Clicking Fuel Injectors

BADs Crew · Post by **BADs Crew** » Wed Feb 28, 2007 3:42 pm

I noticed a few days ago that off and on I would hear a loud clicking noise from under the hood. First I thought I had a exhaust leak at the manifold then it sounded more like the AC compresor was turning on and off like every min and staying on for like 20 or 30 sec.

Today after my ride home from work I got out at the mail box and when walking back to the truck I heard the noise start. Its not there all the time so I popped the hood to catch it while it was making the sound.

Now I don't know a lot about the fuel injection system on our trucks but the sound is coming from a unit just behind the center of the intake manifold. This sound was never there before and the truck runs great, Anyone have any thoughts on this one?

crew cab sonoma · Post by **crew cab sonoma** » Mon Mar 05, 2007 8:07 am

the injectors on these engines are fairly well acoustically isolated inside the manifold.

what is common on these engines, is a slight ammount of valvetrain ticking.

not sure why, but it seems that alot of GM engines, most notably, the 3.8 Buicks, the 4.3 and LSx (GEN3) engines seen to have alot of minor vavletrain tick to them. perhaps it has something to do with the roller rockers, not certain about that.
seems to be harmless, though.

Jim · Post by **Jim** » Mon Mar 05, 2007 2:15 pm

crew cab sonoma wrote:the injectors on these engines are fairly well acoustically isolated inside the manifold.

what is common on these engines, is a slight ammount of valvetrain ticking.

not sure why, but it seems that alot of GM engines, most notably, the 3.8 Buicks, the 4.3 and LSx (GEN3) engines seen to have alot of minor vavletrain tick to them. perhaps it has something to do with the roller rockers, not certain about that.
seems to be harmless, though.

Could the noise be a little backlash in the ballance shaft?

Post by **HenryJ** » Mon Mar 05, 2007 4:23 pm

I have noticed that the crank case evacuation system and the EVAP purge solenoid make quite a bit of noise. If the throttle cable rests on the solenoid an annoying tapping noise will reverberate inside the cab.

BADs Crew · Post by **BADs Crew** » Tue Mar 06, 2007 2:10 am

Its going to be in the 50s this weekend so I will poke around under the hood then. Thanks for the input.

BADs Crew · Post by **BADs Crew** » Tue Mar 20, 2007 1:29 pm

OK today the dealer found the clicking noise. The bearing in the distributer was shot to the point that the rotor was hitting the cap. 90,000 miles and things are starting to wear out. Whats next?

04crewvt · Post by **04crewvt** » Wed Mar 21, 2007 1:40 am

What you are experiencing is what I have gone through with every GM vehicle I have owned. I just expect thing to start wearing out quickly when the odometer reaches 80-90k. You put a bunch of money in them then and then they seem to be fairly happy for the next 80k but they do cost more to keep running each year after that 80k mark.