Anyone ever heard this noise before?

[92danger]

Hey everyone, ive got a 92 2.3. The noise im wondering about seems to come from the engine bay (possible drivers side.) The best I can describe it is that it sounds like a BB shaking around in a coke can. Doesnt do it all the time but when it does, at higher revs, it feels like it almost tries to stall. There are other noises but this one makes for a very stressful drive back and forth to work on an otherwise very peaceful road. Any ideas?

 

[swynx]

i have heard this noise before, but in my 95 saturn 1.9l. i have been trying to pin point this sound but have had no such luck. this seems to happen to me like when im trying to get up to speed in 3rd gear going up a hill and not in the power band.

 

[96firephoenix]

my 97 made a similar noise... right up until one of the heat shields fell off.

 

[92danger]

Hmm. Ill check and see if all the bolts are tight. But that still wouldnt quite explain why it seems to want to die when the noise occasionally gets real pronounced

 

[swynx]

Hmm. Ill check and see if all the bolts are tight. But that still wouldnt quite explain why it seems to want to die when the noise occasionally gets real pronounced

yeah, mine hesitates during the sound.

 

[AgPete139]

Yes, the first thing to check is the heat shield bolt(s) and make sure nothing has broken off of the bracket.

However, this sounds to be like a bad catalytic converter. They can become clogged from wear and make that ting-ding-cack-ting sound in the exhaust. This also explains why the higher exhaust not being able to pass through the catalytic converter, causing your engine to miss at higher RPM & exhaust flow.

I'm actually surprised you don't have an engine code yet. The upstream and downstream O2 sensors/pyrometers usually will tell you if the exhaust mix is becoming lean. The cats are still doing their job of cleaning the up the excess unburnt fuel and carbon monoxide, though.

When you replace it, you can use a generic 2.25" inlet/outlet cat. Or, if you're savvy or a junkyard digger, grab a cat from another like truck/car.

 

[freedom5]

Yes, the first thing to check is the heat shield bolt(s) and make sure nothing has broken off of the bracket.

However, this sounds to be like a bad catalytic converter. They can become clogged from wear and make that ting-ding-cack-ting sound in the exhaust. This also explains why the higher exhaust not being able to pass through the catalytic converter, causing your engine to miss at higher RPM & exhaust flow.

I'm actually surprised you don't have an engine code yet. The upstream and downstream O2 sensors/pyrometers usually will tell you if the exhaust mix is becoming lean. The cats are still doing their job of cleaning the up the excess unburnt fuel and carbon monoxide, though.

When you replace it, you can use a generic 2.25" inlet/outlet cat. Or, if you're savvy or a junkyard digger, grab a cat from another like truck/car.

I agree with the "CAT". My wife drives a 03 Aviator which has two converters (one on each side). The left one started making a similar noise described usually rattling on acceleration. I had it replaced at a local muffler shop and all is well.

 

[92danger]

Thanks guys for the good advice. Ill definitely check all that and being a 'pro' welder (12 years) and access to a shop, would it hurt gutting the cat and resetting the comp? Definitely wouldnt mind a lil more noise maybe some power too. BTW, new plugs, wires, icm, fuel pump, filter, filler neck, (other things but thats all that seems to apply to this problem) and it still 'bucks' on me atleast once a day. I only drive it maybe 50 miles a day tops... and also, my CEL has never come on. Theres something wrong with that im sure. Too bad its OBD1 and I need an analog multimeter to check anything from the under-hood receptacle

 

[huh?]

... this sounds to be like a bad catalytic converter. They can become clogged from wear and make that ting-ding-cack-ting sound in the exhaust.

like freedom5, i would agree with AgPete139.

a few years ago moms' sienna sucked oil through a valve seal and clogged up the catalytic converter. at its most extreme it sounded like she was dragging a muffler under the van.

it must be clogging up again because a midspeed/acceleration/uphill combination of conditions cause a rattling to present itself. the rattling can be described as "bb shot in a can", or the sound a terminally overheated engine gives out when the driver steps on the gas pedal.

edit= i use a blinker assembly i pulled from another vehicle to check the codes on my 87xlt. plug the wires where the probes from a vom are supposed to go and count the flashes

 

[AgPete139]

Thanks guys for the good advice. Ill definitely check all that and being a 'pro' welder (12 years) and access to a shop, would it hurt gutting the cat and resetting the comp? Definitely wouldnt mind a lil more noise maybe some power too. BTW, new plugs, wires, icm, fuel pump, filter, filler neck, (other things but thats all that seems to apply to this problem) and it still 'bucks' on me atleast once a day. I only drive it maybe 50 miles a day tops... and also, my CEL has never come on. Theres something wrong with that im sure. Too bad its OBD1 and I need an analog multimeter to check anything from the under-hood receptacle

Try the above first, and then we'll assess the rest of your problems if they still exist.

 

[92danger]

edit= i use a blinker assembly i pulled from another vehicle to check the codes on my 87xlt. plug the wires where the probes from a vom are supposed to go and count the flashes

Brilliant Idea. Ill try that much later tonight or tomorrow morning. But id still like to know if replacing the cat with a straight pipe would be detrimental at all

 

[Spott]

It won't hurt the truck, but it will make your emissions worse, and won't add any noticeable amount of power.

Removing the cat will make passing an emissions inspection impossible. It's also technically illegal.

 

[92danger]

Well we dont get tested here in alabama

 

[AgPete139]

Brilliant Idea. Ill try that much later tonight or tomorrow morning. But id still like to know if replacing the cat with a straight pipe would be detrimental at all

The blinker only applies if you have a Check Engine Light.

Did you come here wanting to find a proper solution, or the cheapest way to keep your truck running?

The catalytic converter allows the engine to run smoother, by letting it know if the fuel mixture needs to lean or enrich the mixture. Of course, this is usually with an OBDII, not a OBDI. With yours, it helps keep our air clean.

Just because it's not a law in Alabama does not mean that it isn't harmful to the environment as a whole. "My little truck doesn't make a difference." True, it's nearly negligible, but millions of others say that, too.

Yes, on distributor OBDI systems, you can get away running straight pipes (without cats or mufflers). If you want to gut out the cat, you can do that, too.

Your truck is actually considered a classic over 25 years anyways, couple with Alabama's lack of regulations.

You could run straight headers if you wanted to, but that doesn't necessarily mean it's the smartest idea.

It won't add hp or torque. It will actually decrease backpressure a small amount, marginally lessening torque. With other higher output engines, it affects exhaust valve longevity.

It won't hurt the truck, but it will make your emissions worse, and won't add any noticeable amount of power.

Removing the cat will make passing an emissions inspection impossible. It's also technically illegal.

Well we dont get tested here in alabama

Replied above for OP ----^

 

[AgPete139]

Now, on THAT note, I replace the cats because it's overall the "good" thing to do, environment-wise, law-wise, and driving-wise (it gets hella loud with straight-pipes).

On my '92 Mustang, I removed the smog recirculation pump, ran a shorter serpentine, deleted both the cats, deleted the EGR with a blockoff plate, and advanced my timing 7 degrees. HOWEVER, this was semi-justified for the sake of ACTUAL horsepower and torque, since the asthmatic 5.0L need to breathe better to unlock their potential. I still had mufflers though.


SECOND NOTE: If you're going to get all that welded on anyways, why not just spend the $80 to properly replace the cat? Straight pipes, welding, labor, new exhaust hangers, tail pipes, etc. can rack up to $80 anyways.