Cummins intake issue

[Ryan_V]

For the last few days there is a grinding from the air intake when I first accelerate. I let off and go and it seems fine. Looked at the mass air flow indicator and it was in the red. I reset it today and did some driving and it is still fine. I blew out the air filter and put it back on. Drove a while more. After some driving and a couple stops and re starts, the check engine light came on. Any ideas? I should also mention the filter didn't seen too dirty, it's a k&n filter on a cold air intake, and there is only about 15-20k on the filter.

[JOHNBIGDOG]

Your "mass air flow meter" look like this?

If it is, this is called an filter minder, it gets sucked in as the amount of vacuum is increased in the intake system. If this is getting sucked in to the red your air filter is not able to flow enough air that your engine requires to operate properly. I would advise against using a K&N filter as they filter less to flow more and can lead to a dusted turbo. I would suggest to replacing it with the factory air intake system.

[Ryan_V]

Yes, sorry I had the part name wrong. But since resetting it, I've driven 50 miles and it is still at the top. What about the "grinding noise" coming from behind that meter on the intake?

[JOHNBIGDOG]

Well I am a ford guy, not a cummins guy, but have you noticed a decrease in performance? The only thing that's behind the intake is a turbo...? that could make your terrible noise. Take your intake off and take a look at your compressor wheel, fins should look strait, and close to the inlet housing.

DO THIS WITH THE ENGINE OFF FOR THE LOVE OF God, please, and no fingers in the turbo while its moving.

Really its hard to diagnose noise concerns, at least for me, over the internet. I would recommend bringing it in to get it looked at before something goes terribly wrong, possibly.

[Ryan_V]

Turbo was dirty and they cleaned it and reset the emissions. What gets me is how could the turbo be that gummed up? Truck only has 31k on it. This was a warranty repair, but I don't want to have to clean the turbo every 30k! The grinding was the actuator trying to go on the turbo. Should be good to go, guess I better stand on it once in a while to clear her out!

[JOHNBIGDOG]

I am going to assume here, as I am more familiar with Fords, But I bet that has a Variable Geometry Turbo (VGT.) In the Turbine side (exhaust) there are small vanes that move to control boost. These vanes get gummed up with Coak (sp?), diesel exhaust crud, and cause these vanes to stick, also the turbo can rust up from infrequent use.

As you didn't post a Year, Make, Model, Engine I can only assume this from my 6.0L ford experience.

If you EVER have questions about your truck, ask the service writers to talk to the tech that worked on your truck. The more you are informed the better, and it may prevent a future repeat repair.

[Valv]

Ryan, the turbo got gummed up by the K&N oil on the filter. I would ditch it for a AFE or even a stock air box with a good quality filter.

There's been a lot of animated discussion if K&N (oil impregnated filters) are good or not, each has it's own opinion.

I rather skip the whole debate and get something that is proven to work altogether. I had many Dodges w. Cummins throughout the years up to 600hp, and never felt the stock air box was a restriction, backed up by adequate gauges.

[Ryan_V]

Interesting, thanks valv! Something to think about.