back fire?

[bheiting]

Recently I started my 07 5. 9 2500 QC and heard a bang. It was like a back fire. I held my breath waiting for the worst, but it warmed up as usual and

nothing unusual happened. It happened again about three weeks later, but

this time I was about six blocks from home. I will be bringing it to the

dealer, but has anyone had a similar situation. The truck only has 11,000 mi.

It's been babied since new. I have been smelling fuel more lately after its

warmed up, but can't find the source. Any suggestions would be appreceated.

 

[BHaner]

Check your oil... See if the oil level is higher than normal.



You may have an injector leaking...

 

[bheiting]

Oil level is fine and doesn't smell like fuel.

Thanks

 

[cerberusiam]

This happens, infrequently mind you, and it seems to have something to do with the grid heaters and a cold start. Several have reported this issue but I have not heard of a resolution.



Hasn't seemed to be a problem just a little disconcerting at times.

 

[SShafranko]

It's been babied since new.



Theres the problem.

 

[bheiting]

This happens, infrequently mind you, and it seems to have something to do with the grid heaters and a cold start. Several have reported this issue but I have not heard of a resolution.



Hasn't seemed to be a problem just a little disconcerting at times.

Disconcerting is right!! The first thing you think of is a loose chunk of metal

in the works somewhere. Thanks for your time.



This forum is the greatest thing since sliced bread.

 

[rbattelle]

Does this "bang" happen to correspond with changing the heater controls or engaging/disengaging the A/C compressor?

Ryan

 

[sag2]

Most likely the A/C compressor starting, especially if it had been sitting for more than a day.

 

[bheiting]

Does this "bang" happen to correspond with changing the heater controls or engaging/disengaging the A/C compressor?

Ryan

Hey Ryan and sag2,
At first I didn't think the AC clutch had anything to do with it, but after further searches, others have also noticed
a fairly loud noise when the AC builds up pressure. I'll try to make sure the defrost is off when I start the
truck and see if it continues. Thanks for your responses.

 

[EDankievitch]

I've had the same thing if the Ac or the defroter is on the compressor slams real hard after the engin starts. I checked the system pressure and found it to be very low added some refridgerant and made things better and the Ac blew colder air.....