Identify engine sound?

[Edward J.]

Re: Identify engine sound?

Roald,
Its Tough To Dia. Engine Noises Sometimes, Ive Been Working On Cars For 35 Years, I Can Give You A Few Tips That May Help From Past Gm Experence, Broken Valve Springs Can Be Problem, Gm Uses A Inner And Outer Valve Spring If A Spring Is Broken Its Most Likely The Inner, Another Problem Is A Broken Fuel Pump Internal Spring, Thats Sounds Like A Lifter Sometimes, This Can Can Be Check With A Stethoscope Or A Long Screw Driver Put Tip To Pump Housing And Handle To Ear. Ive Also Seen Cracked Flywheel Problems Where It Bolts To Crankshaft,to Much Flexing When Started Causes This- Drop The Inspection Sheild And Use A Drop Lamp To Inspect,will Need To Rotate Flywhell To Do A Complete Inspection,( By The Way If Your Car Is Manuel Trans. Disreguard).dont Forget If The Noise Is Rpm Sensative It Something To Do With Moving Parts Internal Or External.one Last Thing Its Possiable A Piece Of Carbon Could Have Broken Alway From A Valve And Is On Top Of Piston And Is Contacting Cylinder Head- Gm.s Make Top Engine Cleaner Andthis Is Poured In The Top Of Carb. While Running At Normal Operating Temp.

[Roald P.]

Re: Identify engine sound?

Roald,
Its Tough To Dia. Engine Noises Sometimes, Ive Been Working On Cars For 35 Years, I Can Give You A Few Tips

Thanks for the tips

When I bought the car it had a ticking lifter, it sounded a bit different than now and that noise went away after a few oil changes and ~500 miles of driving. The car sat for 20 years before I bought it.

I dropped the oil pan today, would I be able to see a bad bearing without more disassembly?



Are those blank spots on the crank normal? (see the red rings) It looks like its rubbing against the mains



Here is the contents of the oil pan, this cant be good can it?



There is alot of thick black goo with some objects in it. The objects are not magnetic and can be crushed between my fingernails, crystallized oil?





Im not sure, but I maybe think I saw a wiped cam lope when I looked up in the engine. Would this be able to make that noise?

[Edward J.]

Re: Identify engine sound?

Roald,
Saw The Pictures Theres Alot Of Metal In There But It Appears To Be Fine Metalic, If Theres An Bad Cam Lobe The Bad Lobe Would Show Up With Valve Covers Off- Just Rotate Engine While Watching Each Rocker Arm Movement They Should Have The Same Movement Up And Down , If Theres A Bad Connecting Rod Bearing The Connecting Rod Turns Black From Heat,look Also Thrust Bearing End Play This Can Be Done By Useing A Pry Bar Against The Crank Counter Weight And Main Cap ,look For Back And Forth Movement, Only Need Slight Pressure To Move, Normal
Is Only A Few Thousandths
Ps. You Maybe Able To See The Cam Lobes From Under Neath Between The Crank And Block

[Roald P.]

Re: Identify engine sound?

Roald,
Saw The Pictures Theres Alot Of Metal In There But It Appears To Be Fine Metalic, If Theres An Bad Cam Lobe The Bad Lobe Would Show Up With Valve Covers Off- Just Rotate Engine While Watching Each Rocker Arm Movement They Should Have The Same Movement Up And Down , If Theres A Bad Connecting Rod Bearing The Connecting Rod Turns Black From Heat,look Also Thrust Bearing End Play This Can Be Done By Useing A Pry Bar Against The Crank Counter Weight And Main Cap ,look For Back And Forth Movement, Only Need Slight Pressure To Move, Normal
Is Only A Few Thousandths
Ps. You Maybe Able To See The Cam Lobes From Under Neath Between The Crank And Block

Thanks, I checked the crank movement earlier today, I'm guessing the crank can move around 0.2 inches back and forth. Does that mean the thrust bearing is gone? If you look at picture number two in my last post, it looks like the crank counter weights has been in (very light) contact with the main caps.

[Edward J.]

Re: Identify engine sound?

Yes They Are Contacted The Caps. Thats Bad News Only Means One Thing, Its Time For A Beer Or Two, And A Rebuild.

[James G.]

Re: Identify engine sound?

When I first listened to the noise, I thought it was a bad GULP VALVE on your smog pump, but I could never see the smog set up. I see black Californias plates, so my guess is it still has a pump system.

The oil pan looks to me like PENZOIL was used in this engine 'back in the day', and yes lot's of metal shavings.

Camshaft may have a worn lobe, but then the engine may shake and buck. If an intake, it will have no power out of one cylinder.

Just might be time to pull the engine and give her a rebuild. Hell its only been 41 years.

[Edward J.]

Re: Identify engine sound?

I Forgot To Tell You A Reason The Thrust Bearing Failure Causes, Sometimes A Mismatch Between Engine And Trans Torque Convertor, Missing Engine Dowl Pins. Loose Engine To Trans Bell Housing Bolts.those are Most Common.

[Patrick H.]

Re: Identify engine sound?

Just might be time to pull the engine and give her a rebuild. Hell its only been 41 years.

If you're going to do this, I'd highly recommend contacting Duke Williams via e-mail to get some information on "spicing up" your rebuild.

Patrick

[Roald P.]

Re: Identify engine sound?

If you're going to do this, I'd highly recommend contacting Duke Williams via e-mail to get some information on "spicing up" your rebuild.

Patrick

Thanks, I just found one of his old threads on the subject. That seems interesting

[Roald P.]

Re: Identify engine sound?

When I first listened to the noise, I thought it was a bad GULP VALVE on your smog pump, but I could never see the smog set up. I see black Californias plates, so my guess is it still has a pump system.

The oil pan looks to me like PENZOIL was used in this engine 'back in the day', and yes lot's of metal shavings.

Camshaft may have a worn lobe, but then the engine may shake and buck. If an intake, it will have no power out of one cylinder.

Just might be time to pull the engine and give her a rebuild. Hell its only been 41 years.

The smog setup was unfortunately removed before I got the car. What is PENZOIL?

The engine idles without moving at all, but yes it seems like its time for a rebuild.

I found the following number on a piston - 3795704 - and this number on the crank 391100106, is this the original parts?

[Patrick H.]

Re: Identify engine sound?

Thanks, I just found one of his old threads on the subject. That seems interesting

Yep.
He has a written package that he will send you via e-mail if you say "pretty please."

[Patrick H.]

Re: Identify engine sound?

The smog setup was unfortunately removed before I got the car. What is PENZOIL?

The engine idles without moving at all, but yes it seems like its time for a rebuild.

I found the following number on a piston - 3795704 - and this number on the crank 391100106, is this the original parts?

A long-running brand of motor oil:

[Timothy B.]

Re: Identify engine sound?

before going through all the money and labor for a rebuild, find the source of the noise. If the engine runs good and only uses a modest amount of oil it may be fine.

Why do you think it needs to be rebuilt, slow down?

[Edward M.]

Re: Identify engine sound?

Hard to tell from the video, but I will share my experience. I has a 73 350 convertible many years ago that started having a tapping / knocking noise. It sort of sounded like a lifter, but was deeper in the engine.

I chased it down to the lower passenger side front of the engine. It turned out to be the fuel pump rod. I replaced it and all was fine after that.

Ran into the same situation many years later with a 1972 El Camino with a 350 engine. It was driving my friend crazy to the point where he was going to replace the engine. Turned out to be a quick fix and no engine replacement.

[Paul J.]

Re: Identify engine sound?

Roald:

The pitch and sound of the noise does not sound like a lifter or a rod bearing. It sounds more like an AC compressor (or smog equipment which you say is not there). Does the car have AC? If so, remove the belt and run the engine and see if the noise disappears. It's worth a try.

Paul