PCV + Catch Can

Hi,

I am finding oil in my air intake but have noticed something a little odd. The hose coming from the one value cover which has the pcv value goes into the in-take manifold but the hose from the other value cover goes into the air box before the throttle body. I have oil in the air box which I think is because the pcv was stuck close (i know it's not stuck now, because I replace the old one that wasn't stuck closed anyways and the old one wasn't stuck close but maybe it was before I purchases the vehicle) forcing oil vapour to flow back the other way into the air box. So my questions is that what would have caused the oil it get into the air intake? And since I am looking into installing a catch can which line do I use for this? Should I use both? And Do I still need the PCV in place if I go with a catch can.

Thanks,

Carl

Reply to
carlbernardi
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Unfortunately that amount of blowby with a working PCV valve normally means you got suckered into buying a vehicle with a blown or totally worn out engine.

You need the PCV working or sludge will fast fill up the engine, well, the engine might last long enough for sludge to fill it....

A compression and leakdown test might tell you what is worn out.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06
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Reply to
Mike Romain

You don't mention what vehicle or engine you are dealing with here. Are you still getting oil in the air box or did that stop when you replaced the PCV valve ?

You do not want to modify or disable the PCV system. The PCV ( positive crankcase ventilation ) system removes harmful vapors from the crankcase that otherwise might cause sludge or engine deposits. The hose with the PCV valve sucks air out of the engine and into the intake were it is burned. The other hose, on the opposite valve cover, lets clean air into the engine. Possible causes of your problem would be a plugged PCV valve, a plugged or collapsed PCV hose, a leaking PCV hose, PCV hose vacuum port plugged at intake manifold. Remove the PCV valve with the engine running, you should have vacuum at the PCV valve. If no vacuum remove the PCV valve from the hose and check the hose for vacuum, if no vacuum checked for plugged intake vacuum port.

Reply to
Mike

I was also thinking that a bad evaporative control system part like a charcoal canister blown can interfere with the PCV if you have such a thing on the vehicle.

Reply to
Mike Romain

It's a 1998 Ford windstar. They are known for problems with oil in the air box caused by a value cover that does not have a cover/baffle where the pcv valve outlet is which gets oil in the value and blocks it. The motor runs fine but runs rough for a few seconds after I started from hot, starts excellent from cold. After I replaced the pcv value it ran great for about two weeks then the restart problem started again. It never stalls, not even in gear, just idles rough for a bit. Anyhow, I didn't quite a bit of research and one solution was to use a catch can but I could find more in formation on which line to put the catch can on. I think I am just going to do both and then figure out a way to get a cover for the pcv valve inside the valve cover.

Thanks,

Carl

Reply to
carlbernardi

You are going to want the PCV to still suck or the engine will fill with sludge. You put the catch can on the intake line that went to the air filter. I would recommend some kind of filter on the can so dirt doesn't get sucked into the engine when the PCV does work.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail > It's a 1998 Ford windstar. They are known for problems with oil in
Reply to
Mike Romain

Hey,

I just bought a OBDII scanner and it gave codes p0455, p0174, p0171.

P0455 is a EVAP Emission Control System Leak (large) P0171 System to lean(bank 1) P0174 System to lean (bank 2)

The van ran fine all day until I clear the codes then I started to have the restart idle problem. It never throw another code though. I also picked up a desiccant dryer that would normally be used for clean an air line for air tools. It comes with a cartage the filters, dirt, dust, water, and oil. The cartage is replaceable and cost about $2. Still have to hook that up.

Thanks,

Carl

Reply to
carlbernardi

Bingo. The code PO455 will usually result in oil puking into the air filter and a rough idle by leaning the crap out of the engine.

Your charcoal canister has issues....

Mike

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Reply to
Mike Romain

A stuck PCV valve will force oil vapor back through the vent tube from the other valvecover into the air cleaner. It will leave an oily residue there, maybe even a little puddle of oil.

Unfortunately, badly worn rings and a lot of blow-by will do the exact same thing even with a working PCV valve.

Reply to
Steve

Nope. Charcoal canisters are for fuel vapors, crankcase vapors don't go there.

Reply to
Steve

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