1983 Cali 300SD, Brass fitting , induction side of turbo..... - PeachParts Mercedes-Benz Forum

Chadahar · #1 06-29-2008, 02:43 PM

....looks like a water connection, has the remains of a rubber hose and speed clamp on it. Cannot see where it was connected. Does this need to be connected. To where? Found it when chasing down the "Wobbly" Air cleaner mountings.

Yep I need a new mount and 3 new rubber mountings too. Did the backup threaded hole on the front mounting and moved the outside one back also so at least the broken rubber mount can ride on it's bottom plate.

Turbo intake seal had come off. Now everything is tight(except two air cleaner rubber mounts. Air filter amazingly clean after last change by PO in March. (not driven but 200 miles or so before I got it last Sat.).

I also changed out the Crusie actuator that PO's Indy said the car needs in later paperwork that came with car. Will check this out later today. Cleaned the connector for the actuator and the tach sensor as they were not clean.

300SD81 · #2 06-29-2008, 02:46 PM

I do not believe there are any brass fittings on the turbo stock. It may be a boost gauge connection or a water injection fitting.

Chadahar · #3 06-30-2008, 12:30 AM

Anyone have a guess what this fitting is/was. It's in the delivery tube casting between the turbo body and the intake. 90 degree Elbow in brass, open to atmosphere right now.

bgkast · #4 06-30-2008, 12:38 AM

That is the pressure signal nipple. It should have a hose that runs to the wastegate on it. Your car has likely been over-boosting with no wastegate operation.

Chadahar · #5 06-30-2008, 09:03 AM

OK I'll track that down today. Hopefully the other part of the hose is intact and i can find it and where it should go.

charmalu · #6 06-30-2008, 12:10 PM

go into buy parts and under air intake at the bottom is waste gate hose.
this way you will have a nice pretty new one

Charlie

Chadahar · #7 06-30-2008, 02:14 PM

Thanks Bgkast, and Charmalu,
I looked in there this morning and found the tube that was disconnected (broken off at forward end at fitting. Haven't the foggiest how long it's been broken but some time for sure. Not a fresh break.
I trimmed a bit off both ends of the tube due to age and break. There was just enough to hook back up and reinstall the air intake to the the turbo. I will get a new hose asap.
I have not driven the car since I fixed it.

Has this done irreparable damage to the car?

It has no smoke on startup and none I can see driving, but it certainly acted like it didn't have a lot of power. It starts really easily and seems to run good. will run 70 mph ,easily and effortlessly, but takes a while to get there. More of a tortoise than a hare, but that is expected. Getting very good MPG so far.

Also changed out the broken hood star ass'y. I studied the old locking setup and realized that one could grasp the locking ass'y and twist the one way it'll twist. I clamped vise grips gently on the round base(surrounding pin through spring), and gently pulled down and twisted the feet onto the star base casting, and popped the old one out of the hole. Popped the new assy in, pulled th locking base down and twisted the feet to catch the hood metal and VOILA! I was done in a minute.

bgkast · #8 06-30-2008, 03:27 PM

If your over-boost valve was working correctly it should have been cutting the boost signal to the ALDA giving you less fuel and therefore less power. If the over-boost valve has been bypassed then you should have had close to normal power levels, but your turbo was being overworked and putting out more heat than it should. Likely there was no damage.

Chadahar · #9 06-30-2008, 04:07 PM

It wasn't deliberately bypassed, the hose broke on the upper end at the brass fitting and there was a hole in the bottom of the hose at the fitting there. I trimmed both ends and reinstalled the hose. Drove to the post office and really could not tell much of a difference, but I'm so new to the diesel that I probably could not tell. I may take it out on the freeway this afternoon and drive her up a bit.