Now that we have the RH cylinder head off this 2014 Subaru Forester, let’s replace some EXHAUST VALVES!
One out of 4 valves is obviously severely burned, but what do the other 3 look like?
What is the ROOT CAUSE behind this weird failure?
Lisle 36050 Valve Keeper Remover and Installer Kit:
https://www.amazon.com/dp/B0012S61IO?tag=onamzpineholl-20&linkCode=ssc&creativeASIN=B0012S61IO&asc_item-id=amzn1.ideas.2N7WCA81DLG3L
Enjoy!
Ivan
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Hate to say your lap technique could use some tweaks… Those seats should have been ground
Uh oh here come the experts
Hi Ivan, that all most looks like someone has been running E-85 in that engine and the alcohol has been eating away at the valves.
Exhaust temps way too high. running lean.
I think I would have taken that head to get a valve job on it, the lapping isn't removing much of the pitting.
I was just Gunna ask that. what would cuz the exhaust valve to start split like that?
Noticed the right angle cordless wrench you were using. Thinking of buying one. Which is more useful, an impact version, or ordinary cordless wrench type ?
We used a stick with a suction cup on it and spin it like you would start a fire in the woods.
Ivan I thought new valves were “E3” not E2’s. Did I misread that table you referenced.
Hope you made a disclaimer with customer not having machine shop recondition the head. New keepers maybe??
If you use a drill and hose to lap the valve you get a great product.
Valve is not cracked its burned and was run quite a while after being burned.
In all conscience I could not have put that head back on without more work on the valve seats. Agreed budget or not, having gone this far a few extra minutes spent makes no difference to profits. Also I would have fitted the camshafts and checked the valve clearances before reassembling the engine.
I am guessing that the valve was leaking in that one spot, and the heat of the exhaust blow torched it's way through it over time. This could be the result of worn out valve guides or a manufacturing defect that took a long time to develop. In either case, it is important to know that a valve dissipates most of its heat by conduction by making contact with the seat. If it can't do this, either due to a negative valve lash or a guide that lets the valve close a bit too crooked, something like this is the end result over time.
Reusing toque to yield head bolts….. EPIC
What about the wrong fuel being used 91 vs 95 causing this problem
Your trying to do a budget repair for the customer people need to understand that , you can only do what the customer will pay for nothing more . The quality of those valves makes you wonder what's happening in Japan these days I suppose the metalurgy cannot be 100% all the time and mistakes are made. I would be giving zero warranty on this job if you cannot do it 100% correctly because of money constraints .
The customer may be using cheap/inferior fuel. I'd use premium from now on,…..
Did you check any intake valves while you had it apart?
umm, that seat is very trashed, it may even be loose in the head after being torched like that. the guide is likely spent also, even if it seems tight and in place.
may get by with it like that on an old mower engine, but it wont hold up long on higher compression injected stuff.
Hello Ivan and nice work as always.
I'm shocked that the valve seat actually survived. WOW! Must be a terribly week (and weak..edit) valve to decay so much and not blow a groove in the seat.
Also loved the review on the Lisle keeper tool. I have used sockets and small/heavy hammer for removal, but the install was amazing! Now looking at this tool to purchase.
PS: No valve stem seals or not an issue with Subaru? BMW's are terrible with stem seals.
P-Chi
I believe the valve burnt because it's a Subaru. Next up; Stripped head bolt.
Using the wrong fuel, or getting a leak from the gasket. Those valves are heat burnt.