What does a failing turbo feel like? 300SD CA model.
 

Posted a ? about/maybe a blocked oxy/cat on my 617 but I'm thinking it might be the turbo/wastegate.

What i use to feel, 3 weeks ago:1985 300SD 617 ca model, new oil, new trans thats great, perfect shifting and holds and pulls at the 'big hill' past 3000 rpm when the 4/3 down shift happens. Oil pressure guage(dummy) reads 3 and right at 2 at idle.

What I feel now: Loss of power and weird surging/pulsing going up hill. Only problem is going up a steep hill and third kicks in and rpm/power drops and keeps dropping till i reach the top. Third gear is lagging on highway 4 to 3 down shift power too. RPM 3000- 4100 till i let 4th kick in. No other problems at any other speed. Totally different than before.

Now, it could be the waste gate or boost?

thanks for any info you can give me or a general direction.

Start with ALDA.

Sounds like plugged fuel filters to me.

Ya now that I reread it. New filters!

Ive blown lots of turbos (not on a Mercedes, but anyways) usually when a turbo is blown you will get quit a bit of white smoke. Ive never seen a turbo just simply seize, they all get excessive shaft play which ruins the seals, and then start blowing smoke.

Filter. I'll check and see. THAT sounds like it could be it. When i need the gas the most, its not there.


Gee....restrictive fuel. Maybe thats why i'm getting 45 mpg:rolleyes:!

45MPG ??? did you buy it off E-Bay :confused:.

Like 12MPGHWY, said ,"lots of white smoke". I blew a turbo on a dump truck. I was hauling a load of hot asphalt from Redwood City, Ca. up hwy 84, then on to 35 north. the whole way is a really good climb especially a spot on 35 it really climbs. the truck was an automatic with a poor trans cooler, so this thing was always running hot. the truck had about 140000 miles, plus this day was around 100 deg.

I heard this pop sound, check the gauges, all fine. but when I looked in the door mirror,all I could see was white, never seen so much smoke. must hav looked like one of the air planes at the air show.

I pulled over, the eng. died, and I could hear a crackling sound under the hood. opened the hood and and a ball flames shot up out of the turbo. I quickly died down, but the turbo was glowing hot along with the manifold and the down pipe. plus there was a large hole in the exhaust side of the turbo.

So I guess the seal was leaking oil, it got hotter and hotter. Then it was down hill from there.

Turbos last a long time, even with abuse as this truck always got with multiple drivers. and this was the original turbo.
let the engine idle a minute or two to let the turbo cool down and to stableize the heat in the engine. this is if you have been pushing hard on the freeway, climbing a hill etc... most people don`t.

running w/o an air cleaner sucking up debris, birds, etc... will do them in real fast plus a loss of oil.

charlie

sounds like you are not getting enough fuel. probably filters, but check everything.
check all the vacuum lines, especially the Banjo bolt and the line going to the ALDA. I had a similar situation and the rubber line going to the ALDA had a small crack in it. doesn't give enough fuel under boost.

Did you get this problem solved?
 

I have been experienceing the exact same problem in my 1979 300SD. Not only the mysterious loss of power and switching back and forth between 4/3 on a hill, but also 1-second on/1-second off pulsing and surging of acceleration when going 70 MPH on the freeway.