Damn engine knock (with sound clip)

[DBurkhard]

I think I may have this same injector knock as several others that have posted recently. I have 20K miles on the truck and noticed the knock a couple weeks ago during a drive from Southern CA to Eden UT. When I idled up to the pump after being on the road for 5-6 hours, the truck sounded kinda sick. I have the same symptoms as others, I only hear the knocking when the transmission is in drive and engine idling. The noise subsides at around 1100-1200 rpms.



I made a recording of the knocking (click the URL below). The first 8 seconds are simply idling in neutral. The remaining time is with the transmission in drive with the brake applied.



http://mysite.verizon.net/res1h7d2/



Guess I'll be taking a trip to the dealer. Everyone at work that has ridden with me the last couple of days has said "what is the matter with your truck? mad:

 

[Jeff_K]

Can't access your sound clip. Says website is locked.

 

[swexlin]

I just listened to your clip. Sounds like my former 7. 3 PSD with the famous "idle knock" (mine had a mild case of it).



What is the build date of your engine? Please keep us posted what you find out.

 

[nwjetboat]

Sounds EXACTLY like mine did. :{

 

[Prairie Dog]

Jeeez I had to stop listening - I just couldn't take it any more. Thats definitely bad.

 

[Johnstra]

Yep, that sounds exactly like mine.

 

[Jim Fulmer]

It sounds more like a valve not seating to me but I am going off of a clip. Your truck is in Warantee mine isn't, if it were mine something would be coming off or out!



Jim

 

[nickleinonen]

um, that sounds fine to me... the engine loads up when the transmission is put into gear and the ecm adds more fuel to maintain the 750rpm idle. mine makes a similar injector knock when i start off in 2nd and bog the engine down to like 500rpm and the ecm fuels to try to maintain 750rpm...



unless i am missing something, there isn't anything wrong there



[and i did listen to it many times for like 10 min straight to try and hear everything. i can hear your accessory belt make a small chirp in the first few seconds, and i can hear a small metalic ting sound half way through when the transmission is in gear]

 

[CumminsBu]

um, that sounds fine to me... the engine loads up when the transmission is put into gear and the ecm adds more fuel to maintain the 750rpm idle. mine makes a similar injector knock when i start off in 2nd and bog the engine down to like 500rpm and the ecm fuels to try to maintain 750rpm...



unless i am missing something, there isn't anything wrong there



[and i did listen to it many times for like 10 min straight to try and hear everything. i can hear your accessory belt make a small chirp in the first few seconds, and i can hear a small metalic ting sound half way through when the transmission is in gear]

That sounds fine to me also. I think the sound has something to do with the pilot injection. My . 02

 

[sbrennan007]

I have noticed the same thing with mine. Again, only when stopped in drive at idle. Put it in park and all gone again...



Is this an issue? Other than this (and it's not 100% consistant as it sometimes does it and then sometimes doesn't) the truck runs great.

 

[RKerner]

Sounds like mine, except mine is louder in neutral or park. It's mostly been that way since new (3K miles now) Had a buddy comment that his 555 is quieter than mine. If I get a chance, I'll be stopping by the dealer Thursday for a listen.

 

[txhawg]

Sounds like mine since new. I didn't know this was a problem. Now you hav me wondering

 

[nwjetboat]

I think the 600's are noisier at idle that the 555's. I can't say for sure, thought it was posted here when the 600's first came out. Anyway, that sound clip is not what a 555 sounds like when running normal. That hammer on metal sound is probably one injector not firing the pilot shot.

 

[John - K5AWO]

Tappet/Valve knock

To me, that is a lifter/rocker arm knock.



Back the nut off on a Chevy 350 rocker arm and get the lifter loose, sounds the same.



Have you tried to use a stethoscope on it to narrow down where it is coming from?

 

[DBurkhard]

Half the people here say the truck sound normal and the other half say it sounds like crap... ... .



I took the truck in this morning and the service writer said "sounds like a diesel to me". I'll have to wait and see what the mechanic has to say about it.



The engine NEVER knocked like this before and sounded exactly the same whether in park or loaded with the transmission in drive.



Dan

 

[rbattelle]

My knock sounds exactly like that. But since I have a manual, it only knocks when taking off from a start from idle to around 1100 RPM. It comes and goes (at the moment, for example, there is no knock at all): 2 months of really bad knocking followed by about 3 weeks of absolutely no knock at all. I have 30000 miles now.

 

[Sledneck]

My 04 6spd doesnt do it, but. . Just today I stopped at a traffic light next to a 3rd generation 2500 QC 4x4 auto, And I said to myself. . damm that doesn't sound good. I hope mine doesnt develope that noise. I just turned 10K on the clock, and I am getting 17MPG mixed driving.

 

[BHaner]

My 03 was making that sound whenever I started in 2nd. Started about a month ago. Then as we got back from Denver last week, I started running on 5 cylinders! :--)



Took it to the dealer and they found that #3 injector was junk. All better now.

 

[DBurkhard]

Just got a call from the service advisor who took a ride with the mechanic. They acknowledged there is definitely something wrong. They indicated they are working with engineering to troubleshoot the issue.



I'll let you know more as I get the details.



Dan

 

[sag2]

It does not sound that different than mine. Not saying there might not be something up, but it sounds like ignition noise to me. I certainly would not get all worked up about it. It can't hurt anything even if it is making noise. Just listen to a 1st or 2nd gen!