Injector Tick?

[BrianJ]

So I was at the dealer service center this morning having a stock belt put on to bypass the jacobs vacuum pump that is failing (making a lot of racket). Once the noise of the vacuum pump was out of the way a pretty good tick was noticed. The service writer gave a listen and thought for sure it's one or more injectors. There is also a strong vibration on the No. 1 injector/fuel tube and a less but noticible vibration on the No. 4 injector/fuel tube. Service writer is thinking a good likelyhood that No's 1 & 4 injectors are bad.



Do those of you in the know concur with the likelyhood that the symtoms point to one or more injectors? The truck is still under the cummins 7yr/100k warranty, so I have an appointment set for Monday for them to run their diagnostics. Is there any risk driving it like it is for another 200 or so miles between now and the time it goes in? My work commute is short, but I have plans to head to the mountains this weekend (about 60 miles each way). I sample every oil change, and while the last one was about 5,000 miles ago, there were no signs of fuel, and the current oil level is not increasing. So at least it doesn't look like fuel is leaking down.



Any input on the thought of it being injectors or something else, and the risk of driving it before it goes into the shop would be great.

 

[JJPage]

The tick could be the injector line hold down clamp, the little blue plastic clamps, around each individual injector line. Try snugging them up, see if the tick diminishes.



Let the dealer run their diagnostics, shouldn't hurt anything.



After checking the hold down clamps, I would drive it.

 

[rscurtis]

I believe that the pulse on # 1 line is normal. My '03 has a slight tick at times, has had it for many thousands of miles. It is more pronounced from outside the truck, when you open the hood and listen to the engine, it sounds fine. When the engine is fully warm, it goes away.

 

[DogramTD]

The pulse is normal but much more pronounced when the clamp comes loose which is very common. This happened to me as well as many other members here. You may be able to save yourself some hassle from by checking the snugness on those clamps.

 

[EDankievitch]

I found a cracked nozzle on my cylinder number 4 , I wonder if it was the cause a few years back for my fuel line to cylinder number 4 cracking???? The support clamp was tight at the time of the failure...

 

[BrianJ]

Thanks for the feedback so far. I didn't have a chance to check the clamps last night, hopefully tonight. Mine is the opposite of what rscurtis is describing however, it is definately more noticeable with the hood up. It can be hard to hear in the cab. I am not sure "tick" is the correct word to describe it either, it is almost more like a pulsating, very short "whoose". Standing back I would swear it sounds more like it would be a noise coming from the vacuum pump, but that is bypassed and when up close you can tell the noise isn't coming from the pump. I didn't really hear it as loud this morning with a cold engine (not sure I would notice it if I wasn't listening for it), but it was real noticable last night when it was fully warmed up.



Oh well, I guess I will find out Monday. Diagnostics will cost me $150 if they don't find anything wrong (i. e. nothing to cover under warranty), otherwise it will just be the $100 deductible for any warranty work. Service writer was quite adamant something was wrong, and seemed pretty confident it was injector related.

 

[BrianJ]

The tick could be the injector line hold down clamp, the little blue plastic clamps, around each individual injector line. Try snugging them up, see if the tick diminishes.

JJPage hit the nail on the head. It was the No. 4 injector hold down clamp. They still ran their injector diagnostics, and while not optimum (in the techs words), it was within Dodge specs so they couldn't do warranty replacement. I have engine warranty until next June, so the tech and service writer suggested I come back in for testing before it expires. They didn't charge me for the injector diagnostics, just had to pay 1/2hr labor for tightening down the clamp(s).

 

[HBarlow]

The injector tick is fairly common. I don't know if it is a sign of anything or just normal. I used to hear it intermittently on my '06 and heard it recently on my '08.