Blowby troubles
 

Hi Everyone.

Brand new here so please bare with me.
I have looked and looked without luck to find a solution to our civic problem.
My wife has an 01 civic that she bought new. She has never taken good care of it and I often find there is no oil on the dipstick. Burns some oil....
One oddity I have seen is the air filter is covered in oil. I have seen the breather tube from the valve cover to the throttle body and I'm sure there is oil in this blowby gas but this is all downstream of the filter.
My question is; is there any other crankcase gas entering the intake system UPSTREAM of the air filter that would account for all the oil on the upstream side of the air filter?
I'll be looking at changing/cleaning the pcv valve today in hopes to handle the crankcase gas better and I've also read that with all this blowby that the EGR valve will be fouled.
Oddly enough, this car runs and has run VERY well over the last 15 years and I'm counting on it running for some time to come due to new financial challenges.
Thanks for your help everyone!

Re: Blowby troubles
 

No, especially if you have a stock intake. You can try removing and cleaning your EGR, throttle body, idle air control valve, intake, PCV and get a new filter if you think it will help. Honestly if there is THAT much blowby, you should consider taking it into a shop to get it checked out.

Re: Blowby troubles
 

Thanks for the response.
The car doesn't have any blue smoke nor does it smell at the exhaust.
The TB is super clean. It may use 2 litres of oil between changes (5k) with a lot of leakage.
I will likely do a pressure balance test to see the compression across the cylinders.
Does anyone have any ideas why there is oil on the upstream side of the air filter. Nothing in my mind can explain it. There has to be crankcase gas introduced upstream of the filter....
Thx

Re: Blowby troubles
 

I would change out the PCV valve and not clean it. I would not think they are expensive. The next issue is the lack of engine oil maintenance you hinted at. Years of neglect in oil changes may have resulted in restricted or blocked oil passages from oil deposits/sludge. If the new PCV valve (and new air filter) does not help then you may consider an engine oil flush formula to clean your engine. Make sure you stick to an oil change regiment or you will ruin your engine.


No blue smoke is a good sign for piston ring damage.


These engines are notorious for bad head gaskets. Have you had to replace it yet? Have you had any overheating issues, oil in coolant, bubbling of coolant reservoir etc.

Re: Blowby troubles
 

Thanks for the reply.
Yeah, I will replace the pcv valve and look at the egr valve and Air filter. Beauty spot for the pcv valve I might add. I'm sure it'll be the first time I've lifted a car to do a pcv valve!:-bs:
Engine oil has been changed regularly but it does get quite black between changes. I have done many flushes over the years.
At some point I think it may have been starved of oil resulting in some ring/cylinder wear. I'll do a compression check one of these days. The car does leak a bunch of oil from the valve cover.
Never heard of the head gasket issue for these engines. I'm a Subaru guy so I'm well read on the symptoms and this unit definitely does not have a HG problem. Very good to know though thank you.
I will be looking at all the intake system upstream of the air filter to find the source of the oil. I believe maybe the leaking valve cover may be misting and it is picked up at the inlet nozzle. Just a thought.
Thanks again for the help.

Re: Blowby troubles
 

I removed the intake piping/plenum upstream of the air filter housing and solved the mystery. I think.
So it looks like the plenum before the air filter housing was improperly fitted at the factory. (it's never been apart since new) Rubber gasket was pinched/folded over deforming the plenum nozzle. There was a significant gap allowing air to sneak in at the joint. I suspect the misty crankcase gas was sucked into the air filter housing through the misfit joint and fouled the filter on the upstream side.
Reshaped the nozzle and gerry rigged the rubber gasket and get it back together.
Put a new filter in there and will monitor.
I'll stop by honda and get a new pcv valve in there and we will see where we're at.
Thanks for your help all!

Marko