This is what's under an M50 intake manifold

[flyfishvt]

We get a lot of issues that require fixing stuff under the intake manifold. I'm tearing apart the engine in my 325 vert so I thought I'd snap a few pics.

I'm pretty sure I got everything. If I missed anything I'll add it in later.

This large hose on the crankcase vent on your valve cover attaches to the throttle body.




This small hose on the crankcase vent attaches to this connector. That connector is on the large ICV hose and plugs into the manifold opposite the throttle body.





If it becomes disconnected you can put a screw driver through these holes on the intake and push it back into place.



This connector and small vacuum hose plug into the back end of the manifold. The connector is for you incomming air temp sensor and the small vacuum hose goes to the fuel pressure regulator.





This hose with the plastic nipple plugs into the rubber Intake Elbow/Intake Bellows. It runs to the Idle Control Valve




And your Idle Control Valve. Its held in place with a rubber ring. The harness connector is on the front and the hoses for it are on the back.



Now onto coolant hoses. There's alot of them.

First the heater control valves. They get coolant from a large hose off the rear of the head.




Next are the ones are the hoses that run coolant through the throttle body to prevent icing. They run from the block to a temp sensor/valve in the intake manifold then to the throttle body then to a large 4 hose T.

From the block to the sensor




From the sensor to the throttle body




From the throttle body to the 4 hose T




Just a word about that large T. It is a coolant return line. It starts as the return line for the heater core. It comes through the firewall next to the heater control valves. From there it runs back to that large T. Then it goes to the front of the head where it is pumped back to the radiator.




The large hose that branches off that T goes to the bottom of the expansion tank.





Now for the fuel rail. Fuel enters the back of the rail at the pressure regulator. Then it go up throuh the rail passing the injectors and exits the front of the rail. Now it goes back to the tank through the fuel return line



Now the intake manifold itself. There are a bunch of bright orange gaskets that should be replaced if you take the throttle body off or take the intake off. If you don't replace them you could end up with a vacuum leak. If you've already got the intake off or the throttle body off it makes sense to replace them so you don't have to tear things apart again.




And now there is the vanos oil lines. The oil line runs from the back of the oil filter housing to the vanos solenoid. It exits the oil filter housing right next to the oil pressure sensor.



Some misc items:

Front knock sensor. There is a second one towards the rear.



On the head are 2 coolant temp sensors. One goes to the gauge in the cluster and the other goes to the DME. The blue one is the DME sensor. The black one is for the cluster gauge.

[UnderCoverGuy11]

Definitely subbed for reference, this is very comprehensive, thumbs up to fly again

[airforce7882]

Great post! Saving this for reference.

[NJohc]

Always informative posts from you! Great stuff..... I have a strong hatred for that T hose lol

[flyfishvt]

After uploading and labeling all those pics my brain is tapioca . I wish someone would do one of these for the M52.

They only allow 30 pics per post so here's some additional stuff.

M50 engines have the charcoal canister in the engine bay. it has 2 hoses on it. One of them just vents down to the ground



Ever try to find or read the tag on your alternator? It probably just covered with dirt.

[cabezzzdb8]

I tried to delete the water lines to the throttle once, car ran like crap

[sar5036]

After uploading and labeling all those pics my brain is tapioca . I wish someone would do one of these for the M52.

I will volunteer my engine! Wanna help? haha. Awesome write up. I need to take off my mani soon. Ive never done it before though so it will be a learning process

[casperlynn]

what's up with the bloodied up hands Fly????????

[flyfishvt]

what's up with the bloodied up hands Fly????????

So you caught that huh? Yup...I bleed grease and oil for this forum.

[casperlynn]

So you caught that huh? Yup...I bleed gease and oil for this forum.

I can do a vacuum pump oil change and somehow end up with bloody knuckles lol!

[94E36Drift]

Hallelujah! I found my answer in the first pic. The large hose that goes to the valve cover, was super loose. I followed it and saw that it was disconnected! So it just connects to the throttle body?
I bought a 1994 BMW 325iS, pretty modified. It was running fine, until one day it idled REALLY rough. I figured vacuum leak. I spent awhile spraying all the lines to see if they were leaking until I found this hose disconnected. I hope this will solve it!! Where exactly on the throttle body does it connect too? Thanks!

- - - Updated - - -

This is exactly what my intake and throttle body looks like. So where does the crankcase vent hose connect too?

[hide1]

This is exactly what my intake and throttle body looks like. So where does the crankcase vent hose connect too?

To the ccv/ oil separator/ aka cyclone valve..

[flyfishvt]

To the ccv/ oil separator/ aka cyclone valve..

Not on an m50. M50 doesn't have one.

[94E36Drift]

Yeah I dont have a ccv. So where does it go? Its like 18" long

[flyfishvt]

Throttle body

[94E36Drift]

Exactly where though? Thats what I need to know. Like under it?

[UnderCoverGuy11]

.

[flyfishvt]

Look for an empty spot on the throttle body. It's not hard to find.

[RobMCoupe]

On my 94 325is, it goes to intake. There should be one for ICV and the other for CCV.

http://www.turnermotorsport.com/p-32...thout-asc.aspx

[94E36Drift]

Alright I found out where it went, it was right behind the throttle body kinda under it. BUT IT DIDN'T solve the problem. It seems to be running rich. I don't know what else to do. I thought o2 sensor, but that would throw a check engine light, and I don't have one... So I don't know. I'm just gonna sell it for cheap.

[94E36Drift]

So i took a look at it one last time, and i found this part broken.. http://www.ebay.com/itm/BMW-Genuine-...3b23fa&vxp=mtr
Would that cause my idling and stalling issues??
And what about the o2 sensor?? I dont have a CEL though..

[alwaysinboost]

very helpful thread!!

94e36Drift, do you have a pic of where you wound up putting that large diameter hose coming from the valve cover? I looked around my m50 throttle body and can't find where that damn hose goes.

I have a 95 with ASC so there is only one port on the intake tube and its being utilized already by the hose coming from the idle control valve. There is a smaller port on my throttle body where the throttle cable bracket attaches too, but that is being used by the charcoal/evap system.

if anyone has a pic of where that large diameter hose attaches on an M50 car with ASC I'd really like to see it please.


edit: I think I found where it goes using the google. there is a large barbed nipple on the ACS throttle body, that looks like where it should be. I'll double check tonight when I am in the garage.

here is the pic i found:
http://www.ebay.com/itm/BMW-E36-ASC-...-/161801434132

[mike318]

We get a lot of issues that require fixing stuff under the intake manifold. I'm tearing apart the engine in my 325 vert so I thought I'd snap a few pics.

Fly, always helpful and I thank you too.
You list a 97 vert328i, do you own this car too?

[flyfishvt]

We get a lot of issues that require fixing stuff under the intake manifold. I'm tearing apart the engine in my 325 vert so I thought I'd snap a few pics. Fly, always helpful and I thank you too. You list a 97 vert328i, do you own this car too?

The 325 was a flip. Sold it a year ago. Current cars are a 97 328 vert and a 98 turbo m3 vert. I haven't put 500 miles on the 328 since I went turbo m3 this year. I have a buyer for the 328 as soon as I fix a few things

[MisterM52]

Yes, M50 Manifolds are the easiest things in the world..once you understand how the cars vac system works you can do swaps in 30mins

Alright, I think you are talking about the CCV/PCV the large hose that comes out of your valve cover on the M52 and newer motors, you buy some hoses and L bends to put the PCV in line, you put the catch can/ccv's top in line with the ICV & M50 manifold vaccume line, then you put the bottom on the oil dipstick and the big hose of valve on the other nipple. Done!