I have a 1998 Dodge cummins turbo Diesel. The boost guage will only read 12 lbs max and then it starts to whistle. I have an AEM cold air intake on it and changed the stock muffler to a 21 inch strait through muffler. The engine runs fine, just can't get more boost and stop the noise from the guage. I also put a new guage on it thinking that was the problem. Does anyone know what the problem is?

 

leak

 

Could very well be a leak. Check all your boots and clamps real close

 

Its probaly the boots coming to and from the inter cooler

 

Check the intake horn as well. Mine's leaked there before.

 

welcome to diesel bombers and you have a leak somewhere i would double check everything that has been mentioned

 

You should also check the tube under the turbo.I found the negative battery cable rubbed a small hole in the tube under my turbo causing a whistle when the turbo builds boost pressure.

 

Thanks guys for your replies to my problem of an air leak. If there was a bolder within 100 miles in the rosd I probably would have run in to it. The upper hose on the drivers side had dropped down till there was an air gap on the back side of the hose. Fixed it and noise went away and with out a load behind it I have 20 psi on the boost guage. Thanks again :

 

Good to hear it's fixed