I have had an exhaust shop test my cars pre cat pressure and it was 5 psi at idle. They were trying to hunt down a leak - which was non existant.

Infact if any exhaust experience guys can chime in Id really appreciate it.

I have a leaky exhaust sound at mid rpm and absolutely no exhaust leaks. Uptil now no exhaust shop has been able to repair this. All say that It "may" be the mufflers, it "may" be the header pipes resonating, - One shop said that I should buy a complete brand new MB exhaust system to repair this.

hmm about $2800/- Nopes.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

95 e300d new exhaust pics

I thought my sluggish E300D was being caused by a blocked cat. It wasn't after all. It's still sluggish.

__________________
2009 E320 Bluetec 117,000
1995 E300D 306,000 Sold
1996 Ford Taurus LX 130,000 Sold
1985 300TD Still 225,000 Sold
2016 Ford Fusion 24,900

I do happen to know for sure that the exhaust manifold is a separate piece from the front section, which is why I asked the question in the first place.

Yes, it would be loud, but I would not drive it around the hood, just run it in the driveway for 30 seconds or so to see how the engine revs- better or the same.

Called Pelican Parts. That front pipe? $1500! I don't think so.

__________________
14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

So, if it ends up being a clogged cat, and I choose to go the route of replacing the cat with a straight pipe, would there be any noticeable effects to that....other than the possibility of not passing emissions?

__________________
14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Slight increase in exhaust sound.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Can you run biodiesel to pass emissions? Does a 1995 diesel need to pass emissions in RI?

__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

Car has to be at least 25 years old in RI to be exempt from emissions.

__________________
14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

5 psi? That seems huge. And the previously quoted 2 bar figure seems very wrong to me. The back pressure of engines is usually measured in inches of water column - fractions of a psi. Or kPa if you are a Euro guy. I'd like to see that 2 bar figure in writing somewhere.

I know for a fact that the limit for exhaust back pressure in one particular brand of multi thousand HP diesel engine is 12" water column, which is less than 0.5 psi.

Rgds,
Chris W.

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Objects in closer are mirror than they appear.

The number I quoted is from section 14-150 "Testing exhaust backpressure - Turbodiesel" in the FSM "Service Manual / Diesel Engines 603,603." It was the only number I could find and I noted in my post that the number was for a turbodiesel.

The current case is NOT a turbodiesel and I agree that the back pressure ought to be much less, providing the exhaust system is not blocked. Unfortunately, I cannot find any notes on exhaust backpressure in the OM606NA engine in either the W124 (CD-ROM) or the W210 (DVD) manuals.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

let me scoot back to the shop and look at the gauge he used.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Mechanic confirmed it's a clogged exhaust. That's a relief. Now I'll just take it to an exhaust shop and have them weld in a new cat.

__________________
14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

you will need the magnaflow 93000 for the converter and 10758 Y pipe.

check for an autozone/advance coupon to save some $

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

So you are going with a cat, then? Is this because you have to pass emissions?

__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

Please don't forget to post here with results of replacing the cat.

__________________
2009 E320 Bluetec 117,000
1995 E300D 306,000 Sold
1996 Ford Taurus LX 130,000 Sold
1985 300TD Still 225,000 Sold
2016 Ford Fusion 24,900