Volkswagen Owners Club Forum banner

1 - 20 of 155 Posts

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #1 (Edited)
So I went to scope around my intake to see if there were many carbon deposits and immediately dipped the lens in some oil.

with oil:


without oil:


So I closed up everything and decided I needed to perform a cleaning on the intake manifold. It's been over a hundred thousand miles so it was probably due for a cleaning.

NOTE: I'll be editing this over the next day or two to make sure the tool sizes are correct.

Tools needed to perform this DIY:

  • Floor Jack
  • 1 Jack Stand
  • Assortment of Torx Bits
  • T-Handle Metric Allen Wrench (10" in length)
  • Triple Square Bits: M8 & M10
  • 3/8" Ratchet
  • 3/8" Drive Extensions
  • Pliers (to remove hose clamps)
  • Large Flat-Head Screwdriver
  • Throttle Body Cleaner - Aerosol
  • Cleaning Rags
You'll need to remove your engine cover before performing the next steps.

Take the M10 triple square bit and remove the two bolts holding the injector harness bracket that runs across the the top of the intake manifold.


Once you remove these bolts, you can un-clip the two wire harness clips holding to this bracket and disconnect the fuel injectors and any other sensors in the general area.


After everything is disconnected, go ahead and maneuver the bracket out of the socket to completely free the bracket. You'll have to pull to the passenger side to slide it out of the hole.


Now remove the two T20 torx screws that attach the fuel rail to the intake manifold.


Once they are removed, you can gently and evenly pull the fuel injectors/fuel rail directly outward. I didn't feel like opening up the fuel lines, so I just positioned the fuel rail/injectors to where they were out of the way.


On the throttle body side, remove any air intake attachments to make room for you to remove the four T27 torx screws that hold the throttle body to the intake manifold.


Un-clip the harness plug that attaches to the throttle body. Note the carbon buildup on the butterfly valve. Having this here can cause rough idling, so you'll want to clean this up with throttle body cleaner and a clean rag.


Continue by removing the 4 torx screws. Being that I didn't want to un-clip that oem clamp for the vacuum line, I just moved the entire assembly out of the way for now. No sense in taking off something if you don't have to.


Just put a towel down on the engine coolant reservoir to create a place for the throttle body to sit upon. I ended up cleaning it right here.


Remove the MAP sensor harness clip.


Remove the this vacuum line hose.


Afterward, go to the opposite side of the intake manifold and find the vacuum line on the underside and undo the clamp to slide off the vacuum hose.


Now it's time to head to the underside of the vehicle. Go ahead and lift the drivers side of the vehicle and place it on a jack stand. Chock the back tires in addition to making sure the parking brake is set. Once the vehicle is safe to get under, slide under there with your triple square on the end of a few ratchet extensions.


You'll find two bolts that secure the the intake manifold to the intake manifold bracket. Remove these two bolts and set them aside for safe keeping.


There is a clip on the front of the intake manifold that needs to be removed. It holds the oil dipstick tube in place against the manifold. Just use a large flat head screw driver to gently pry it out of place.




Now the intake manifold should be ready to remove the metric allen socket screws that are holding it in place. You'll need to acquire a special ultra-long allen wrench to remove two of the screws on the underside of the intake manifold. There is no way around this. Being that I started this removal process without this knowledge, I just dusted off my angle grinder and some duct tape and crafted something to get the job done.



Anyway, remove all the allen head screws including the two that require the use of the long allen head wrench.


When you begin to wiggle out the intake manifold, you'll be able to un-clip the oil dipstick tubed to allow the manifold to be freed.


Once the intake manifold is completely removed, remove all of the screws and set them aside. Go ahead and and carefully wipe the mating surface on the head while admiring the cleanliness of your intake ports/valves. Try not to get any debris inside the ports. If you do, you'll have to vacuum it out and wipe them clean to remove any of it.


Here I show how it looks when I start to clean the manifold ports. This buildup seemingly spans the entire length of the runners, so be sure to thoroughly clean them. I was using a throttle body cleaner spray on the end of some socks that i pushed back and forth through the runners until each one of them was clean. On the plenum side, I sprayed the cleaner in there and dropped in a few socks and moved them around with a small bamboo stick to get into the corners and such. After it was all wiped down, I hosed it out with the air compressor to remove any free sock particles :)


Now I flip the intake manifold over to remove the MAP sensor for inspection. Mine had a good amount of oil residue even after I had cleaned the rest of the manifold. I wiped this oil off with a few napkins and reinstalled the sensor after wiping the sensor port a few times.




Reassembly is basically the reverse procedure of the removal. Insert your new manifold gaskets into the gasket channels and lower your intake manifold back into place; while clipping the oil dipstick back in place.




One hint here is to put all of the allen screws back into their places on the intake manifold. If properly placed, they'll remain suspended in the hole via a small white plastic clip. This way they will not be in the way while you are positioning the intake manifold against the head. You can choose to put the allen screws after the intake manifold is in its place. If you choose this method, you still have to put the two screws that are on the under side of the intake manifold, because you will not be able to reach them once the manifold is lowered in.


Tighten all the screws finger tight working from the center ports outward, then repeat this process another two times to make sure the manifold seats properly against the head. Afterward, tighten them down using the same process.

Some photographs/notes showing the reassembly.

Screwing down the fuel rail:

The other screw hole for the rail:


Attaching this vacuum hose:


Attaching the MAP sensor harness clip:


The throttle body gasket put back in place:


Attaching the harness clip to the the throttle body:



Reinstalling the lower vacuum hose and clamp onto the intake manifold:



Positioning and installing the harness rail bracket:




Plugging back in all the fuel injectors and sensor harness clips:




Re-seating the check valve on the stand-off bracket:


Everything reassembled:


Monitoring fuel trims after the engine warmed up:


Cleaned cover back in place:
 

·
We're Geekin'
Joined
·
8,488 Posts
Nice writeup.

I believe a throttle body alignment would need to be done after cleaning the throttle body/butterfly valve.
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #3
^^ Yeah, I've read such as well. I'm just going to let it try to adapt itself.

After two weeks I'm going to reset the system via unplugging the battery and the throttle body should align itself again. Right now I'm still trying to get rid of an intermittent P0106 error.
 

·
Premium Member
Joined
·
12,610 Posts
Good DIY writeup! The throttle body will align itself after you turn the key off....so don't worry about disconnecting the battery.

I prefer to leave the injector rail on...makes things easier and less to remove. also, that clip that holds the dipstick tube in place is installed backwards. It is supposed to go up from the bottom and clip in ;)

Notice any driveability improvements?
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #5 (Edited)
Thanks, man. You know, I was wondering about that clip going the other way. I think it looks better this way, hah hah.

Edit: and yes, the engine seems super smooth now. Not that it was bad before, but now it feels like it's new again. I'm really enjoying it.
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #6
Right now I'm still trying to get rid of an intermittent P0106 error.
ok, so after one week of driving and almost 500 miles. still no check engine light.

i thought it would be worth a shot to take this "cleaning approach" after reading that some people were automatically changing the map sensors only to have the P0106 come back about a week later.

if you think about it, putting a new sensor would work for a few days until the surrounding oil residue creeps its way back onto the probe of the sensor. having a fluid contact on this probe could cause a pressure variable that doesn't gel with the other component variables; which in turn causes the system to throw a map sensor fault.

but then again, this is all just theoretical at this point. i'll update in another week or so.
 

·
Premium Member
Joined
·
12,610 Posts
Could also be from a dirty throttle valve......
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #8
Very true, but now I won't be able to know because I cleaned both at the same time.

Someone else with the error would have to guinea pig it by cleaning one or the other.
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #9
i'll update in another week or so.
hmm, i honestly think it is fixed. still no MIL.

also, i read on vortex that one P0106 diagnosis was that the oil residue damaged the MAP sensor: "Secondly, they claim that the MAP sensor has failed due to being "soaked" in oil that was sucked up by the damaged PCV valve."

found here: http://forums.vwvortex.com/showthread.php?5626102-Picking-your-brain-again-vortexers.-09-Rabbit-P0106-P2178-P2188

^^ highly unlikely for it to be damaged by the oil even if it was submerged in it, because oil is non-conductive. however, depending on the amount of oil present, the pressure reading could easily be affected.

the main reason is because devices that measure pressure read different pressure gradients when a measurement is taken in water, oil, or gas (outside air). to further add to the diagnosis complexity (intermittent faults), we have to consider the temperature variable as well. intake manifold temperatures are different when parked in idle, neighborhood speeds, highway speeds. so, when the temperature fluctuates, the pressure fluctuates right along with it.
 

·
We're Geekin'
Joined
·
8,488 Posts
I'm gonna have to do this, or at least clean my throttle body. I think the issues with my mounts are that my engine isn't exactly smooth, lol. I've only got 47-48k miles on my engine. Though it's had some sort of ECU tune since around 8k miles.
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #11
one torx screw/harness clip and the map sensor comes out. if you don't have a stock air box, it's an easy inspection point to check for oil residue.

yeah, you're probably just feeling that fifth cylinder through your new mounts.

as far as cleaning the throttle body, i should have done my a while back. as you can see, it was looking pretty bad...
 

·
We're Geekin'
Joined
·
8,488 Posts
I'll keep my engine mount jabber out of here.

Going to try and clean the throttle body this weekend. So I'm assuming your PCV was bad for the intake manifold to have all that oil residue?
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #13
So I'm assuming your PCV was bad for the intake manifold to have all that oil residue?
i don't believe so. the engine was/is running great. i've had broken or clogged pcv valves on other vehicles and it does a number on your idle.

eventually, you're going to get liquids dropping out of crankcase vapor that is supposed to be getting all the way to the cylinder and burned for emissions reasons.
 

·
Registered
Joined
·
71 Posts
Awesome write-up. It was clear enough that I feel pretty confident that I could do this with minimal issues. Thanks for taking the time.
 

·
Registered
Joined
·
104 Posts
aside from the benefit of removing the intake to replace the gaskets...wouldn't it have been easier to do a spray in style intake cleaning..?
or maybe seafoam the thing?

tho i suppose if the oil got trapped in the intake...so would any of the cleaning chemicals...

either way...great write up...
grea job with all the pics and descriptions...(as well as home made/improvised tools..haha)
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #16
aside from the benefit of removing the intake to replace the gaskets...wouldn't it have been easier to do a spray in style intake cleaning..?
or maybe seafoam the thing?

tho i suppose if the oil got trapped in the intake...so would any of the cleaning chemicals...
spray-in style intake cleaning? if you're describing some solvent that you'd spray into the intake (via atomization at the throttle body), the evaporative/volatile cleaning chemicals would most likely vanish by themselves (i.e., won't get trapped), however, they aren't going to take any of the oil with them that's in the plenum. they will however, cleanse the intake runners to some extent.

if you want to clean the intake manifold plenum, just remove the throttle body. you'll have plenty of room to work. you'll also need to remove your MAP sensor before poking around in there with anything. just clean the sensor with the spray and a rag, then place it in a safe spot while you work.

just use throttle body cleaner and some clean, lint-free rags along with something (a strong dowel rod) to move them around the plenum with.
 

·
Premium Member
Joined
·
12,610 Posts
There is now an update to correct the fault everyone is having with the map sensor :)
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #18
There is now an update to correct the fault everyone is having with the map sensor :)
but does it remove the oil residue from the plenum and give your engine that fresh minty feeling? :)

i kind of like knowing those conditions will trigger the fault.
 

·
Registered
Joined
·
104 Posts
spray-in style intake cleaning? if you're describing some solvent that you'd spray into the intake (via atomization at the throttle body), the evaporative/volatile cleaning chemicals would most likely vanish by themselves (i.e., won't get trapped), however, they aren't going to take any of the oil with them that's in the plenum. they will however, cleanse the intake runners to some extent.

if you want to clean the intake manifold plenum, just remove the throttle body. you'll have plenty of room to work. you'll also need to remove your MAP sensor before poking around in there with anything. just clean the sensor with the spray and a rag, then place it in a safe spot while you work.

just use throttle body cleaner and some clean, lint-free rags along with something (a strong dowel rod) to move them around the plenum with.
yea thats what i mean...atomized through the TB...
wouldn't the chemical help dissolve the oil and make it easier for the engine to suck out since it probably would evaporate easier when mixed with the cleaning chemical as the engine heats up and runs..?

i suppose you're right tho...your way probably works best(right off the bat...where you'd be taking a chance with the chemical cleaning as to wether it would do anything about the oil or not)

i did see another thread somewhere(i think it was in another vw forum)...
where another guy basically did the same thing you did, except he didin't remove the manifold...he removed only the TB and MAP(and cleaned it), then used a rag on a stick to remove as much of the oil in his intake as possible...then reinstalled the TB, MAP and air tube back on and done..
and described the same result...(but it's less work since you don't need to remove the intake from the car...might make it a bit harder to clean tho, since you can't move it around at your convenience as with it removed)

ps since you had the manifold off...a parts washer or sumn(if available...im oinly assuming you didin't have one available) would help greatly to get the oil out and manifold cleaned too
 

·
Super Moderator
Joined
·
13,746 Posts
Discussion Starter #20
^^ one member on vortex was having problems with the P0106 fault code and his inspection was coming up. he had already replaced the map sensor and the dealership tech didn't find anything to be in error. he got the fault code again after a few weeks; so he was about to get another map sensor installed just to pass the inspection, knowing that the same thing would happen again. so i signed up on vortex to share this info with him and any other members.

it would only be slightly harder to clean with it still on the engine, however, you're talking a lot less work, with no special tools or getting under the car or, purchasing the intake manifold gaskets.

of course you won't be able to wipe the runners clean, but i want to believe that seafoam would handle the buildup there. it would be interesting to see what a round of seafoam actually does to the runner buildup on the 2.5, because it was pretty nasty.

as far as parts washer goes, any kind of pressurized device would work. dawn liquid soap and a water hose nozzle would do just as fine. it's what i did with mine after i cleaned it with the intake manifold cleaner. it was dark outside and i figured it would be nice to really clean the manifold, inside and out. i blew the excess water out with the air compressor and let it dry in the house over night. but for the sake of this diy, i left that detail out so that no one would introduce water into the situation.
 
1 - 20 of 155 Posts
Top