Jump to content

92 1500 Loud Tapping Noise when accelerating

Jared Stangenberg
 Share

Recommended Posts

Jared Stangenberg Enthusiast

Jared Stangenberg

Posted
Posted

My truck (92 1500,2wd w/5.7L) has developed a wierd and annoying noise in the last 100 or miles of driving.

It's a loud rattling/tapping that sounds like it is coming from the front driver's side of the truck, it has a very metallic quality to it.

It only happens when the truck is gear and the accelerator is pushed, it seems loudest when the motor is at about 2000-2500 rpm and actually seems to get quieter beyond that point (although the engine may just drown it out at higher rpms).

It only makes the noise when the accelerator is pushed while in motion, if I take my foot off the gas it stops immediately. It doesn't make the noise when rev'd in park or neutral only in drive while in motion. The degree to which the steering wheel is turned or not turned seems to have effect on the presence of the noise.

The truck has 204000 miles on it, I've only been the owner for 4000 of those. The vehicle was previously used as a farm truck and probably saw some semi-abusive use there.

I'd really appreciate any opinions or know how on what's making this noise. I've had wheel bearings go out before on a different vehicle, but this isn't really the same noise or conditions causing the sound. I'm pretty stumped. :confused:

  • Replies 46
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Jared Stangenberg Enthusiast

Jared Stangenberg

Posted
  • Author
Posted

Symptoms unfortunately got worse today.

I drove to work and back (about 20 mile round trip), the noise continued and I also had noticeable loss of power going up a couple hills.

I managed to shoot a short video on my phone, which was precarious since the truck really has to be in motion to hear the sound. Although I can briefly replicate the noise to some extent in park. I'm leaving the truck in drive-way until this gets sorted out.

ifixedit Enthusiast

ifixedit

Posted
Posted (edited)

Pull the valve covers and check for a broken or cracked rocker arm, sounds like that's what it is, they can break on a moments notice. If a rod was hammering that hard the engine would have very low oil pressure, would likely be smoking like a steam ship, and probably would have already quit by now, so I doubt it is a rod bearing. The 350 bottom ends are about as bullet proof as they come so it would be very uncommon for anything in the bottom end on these engines to let loose just like that under normal driving on a daily basis, that is unless you had REALLY abused it with some very high and prolonged RPM's over and over which I doubt you've done.

 

If all the rocker arms are fine, it could also be a collapsed lifter. Get the valve covers off, go over each rocker arm carefully looking for one that's loose. If you find a loose rocker arm that appears to be intact, then you've got a collapsed lifter and possibly a bent or damaged push rod as well as things were likely banging into each other with all the excess clearance. Look the parts over closely for damage before you decide to re-use them. Unfortunately a collapsed lifter that refuses to pump up will require removal of the intake to replace it. An old trick to free up the lifter is to add about a quart or so of kerosene to the oil and let it idle for a few minutes, if that doesn't take care of it the intake is going to have to come off to get at the lifter. If the kerosene trick does work you're going to want to change the oil ASAP.

Edited by ifixedit
Jared Stangenberg Enthusiast

Jared Stangenberg

Posted
  • Author
Posted (edited)

Thanks, hopefully I'll get to fool with it some in the next fews days. We've just been using my wife's car for everything in the mean time.

We've got our first baby due in less than four weeks, so I've been pretty short on time and money to mess with this recently.

 

At my wife's request, I did change the spark plugs this morning to see if that made a difference. I hadn't changed them since I got the truck and had no idea how long they had been in (looks like a long long while). the new plugs haven't changed the tapping noise at all, but have brought some power back into the truck.

 

I know you can supposedly "read" plugs, and I've got the chart to look at for it. I also took pictures of each plug by cylinder to get opinions. Other than they were obviously "vintage", does anything else stand out?

12141666_10153045267301881_3663325299155

Hopefully I can take the valve covers off later this week and check out the rocker arms.

I also have a question, "What is this and should it be connecting to anything?". It was underneath the air intake pipe/silencer box when I pulled them out.

12122492_10153045289741881_5962028296346

Edited by jstange
Jared Stangenberg Enthusiast

Jared Stangenberg

Posted
  • Author
Posted

How is your oil pressure during the times it "taps". Sounds like it could be a drop off in oil pressure??

The oil pressure never drops during the tapping.

 

At idle pressure is a little about 30 and when I'm on the gas it goes up to about 45.

Duelin Enthusiast

Duelin

Posted
Posted

What happens when you power brake it around 2000 to 3000 RPMs? I would try that and have someone listen under the hood. Also check and see if you fan is hitting the shroud.

Jared Stangenberg Enthusiast

Jared Stangenberg

Posted
  • Author
Posted

What happens when you power brake it around 2000 to 3000 RPMs? I would try that and have someone listen under the hood. Also check and see if you fan is hitting the shroud.

By "power braking", do you mean putting it gear and standing on the brakes while revving the engine?

 

If so I haven't tried it.

Duelin Enthusiast

Duelin

Posted
Posted

By "power braking", do you mean putting it gear and standing on the brakes while revving the engine?

 

If so I haven't tried it.

Yes. But when you do this you have to use common sense. Make sure your brakes are good and able to hold at those RPMs and make sure you are no where near something that you could run into in case your brakes let go. And you might have someone standing near the truck so they could hear where the noise is coming from.

1997SierraSLT Enthusiast

1997SierraSLT

Posted
Posted

sounds like a sticking lifter. had it happen at about 120,000 miles on my truck. Ran a cleaner through it purchased at the local auto parts store, changed the oil per instructions, and it solved the problem.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Chuck FB
      OCI, not when but why?

      By Chuck FB · Posted

      I certainly could be wrong but I hear of pickups far newer than that 2007 cutoff which may not be going to the wrecker but are having engine work done and be that a reman engine or new engine or trying to repair the existing engine. Some of it would be design issues as per the cylinder deactivation system that GM has and one of those lifters wiping out the cam and the question of oil changes moving the needle or not on that whole mess, or in the case of Ford pickup engines that have the long timing chains and wearing them out and the roller followers and phasers and some of that certainly goes back to oil change intervals. But in those various cases the truck has all sorts of life left in it and so the unfortunate owner and may be original owner or used market owner that is pouring money into repairs so the truck is not seeing the salvage yard yet but damage is happening by infrequent oil changes. A friends son had bought a 2018 I think it is half ton GM and it had some sort of extended or used dealer warranty on it and of course the lifter issue bites and its rattling and so the dealer had to swallow the bill and was at least 7000.00 and I think they only replaced what they felt they had to replace so yeah, I can see that being a ticking time bomb in the not too distant future. Would frequent oil changes cure all these engineering "marvels", probably not but some engine designs have shown that they do much better if the oil is changed a lot more often then if the manufacturer service claims are followed. New trucks cost so much that there is an incentive to keep the existing truck on the road by repairing. 
    • davester
      Tranmission stays in Low

      By davester · Posted

      get a good code reader, and find out what problems the truck has noticed by reading codes. cheap ones can only get basic engine codes, you may want to get one that can get codes from all the computers in your truck.
    • asilverblazer
      OCI, not when but why?

      By asilverblazer · Posted

      This is sort of my point, salvage yards aren't overflowing with all these 'poorly' maintained trucks - excellent/good/servicable condition otherwise, salvaged only as a result of a bad engine from poor oil change regiment.    In my area, there are no 2007 to newer gm trucks/suvs in any salvage yards. A few are in the 'recyclers' with very obvious reasons for being there - wrecked.
    • asilverblazer
      Stabilitrak conversion to Z71

      By asilverblazer · Posted

      Stabilitrack was a stability control, traction control system, that functioned independently from the transfer case.   Z-71 has nothing to do with the transfer case or differential.   If it does have an AWD system, my memory recalls this being specific to the Denali trim, converting won't be as simple as swapping out mechanical parts like differentials and transfer cases. It will require reprogramming at a minimum. Long story short, not likely worth it.   Pulling a fuse, may disable the AWD system, it might also prevent any other transfer case functions.   However, the AWD case was generally based on the same transfer case you refer to in the 2006 Suburban. If it still has a 4-High and 4-Low where the transfer case locks and splits power 50-50 front to rear, what are you gaining by changing anything? A true-rear wheel drive only, what good will that serve? Not enough to go through the trouble of changing out all the parts.    Generally, all the factory systems will handle a 33" tire and re-gearing. Probably a 35" tire too, if you aren't driving like a caveman. If 35" tires are in the plan...   If you do plan on driving like a caveman or are fully committed to 35" tires, an entire re-think of the build is probably in order. Starting with square one, an IFS front end isn't going to be the best starting point for 35's and caveman driving. 
    • PunchT37
      Oil Consumption

      By PunchT37 · Posted

      1/2 qt over full ain`t gonna hurt $h!t. Most times, a whole qt won`t either. Most have windage trays now. As long as the crank isn`t slapping itself in the oil, it`s not the end of the world.   We used to overfill 1 qt at the track, at race time. Better to have it over full than having the pan sucked dry at 6500 rpm`s.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...