOTH RIGHT!

"The oil filter is a full flow paper element unit. An oil filter bypass is used to ensure adequate oil supply on cold start or should the filter become plugged or develop excessive pressure drop. The bypass is designed to open at 69-86 kPa (10-12 psi)."

-1996 A Platform GMP/96-A-1 Book 1 of 2 Ciera SL / Century Service Manual GM Service Technology Group. Page 6A5A-3

So, according to this, it's sensing *low* pressure behind the filter which can be caused by a plugged filter or a filling filter. I'm guessing that *some* oil must be allowed to the filter for it to fill, but the documentation doesn't go into any more detail that what's given here. Again, I can't speak for the earlier 3.1/2.8, my only experience and documentation I have is for the dreaded LIM eating VIN M motors!

Ken T.

[6000]

Happens all the time on the newer Ford 4.6 V8s on the limos I service at work. I've tried putting oil in the filter before installing it, Lucas additive, nothing stops it. The motors last 400,000 miles anyway so I guess its not hurting them.

[Duner]

My A and X body cars do not rattle on initial start up after an oil and filter change, however my 3,8 Buick does. What I do is floor the throttle till oil light goes off and no rattle.
Flooring the throttle shuts off the gas like when clearing a flooded condition.
Hope I don't get into trouble for reviving this old thread but was going through the archives looking for possible solution to my X body difficulties.

[mechanizeddeath]

Necropost!

The only engines I've ever changed oil on that didn't make a ton of noise after the change were flat fours and sixes. This is supposedly due to the oil staying at the mechanical top end of the engine longer, since the top ends are horizontal. Also the filters almost always attach vertically, so they can literally be filled to the brim with oil if desired. But all the V6, V8, I4, and I6 engines I've changed have been noisy at first. But as the older posts indicated, this isn't really a problem.

[Jr's3800]

With a Buick motor or most motors for that matter, if you have a bottom end chatter or tap tap thud thud type of noise then you have excessive bearing clearance... You should hear nothing except maybe a little lifter chatter...

[Zaloryan]

With a Buick motor or most motors for that matter, if you have a bottom end chatter or tap tap thud thud type of noise then you have excessive bearing clearance... You should hear nothing except maybe a little lifter chatter...

Have you noticed that 3300s are a bit louder than other engines while idling? Maybe it's just me, but those injectors are really loud, or my lifters are going out.

[Century7667]

Necropost!

The only engines I've ever changed oil on that didn't make a ton of noise after the change were flat fours and sixes. This is supposedly due to the oil staying at the mechanical top end of the engine longer, since the top ends are horizontal. Also the filters almost always attach vertically, so they can literally be filled to the brim with oil if desired. But all the V6, V8, I4, and I6 engines I've changed have been noisy at first. But as the older posts indicated, this isn't really a problem.

The GM 250 inline 6 is (or was in my case) very quiet lifter-wise. It had the same lifter technology as the GM small block. No tricks, just 3/4 turn after they quiet on the adjuster nut. My Buick 3.8 odd fire wasn't too bad either. The 3100? Noisy as hell cold, but gets quiet after a bit.

Ken T.

[Drop Top Olds]

Some of the Older car enthusiasts would disconnect coil wire from the distributor right after an oil change and crank the engine over with the starter. It won't fire off and the slow speed of the starter primes the engine. Plug everything back in and no nasty noises... On a "modern engine" it may not be as simple to do this...

[Pontiac6ksteawd]

Actually its easier with newer GM's. You turn on the ignition, put your foot to the floor on the gas pedal, and then crank over. It shuts off the fuel injectors. The computer assumes you are trying to clear a flooded engine, and helps with the process. My 6000, Enoy, TGP, all do it.