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2016 Forester Diesel
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Discussion Starter · #1 ·
Hi Folks, Need some advice from an experienced tech please. I am new to Subaru, although lve spent many years working on other makes.
I aquired a 2016 diesel Forester with 180,000km on the clock, knowing that it had some engine problem. Not too worried because of the Subi's reputation. However this got quite complex.
The engine had high oil level. Corrected that. Has a knock that sounds like a gudeon or cracked piston.????
Drove it for 20km, it drove perfectly, no codes etc , but oil level came up by about 500mm. When I got back to base,smoke filled the cabin, I found oil& diesel was spilling from somewhere around oil filler cap and burning on top of the dpf heat sheild. The total trip was only 55km.

Ok time to pull the engine out. Pulled off the intercooler and found that I had a brand new short motor. A few checks led me to a local Subaru dealer. The service girl admitted that they had replaced the engine. This one has only travelled 2500km !!
Why had they swapped it when the original engine had only travelled 180,000km? It seized, I was told. And this new short motor came from Subaru and is under warranty. Yippi! They had the Forester for six months while they thought and thought and.....did whatever half witts do. For me, it went typical dealer experience as they tried to gouge money out of me for diagnosis and in the same breath, renege on the warranty. I gave up on them.....Why?

Why? I assume that one of the dealer's idiots has transfered some component from the seized motor to the new one and killed for a second time. Subaru will tell the dealer to go take a jump if he tries to return or swap it. I suspect the HP pump is leaking but cant test it on the engine. Curious about this too- used a stethescope to try and pin point the knock, no luck, but both the metal HP lines going from the rail to the RH injectors give a sharp ringing sound. Can slightly hear same sound from sump via oil filler.
Im winging it without a workshop manual so Im open to any suggestions. Thanks G
 

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2010 Forester Diesel 6sp Manual
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165 Posts
Id guess fuel feed or return is leaking on some injector. Since feed and return are connected to injectors under valve covers it can be hard to diagnose. If something leaks there, it goes straight to oil sump.
 

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2016 Forester Diesel
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Discussion Starter · #5 ·
Id guess fuel feed or return is leaking on some injector. Since feed and return are connected to injectors under valve covers it can be hard to diagnose. If something leaks there, it goes straight to oil sump.
Workshop scanner shows all injectors functioning normally. I cant see how the sump can be flooded with diesel via an injector, maybe Im wrong. Give me your figures.
My calculation is;
20Km = 12.4 miles > half a litre.
55Km = 34miles > flooding
 

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2010 Forester Diesel 6sp Manual
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Thats the only place where fuel meets oil. If the block is new, I doubt there would be piston or block damage causing fuel to get past piston rings. If that would be the case there would also be serious blow-by.
 

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2012 SH Manual Diesel
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788 Posts
Internal leak in fuel pump? Or maybe faulty pressure limiting valve, causing diesel leak?

Maybe a worn shaft, or dodgy seals; somehow allow diesel to seep into where the fuel pump gear, drives off the motor.

Possibly why it seized in the first place (diluted oil); and Dealer fixed the symptom (new short block), but not the problem (fuel leak?).

I imagine, if you had excess diesel in the cylinders, you’re gonna have some rough running. So if it ran fine, it must be via another route. High Pressure fuel pump, is all I can think of too.

I’m not sure how, the two procedures below (attached), actually impact the pump. But its possible that someone missed these steps during the short block install (the second one, being the removal of the M6 fastener). I assume there must be some end-float in the pump gear and sub-gear to allow compensation for injector pulsing, and rpm change 🤷‍♂️
 

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2016 Forester Diesel
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Discussion Starter · #8 ·
@Dogs

Hi Mate,
Thanks for the info.
I think we are in lock step on the HP Pump dumping fuel into the sump. Im not into coincidence, so 99% sure excess diesel caused the original engine to seize. The driver probably always assumed he had oil because of the level on the dip stick.
On the drive across to the low-life dealer I periodically saw smoke out the back, but as said, it ran sweet. P0401 appeared on the return trip.
The ringing sound on the RH injector fuel lines still intrigued me. Spent yesterday avo getting to those injectors. Both are clacking and vibrating. Disconnected them seperately and the source is #3. Something is bouncing around in there.
At this stage, a complete motor from Sydney seems the quickest and most economical way out. Then I can strip this one down at my leisure.
cheers G. ( Brisbane)
 

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2012 SH Manual Diesel
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If the fuel pump gear, still has the M6 bolt still inserted in it (or if the clearance is way out of spec), then thats a ‘New’ engine... Case Closed! Cold hard evidence, that someone stuffed up, as the bolt is only meant to be inserted to measure and adjust clearance between the Gear and sub-gear.

Is the current engine still running ok? Could a new fuel pump (if that is indeed the issue), bring the car back to serviceable condition?

I’ll see if I can find more info. I only found stuff on the 09 Diesel, which I think is the Euro 4 model (or something like that). Also maybe Outback or Legacy diesel searches, may provide some info.
 

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2016 Forester Diesel
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Discussion Starter · #10 ·
@Dogs

Strangley, it does run perfectly... if you ignore the knock. Just that I feel the internal part that is rattling around, is due to make its exit through block or head. With the stethoscope on the RH injectors I could not only hear, but also feel a chronic knocking; most distinct at #3 cylinder.

Like you, I found info on this motor almost non-existant. Ive been working especially on Hyundia for the past 6 years and its the same info vacuum with their diesels.

I bit the bullet this morning and bought a motor from JJ in Sydney. ( They asked if I wanted to go down and pick it up; said I would love to but given covid, not sure if I would ever get back over the border).

I will keep you posted when I have the dealer's brand new engine stripped down.
 

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2016 Forester Diesel
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Discussion Starter · #11 ·
I have installed the Sydney motor and Forester is running ok. Just waiting for Launch to update their current version so that I can change injector codes stored in the ECU.
Now to the 'Bartoned' motor.
The HP fuel pump remains so suss, Im going to dump it. But that only solves the diesel being dumped into the sump.
The new short motor is sweet as. My complements to Subaru.
However, as expected the dealer performance sux. Upon inspecting the heads, I found that they had used the HP fuel pump and camshafts from the original seized engine.
The exhaust camshaft for 1 & 3 , in foreground, is warped and is binding up.
I had noticed that the engine sounded normal when started after a day at rest, but after 10 seconds the knock reappeared ( as oil pressure rose). The head on the test bench was clean and dry. Camshaft turned over but was lumpy. Removed caps and added oil - torqued caps down and it locked solid.
End of the search.;)

555603
 

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Hey @nzenigma , I'm confused. Do you have 2 engines? The one you got from Sydney that works well and the Subaru replaced-but-gubbed engine that was in the car when you bought it?
If that's the case, the new engine is in situ so, problem solved?

Colour me confuzzled.
 

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2016 Forester Diesel
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Discussion Starter · #14 ·
Yes Bro, thats how I solved it. Wreckers motor is in the car. The dealer ( Bartons ) gubbed engine came with the car.
No way I can claim from Bartons on the camshaft or their incompetence.. What I do know is that they couldnt miss the knocking, but still gave the Forester and its new motor back to the orignal owner. They just hoped it wouldnt come back so they could spend time creating another disaster.
 

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2017 Forester Premium 2.5i, 6-speed manual, moon-roof, fog lights, skid-plates, winch, 2nd bedroom
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A bad injector can cause a diesel to knock. It does not take much liquid diesel in the cylinder to cause a knock, and each knock pumps a little diesel past the rings.
 
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