Hey guys-

Been struggling off/on with this for a few weeks now. I can't seem to get started on the retaining spring on the wastegate cover. The end of the tab is in the 12-o'clock position and it's difficult to see and get access. Been trying with mechanic's picks and PB Blaster, getting nowhere!

Any pointers?

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Rob
1979 300SD W116

Get one corner out, put your pick under the exposed corner and run it around.

Yeah, it's the "getting the corner out" that I can't seem to do!

I've been pulling the air cleaner housing (and u-tube), removing the wastegate hose for better access. Maybe I need to pull the alternator so I have some more room in there? Argh.

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Rob
1979 300SD W116

At the end of the spring is a flat edge. Get your pick under that then move down and pull out. Run your pick around the inside edge, you should come across it.

Thanks Lance. It's more of a finesse move than I had thought. Did it with one of my picks. You pull gently down just to hook the tab, then pull out (towards the front of the car). That's what I was missing before.

Pulled the cover and a couple teaspoons of oil dribbled out, just as I have read.

The threaded rod on this one has a 13mm hex nut locking against a 16mm hex nut. There's a paint marking on the nuts. Distance from end of threaded rod to the 13mm locking nut is about 0.140" or 3.5mm. I assume it's never been adjusted.

What's recommended adjustment in? I'm currently maxxing at about 7-8psi. Cruising on the highway at around 70-75 gets me about 4psi boost. The serenitysys webpage recommends 3 turns in, I think I'll try this.

I'm hooking up a Dawes boost controller so I can fine-tune the boost. Doing the adjustment because I think I my spring is soft and I have a "lazy" wastegate valve that's coming open.

__________________
Rob
1979 300SD W116

Just get a MBC. $20 or less and a hell of alot less of a headache.

12psi is what you want.

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Thanks for the advice. MBC=manual boost controller? If so, that's what I have, it's the basic Dawes controller that I've seen recommended here.

I get about 10psi. Today I tried to get up around the 12-14psi range but couldn't. Here's what I tried:

1. Detached wastegate hose. Boost maxxed at 11psi.
2. Detached wastegate hose and boost sensor override (the one on the firewall). Boost still maxxed at 11psi.

Any ideas what this means? I didn't notice any different feel in the car's performance between the two setups...to me this seems that my wastegate is still not seating correctly. Is this correct? My ALDA lines are clean and the ALDA is 1.5 turns CCW from stock, about a half turn from the end of its travel in the CCW direction.

Should I go back into the wastegate and turn down the adjustment nut, tighten the spring?

Is it worth going after the additional pressure?

Thanks-
Rob

__________________
Rob
1979 300SD W116

Yes. It means the exhaust pressure is overcoming the wastegate spring and pushing the valve off it's seat. Shortening the rod puts more spring tension on the arm.

Thanks, turned it down another 3 turns. Getting in there gets easy with practice, I think it took me 15mins to get back to the nuts and adjust, then another 20 to close everything up again

Upshot is no difference, still peaking at 10-11 psi. I'm guessing that it's the wastegate valve not sealing properly or something of the sort.

Will likely just stick with the 10psi, as it's not bad on the highway...and it does have 400k miles on it, after all.

__________________
Rob
1979 300SD W116