190E Vacuum hose question w/pic - PeachParts Mercedes-Benz Forum

babybenz · #1 01-18-2005, 11:44 PM

I can't identify where this intake manifold vacuum hose goes. It is black with a white stripe. If it goes to the transmission modulator then how many hoses is the modulater suppose to have attached?

mbdoc · #2 01-19-2005, 08:21 AM

That is the vacuum source for a thermo-vacuum valve that controls venting of the evaporation system (charcoal cannister).

mctwin2kman · #3 01-19-2005, 08:40 AM

On my 190 that is for the transmission. There is one on the side as well that goes to the HVAC/Economy gauge.

The ones under the AFM that are attached directly to the throttle body go to the Thermo Valve. Unless there was some big change between 1986 and 1993 MB Doc is off. Also I have the Maint CD and it shows all years and they remained just as I stated.

babybenz · #4 01-19-2005, 09:11 AM

The 1993 models don't have an ecomomy guage. The transmission is shifting very hard so I was thinking the hose may go to a transmission function. I got underneath and found the modulator on the passenger side, but 2 hoses are already connected there. How many hoses are suppose connect to the transmission modulator?

mctwin2kman · #5 01-19-2005, 11:34 AM

Even without the economy gauge the one vacuum line still goes to the firewall and into the car for the HVAC system! Just does not split for the economy gauge.

mbdoc · #6 01-20-2005, 08:12 AM

The WHITE/BLACK pictured on the throttle housing goes to the thermo vacuum valve & The Black/WHITE for the modulator comes off of the intake runner for cyl # 3.

ONLY 1 hose goes to the modulator & it should have vacuum with the engine running.

mctwin2kman · #7 01-20-2005, 08:31 AM

Quote:

Originally Posted by M.B.DOC

The WHITE/BLACK pictured on the throttle housing goes to the thermo vacuum valve & The Black/WHITE for the modulator comes off of the intake runner for cyl # 3.

ONLY 1 hose goes to the modulator & it should have vacuum with the engine running.

Not to question you but on mine that one in the picture is right beside the IACV and goes to the tranny! Under the AFM is the one that goes to the thermo valve and another that goes over to the cannister. Those two are actually on the throttle body so when the throttle plate is closed at idle no vacuum is present since the hole are somewhat blocked. Did they change this in later models, since mine is a 1986 2.3? Also the one in the picture is the one between intake runner 3 and 4!

babybenz · #8 01-20-2005, 09:51 AM

This is a picture of the nipple on intake runner #3. It is a small hose in diameter. I found the transmission modulator and there already is one larger diameter hose attached. I found the thermo vacuum switch and both its short nipples have broken off, so maybe that is why this loose hose is not attached to anything. Maybe I should follow that larger diameter hose attached to the transmission to see where it goes now! Thanks guys

babybenz · #9 01-20-2005, 09:53 AM

Pic attached now

mctwin2kman · #10 01-20-2005, 10:09 AM

Ah I see. You should at least cap that nipple off until you can get a new thermo valve so you do not have a leak. That one there goes to my tranny, then there is another almost directly under the throttle linkage for the HVAC system vacuum. Then two under the AFM that go to the thermo valve and back from the Charcoal Cannister. The one to the valve also splits on mine and goes the the vacuum advance on my distributor. But yours is newer and has KE-III so you do not have vacuum advance, but you should have a vacuum line going to your fender well for the Ignition Controller module. So my lines may be all diferent from yours. But you need to at least make sure yours are all hooked up. I traced all mine when I first started sorting them out. Mine were all going to the right places though. I had traced them all out when I was putting new rubber in to replace the cracked old ones that were there causing slight leaks.

babybenz · #11 01-31-2005, 09:16 PM

Correction for the archives:

The port in the pictures on the UPPER side of intake runner #3 is for the transmission modulator located on the driver's side of the transmission. The ports on the UNDERSIDE of the intake manifold go to the thermo vacuum valves. My transmission shifts like a new one with this hose attached. A vacuum hose pic of the EGR system is attached.