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[LairdScooby]

Hi All,

while doing some other repairs on my recently acquired Cherokee i noticed just how badly covered in oil the entire engine bay is. Two probably causes spring to mind, or maybe a combination of both.

First is some numpty left the oil filler cap off between services and the engine oil got sprayed here, there and everywhere.

Second is the breathers are blocked and consequently the engine is blowing oil mist out wherever it can, probably the valve cover gasket as that doesn't look too great. Also the oil level seems a little high which will be sorted soon during an oil and filter change but suggests someone has overfilled it to compensate for the fact it blows oil out when it can. Of course it could be blowing oil out simply because it is overfilled but that's another story.

Anyway, back to the main point of the thread. There appears to be two plastic elbows sitting in a grommet each in the top of the valve cover. Can anyone tell me if these elbows are the same internally or does one have some sort of one-way valve or anything? Also are there any filters and/or valves within the rocker cover for the PCV system?

Better still does anyone have an exploded diagram of the PCV system please? At the moment all i have to go on is a Haynes Service and Repair manual which is about as much use as a chocolate teapot.

Either way round, i plan on replacing the valve cover gasket but really want to get the PCV system sorted first. At present, any leaks in the valve cover gasket are probably saving more important seals such as the crankshaft oil seal etc.

Any help/advice gratefully received!

[Dave69]

pop one off and with a bit of kitchen towel blow through, if there is a one way valve it will then be obvious

[LairdScooby]

pop one off and with a bit of kitchen towel blow through, if there is a one way valve it will then be obvious

Thanks for that - at the risk of being thick, if it's a blocked one way valve surely that will be the same as a blocked "straight through" elbow?

I did manage to find a diagram in the Haynes "Service & Despair" manual that depicts the fuel injected straight 6 PCV system and the description said the elbow that connects to the inlet manifold has a restrictor of 2.2mm inside while the elbow that connects to air filter housing is unrestricted. Also on this layout there is no PCV valve as there is on many other cars. The big bug bear though is it didn't indicate if that was a global layout, just for Canada, the US, Europe, UK or what.

I'm kind of reluctant to remove any of the bits without having new bits to fit as they all look incredibly fragile (including the grommets in the top of the rocker cover) and the last thing i want at the moment is to end up having to strip half the engine down to retrieve a broken bit of plastic or rubber from one of the elbows or grommets - hence my question in the first place.

Maybe it sounds like i'm looking for problems, in some respects i am. However, the car has done 245k miles and while it appears some basic maintenance has been done in recent years, there seems to be a lot of neglected items that should be checked, greased, lubed, cleaned, replaced or whatever. For example, it has near new plugs and leads but the dizzy cap has seen better days, it has a new radiator but the coolant is nice, clean, fresh water and the ATF is a watery pinky-brown.

[Mike Pavelin]

 The rear elbow contains the PCV valve. It is supposed to be changed every 60K miles IIRC.

[LairdScooby]

The rear elbow contains the PCV valve. It is supposed to be changed every 60K miles IIRC.

Brilliant! Thanks very much for that, know what i need to try and find now.