a nice leak OM617 - Page 2 - PeachParts Mercedes-Benz Forum

mikeyfev1 · #16 07-16-2013, 08:20 PM

From what I see, your wastegate and ARV control connection lines are plugged.

Photo1 identifies the parts.

Photo2 shows the normal routing of the wastegate line. It runs from a tap (a right-angle brass tap) connecting pressurized turbo air back to the wastegate. The wastegate is calibrated so that if the turbo creates air pressure that is too high, the high pressure air opens the wastegate. I don't see either the hose or the tap on your photo.

ROLLGUY · #17 07-16-2013, 09:51 PM

EGR plated off as well.

bricktron · #18 07-16-2013, 11:50 PM

very helpful, all, thanks for the pics.

when i got this engine the wastegate and ARV were connected by a short hose. i thought shutting these ports up was part of disabling the EGR & ARV systems.

where is the other end of the wastegate control hose, the brass angle tap mentioned above, supposed to be installed - on the intake manifold?

as far as the leak, it sounds like i need to, at least, rebuild the wastegate, and at most, the whole turbocharger.

mikeyfev1 · #19 07-16-2013, 11:56 PM

I have my turbo apart on the bench right now; recently posted some pictures and questions about the ARV. You can easily see the brass barb for the wastegate hose in the pictures.

bricktron · #20 07-17-2013, 01:21 AM

mike, thanks for those mockups, i think i get it now. i don't have the brass angle plug in that hole, i have a headless slotted screw (i had previously assumed this was the wastegate adjustment, which it is clearly not).

is the pressure at this point different from that sampled at the other end of the manifold?

DeliveryValve · #21 07-17-2013, 01:29 AM

Oh, I missed that wastegate hose not hooked up. Good catch mikey.

Pressure should be the same, but you will get a lag in signal.

.

mikeyfev1 · #22 07-17-2013, 10:15 AM

Quote:

Originally Posted by bricktron

mike, thanks for those mockups, i think i get it now. i don't have the brass angle plug in that hole, i have a headless slotted screw (i had previously assumed this was the wastegate adjustment, which it is clearly not).

is the pressure at this point different from that sampled at the other end of the manifold?

Sounds like somebody just removed/plugged everything on your turbo.

So, from what I've seen:

Your EGR has been removed and a plate installed to block-off the port into the intake manifold. The vacuum control line for the EGR is not visible in your photos; if the modifier was consistent then the vacuum line was removed and plugged at its source. Strictly speaking this is not a turbo issue, but it has been pointed out as a modification which is visible in your photos.
Your ARV control line has been removed and the tap plugged. Same story for this vacuum control line.
You wastegate line has been removed and plugged.

I have made the first two modifications to my 1985 300D KaliKar. These changes do not affect driveability and tend to fall under the "I don't want that pollution-control power-robbing cr*p on my car" category. You might get an undetectable amount of performance boost from these changes.

It appears that most members on this forum believe that having the wastegate line in place is a good thing; however, that completely depends on having a functional non-leaking wastegate. If the wastegate mechanism is opening too easily (or leaking), it will be to a large degree negating the entire reason for having a turbo.

If you had a malfunctioning wastegate there are only two real options: change the wastegate internals (I've never heard of anyone doing this) or remove the wastegate line and plug the ends.

This means that if you wanted to reconnect the wastegate line you would be wise to verify the operation of the wastegate first. One crude method is to blow low-pressure air (in the 8-10psi range; DO NOT exceed 10psi) into the wastegate port and listen for an audible "clunk" when you stop the air. Use care to not blow air at too high a pressure; you can blow out the wastegate diaphragm during testing. I'm sure other methods can be found on this site.

vstech · #23 07-17-2013, 11:30 AM

back to the oil drops on your fender... look at the spray pattern on your hood... my bet is something is spraying oil onto the hood, and it's dripping on your fender... find out how it's getting to the hood...

bricktron · #24 07-17-2013, 01:07 PM

vstech, i haven't found any oil on the hood pad. that was one of my first thoughts too. the material may be somewhat resistant, but it would be obvious if it had had oil sprayed onto it, i hope.

the previously wiped-down wastegate gets oily again when i drive. it's still my prime suspect.

mike, the wastegate hose sounds like a prudent thing to have. i'm surprised how similar it sounds to the pressure-activated switchover valve between the manifold and the ALDA. maybe they do not activate at the same pressure, but it sounds like when boost gets too high, both the fuel is cut and the extra pressure is vented out of the wastegate. i will see if i can get my hands on one of those angle plugs at the junkyard.

thanks all for the advice!