Pauls94accord

Hi everyone,

I have a 1994 Honda Accord LX with a manual transmission pushing 332K miles on the original engine, transmission, and clutch. For the past 2-3 years I have been dealing with oil issues. I did some fixes (seals, gaskets, etc) and what I found out recently is that my PCV valve works but not when it is installed. Let me explain: if I pull the hose off the PCV valve no air comes out and if I remove the PCV valve I get tons of air...but if I blow on the PCV valve while it is in my hand it pushes air just fine. When I shake the valve I hear the ball rattling inside. I purchased this unit about 2 years ago from Amazon and yes, it is an OEM unit. I also blow into the hose that goes into the Intake Manifold and it is clear.

My symptoms are I am getting oil pushing through the rear main seal. I was getting oil pushing through the oil pan but I fixed that and now it is pushing through the rear main seal. My question is what is causing the PCV valve to act the way it does while installed on the car but works fine in my hand? Is my engine producing so much pressure from being high mileage that it pushes the ball inside the PCV valve and blocks the air flow? Can that even happen? I can't think of why else it would do that.

Is there a way that I can resolve this if we can't figure this out? Any solutions would be helpful. I have a good amount of experience working on this car and I have done an engine swap on another car so I am not afraid to wrench away.

holmesnmanny

if the rear main seal has never been replaced then it's way passed due to be changed

Pauls94accord

I ordered the rear main seal but I was told after the fact that it will still leak because of the PCV blockage. If I can get this PCV issue fixed then I will see how the rear main seal holds up and replace it if it's still leaking.

MAD_MIKE

Have you tried cleaning the PCV with some TB cleaner? If the PCV ingested some goo it may be sealing closed, which it shouldn't totally under high vacuum(idle).
High Vacuum, low flow.
Low Vacuum, high flow.
Positive pressure(boost or backfire), prevents backflow.

If the PCV valve is operating insufficiently and not allowing crankcase gasses to escape, this will cause sealing issues later.
Why did you replace the PCV valve the first time?

Pauls94accord

I just cleaned it with some Intake cleaner and it still operates the same - it plugs the crankcase air trying to escape and if I take it out and blow into it the air flows just fine. I may not have waited long enough after starting the car but I have only ever seen a high positive pressure coming from the crankcase.

Why did I replace it in the first place? Because I was dripping oil from my oil pan and I had a lot of positive pressure coming from the crankcase and was told to replace my PCV valve because it was most likely not working correctly. I am looking at it again because I finally fixed the slow constant leak from my oil pan and now I am getting much more oil from my rear main seal.

MAD_MIKE

With the PCV valve connected to the manifold and engine idling, when you place your thumb over the end of the valve can you rattle the valve or is it stuck ? Some PCV valves may seem like they are fully sealing but if you put your thumb over the end(properly sealing it) and the ball inside rattles then it is not sealing and is working properly.

Have a leak down test performed. A compression check might show a low cylinder, but if it was like my old engine the compression check showed fine. #4 piston stated to make a racket finally after blowing out several seals, replacing them and then chasing them again. RMS finally blew and made a mess.

Pauls94accord

I am also getting lots of rough idle from 1600 up to 2500 back and forth that I didn't have before. It would just jump up to about 1600 rpm and then idle back down when it was warmed up.

Edit: the rough idle goes away when I connect the hose between the pcv valve and intake.

Pauls94accord

Mike, with the PCV valve connected to the manifold and engine idling I placed my thumb over the end of the valve and I can feel the vacuum on my thumb and when I rattle it I don't hear or feel any movement of the ball inside. So does that mean that I need a new PCV valve? Strange because I probably only put about 10-15K miles on it max.

MAD_MIKE

That would most likely be the FITV on an otherwise normally running engine. You can check it. Pull it off and make sure it is clean and the locking ring is not loose if so it will need to be snugged up against the ball. Check the FAQ at the top of the page on IACV/FITV cleaning/adjustment.

If there is a dying cylinder it may be causing some erratic behaviour and crankcase overpressure and blowing seals.

MAD_MIKE

If your thumb is feeling vacuum then the valve is not sealing completely, which is what you want.
You might not be able to feel it rattle completely but you should be able to feel some movement. Newer style PCV valves are made to be much quieter than typical 70's/80's PCV valves which rattled quite a bit.

Pauls94accord

Not sure if I have stuff blocked since I am new but I searched for IACV and FITV in the FAQ page and I get nothing. Can you point me to the page?

Also, will any codes be thrown if a cylinder is dying? I haven't noticed any loss of power or fuel consumption differences. I still get 400 miles per tank as before...even higher at times.

MAD_MIKE

Don't think you can block the stickies, unless there is a difference between PC and Phone.

1990-2002 Accord FAQ

Is at the top of the page. Or click on this^ link.
It will be in the 'engine' section.

holmesnmanny

its very easy to test a pcv valve, you simply pinch off the hose while the car is idling, if the valve clicks it's good

Pauls94accord

Thanks guys for your help. At this point I think the PCV valve is good to go. I also feel that I jumped the gun on the rear main seal because I have a sneaking suspicion that my oil pan is still leaking and that is causing my oil dripping and not the rear main seal. It is probably leaking right next to the transmission (and looks like a rear main seal leak) so I will take care of that first and then see how it goes after that.

I will let you all know after that...probably some time next week.

Thanks!

Pauls94accord

Finished what I wanted to do over the weekend and so the verdict is good and bad. The good is that my 1 oil drip/sec is now one drip every 30 seconds so I improved my oil pan leaking by patching it up. The bad news is that with the flywheel cover off it looks like there is a lot of oil covering the area around the rear main seal...so that means I need to take the transmission off and get that replaced. I got the rear main seal that I ordered so after a total of 20 bucks and some down time I should be good to go.

I found a youtube video with detailed instructions on removing the transmission and he stated about 2 hours to remove it so I am planning on waking up a few hours early on a couple of Saturdays to replace it since I don't want to interfere with my family's summer plans. Anything else I need to know while I take off the transmission?

I also got the fast idle issue resolved by cleaning and tightening down the IACV/FITV (and I cleaned out the throttle as it was filthy) so I am happy with that. Thanks Mike for that!

Pauls94accord

I really need some help here! I am trying to separate the transmission from the engine and I just can't get it off. I have everything separated: shift mechanism, starter, the three transmission bolts (the 4th bolt is part of the starter), the five bolts from the bottom, the rear mount bracket and the transmission mount bracket is just dangling, all the other little parts, too. Where I see it is getting stuck is at the bottom of the engine right next to the flywheel at the rear of the engine. If I try prying the transmission at the bottom front of the engine it cracks apart but when I release it, it goes right back. I can barely get a fraction of a millimeter for that spot right next to the flywheel at the back of the engine but it goes right back....there is almost no play there. I use my feet with a pry bar but the entire engine just seems to rock back and forth.

There was also a spot from the top of the transmission that I used a pry bar against the engine but that little tab broke.

Any ideas at this point? I probably won't work on it until next Saturday.

holmesnmanny

it's likely there's a bolt there that you haven't pulled