I did not want to leave all of the turbo experience on the 700 forum out of the loop on this so I have posted to both the 700 and 900 with it...

1994 944T 176,000

Current project car that I thought was ready to declare “done” other than chasing an air conditioning problem.

Traveling today at interstate speed when out of no where a terrible noise from under the hood. My first thought was the sound of a fan blade coming into contact with the radiator, or a water pump whose bearings were breaking up. Of course, this car has no mechanical fan and the water pump is brand new Hepu.

Pulled over and lifted the hood to find nothing to account for the noise which was still very loud at idle. I got off the interstate and slowly made my way to my destination about a mile away. The noise was loud enough to attract the attention of people on the street.

After my meeting I started the car and the noise was still evident but it was not affecting the drivability of the car. I decided to make my way home on secondary roads. About 10 miles into the drive there was a final “ping” and all was quiet.

Once I was within half a mile of home I accelerated enough to call for boost and the car responded. Near the limit of boost the noise started to come on again but backing off of the throttle caused it to go away.

I have removed the turbo hoses and had a look/feel. The turbine rotates freely. I have limited experience with turbochargers but the lateral play does not seem excessive. The car does not smoke and the hoses are as oil free as I have ever seen. The car did not display signs of love and good maintenance when I purchased it, nor do I have any records.

Anybody have any ideas of other things to look into? Is this noise description familiar to anyone? Am I looking at a turbo replacement in this cars immediate future?

If the blades have contacted the housing does that rule out a “simple” cartridge replacement?

Thanks for you input.