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2011 Forester 2.0 diesel manual 6 speed
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Discussion Starter #1
Hi all,

I have recently had to replace my inter-cooler turbo rubber hose (cracked). While doing so, i noticed huge soot buildup in the intake manifold. I have 150k kilometers on the clock, car year is 2011. I started investigating the issue after getting more and more DPF light warnings and also had some engine jerkiness in the 2500rpm range. Since I have change the turbo pipe I haven't had any DPF lights and the jerkiness stopped. But I'm a "prevent it rather then cure it" kinda guy and I know that this full of soot intake will cause more problems eventually.

So I have downloaded the Forester service manual and started reading up on how to remove the intake manifold. It seemed like a pretty straight forward job, everything except step 24 which says to remove the exhaust manifold (LH). Now LH should stand for left hand drive. Does that mean that this only needs to be done for LH models? Mine is a RH.

Once I had a look what goes into removing the exhaust manifold then I was really disappointed because it seems I should drain coolant and do all sorts of other stuff. Which makes no sense to me if i only want to remove the plastic intake manifold.
So my question is, do I really have to do this step??

I have bought genuine Subaru gaskets for everything when i put it back together. Was around 90 dollars.

Thanks
 

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2012 Forester 2.0D 6MT
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I removed and cleaned the intake manifold on my 2012 RHD diesel Forester, and I definitely didn't need to remove the exhaust manifold. I can't imagine why that would be necessary.

Prepare to be amazed. Here are some photos of mine at around 150,000km. The bottom of the plenum just after the EGR inlet is probably the worst spot. Oven cleaner will be your best ally.

523750


523751
 

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2011 Forester 2.0 diesel manual 6 speed
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Discussion Starter #3
Holly smokes! Thanks so much!

Do you have any other tips/tricks to getting it done? How long did it take you to get it off? Let me show you the instructions that i have, does it seems about right to you?

 

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2012 Forester 2.0D 6MT
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It's not as difficult as I expected. The intercooler is easy to take out (I can do it in about 60 seconds now), and from there, you can see much more easily what needs to happen next. There is quite a bit of cabling and tubing to unclip/unplug and move off the top of the manifold, but if you keep track of what goes where, you'll be fine. Maybe take some photos or draw diagrams.

Regarding the instructions - the main differences that I found were:

1) A minor point of difference on the intake ducting. I'm pretty sure I didn't remove the black plastic hard pipe that goes from the turbo to intercooler inlet. On my Euro 5, it was all one piece, no flexible section at the end where it meets the intercooler. This pipe would not budge from the turbo outlet. So I just removed its supporting bolts, loosened the hose clamps, and held it out of the way. This later proved to be a pain when it was time to lift the manifold out, as it interfered with the manifold on that side. So my advice is to TRY to remove all of the intake ducting, along with the air filter box; but if it's too stubborn, you can leave it in-place and manage it later on by holding it to the side while the manifold lifts out. Whatever you do, be careful with this pipe, because it apparently cracks easily, and is expensive to replace.

2) As discussed already, you don't need to remove the LH exhaust manifold. And you don't need to remove the EGR cooler. You only need to remove the two studs/nuts holding the EGR cooler hard pipe onto the EGR valve body, so that the valve body can lift out with the aluminium plenum (with the throttle valve on the other end). The studs conveniently have 6-point, star shaped ends, so you can remove them with a small 6-point socket (6mm, I think). Luckily they came out quite easily (for me). The EGR valve body then unbolts from the plenum with four bolts.

3) The Euro 5/6 intake manifold is two-piece, while those instructions show a Euro 4, one-piece manifold. You can see in my photos that the black plastic section lifts off the aluminium plenum, after you remove the three bolts on the flange. Then there is that large opening which makes it easier to get in and clean. With the Euro 4 engine, I believe the entire manifold and plenum is one piece of aluminium. (I'm not sure which year was the changeover from Euro 4 to 5, but I think your 2011 will be a Euro 5.)

Some more pictures for reference:

523819

This is the aluminium plenum as viewed from above (after cleaning).


523820

The plenum from behind (after cleaning). You can see the EGR passage that snakes from the right hand side, along the back, and enters the plenum under the hex plug (immediately behind the throttle valve). This is a hotspot for sludge accumulation, as this is where EGR soot meets the oil vapour which entered upstream of the turbo. The floor of the plenum here will be full of thick, sticky sludge.

523821

After removing the throttle valve, you can see the MAP sensor probe inside the plenum. Lots of sludge here.

523822

The same view, zoomed out.

523823

Same view, with throttle mounted, after cleaning.

523824

Plenum cleaned and back on the motor.

523825

The intake ports didn't look too bad. There was soot, but it was only a thin coating.

523826

The volume of soot/sludge that came out was astonishing.
 

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2011 Forester 2.0 diesel manual 6 speed
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Discussion Starter #5
This really is astonishing. Nice pics, good job man. My intention was to take out the plastic intake manifold out, but i see you also took out the aluminum parts. I will try it. Do you know what is the name for the 6 point star shaped tool? Allen key has 4 sides i believe. Do you have a picture of that bolt?

I already know how to take off the inter cooler and the throttle body (and the hose that connects them) so everything from that point will be new to me.
But you did encourage me with this info. Thanks again.
 

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2011 Forester 2.0 diesel manual 6 speed
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Discussion Starter #6
Just checked, Allen key actually has 6 points so i guess this is the one you're talking about?
 

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2015 Forester 2.5i Limited CVT
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Just checked, Allen key actually has 6 points so i guess this is the one you're talking about?
Those studs may be torx heads. Commonly used on the intake and plenum. For those, you would use female Torx sockets. They come with an e designation. E6, E7, etc.

Could you post a photo of the stud bolts? Thanks. Great write up.
 

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2012 Forester 2.0D 6MT
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I don't think I have a photo of the studs, sorry. But yes, the end of the stud looks like the tip of a Torx tool. I found that a normal hex socket fit over it perfectly. If you have a set of 1/4" 6-point sockets, you should have it covered.

If you hit a snag here, there are other options - leave the studs in the EGR valve body, and just remove the nuts. Then pull the EGR pipe back out of the way while you lift the plenum out. There is a support bolt (14mm, from memory) further down which holds the EGR cooler and piping onto the motor (or gearbox, I can't remember). You can remove this bolt to allow the hard pipe to flex back a bit more.

I am a highly amateur mechanic with pretty basic tools, and I didn't struggle too much with this job. If need be, you can shoot me a message or keep posting here for help.
 

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Thanks. Yes, indeed. Those are torx studs. They use female e torx sockets.
These studs are commonly found on intake manifold and plenum, etc. maybe e6 or e7 size. I’ll have to buy a few e torx sockets.
 

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2010 Forester Diesel 6MT
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Great work, notnothing. In my opinion your 'amateur' mechanic skills are better than a lot of 'professional' ones.
 

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Great work, notnothing. In my opinion your 'amateur' mechanic skills are better than a lot of 'professional' ones.
Thanks mate!

I have to admit one mistake on this job. I threaded the three bolts into the flange between the plastic manifold and the plenum, but forgot to torque them down. The next time I opened the bonnet, I found black sooty oil had sprayed out of the gap, and all over the fuel pump and alternator. I got a laugh out of it. All good ever since.
 

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2011 Forester 2.0 diesel manual 6 speed
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Discussion Starter #14
Job done :) Pics: https://app.box.com/s/7lopuxlzek1uoct9sfr44qms3g9un498

I have to say, it's not that hard, but it did take about 3h to take everything apart. I took my time and made sure I label everything to know where it goes later etc. But man it's hard to clean this stuff. The cleaning part took almost 5h for me and it's still not as shiny as one would expect but I'm happy with it. Took me about 2h to put everything back together. Torqued to the correct spec and put in all new gaskets.

Unfortunately for me, one of the EGR bolts (the torx one) would not budge, but I did get one of them off. So with some clever maneuvering I was still able to get the EGR off without removing the cooler. Other than that, everything unbolted pretty much without issues. I would suggest to anyone doing this to have a magnetic extender of some sorts because it's sooo much easier to remove the hard to get bolts once they are unscrewed and also much easier to put them back into place.

Some concerns I have:
1. The Subaru dealer actually sold me the wrong EGR gasket (there are 2 of them, one was ok but the other is way off) so I had to reuse the old one. It was all gummed up and I didn't want to put it back like that so I sanded it down. Unfortunately the stores did not work anymore as this was late in the evening and the only sand paper I had was 80 grit. So I'm a little bit scared I made it a little too scratchy, you can see it in one of the pictures. Not sure if air can escape through those scratches. I put the bolts back quite snug so I hope it will be ok.
2. I have found oil in the intercooler rubber hose as well as in the main intake chamber (the center big one). Not sure if it's normal? It was not an excessive amount but also not that little.

And just to mention the sensor in the chamber was so gummed up, I have no idea how it could actually measure anything. Got it nice and clean now. Should I expect the engine to run a bit more efficient?

And lastly, thanks to everybody who posted. It really did give me the confidence to do it myself.

@notnothing I messaged you on hangouts but I think you didn't get it. Anyway I made so it's all good :) Thanks man
 

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2012 Forester 2.0D 6MT
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@notnothing I messaged you on hangouts but I think you didn't get it. Anyway I made so it's all good :) Thanks man
Sorry mate! How weird. I can't see anything on Hangouts. Anyway, glad to hear it went well.

If the EGR gasket does leak, you will probably be able to see black soot coming from the joint. And the oil in the intercooler is normal - it just comes from the breather hose and gathers in there.

My fuel efficiency only improved a small amount after cleaning, but top end power was significantly better, and turbo lag was reduced too. I'll be interested to hear how yours runs after the cleaning.

My biggest improvement in efficiency actually came from installing an EGR block-off plate. I went from 6.8L/100km to 6.0. I didn't expect such a difference, but that's how it went.
 

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2011 Forester 2.0 diesel manual 6 speed
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Discussion Starter #16
Oh wow that's a nice difference in fuel efficiency! It hasn't even crossed my mind to block the EGR. Now you're making me consider repeating the process haha. Coincidentally my avg consumption is also 6.8L.

So far I don't see anything leaking from the EGR. To be honest I don't feel any difference in driving the car. Had a nice drive today, everything working as expected. My main concern why I did this cleanup was that my DPF is clogging up faster because of engine not running efficiently. We will see if it had some effect on the DPF over time. My second concern (and more important) was that sometimes I got some jerkiness from the engine around 2500rpm. So far I don't feel it. Again, time will tell.

That EGR thing though...arg, why haven't I though of that at all? :D
 

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2015 Forester 2.5i Limited CVT
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I would buy a new egr gasket. The torque spec is only around 168 inch pounds. , or about 12 foot pounds. Not a lot of torque, so a new gasket is required.
 

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2011 Forester 2.0 diesel manual 6 speed
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Discussion Starter #18
It's 19NM so 14 food pounds. I have it a little bit more than that and used a medium strength thread locker. I will keep monitoring it for leakage but seems ok so far.

It should be possible to wiggle out the EGR without disassembly of the whole intake manifold, but for that I would have to get one of the stuck torx bolts loos and I have no idea how to do that as I have already damaged the torx thread on the top of the bolt. One idea comes to mind though, and that is to take some massive piping pliers and just grab on to the torx groves (completely ruining them) but hopefully that would have enough force to open it up. Any other ideas?
 

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Discussion Starter #19
@notnothing just a question about the EGR blocking, has it triggered an engine light on? Or the ECU does not notice this? Also, which side of the EGR did you block? I'm assuming the one before the EGR itself. Thanks
 

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Discussion Starter #20
And also...did you buy the plate or make one yourself?
 
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