Here I am

Slapping noise coming out exhaust

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

Manual Swap Confusion

Possible manual transmission alternative

Hey all!

New here & trying to narrow down an issue with my 2003 CR. Any info is greatly appreciated! Rather loud slap/clap noise coming out the tail pipe; no exhaust "restrictions". Can't hear anything odd under hood. Truck has 317k on the clock with no major engine work done except injectors 5yrs ago. Slightly hard to start but, runs/idles normally. I'm leaning towards a dropped valve seat but, please correct me if I'm looking in the wrong direction!

Here's what I've trouble shooted so far: Had a friend come over and using his Snap-On scanner, shut down each injector to rule them out. Doesn't seem to be an injector issue. Pulled valve cover and checked valve lash; it was past due honestly. Cylinder 5 had WAY too much play on the exhaust valves. I probably could've put 3 .020 thousands shims in... yikes! Pulled off rocker/bridge to make sure valve stems and keepers/locks were still in place & all looked good. Push rods are nice and straight. Pulled injector, inspected and all looks well. Decided to put it back together and hoped maybe it was just the one loose exhaust valve but, nope. Same noise. Waiting on him to come back with tools for a compression test!

Here's exactly how it played out:
Was coming down a mountain doing about 55 in 4th and engaged my exhaust brake so I wouldn't have to shift into 3rd. After a few seconds, an extra noise came into play, kind of a puff puff/tick tick sound. Wasn't super loud but, noticeable. Got back to my office, shut truck down and everything seemed/sounded normal.

After 2hrs, it was time to go home. Started truck and immediately there was a SLAP SLAP SLAP coming out the exhaust. Had a very tight sound/rhythm to it. Truck has no exhaust "restriction" devices. My first thought was that maybe an injector was missing. Shut truck back down After doing some quick deductions, couldn't figure it out. Home was only a couple miles away and I was exhausted so, drove it. Oddly, the truck ran fine when I got RPM's over 1,000. You could still slightly hear something but, it was almost inaudible. No issues with performance but, I also drove it lightly. Parked it when I got home and that's where it's been while I've been diagnosing.
 
Thanks for the reply Ozy! I honestly hadn't thought of that! Went out and double checked but, alas, return spring is good.

Frequency is about twice a second

Can't be an Injector then.
At 750rpm/m idle, we have 12.5rpm/s or 6.25 injection events each second.
So each cylinder fires once every second.

I think more about it.

Do you have an infrared thermometer? I'd like to know if there is one runner hotter then the other five.

Twice a second guides me to an exhaust valve problem.
As a piston comes up twice a second, once compressing/firing, once exchange.

I guess you checked the valve springs too when you were in there, that there isn't a broken one in.
 
Back
Top