My husband has an 05 duramax. It has been loosing power once in a while. it does not stall all of the way but sounds rough and looses power. Could this be bacteria in the fuel. We drained the water vavle and that seemed to help but it did it again in about 30 miles. This problem seems to be happening more often so we thought we would get some help solving the problem.
The computer is not coming up with a code either. Thanks for any suggestions, Megan

Could be a bad batch of fuel clogging you filter.

First, I'd change the fuel filter, and see if that helps. If it does, but only for a short while, your tank may have water or crud in it. If you drain the water, run for a while, and get more water, then the tank needs flushing.

I hadn't heard of bacteria, but if you're running bio diesel it can gel up.

Second - check the air filter. If you're running a non-stock oil soaked air filter (K&D) - the MAF sensor can get dirty.

Step three - take it to a dealer and have them check for codes which could indicate failed injector connectors

replace the fuel filter than let us know... also ck air filter you need air as much as you need fuel.

first let the tank go almost empty, add fuel from a different station and then immediatly change the filter.so this way you have good fuel going through known good fuel filter. see if this works out. if you had water or the station has dirty tanks bacteria could form. so it's not out of the question.

Thanks guys we will try these and see what happens, Megan

Hi Megan:

:welcome2: to you and your husband!

I agree, get rid of the existing fuel, change the fuel filter and obtain new fuel from a reliable source.

You may wish to add a diesel fuel additive / fuel injector cleaner to clean-up any residual water or crud in the fuel system; ie: FTTP or Stanadyne. Both are available from supporting vendors; Stanadyne is also available at NAPA. :)