Engine condition via listening???

Don McCullough · Dec 20, 2009

To what degree can an engine's condition be told by listening to it? Have heard mechanics even use stethoscopes.

Is dropping the pan on my tractor and having measurements taken the only sure way?

Engine wear via fuel in oil is my reason for this question. This problem now fixed but don't know how long previous owner drove it with diluted oil.

BCnT · Dec 20, 2009

stethescope works great IF you know what youre hearing...loose rocker arm and worn wrist pins sound alot alike to the untrained ear.

chances are if you have good oil pressure and no noticable knocking your tractor is good to go...fuel in sump might have taken a couple hundred hours off engine life but not deal a death blow.

Don McCullough · Dec 20, 2009

BCnT,

What would you call good oil pressure? 40 plus at full throttle? Excellent would be??--60?

Thanks for your response.

Lefty · Dec 20, 2009

Lacking a mechanics stethoscope,take a hardwood dowel,3/8-3/4 diameter and gently round one end like the end of your finger.Placeing the rounded end in your ear,hold the other end against various areas of the running engine.BE VERY CAREFUL of moving parts!You'll be amazed at what internal sounds you hear in adjoining internals..the click of tappets,the whirrrr of a ball bearing,the growl of something binding...Good cheap "old school" technology

JK-NY · Dec 20, 2009

Engine oil analyis might be a better idea than tearing the bottom end apart just to check it out. Do you have decent oil pressure when engine is warmed up and under load ? Not confusing a misfire with a knock ? Good compression if gas engine- decent starting when warm if diesel( or ck compression if you can find a diesel compression tester)? Excessive oil consumption/ oil smoke in exhaust ? Hearing knock from engine? If oil pressure is good with fresh oil and no other obvious issues I would run it and take an oil sample at next change if your still worried.Listening with a stethoscope or piece of broom handle can help if you are isolating a knock, if no knock it wont tell you much.

JOCCO · Dec 20, 2009

I have 2 friends that can listen to motors and tell you what is wrong inside don't understand it but they are good. Me i would be lucky to hear the noise let alone where it came from. The oil sample or radiator/carbon test is a little better. We went to look at a large truck one time he told the fellow some thing is wrong in #3 cylinder, guy said your a crack head. Two weeks later it threw #3 rod.

BCnT · Dec 20, 2009

it really depends on the engine...40# at full throttle is pretty good but i'd look more at the idle pressure...under 20# at operating temp would have me wondering on most engines.

Anonymous-0 · Dec 21, 2009

I had a ticking sound on my truck and thought something was loose and rattling around. Was getting some other work done at a garage and asked the mechanic what the ticking might be. He had a stethoscope and let me listen. Fuel injector was ticking, so it wasn't a problem at all. 40 PSI is good oil pressure. If the problem is fixed and there's no strange noises, you're probably OK. Dave

Anonymous-0 · Dec 21, 2009

or a piece of garden hose, as suggested in my Ford book.

Anonymous-0 · Dec 21, 2009

or a piece of garden hose, as suggested in my Ford book.

Anonymous-0 · Dec 21, 2009

You will get much more useful help if you post a little more info. tractor brand, engine model, hours, oil brand and weight, oil pressure at hot idle and pto speed, oil comsumption, power, sound, compression results dry and wet - - for starters. Tom

Don McCullough · Dec 21, 2009

The engine I'm refering to is a 531 cid in a 5020 John Deere. Now have rebuilt injector pump so fuel in oil problem should be fixed. There was a "crack" in one of the unbrella seals so no doubt this is where the fuel was getting into oil.

Haven't changed oil yet but mechanic says once I do the new, undiluted, oil should give me a little more pressure. Now it's about 40 at full throttle and was not warmed-up real well. I have noticed that I gain considerably on oil pressure once engine warmed-up well.

Mechanic says no worrisome sounds coming from motor so I should be O.K. Well.....untill I get the bills !

Mark - IN. · Dec 21, 2009

I have a stethescope that I use from time to time and as a matter of fact just moved it on a shelf in its cabinet the other day to get something. Lisle Tools makes them. Good for valve train noise like lifters and rockers. If you can get close enough to the side of the block, connecting rods too. How well it'd work around an injector pump, I don't know.

Somewhere I've got an old picture of Bill Jenkins wearing a Bell Helmet with car horns mounted on both sides of it, plumbed into his ears. He was most definately in tune with that Camaro's engine on that 1/4 mile pass way back when. Never argue with The Grump. Grin.

Mark

rhouston · Dec 21, 2009

I have done it using a board. It is neat what you can hear and track down just by the sound changes as you move the board around the block.

Engine condition via listening???

Don McCullough

Member

BCnT

Well-known Member

Don McCullough

Member

Lefty

Well-known Member

JK-NY

Well-known Member

JOCCO

Well-known Member

BCnT

Well-known Member

Anonymous-0

Well-known Member

Anonymous-0

Well-known Member

Anonymous-0

Well-known Member

Anonymous-0

Well-known Member

Don McCullough

Member

Mark - IN.

Well-known Member

rhouston

Well-known Member

Similar threads