Has anyone ever experienced a banging noise under load while accelerating at lower speed due to a water pump pulley?...I know this seems like a dumb question....I had a small amount of water pump shaft play in a small block Chevy...I replaced the pump with a new unit that has equal play as the one I replaced....The car has a cheap chrome plated single groove pulley that is not cracked or severely warped...I can grab the stock GM 4 blade fan and rock the assembly together ...No noises at idle or free revving the engine in neutral...I have replaced 100's of dollars worth of other items in an attempt to rectify the problem....(Long Story ),,,,,,It sounds like chassis noise...Not engine knock
I thought the noise was chassis related....Here's what I have done so far....Replaced spindles and king pins....Replaced both ends at frame mount on split bones...Removed spacer that was installed on top of front spring...New front shocks...Replaced questionable pitman arm...U joints...Checked all fasteners in chassis....If I am traveling over bumpy roads there isn't a noise...Pulling out of a parking lot for instance and merging into traffic under acceleration...I hear a banging for lack of a better term that sounds like a loose suspension connection....Once up to a desired speed and steady RPM....Noise goes away...I am clawing now at possibilities of what it could be...Engine mount is a Speedway Hurst style saddle mount and transmission is rubber factory style (New)..The only movement I can find is in the fan/pulley assembly that I can make a sound if I pound on the fan with the side of my fist..Never have I had an automobile that I have spent as much money and time on chasing a problem
Quit throwing money at it. You need to have another ear listen for the sound. Drive it over here and I'll go for a ride with you.
BJR is the man on this one. Is the noise a repeated "bang" or just one bang? I ask because you said it "goes away" when you get up to speed. I was working on a Ford motor one time that had a "knock" turned out to be loose bolts that mounted the pulley on the damper.
It comes up with RPM and sounds like a rattling/banging chassis part....Once load is taken off and into higher gear..It goes away..Def coming from front end area of the car and not internal engine
Flex plate. Don't laugh! Have heard and seen one doing exactly what you're saying. Center was torn out, roughly, and would 'disengage' at slow speeds / higher torque making a noise but then would seem to quieten down (maybe jsut couldn't be heard / felt). Eventually just made a noise as it'd worn out so much it couldn't catch anything to 'engage'. Chris
That's a lot of yoke extension and could be a problem. You say the noise is definitely coming from the front of the engine. If it turns out the noise is coming from a pulley, try sanding or blasting the pulley groove to roughen it up. I've done this in the past with noisy pulleys and it does work.
Here's another problem while I am at it....Using the early Chevy truck combo clutch/brake master cylinder...Front brakes are the MT products Lincoln style http://www.mtcarproducts.com/Brakes.html and stock 10x2 Ford drums on rear....Brakes are properly adjusted to include the push rod...I have very hard pedal and not what I would consider great stopping power....Not my first car with manual drum brakes...So I am familiar with the type and feel..Any Ideas?
Pedal ratio and master piston size are the two things that come to mind. Not enough ratio and/or too large master piston will both cause a hard pedal with less than ideal stopping power. Pads and shoes not bedded in or glazed over can be an issue also.
When you're bleeding the brakes before pressure builds up, does the pedal move freely and smooth? If not, maybe the linkage is kind of binding a bit?
Do you have a fan shroud? I was thinking flex plate also, but you have a stick. Are you coordinated enough to brake torque the car in a position where someone can look at it while applying a load? Not being a smart ass, some just can’t do it.
No fan shroud...I'm going to go to a parking lot this evening and remove the belt..The car always makes the noise when I am leaving this particular area....Going to drive that piece of road and see if noise is still present...As I said I am clawing for possible reasons of the noise as I have checked or replaced most everything that could cause it...The pulley idea of banging is pretty far fetched as I've never seen one make this type of noise...But it's the only thing that I can find that shows an noticeable play....But if it was in fact it....Why would it not make noise at idle or free rev?..As I said earlier in the post....It happens at low speed under medium acceleration a heavy metal rattle sound
Lots of things come to mind , some not so easy to fix. Crank thrust bearing ? Are you sure it’s not an engine miss , that sounds as a bang in the exhaust ? Alternator shaft bearing ? Removing the fan belt sounds as the best place to start for me also . . Using another set of ears and eyes sounds as a good addition to helping locate your issue.
Does it sound or feel like it’s coming from the transmission? You say it goes away when you change up into a higher gear. Clutch , pressure plate? Exhaust pipe rubbing and rattling sounds can really come and go at different rpms.
I knew the pulley idea was a long shot and was not the case...Here's what I have done in the meantime...Front spring had a homemade spacer and also a shim wedged in one side...I removed these items and now both springs front and rear have center pin properly located in the cross member holes. All shackles are hanging at 45'...There also was a shim wedged in the front spring making the driver shackle hang nearly flat and in line with the spring. I replaced this dangerous pitman arm that the previous owner had removed nearly all the material from the backside because the steering box was not properly located to the frame rail. It was also cracked and I thought this was the noise to begin with .Not sure that I like the longer arm as it's now even more twitchy on the road at higher speeds..Does any company make a shorter one? (53-56 F100) The king pins had no shims and were loose..I added a MT products brake kit and while doing that I replaced the spindles and pins and are now properly installed and shimmed. The center mounted wishbones had tie rod ends mounted in Non Tapered holes.I recently replaced them with heim joints. The gaps between the radius rod to axle and shock mount are not 100% tight (meaning perfectly closed at all points of contact) a slight amount of light can be seen here and there. I checked all fasteners again. Front shocks are new. There is still a small about of suspension banging/rattle at speed on rough pavement and seems to be a little more pronounced if I am accelerating as if I am transferring weight off the front end to the rear and leaving space for whatever is making the noise
I think you could find shims to take up the excess space between the axle and wishbone mount. Also I’m not a fan of heim ends, and think that might be a source of a rattle or thunk.
Thanks for the info. The replacement of the tie rod ends was the beginning of the search for the noise. I had some king pin shims so I shimmed the wishbone to axle on both sides today. It’s raining here after a month of none. So I won’t be able to road test and see if it completely eliminated the problem
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