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Intake Manifold Is Off! - Now to fix the hard pipes

7787 Views 110 Replies 20 Participants Last post by  fanatichuman
Finally got the manifold off and mostly followed the ShopLife video on how to do it. Now I can start replacing the coolant and heater hard plastic pipes.

Lessons learned with taking off the intake manifold:
1) Have instructions so you can remember how to put it all back together
2) The last manifold nut in the back was hard to take off because I didn't remove the fuel rail
3) Even after vacuuming the areas near the intake ports I found debris near the holes so I covered them up as soon as I removed the manifold but not fully removed
4) The intake manifold gasket is hard to get out and it is breaking while I try to pull it out.

What is the best way to clean the intake manifold and block? I'm going to put aluminum foil over the CCV pipe and fuel hose to make sure nothing gets in them.


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With all the wires, starter and alternator there, near the block., I would not go crazy with a a lot of water and/or a pressure washer.

After you remove both coolant pipes, I would use some diluted simple green on the engine block and maybe a garden sprayer to carefully rinse off. Do a section at a time.

I would not clean the inside of the intake. Wipe down the outside if you want to.
Sounds like a plan! :)
So how did you remove the intake with the fuel rail attached? I also remove the fuel rail off the fuel line for more room. It's easy with the Quick disconnect connector.
I just kept the fuel rail attached and remove the fuel line once I got the IM off the block a little.
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I tried to vacuum all debris before removing the intake to avoid debris drop in the intake ports and may cause leaking valves.
I did use compressed air and vacuumed and dug a little with my screw driver. There was some debris when I changed out the CCV system a few years ago but vacuumed most of it up.
I'm not understanding why you didn't remove the fuel rail and disconnect the fuel line before you removed the intake manifold. IMHO, you've made your life much more difficult when you did that. If you're worried about putting the last nut back (in your other thread), remove the fuel rail so you have access. Problem solved.

Stick a shop vac with a crevice tool into the intake runners on the block side when you reinstall the intake manifold just in case something fell in.
I think 10 posts ago it was recommended that you change the upper and lower o-rings to the injectors. If you decide to do that, my personal preference is the label the injectors so they go back in the same sequence or better yet, do them one-at-a-time so they don't get mixed up. Having said that, I'm sure others will say it doesn't matter where they go back in :)
I tried P21 per MrMCar's recommendation to clean the engine. Holy crap I was impressed.
Don't forget the missing vacuum hose to your vacuum canister. It goes from the canister to a port on your firewall. 3.5mm ID vacuum hose.
I didn't remove the fuel rail to save time and not to mess with the injectors. I was following the ShopLife video. I may have to take the fuel rail off because of that last nut on the intake manifold.

Good idea to shop vac the intake runners before reinstalling.

I wasn't planning on changing the o-rings on the injectors since I wasn't taking them out but now I may have to.
Is this a good kit with Using Viton Fluoropolymer O-rings? $16.99 with Two Day Prime Shipping

Or should I just get the ones at FCP Euro?
$10.14 for 6 BMW Fuel Injector O-Ring (9.2 x 2.8mm) - Elring 13641437486
$5.36 for 6 Audi BMW Mini Porsche Fuel Injector O-Ring - Elring 893.889

Never heard of P21. Is the one you got?
$26.29 P21S 13001R Auto Wash Refill, 1000 ml

What missing vacuum hose to the vacuum canister? Do you have a picture or diagram?
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Not saying my way is right, but I never pull the fuel rail out when I remove an intake... I simply unplug (carefully) the electrical harness that plugs into each injector, and disconnect the fuel hose that connects to the fuel rail.
That last nut on the intake manifold is hard to get to because of the fuel rail metal hose which blocks easy access.
I could barely get my hard in there to take the nut off,

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Take advantage of the manifold being out and replace all of your deteriorating vacuum lines before reassembly.
That's the plan! :)
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A wobble extension or a universal joint attached to your socket will get that last nut no problem.

Be sure to put a piece of tap inside the socket when you reinstall those nuts...I have lost a couple that I have never found...
I used universal joint to get access
A wobble extension or a universal joint attached to your socket will get that last nut no problem.

Be sure to put a piece of tap inside the socket when you reinstall those nuts...I have lost a couple that I have never found...
I used a universal joint and a 11 mm deep socket (didn't have a regular socket) to get it off. I could see how those nuts are easily lost.
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I bought my injector o-rings from FCP Euro. I know nothing about the ones you linked from Amazon. It's really up to you to decide what you want to do.

Yes, that's the P21 that I bought. Worked well for me. You can of course use any of the 1000's of engine degreaser that you can buy :) and I'm sure they would work just fine.

This is the vacuum canister that I was referring to. Note the vacuum hose that's broken off on the left side of the picture? This vacuum canister takes vacuum from the back of the intake manifold and sends it to a connection on the firewall that is to the left and maybe 10 inches down from the brake booster. This vacuum is used to open/close the exhaust flap. You may of course simply not use this and plug the vacuum connection on the back of the intake manifold.

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It looks like there is a hose from the back of the intake manifold that goes to that vacuum canister. It may have come off when I took off the manifold because I don't remember disconnecting it. It almost looks like it may have broke the tip of the canister when I took it off. I plan on replacing all of my vacuum hoses today so should I get a cap for vacuum reservoir/cannister and the back of the intake manifold?

$3.49 BMW Vacuum Cap - Genuine BMW 11611437560

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I don't see this come up enough but i is worth mentioning that the old plastic coolant hoses are brittle and will likely crumble when you pull them out, possibly to the point that an o-ring stays behind. You'll want to inspect your old pipe ends to make sure they're intact and that you got the o-ring out. If not you'll need a pick to fish out the o-ring and any remaining pieces of coolant pipe that were left behind.
I'm ready to pick away! I'm cleaning everything before taking it all out.
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Your vacuum canister tip did not break, the vacuum hose simply crumpled due to age.

If you're going to basically "delete" the exhaust flap, then you need to plug the vacuum port on the back of the intake manifold. You already purchased a mixed packaged of vacuum plugs based on your other posts, just use one of those that fits.
I realized that once I started taking off the hoses on the intake manifold and they just crumbled. :oops:

I didn't purchase a mixed bag of vacuum hoses...just the big one for the back. Now I have to order a couple of this 3.5 mm caps, fuel injector o-rings and some extra intake manifold nuts in case I lose one. Anything else?

This is what it looks like so far. The secondary air vacuum hose hard line broke so I'm just going to use a silicone hose all the way from the back to the cannister. The hoses were falling apart. :-(

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Don't confuse vacuum hoses with caps :). If you go back to some of your old posts, there was a recommendation that you should get a mix package of vacuum caps. Something like this you can get at your local auto parts store. For example:

Some have epoxied the vacuum port shut completely at the back of the intake manifold. Personally I would never do that, but it's your choice. You can't un-epoxy something easily :)
I missed where they said to get a mixed bag of caps. :-(

So cap the line behind the manifold (where I have the blue silicone hose) and the cannister under the intake? Benefit is less vacuum leaks. Any cons?
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It’s been a couple years now since I did this job but there’s still dried blood all over the place trying to reinstall everything. I think it was the hose clamps/boots/CCV connections. Hope you don’t have “paws” like I do.
Not looking forward to putting everything together! lol
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If you cap the intake manifold port that goes to the vacuum canister, your exhaust flap (in the muffler) would stop working. Some folks prefer that since they get a slightly louder exhaust sound at idle and lower RPM's. In doing so, you would avoid potential vacuum leak between the canister and the muffler.

Side note - I always wondered if that vacuum canister has a one-way valve built in ....? Any reader knows if that's the case?
Sounds good to me! I like a little louder exhaust! :)
Decided to clean the engine a little before I start taking off the hard pipes. It looks better but not prefect.

Is the ports section clean enough to put the intake manifold back on? There shouldn't be an oily residue but there are stains on it.

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I’m pretty sure the manual had me dismount the power steering reservoir and remove that vanos oil line. You’re going to be working a bit over there and you also want a real good visual and feel when you insert the new pipes.
I did remove the bottom banjo bolt to get access to the pipe. It still broke inside the hole! lol
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Yes it is...You will want to hit it with brake clean one more time...but clean enough...
Wipe it down with brake clean right before putting it back on?
Just removed the hard pipes! Of course the part inside the block were broken and corroded. I had trouble with the bottom pipe and the hose connector. I pulled up on the clip and it wouldn't pull or twist off. Luckily I bought new hoses.

Tomorrow I start digging out the pieces of the of the old pipe in the block. Should I use a pick with a 90 degree angle to pull the stuff out? Once I get all the stuff out, I'll put a ball of masking tape inside and sand it smooth.
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Not sure I have a hooked pick tool. I have the green scotchbrite pad but I was planning on using some sand paper.

I was planning on pressure testing the system once I got my hard pipes and new hoses on with 15 psi. :)
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The pick tool works. However many get somewhat aggressive when trying to pull the broken off bits in any blind hole.
The trick is NOT to gouge/scratch the outer perimeter of the round hole (It's aluminum folks! and the tool is steel.) so that a scribe mark remains behind.

If it's deep enough, could be well the source of a future leak as a small amount of pressurized coolant follows past the O Rings down the scratch you placed in there in your zeal to remove the broken pipe.

O Rings work very well inside a clean round hole. They do NOT work well in filling a small scratch inside that hole.
So be careful and check prior so buttoning it all up.
I was very careful when picking the out the debris so hopefully there is no damage in there.

I used a pick and a pick hook to get the stuff out. Then I vacuumed the holes to get whatever debris fell into the hole, The first o-ring came out, then pieces, then the second o-ring and then more pieces.

I used a 16 mm deep impact wrapped with 500 grit sandpaper and then 1000 grit to smooth it out. It feels pretty smooth in there but the stains remain. I'm really to start installing the new hard pipes. Are the holes clean enough?

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