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4Af Never Ending Oil Leak Inside Air Filter :(


cool_rolla

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Hi everyone! I'm having hard time figuring out why there's oil on my air filter. By the way, spare me I'm newbie and I am very thankful if you guys could help me out..

 

Here's what I'm up to:

 

I haven't checked the pcv valve yet though I'm not sure if this related to the problem and I feel that the oil came from the other pipe of the crankcase cover. I don't know this other pipe called and how it works (please see attached)?

 

 

Best Regards,

Zandy

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The PCV pipe vents blow by from the rocker cover into your air filter housing, it carries oil with it. Air filters on these systems just end up getting oily. EDIT: the other one sucks fresh air in to replace the crap the PCV sucks out.

Edited by B.L.Z.BUB
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If the pcv is faulty the block can build gas pressure and potentially cause a number of other oil related issues. Pull your pcv and blow through it. They can only breathe one way, from engine to inlet, so that the inlet sucks out spare gases that are a by product of combustion. As you can imagine combustion causes a lot of hot gases to expand, that can be forced through a number of areas into the block.

 

Make sure your pcv works properly, and reinstall it. If the problem persists its something else. Could be you have a tonne of blow by and it pressurises the bottom end and forces the oil out. Mow many ks?

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I feel that the oil came from the other pipe of the crankcase cover.

You're right-

 

As the other guys said, the PCV sucks the fumes that get past the rings out of the motor. However the PCV only works at partial inlet manifold vacuum, such as overtaking, and at idle the valve gets sucked closed. When the PCV is working, the vent tube passes clean air from the filter into the motor. When the PCV is shut the vent tube passes fumes from the motor into the air filter.

 

That is where the oil is coming from, and it is a sign of worn compression rings. How worn?? Well, when you're finding adding oil to the motor is getting too expensive, they're too worn. Until then, its not a problem, just ignore the oil in the folter box.

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@LittleRedSpirit it's been 200k km already.

 

Today I'm about to examine the pcv valve and if it needs a replacement. By the way, do I need to remove the valve cover for me to take off the pcv valve? Another thing, it has air coming out with this other pipe is that ok?

 

I'm very thankful that you guys exists! Thanks a lot for all the replies. :)

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Air comes out of the other pipe when the PCV is shut.

 

The PCV just pulls out of the rocker cover. It has to be vertical to work so look up as you cover your mouth with oil! You can blow one way but not suck the other if you suck quickly. You actually suck the piston down onto its seal against a light spring, same as the inlet manifold does.

 

If you can suck and blow easily it is broken. However I would expect it to give the motor a massive air leak if it was busted, so I reckon it is OK.

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Hi Guys! (me feeling excited)

 

I just replaced the pcv valve and yup it has to be replaced. I bought a replacement and so far it seems ok and the other pipe is now sucking the air. Now I have to wait if oil still persist from the air filter. I also bought a carb cleaner and sprayed on the fuel vent and almost part of the carburettor. :)

 

Thank so much guys for helping me out!

 

Cheers!

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I had a funny feelng that was what you meant, but I couldn't see why anyone would replace the housing and not just the filter.

 

The attachment is a one-way valve, part of the anti-pollution gear I think, but I can't remember what it does. I'm pretty sure if it leaks it affects the idle straight away, but this was 40years ago on Datsuns. I took all the non-essential hoses off the KE70 and blocked the tubes when I bought it, then I fitted SU carbs.

 

Someone on here will know....

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That looks like a thermo-sensor that attaches to a vacuum motor to open/close a flap in the inlet tract to allow either warm air from the exhaust riser pipe into the air filter, or air from the inlet pipe. 2A-C & 4A-C's were fitted with them at least, I recently discovered my old one was locked shut, meaning my engine was always sucking in hot air from the exhaust manifold.

Edited by carbonboy
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Hi,

 

I replaced the air filter with this one image attached. Now, there is no other way to attached the thermal valve thingy otherwise I could make a hole to the air filter housing to fit in to it though I'm not sure if its going to work. Is there a way to test if this thermal valve thing still working? I'm trying to suck/blow the pipe if air is coming out (me looking stupid :P).

 

Last thing, Is it safe if I temporarily plugged off the thermal valve thingy?

 

Best regards,

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