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Slight engine knock

 
scasey
New User
Posts: 1
Joined: 12/10
Posted: 12/01/10 10:11 AM

had a 66 mustang with a 289 had the same problem,been a mechanic since 1969.found i had a wrist pin knock..i know you said engine was rebuilt but a lot of people fail to check the wrist pins.if you checked everythings else i'm pretty sure thats your problem.if you pull the motor you might you should have them all done.  

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cushman350
Enthusiast
Posts: 648
Joined: 07/06
Posted: 12/02/10 03:11 PM

Icon Quotejmoudry:
should I leave the engine running and pull one plug at a time or shut it down between plugs?

Forgot to mention that my oil pressure averages in the middle of the guage and the dipstick shows in the middle of add and full.  So the oil pressure seems dead on.  Prob a good sign that the there are no serious issues with the mains?

Thanks


I would pre-loosen the boots from the plugs and have them just resting on the plug tips so they can be easily removed while running, one at a time, while the engine is idling. Rubber coated pliers would be nice, I hate getting shocked.

Also, being louder around the fuel pump could be the issue too. I have encountered failing pump arms that knock. I'd try a new pump (not that expensive) or take the old pump off to inspect for looseness at the arm. It very well could be slapping. Worth a try before a tear down. Good luck.  

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jmoudry
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Posts: 63
Joined: 06/08
Posted: 12/03/10 01:00 PM

I will have to try the plug trick again.  I gave it a go last week and could not hear the noise when I disconnected any one of the plugs.  
66 289 coupe

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jmoudry
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Posts: 63
Joined: 06/08
Posted: 12/03/10 04:45 PM

did you guys have a chance to listen to the video http://www.youtube.com/watch?v=QBdtcIUxVIQ ?

Thanks  
66 289 coupe

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jmoudry
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Posts: 63
Joined: 06/08
Posted: 12/03/10 05:26 PM

Just check again and the noise gets a little quieter when I pull any one plug but is still there.  I went through all of ther several time while the engine was heating up and the same results.  Did notice that I may have an exhaust leak.  I guess I will just keep an ear on it.  
66 289 coupe

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jmoudry
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Posts: 63
Joined: 06/08
Posted: 12/06/10 08:08 PM

Ruled out the flex plate and accessories.  Tried the plug trick one last time and no one cylinder is worse.  Maybe its a bad lifter?  I really don't want to tear the engine apart unless it gets worse.  Also I will most likely get a 5.0 crate engine and mothball the old one.  Dollar for dollar a crate engie would be the best deal.  Not even sure if the block would be salvageable.  
66 289 coupe

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cushman350
Enthusiast
Posts: 648
Joined: 07/06
Posted: 12/11/10 11:43 AM

If a small block Ford is already bored .30 over I would not rebuild it. Cylinder walls are too thin. Crates are very reasonable bang for buck.  

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jmoudry
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Posts: 63
Joined: 06/08
Posted: 12/11/10 02:33 PM

Well I added about a half quart of oil bringing the level on the stick from half to full and the noise is almost gone.  Pressure is still half way on the gauge.  I can still barely hear it but it is much better.  
66 289 coupe

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2ltime
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Posts: 18
Joined: 10/08
Posted: 05/31/13 07:19 AM

Maybe slap from the timing chain, or my 289 had a a noisey fuel pump.  

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kepaloha
New User
Posts: 10
Joined: 02/14
Posted: 02/13/14 11:31 AM

I have the exact same sound on my 65' Mustang 289, and I'm still searching and have tried almost all of these tips except the plug wire trick, I will try that tonight.  

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kepaloha
New User
Posts: 10
Joined: 02/14
Posted: 02/13/14 11:34 AM

jmoudry

 I watched your video and it's literally is the exact same sound except mine is on the passenger side as where your sound looks like it's coming from the driver side.  

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wayne712222
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Posts: 127
Joined: 10/13
Posted: 02/14/14 01:50 AM

use a LONG screw driver.. a broom stick without the broom.. an automotive stethoscope to listen to various parts of the engine. you will get closed to the location of the knock..

long screwdrivers or broom sticks.. place against the various components. using extreme care.. hold still with hand. move head to the end of the tool.. just in front of your EAR..

a HUGE WARNING.. if it slips off where you have probed on the engine.. and gets in contact with the rotating parts .. you could need more than a doctor to remove it from your head.. or garage wall..

automotive stethoscopes are under 10 bucks at most parts stores..  

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kepaloha
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Posts: 10
Joined: 02/14
Posted: 03/19/14 07:38 AM

I picked up the stethoscope and I couldn't pin down the knock, it's loud enough to make it very hard to find out where it's coming from.

I ended up dropping the oil pan and checking each piston to see if there is any movement on the journal or check if there are any bearings that are blown or not. It's all solid and no movement at all, but that still doesn't mean that it's a bad bearing though.  I put it all back together and still having the knocking sound.  Replaced the oil pump and even had to replace the starter while I was at it.

I'm hoping that jmoudry might have found something too? I'm about ready to admit defeat and just buy a cheap running U-Pull-it engine, and then rebuild my 289 and start from scratch.  

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wayne712222
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Posts: 127
Joined: 10/13
Posted: 03/19/14 09:21 AM

take fan belts off.  start engine.. does it still knock...

you can operate an engine for about 1 minute without the water pump spinning without damage..

things that can go knock..

loose timing chains..  check by rocking crank back and forth with breaker bar on crank bolt..

loose crank center bolts.. allowing the damper to widen the keyway until it shears..

loose cam bolts.. allowing the fuel pump eccentric to rattle against the front cover might also have the cam gear working loose...


fuel pump lever rattling or the fuel pump spring ...


flex plate to torque converter nuts..

cracked flex plate..

flex plate to crank bolts..

turning engine with TIGHT FITTING breaker bar.. use plastic bags in hex socket and in square drive to tighten fit of socket on crank bolt and of socket on breaker bar to remove slack..  rock crank small amounts..  while listening..  turn 1/8 turn.. try again...  turn 1/8 turn try again.. keep going through 3 or 4 complete revolutions..


crossfiring ignition system.. where the spark plug wires are TOO CLOSE and induction takes place.. this is REAL..
usually the last 2 on the driver side are effected..  later 5.0 motors require the spark plug wires in the holder over the driver side valve cover to be in this order.. 7, 5, 6, 8... so the wires do not lay close to each other for any distance..

cracked or carbon arcing in the distributor cap...

examination of the inside of the cap.. if you have a timing light.. move it from one spark plug wire to the next..  if you get a double flash.. instead of a single.. you have found the issue.....

overadvanced timing...  

does the vacuum advance work.. apply vacuum.. the breaker plate should rotate and snap back when vacuum is released..

does the mechanical advance work.. twist rotor..  does it have some spring tension in one direction and snap back freely..  and snap back to the hard stop...

do a video with the fan belts off.. or remove the fan and bolt the pulley up tight ..  only 30 seconds of video is needed..

if the engine has been apart.. heads off.. there is a SQUARE corner of the head gaskets that stick out from under the corner of the heads on one end.. where is the square corner sticking out of on both sides..   should be the front on both sides. indicating the head gaskets were installed properly with the water passages open at the rear. so coolant flow is in the normal direction...

lastly.. and i have not seen an issue on small blocks.. usually on FE motors.. run a compression test.. the gauge should come up smoothly..  not JERK up part way then hard jerk to the top..  persons installing the piston pin snap rings sometimes over squeeze them.. instead of just enough to get them in the groove.. they crush them.. they then fall out and the piston pin slides to the side and wears a slot in the cylinder wall..  

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kepaloha
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Posts: 10
Joined: 02/14
Posted: 06/13/14 08:06 AM

Hey wayne712222,

Sorry for late reply, but have been trying to find the time to complete this shopping list. And thank you for the list of things to try.

-replaced timing chain
-replaced fuel pump
-replaced Oil pump
-replaced distrib as vacuum advance wasn't working
-reset timing
-checked compression #8 was a bit low, but still with tolerance
-replaced the starter

Still the knock hasn't changed.

haven't gotten to the Flex plate yet, but checking the heads and it looks just the way you said that it would look just the way you said the would look.

A few of these I haven't gotten to yet, as I'm still new at working on engines and need to work up the nerve and read more up on "how to" take apart these things and put them back together.

Funny thing is when I replaced the above things listed, I never tried ran the motor with the belts off, I'm going to be so pissed when I do that tonight and there is no knocking.....  I may just create a new problem for the car just out of spite!

I'll keep you posted.  

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