126 resonators - Page 2 - PeachParts Mercedes-Benz Forum

toomany MBZ · #16 06-23-2007, 03:38 PM

Quote:

Originally Posted by toomany MBZ

Yesterday, I started the car after a couple of days of sitting. Started fine, smooth idle, got to a stop light, still smooth, then sitting there, the shakes, lopping, what have you started. (less than five minutes) It seems to me to be a pressure build up somewhere. Only other thing I can think of, is exhaust back pressure. Seems okay with higher rpm.

Would a fuel issue of some sort cause this? Just did a purge, new filters, hoses clamps, did not shake during purge took twenty minutes, may have been sitting awhile, can't remember that. That tells me it's not exhaust related, now that I think about it. Would a tank problem be the culprit? Primary filter still clear as a bell three weeks later. Not RD bolt related. Should I have muffler replaced, first? At all? 'Bout pulling my hair out!

Brian Carlton · #17 06-23-2007, 04:30 PM

Quote:

Originally Posted by toomany MBZ

Would a fuel issue of some sort cause this? Just did a purge, new filters, hoses clamps, did not shake during purge took twenty minutes, may have been sitting awhile, can't remember that. That tells me it's not exhaust related, now that I think about it. Would a tank problem be the culprit? Primary filter still clear as a bell three weeks later. Not RD bolt related. Should I have muffler replaced, first? At all? 'Bout pulling my hair out!

Low fuel pressure can give the symptom that you describe. But, you'll also notice that it won't move..........probably won't rev up above 2500 rpm either. Very sluggish in all modes.

If it runs well when on boost, fuel pressure is not your issue. Exhaust backpressure is definitely not your issue at idle.

If you suspect a tank screen, reverse the supply and return hoses to and from the tank and drive it again.

toomany MBZ · #18 06-23-2007, 04:50 PM

Quote:

Originally Posted by Brian Carlton

Low fuel pressure can give the symptom that you describe. But, you'll also notice that it won't move..........probably won't rev up above 2500 rpm either. Very sluggish in all modes.

If it runs well when on boost, fuel pressure is not your issue. Exhaust backpressure is definitely not your issue at idle.

If you suspect a tank screen, reverse the supply and return hoses to and from the tank and drive it again.

Sluggish before turbo kicks in, yeah. Cruises at interstate speeds all day. Sounds good, runs good with throttle at 3000 rpm. Spends 60 miles a work day there. Or anything above 1000, for that matter. Use Exxon ULSD 45 cetane. Do not suspect tank screen, does this this with full tank, now, or low tank. But will try anything. Why does it get worse after just a minute or two? Just got back from store, two minute drive, not bad, got home, not bad, then worsened noticeably. Have the same problem with oil cap off, or fuel cap off.

Brian Carlton · #19 06-23-2007, 04:56 PM

If it's just a rough idle problem, have you adjusted the rack dampening screw?

Temperature affects the rack and the tension on the spring. What works when cold may not work when hot.

toomany MBZ · #20 06-23-2007, 11:01 PM

Quote:

Originally Posted by Brian Carlton

If it's just a rough idle problem, have you adjusted the rack dampening screw?

Temperature affects the rack and the tension on the spring. What works when cold may not work when hot.

Yes, new adjusted RD bolt. May not have had to replace, {it's gold} did so anyway just after purchase last November. Did a purge then too, noticed a smooth, slow up and down rpm change. Did not not know of RD bolt at the time, thanks to this forum, I found out. Current problem not a fluctuation, a very hard shake, miss kinda thing. Will rattle your teeth fillings out! Exhaust was slamming side to side, so I replaced all rubber parts. I know this is prematurely aging things. Don't know if I'll go with the resonator removal or not. If that won't cure this, money wasted.

toomany MBZ · #21 06-23-2007, 11:08 PM

Quote:

Originally Posted by t walgamuth

I have replaced the rear muffler on several benzes with straight pipe. The result is a little growl and perhaps a little more mileage and power. No ill effects were noted except the mrs. thought it was kiindof juvenile.

Tom W

Juvenile, perhaps, don't have a problem with better performance, that doesn't sound like a dump truck next door.

pwogaman · #22 06-23-2007, 11:13 PM

I've been running without the resonators for a couple of years now without any problems. Can't say I even notice anymore noise - but then again, before I had lots of holes in the system.

This link shows how I suspended the system in the middle. The pipe has never leaked or come loose once!

Welded the new exhaust

toomany MBZ · #23 06-24-2007, 12:30 AM

Quote:

Originally Posted by pwogaman

I've been running without the resonators for a couple of years now without any problems. Can't say I even notice anymore noise - but then again, before I had lots of holes in the system.

This link shows how I suspended the system in the middle. The pipe has never leaked or come loose once!

Welded the new exhaust

Nice work. Looks like a little much to pay for, as I'm having to do. Thinking an extra hook on tunnel and pipe to hang "rubbers" ha, ha! You mentioned much better performance, seat of the pants? I have no leaks or rust, just trying to deal with an idle problem, don't know if it will affect.

Brian Carlton · #24 06-24-2007, 10:24 AM

Quote:

Originally Posted by pwogaman

I've been running without the resonators for a couple of years now without any problems. Can't say I even notice anymore noise - but then again, before I had lots of holes in the system.

This link shows how I suspended the system in the middle. The pipe has never leaked or come loose once!

Welded the new exhaust

Yes, I remember that system. A very thorough job. I'd never get an exhaust shop to manage that workmanship........LOL.

In reality, a simple hangar with rubber donuts off the drive shaft cover should also do the trick.

Brian Carlton · #25 06-24-2007, 10:25 AM

Quote:

Originally Posted by toomany MBZ

Yes, new adjusted RD bolt. May not have had to replace, {it's gold} did so anyway just after purchase last November. Did a purge then too, noticed a smooth, slow up and down rpm change. Did not not know of RD bolt at the time, thanks to this forum, I found out. Current problem not a fluctuation, a very hard shake, miss kinda thing. Will rattle your teeth fillings out! Exhaust was slamming side to side, so I replaced all rubber parts. I know this is prematurely aging things. Don't know if I'll go with the resonator removal or not. If that won't cure this, money wasted.

What's the condition of the engine mounts? If the rack damper is adjusted properly and the mounts are good, it should have a light buzz at idle but the engine should not be visually moving.

pwogaman · #26 06-24-2007, 11:17 AM

Quote:

Originally Posted by toomany MBZ

You mentioned much better performance, seat of the pants?

Yep

toomany MBZ · #27 06-25-2007, 02:20 AM

Quote:

Originally Posted by Brian Carlton

What's the condition of the engine mounts? If the rack damper is adjusted properly and the mounts are good, it should have a light buzz at idle but the engine should not be visually moving.

Engine mounts appear in good shape, one of the things that will wear out prematurely if not corrected. When rpm gets to 1000, no problem, mounts or shake. This is inconsistent, twice yesterday normal idle, cold engine, warm engine, then starts to lope.

toomany MBZ · #28 06-25-2007, 05:42 PM

After more adjustment on new RD bolt, kept backing out while idling at operating temp, no change, darn thing finally fell out. Shut off at lever. Noticed flat cone shaped "o" ring turned around. Corrected, reinstalled, SO FAR so good, only took a very hot hand. Still having resonators replaced with straight pipes, new muffler too.

ConnClark · #29 06-25-2007, 05:58 PM

I put a cherry bomb muffler on my 300SD.

Cherry bomb muffler( I'm going to get flack for this)

It is ever so slightly louder, but it is still nothing compared to the roar underneath the hood. It made the car feel more spunky and my mileage went up a little. The resonators offer very little resistance to flow and help eliminate the deep droning sound. Elimination of the resonator doesn't get you anything really, the muffler on the other hand blocks flow a lot more.

Dee8go · #30 06-25-2007, 06:06 PM

I never heard of using this type of muffler on a diesel before. Is this common? Any problems with doing that?