Hi All,

I just rebuilt the turbo in my 1985 300SD and I'm seeing low boost now. It peaks at about 8 psi. (I'm sniffing the boost line at the ALDA with a boost/vacuum gauge.) It spools up right where it should; just a hair under 2,500RPM's but it also sounds like a police siren instead of the jet engine that it used to be. The shop that got the parts for me also checked the balance and declared it good. The rebuild kit included new thrust washers/seals, bearings, and new nuts & bolts. I did not touch the wastegate.

Per Click & Clack, they say if you hear a police chase under your hood, its the sound of a turbo headed for the recycling bin. "The next sound you'll hear is the whooshing of money leaving your wallet..."

My only suspicion at this time is the nut that holds the impeller on the shaft - the guys at the shop said just get it nice and tight, maybe 25 ft-lbs. I got it to about 22 and decided that the little nut had seen quite enough thank-you. I suspect I may have over tightened it which does not allow the turbo enough play to spin up properly - am I off in the weeds? What else could it be?

Thanks!

Travis