Post head gasket issues

[Fozziebare]

So I have a 2009 base Forester with the EJ253 NA CARB model. We bought it back in 2010 used with 18K miles. Found out it was a former Enterprise rental vehicle. It was rock solid until last June at 183k miles it started having misfire codes.

I did a compression check and I had 2 cylinders that were low. The head gaskets had been leaking oil for quite a while so I just bit the bullet and pulled the engine. Took the heads to a machine shop that is familiar with Subie's and he went through them for me cost $600. I put it all back together using Fel Pro MLS gaskets which I have recently heard are junk? Everything else was Aisin OEM stuff if memory serves me.

Not long after finishing that job the car suddenly one day wouldn't seem to accelerate and was stumbling very hard and stalling. Come to find out both catalytic converters were clogged. I got a cheap manifold/cat off eBay and hogged out the rear cat to be sure that would fix it. It did. But the cheap manifold/cat only lasted a couple weeks before it broke up inside. I contacted the seller and they sent me a new one.

At some point I purchased a Walker manifold/cat and a Walker rear cat pipe. The car has been running perfectly with that combo up until about a week ago when I took the car to get some dinner and it started acting up again just like when the cats were clogged up. So I yanked off the manifold and the rear cat pipe and found them both plugged up again?

I still had the cheap eBay manifold and my old rear cat pipe minus the cat which I put back on and the car is again running. But the exhaust doesn't smell right, what I mean is it smells like burning oil? When I did the head gaskets I was going to just purchase a JDM complete motor with low mileage but the machine shop guy said that wasn't necessary that all I needed to do was have the heads done and replace the gaskets and I would be good to go.

So now I am thinking I wasted my money and should have just gotten the JDM engine and slapped that in? Looking for any/all input on next steps. I have been looking at used Foresters instead of screwing around with this thing anymore but not sure what to do???

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[arse_sidewards]

First off learn how to use a paragraph.

Second off you need to verify if oil is actually going missing and if so where. If it's being burnt then the plugs will show it. There's no real good path for that though so...

[Fozziebare]

Originally Posted by arse_sidewards

First off learn how to use a paragraph.

Second off you need to verify if oil is actually going missing and if so where. If it's being burnt then the plugs will show it. There's no real good path for that though so...

Well thank you Mr. English teacher. I have edited it for you……..

[TurboRev]

If you enjoy the car and are comfortable continuing repairs, focus on addressing the root cause of oil burning, as that's likely leading to the catalytic issues. However, with the time and money already spent, it might be more practical to move on to a newer Forester with lower mileage. If you really want to keep it without rebuilding again, a low mileage JDM engine swap could be a good middle ground.

[Charlie-III]

Thanks for cleaning the original post, much easier to read.

Since the work done, did you do another compression test? If so, what do the numbers look like now?
Did you ever do a leakdown test? If so when and what were the numbers?

Low compression can be a number of things, but you don't know which ones. Some oil in the cylinder during the test can help diagnose bad rings.
Leakdown tells a lot more. Specifically, intake valve, exhaust valve, rings, or some combination.

If you haven't done the tests, please do so before deciding on anything. Then you can make an educated decision rather than guessing.

[Elbert Bass]

Originally Posted by Fozziebare

So I have a 2009 base Forester with the EJ253 NA CARB model. We bought it back in 2010 used with 18K miles. Found out it was a former Enterprise rental vehicle. It was rock solid until last June at 183k miles it started having misfire codes.

I did a compression check and I had 2 cylinders that were low. The head gaskets had been leaking oil for quite a while so I just bit the bullet and pulled the engine. Took the heads to a machine shop that is familiar with Subie's and he went through them for me cost $600. I put it all back together using Fel Pro MLS gaskets which I have recently heard are junk? Everything else was Aisin OEM stuff if memory serves me.

Not long after finishing that job the car suddenly one day wouldn't seem to accelerate and was stumbling very hard and stalling. Come to find out both catalytic converters were clogged. I got a cheap manifold/cat off eBay and hogged out the rear cat to be sure that would fix it. It did. But the cheap manifold/cat only lasted a couple weeks before it broke up inside. I contacted the seller and they sent me a new one.

At some point I purchased a Walker manifold/cat and a Walker rear cat pipe. The car has been running perfectly with that combo up until about a week ago when I took the car to get some dinner and it started acting up again just like when the cats were clogged up. So I yanked off the manifold and the rear cat pipe and found them both plugged up again?

I still had the cheap eBay manifold and my old rear cat pipe minus the cat which I put back on and the car is again running. But the exhaust doesn't smell right, what I mean is it smells like burning oil? When I did the head gaskets I was going to just purchase a JDM complete motor with low mileage but the machine shop guy said that wasn't necessary that all I needed to do was have the heads done and replace the gaskets and I would be good to go.

So now I am thinking I wasted my money and should have just gotten the JDM engine and slapped that in? Looking for any/all input on next steps. I have been looking at used Foresters instead of screwing around with this thing anymore but not sure what to do???

Did you perform a cylinder leakage test before repair? What were results?

Do you recall inspecting cylinder bores for wear patterns/scoring?

When you cleaned the block did you make sure you got any residue out of cylinders before reassembly?
Was there any pitting?
Did you check the deck for flatness?

What did your machine shop do exactly for $600?
Resurface heads?
Grind valves and seats?
Replace or knurl/ream valve guides?
Replace valve seals?

If you can rule out a severly rich fuel mixture and you smell oil, then chase down the oil issue.
First thing would be pull the spark plugs to see if the oil is burning in the cylinders. They will be fouled and may have residue if that is the case.

Next would be a cylinder leakage test, that can verify condition of compression rings and confirm any valve work done. 5% - 10% would be normal - maybe 12% given mileage if it is rings. If there is excess leakage you will be able to determine area of fault.
Intake valves will hiss in intake.
Exhaust valves will hiss in exhaust.
Rings will hiss in oil fill cap.

If you have signs of fouling on plugs but acceptable leakdown pull your intake and see if there is oil on valve stems. That would indicate old/loose/damaged valve stem seals or worn out guides/stems. Heavy oil residue up in the intake manifold would indicate a fault crankcase breatherPCV system.
If no plug fouling and acceptable leakdown then pull the exhaust and look at those ports and valve stems same as intake. It is very common for old exhaust valve seals to leak oil and I have seen this as a the primary cause for failed cats may times.