Lack of power, how to test turbo? - Page 2 - PeachParts Mercedes-Benz Forum

#16 06-19-2008, 04:05 PM

Quote:

Originally Posted by JHZR2

Supposedly the wastegate springs get tired and soft.

People keep saying that yet every 300D/CD/TD/SD tested with a stock wastegate sits around 9psi no matter the age, mileage or KKK/Garrett.

1983/300CD · #17 06-19-2008, 04:54 PM

True, and I adjusted both my T3 and KKK to 12 without problems.
(Don't have an EGT gauge, though.)

jugganaut · #18 06-22-2008, 02:47 PM

I've bypassed the tank and am using a small receptacle for a temporary tank. I also just cleaned out the lines, bolts and banjos on the ALDA, but still no change. When I rev it in park, engine sounds great and strong. When I drive it, its creeping off the line, but the higher RPMs the more power I get. When I floored it, some black smoke came out but not that much and after doing that 6 times no more smoke... Any other ideas? I'll post pics later....

JHZR2 · #19 06-22-2008, 09:28 PM

remember that revving in park tells you nothing about your turbo's health - you need to be under load to generate boost.

Put a gauge on it and report back - it will tell us a lot...

JMH

JHZR2 · #20 06-22-2008, 09:43 PM

Quote:

Originally Posted by ForcedInduction

People keep saying that yet every 300D/CD/TD/SD tested with a stock wastegate sits around 9psi no matter the age, mileage or KKK/Garrett.

Well as of 2003 or 4, when everyone was slapping dawes (sp?) boost controllers on, some were reporting the "softening". My turbo on my now wrecked 83 gave about 9psi before the controller, so I think you are correct.

Dawes boost controller installation advice

JMH

jugganaut · #21 06-26-2008, 09:49 AM

Quote:

Originally Posted by JHZR2

I'd clean the banjo bolt and then buy a cheap boost gauge to plumb in at the boost control on the firewall (the line from the banjo bolt goes there) with a three-way vacuum connector.

You need to drive the car, you wont get boost revving it in neutral... See what you get. Optimum is about 10-12, I dont exactly recall the best value.

JMH

Where can I get a "boost gauge" and do I need to plumb in fitting at the line that goes to the manifold, or the line that goes to the ALDA?

winmutt · #22 06-26-2008, 10:12 AM

Ideally on the ALDA side. Please make sure its a good seal, proper pressure to the ALDA is very important.