Hi all,
I'm getting a code 49, vacuum leak, but I can't seem to find where the leak is. Theres noise coming from the EGR valve and hose...I've replaced the EGR valve and rubber grommet but still have the noise. If i pinch the hose it seems to stop. The hose is not kinked or blocked (i made sure). How can I find the leak?

Thanks
cadman33619

 

is this on your 92 sl2?

 

i know i haven't addressed this is a while... i need to take care of this vacuum leak that i've had for a while now.

1992 SL1

any ideas?

 

Uuhhh -- replace the hose you pinched?

 

lol..yea...seems obvious to me, too. but that didnt work. replaced it with a brand new one. still getting noise from that area. and i'm not even sure if thats the source of the vacuum leak...thats just a symptom i thought i should mention.
i also noticed today that theres a noise that sounds like rattling aluminum coming from under the car when i let out the clutch to start moving. i know it has nothng to do with the vacuum leak.......i can't seem to find anything loose under the car.

 

is the catalytic converter the original?

 

Have you tried spraying carburetor cleaner around the intake with it running? If there's a leak, the engine idle will speed up for a couple of seconds. That will put you in the correct vicinity. Then you can concentrate on that area. It sounds more like an intake leak to me. But I'm no mechanic. That rattle is probably a heat shield, or like derf is suggesting, the cat con.

 

the cat conv is the original.
the heat shield...? where exactly would that be? i've something that looks like a heat shield around the muffler pipe...would that be it?

 

That should be it. Just tap it lightly with a screwdriver or something and see if it vibrates.

 

no I meant the heat shield on the bottom of the cat which if it is 20 yrs old I'll be surprised if it didn't rust off already. Actually I was more thinking the cat itself is internally disintegrated and the pieces are rattling around in there.

Also press up on the exhaust at various locations (when COLD) to check for a loose hanger or such.

And check that the heat shield material mounted to the underbody along the path of the exhaust piping is not hanging down and contacting anything