The mess under the intake

[monty23psk]

I was looking at the e30 factory manual and found this picture under remove intake for the m42. Look how the use the hoses to the intake elbow, and not to the throttle housing. Weird.

[DesktopDave]

I suspect there are quite a few variations on the M42 hose routing theme.  Seems like that whole system was a band-aid from the start and running production line changes didn't help it much.

[ryanjv]

my rear hole for the elbow had a plug in it, don't you use the hole from the throttle body in that case?

it's been several months (including the ridiculous winter we had up here in toronto) and everything is still running great.  Not once did the throttle body stick without the heater plate.  Plus it looks much better

i need to get my vehicle e-tested in the next couple months, but i don't think we do visual tests.  and even if we did, i'm sure i'd be fine.  THe last time i got tested, the idiot didn't even know how to open the hood.  he kept trying to lift it like any other car :/

[monty23psk]

Here pics of my install using silicone hoses for the two runs. Also getting them in the size you need is easy since they come in everysize and even different colors. Tried to keep it stock locking.

Here is a better pic of the VC to throttle hose plus the new one installed.


Here is newly added hose, hard to see under ICV.


Here are how both hose look under boot/throttle plate:

[anthonymax007]

Anyone in the central FL area done this yet? I'd like to, but I'm not gonna lie, I have no idea what I'm doing lol

[Nelson_40]

Anyone in the central FL area done this yet? I'd like to, but I'm not gonna lie, I have no idea what I'm doing lol

This image is NOT to scale at all.

I am in central FL, but I am not really near Orlando. Anyway, I hope this helps things, and I hope I didn't make any errors.  Essentially you will have to find hoses that will fit in the areas to be replaced.  The best bet for finding the coolant hose you need is to take both hoses that would have connected to those two areas to the auto parts store and find a hose that will accommodate the outlet size difference.  As far as the vacuum lines that need to be replaced I think I purchased 5/8" line, but I don't really remember.  Just be sure to measure for yourself and it will be easy.

[Matt-B]

guys this is easy. dont make it hard on yourself.

[cyborgben]

it really is. it all makes sense when you do it.
thanks to nelson it is even possible if you can't read!
and for the record all my hoses were split an inch or so... amazing it ran at all (of course that may be why i was able to pick it up cheap )

[Dhohn]

on pre 10/91 vehicles that have this throttle body,where is the vaccuum port ?

I know on the post 10/91 vehicles it is located directly under the throttle body as a tube which opens towards the driver fender.

I have access to a post 10/91throttle body out of the local junk yard. Would it be easiest just to pull the other throttle body ? or am I over complicating this ?

Thanks in advance

[jeff2051]

Morning Gooch.  What size reducer and 90 degree did you use?  1/2 inch? Reducers?  3/8 to 1/4; 5/8 to 1/2?  Both?  

Jeff

Hey guys, I just did this over summer, and wrote the following up for a friend who is about to tackle "the mess under the intake".  I wish I took pictures to help document, but sadly I did not.

I got rid of the throttle body heating plates, so if you're looking to do the same, this is what you need to do:

11531714738 - coolant pipe from block
11531709157 - o-ring for pipe
13541743261 - throttle body gasket
11611717761 - upper/lower intake gasket
11611734684 - lower intake/block gasket
11531709052 - lower rad hose
64211386691 - coolant hose
13411721971 - vacuum hose from intake to ICV
13411721972 - vacuum hose from ICV to intake boot (lengthened with plastic/brass barbed fittings)
11151717858 - valve cover to throttle body (lengthend with plastic/brass barbed fittings)

Reuse a bunch of the plastic couplers, reducers, etc from the mess, you'll have a bunch extra from a lot of the stuff you'll be throwing away.

Brass barb fittings (http://www.plumbingsupply.com/barb.html)...I forget exactly what you need but with the intake off you'll be able to figure it out, you're gonna want a bunch of 1/2" splicers, a few reducers, and a 90 degree reducer, that you make out of a barb x fips and a 90 degree elbow barb x mips.  You want to use the reduceres and splicers to change between different size hoses, and also to space out like 5-6" of hose so that it doesn't collapse under vacuum.

Obviously you're going to need some  hose clamps, coolant (heater) hose, and vacuum hose for the brake booster if you mess yours up like I did.  I got the vacuum hose from rockauto (Gates part number 27230).

I did not replace the 2-3" of fuel lines between the hard lines because they looked alright.  But if you want to replace them, then you need to add some 5/16" fuel injection hose to your parts list.

Like I said before it's fairly obvious with the intake off what you need depending on what you want to do.

It is definitely way easier to use the OEM lines for the ICV to intake and valve cover to throttle body and extending them with the barbed fittings rather than using regular heater hose or vacuum hose because they have the correct bends.  Trust me I tried using regular hose and it didn't work very well.

Good luck!!!

[heltfeil]

This is for the infamous M40, so not quite the right place, but you guys really seem to have it figured out.

Watercooling:


Would I be correct in assuming the parts I could delete is 10, 11 and 14, if I wanted to get rid of my throttle heater? Or anything else I can get rid of there?

For vacuum-lines, I don't think the M40 got the same mess the M42 does, but if anyone sport the M40 and know of anything that can be deleted or rerouted, I'd love to hear it.

Thanks

[Geoff]

I think you pretty much covered it,  except for the smaller hoses that go up to the throttle body itself.   Then, you only need vent from the valve cover to throttle body port,  and ICV to the rubber intake boot, and you're good to go.
                                        Geoff

[heltfeil]

Thanks for the reply

By small hoses to the throttlebody, are you talking about vacuums now or waterlines? Don't have the throttlebody heater-plate on this car, only the heater below.

But if its vacuum you are referring to, mind give me a couple of pointers on these diagrams?



Here you got the main vacuums going. I think what you suggested there is already stock. The hoses there go from upper intake manifold to ICV to rubber intake boot. The vent hose goes from valve cover to the throttle body. This next diagram doesn't really relieve where it ends, but it do go into the left side (if facing) of the throttle body.



Do I have it right, or more correctly, did they get it right as stock?

Might be there was at least something done right with the M40. Even the ICV is placed out in the open as stock.

By the way, anyone knows of someone that supplies an aftermarket intake rubber boot that would fit this car? Part number 13 71 1 727 636.

[Geoff]

no,  I assumed it had the small hoses going to a spacer plate behind the throttle body.  If you dont have them,  you're good to go with the deletion process on the other stuff the way you propose:)

[Wrench]

I just bypassed the plate only with this simple procedure. I left everything alone (since all was in OK condition) and only replaced one hose. It's the one coming from the head. It is now connected to the aluminum u-shaped tube on the end nearest the firewall. I simply recycled one of the coolant hoses I removed. Now I can just put the plenum back on leave the plate off.