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-   -   Check the condition of the secondary exhaust tip (http://www.maxbimmer.com/forums/showthread.php?t=129197)

nachos23 01-25-2010 08:31 AM

Check the condition of the secondary exhaust tip
 
I was just going through the car yesterday inspecting the rear suspension to make sure everything good and decided to inspect butterfly valve on second exhaust tip (vacuum actuated) and it was SEIZED SOLID!!! Not just a little seized, but completely siezed!!! No amount of WD40 and heat would free it, so I forced it open (chisel and sledge)...... gonna have to look @ but the reason for the post is that i've noticed a tremendous improvement in the performance of the car since opening valve. The ECU opens the secondary exhaust under acceleration and load. If it's jammed shut, the additional exhaust gases back-up and reduce performance and HP!!!.

Just the operation of the butterfly valves.... Should move with slight pressre on plate!!!

Car is breathing so much better and revs much more freely......

FYI

Mikeee46coup 01-26-2010 10:25 PM

Time for golf tee mod!

nachos23 01-27-2010 07:33 AM

That was the reason for checking back there initially Was considering doing Golf Tee mod..... Have done it now.,..... Permanently!! No choice; valve completely seized. Will force back into place for e-test.... LOL and open afterwards again. Actually popped the linkage arm to vacuum when freeing valve, so left hoses and lines in place. Vacuum still operates, just isn't connected to anything...... LOL. Very nice sound now!!!! A little "throaty" with a beautiful tone.....

R_JAY 01-27-2010 12:55 PM

Just curious as to why you would force it back for the e-test? My E36 had the line plugged (had a AA Gen III at the time) and I passed no problem. Do they check it if you have the stock exhaust on?

arsevader 01-28-2010 10:28 PM

no need to put it back. It has absolutely no emissions value. Its only purpose is to quieten the exhaust at idle.

Eurostyle 01-28-2010 11:14 PM

Yes, passing etest should be no problem!

carthik 01-29-2010 12:49 AM

really, its controlled by the ecu? do all e46's have this or only the second gen ones? other than quieting down the exhaust is there any other reason for it staying closed (low end torque?) I find this quite interesting.

nachos23 01-29-2010 01:26 AM

actually it's other function is to help heat up the catalytic converter to operating temp more quickly. By restricting exhaust gases, system heats up more quickly. Cold catalytic converters emit more CO2. That's where the eTest might be a concern. If car left cool down before test, it will emit higher CO2 readings (as I understand) until it reaches operating temp.

Eurostyle 01-29-2010 01:29 AM

Quote:

Originally Posted by nachos23 (Post 1385867)
actually it's other function is to help heat up the catalytic converter to operating temp more quickly. By restricting exhaust gases, system heats up more quickly. Cold catalytic converters emit more CO2. That's where the eTest might be a concern. If car left cool down before test, it will emit higher CO2 readings (as I understand) until it reaches operating temp.

All etests are done at normal operating temp tho! *th-up*

nachos23 01-29-2010 07:23 AM

Thx Filip;

Was going to just force it closed again b4 eTest if required..... Have 2 yrs b4 eTest again as it was just done..... so some time to spare..... This post is more of a "make sure you check the function of this part" as I would have never thought to check function of this b4 and since opening it have found a number of bothersome vibrations (at idle) and under load (acceleration) are now gone and were likely as a result of the valve being stuck closed.....Just a warning to all members to check functionalilty of butterfly valve......

Randy 01-30-2010 10:26 AM

Where is this butterfly valve? and how do I check it?

carthik 01-30-2010 10:48 AM

Quote:

Originally Posted by Randy (Post 1386193)
Where is this butterfly valve? and how do I check it?

You might want to read the first sentence in this thread. It could do you some good I think.

nachos23 01-30-2010 02:34 PM

*uzi**th-up*

arsevader 01-30-2010 07:30 PM

Quote:

Originally Posted by nachos23 (Post 1385867)
actually it's other function is to help heat up the catalytic converter to operating temp more quickly. By restricting exhaust gases, system heats up more quickly. Cold catalytic converters emit more CO2. That's where the eTest might be a concern. If car left cool down before test, it will emit higher CO2 readings (as I understand) until it reaches operating temp.

Dunno who told you this but it's baloney.

The secondary air pump is what heat the cats up upon cold starts. That flap doesn't really restrict all that much. Certainly not enough to heat up the cats. A restriction that far upstream that was enough to heat up cats would be a cause for concern.

nachos23 01-30-2010 11:40 PM

Well, thats good news then.... cause the only concern was for the eTest, but gonna have to check with some folks I know @ BMW on that info..... BMW Canada is a client of mine, so I should be able to get the "staight goods" as they say


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