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Oil Consumption - PCV valve or catch can? *SPECULATION*
Alright, I'm new here. I had all but settled on the 4th-gen TL 6MT as my next car when I found out about the oil consumption issue on the J37A4.
I've been reading about it for hours, kid you not. I feel like I understand it. Some owners have it, some don't, and its severity varies. It's a luck-of-the-draw thing it seems.
Some people here have seen good results from switching from 5w-20 to 0w-30 or 0w-40, since those are the recommended viscosities for the same engine outside the United States.
I read the warranty letters sent out by Acura, and they point to carbon build up in the piston rings. Makes sense, it would be a self-compounding issue once it starts. A little oil gets burned, leaves carbon deposits, causes bad sealing, more blowby burns more oil, leading to more carbon deposits.
HERE'S MY QUESTION: In all my researching, I have only seen ONE person report that they replaced their PCV valve. That person said that in conjunction with heavier oil, the new valve nearly eliminated their oil consumption.
Another person said that after a timing belt service and valve adjustment, their oil consumption disappeared. I would assume that the disassembly of the engine to perform the service would involve taking the PCV system apart, and replacement PCV parts is part of the normal timing/valve service. Correct me if I'm wrong.
Am I not reading enough, or is this a maintenance item that has been overlooked?
I don't pretend to offer an actual fix here, but it's a data point that I want to investigate. Reports say the oil consumption starts around 40k miles and some have it worse than others. A bad PCV valve could certainly happen around that mileage, and allow excess oil into the engine and cause carbon deposits in the piston rings.
Furthermore, oil from the crankcase is much less likely to get into the piston rings than oil from the combustion chamber. I believe the oil being burned is coming from above. Even if bad ring tolerances were allowing too much blowby, preventing oil from entering the combustion chamber in the first place may reduce or eliminate the issue, no? If it's coming in through the valve guide seals, then forget it...
My big kicker question: HAS ANYONE INSTALLED A PCV CATCH CAN? I've searched the forum but can't find any indication that anyone has. A catch can could determine if the oil being burned is getting fed through the PCV system. If it is, and that is what's causing the deposits on the rings, the catch can may be a big step in alleviating the issue.
Another thing: Every Honda engine I've ever inspected has had lots of air coming out of the oil fill cap while running. No matter the mileage or age. I've read this is normal, but it certainly points to a system with higher blowby than others. (My 1998 Lexus GS400 V8 with 207k miles has no detectable blow-by and doesn't burn any oil as far as I can tell. I've never changed the PCV.) It makes sense that the PCV would be much more critical on Honda engines.
AGAIN, this is all speculation. There's probably more data out there that I've missed. But I really want to buy this car, and find a workaround or solution to the oil burning problem.
Interesting questions, but I think some of those reporting considerable oil loss have seen it from day one, which would seem to be contrary to the PCV theory, at least as to those cars.
Interesting questions, but I think some of those reporting considerable oil loss have seen it from day one, which would seem to be contrary to the PCV theory, at least as to those cars.
It totally possible, though, that a badly manufactured PCV valve (or crappy design) could cause problems at any stage in the engine's life, even when brand new.
The one thing that would blow this theory to hell is if the problem-free J35 engines use the same PCV parts and setup.
It totally possible, though, that a badly manufactured PCV valve (or crappy design) could cause problems at any stage in the engine's life, even when brand new.
The one thing that would blow this theory to hell is if the problem-free J35 engines use the same PCV parts and setup.
Can't speak to what other J series use, but I would imagine it's very similar to the J37. I have tried replacing my PCV valve with no luck, and most recently had pistons replaced through Acura warranty which has solved the oil burning.
Most recent word seems to be that they had modified the coating of the pistons and cylinder bore to reduce temps and eliminate the oil burning.
It certainly doesn't hurt to take whatever precautions you can to reduce/eliminate oil consumption but I think the problems run deeper than the PCV valve. I've installed on oil catch can on my FWD and got nearly no oil after 7K miles. I couple drops came out. After that I removed it since it obviously wasn't really needed. But it might be interesting to see what results you get from the 3.7L.
It certainly doesn't hurt to take whatever precautions you can to reduce/eliminate oil consumption but I think the problems run deeper than the PCV valve. I've installed on oil catch can on my FWD and got nearly no oil after 7K miles. I couple drops came out. After that I removed it since it obviously wasn't really needed. But it might be interesting to see what results you get from the 3.7L.
Thanks for the info. I'm gathering from your avatar that you installed the catch can on the 3.7. Did you also have any oil burning issues?
No, I'm FWD, 3.5L. Different animal I know. Which is why I said that it might be interesting to see what results from a catch can on a 3.7L. The 3.5L used conventional cast iron cylinder liners, not the siliconized ones the 3.7L had.
No, I'm FWD, 3.5L. Different animal I know. Which is why I said that it might be interesting to see what results from a catch can on a 3.7L. The 3.5L used conventional cast iron cylinder liners, not the siliconized ones the 3.7L had.
I gotcha, I just didn't know what engine you had. I'm not as familiar with Acura's lineup as I am with Lexus.
12-21-2018, 04:34 PM
Oil Consumption - PCV valve or catch can? *SPECULATION*
