This is on my dad's '99.

He is around 350k and has been only getting 12-14 mpg's since early summer. He has always got 14-16 mpg. He had the injectors from my brothers 01 installed at the begining of summer but that didn't help. He called me today and said his turbo fins are rough as well as the edges and think's his turbo is worn out and is causing his poor mileage. I am sure it could use a rebuilding.
I was thinking it could be the map sensor. Any suggestions?

Don't tell me winter fuel .

 

TURBO FINS WORN OUT
If there was enough airborne crud to errode the fins then there must have been enough to screw up the pistons, rings and valves. personally I use an air filter
seriously if anything is making you lose compression you will lose power and milage.

 

If turbo compressor blades are anything like compressor blades in turbine engines, then any damage to the leading edge will change the effectiveness of the airfoil and also induce eddies on the back side of the blades thus causing a spoiling effect on the airflow. This could possibly reduce compression and increase drag on the turbo at the same time. There may not be crud in the air but air is made up of matter and there's enough of it to wear the leading edges of the turbo blades and no other parts simply because of the speed of the blades in relation to the air passing by. Does anyone know for sure if they are airfoils or just angled blades in a turbo?

 

I had my turbo rebuilt earlier this year. It had a cracked fin and the edges were rough. The difference in the fins was very noticeable when I got it back. I think he is going to get it rebuilt. I have never got the mileage he see's but I have a heavy foot.

 

I believe they are just angled blades.....i'll get a pic of a spare compressor wheel i have laying around.

 

All i had was my phone camera but you can still see. They are a hair deformed from contact with turbine housing , this is from the first time my turbo was shelled.

 

Sweeeet rig, hoss