91 Jeep Cherokee 4.0 V6 automatic with approx 100k.
The mother-in-law drove up from Binghamton today and got here around 3pm. I got home around 5 and noticed a 2 foot diameter puddle of oil forming under her Jeep.
I popped the hood and I can see some oil was forced out past the fill cap but the majority was coming from the air filter box. After opening it up the filter is soaked and there’s standing oil in the bottom. Clearly it is being forced out through the PCV valve, down the tube, and into the airbox. PCV valve replaced about a year ago I believe.
I’ve heard of this before but can’t remember what causes it. I’m heading over to google now but figured I’d post here first looking for advice. Don’t want the mother-in-law stuck here any longer than need be.
The pcv does not get its source from the air box. Oil is being pushed pashed the breather into the air box. Which means change the oil and replace the PCV vavle again as it is probably clogged causing the problem.
V6… I6… bah, you get the idea smartass. It’s a POS leaking oil on my driveway.
Pulled the rear line and looking inside the valve cover it’s a mess of sludge and crap. Part of me wants just try flushing it with fresh oil but I really think I should pull the valve cover and clean everything up.
Don’t think you can change the PCV valve on these because it’s built into the valve cover from what I was just reading. From the link I posted earlier:
The valve cover on the 4.0L has two breathers on it, the front one is just that a breather but the rear one is a PCV {positive crankcase ventilation} valve, breather, I say breather because the PCV valve is built into the valve cover. And the only way to replace it is to get a new valve cover, but this is probably not your case. What happens is the rear breather is made of rubber and after time it hardens and tends to close up and or plug up with soot. In tern this puts all the engines crankcase pressure threw the front breather and causes it to carry oil through it to the air filter.
Who the fuck designs something like this? Oh yeah, the morons at Chrysler.
Yeah, re-reading that I can see I wasn’t real clear. I mean the majority of the oil leaking all over my driveway was coming from the airbox. I understand it was being forced up from the valve cover, through the PCV valve, down the tube, into the airbox, then onto my driveway.
Don, do you think just flushing some walmart special oil down through the PCV inlet as well as the oil fill and immediately changing it will do the trick, or do you think I should pull the valve cover and really clean it out? Maybe change it with the cheapest thinest oil I can find, run it for a few minutes, then change it again with decent oil? If it was the mother-in-law’s boyfriend I would take joy in the idea of him stranded on the side of the 90, but I actually like my mother-in-law and want to make sure she makes it back to Binghamton. Obviously I’ll be changing the PCV breather and blowing it’s line out with brake cleaner.
drain whats left of the oil, put in 3 quarts cheap oil and 2 quarts tranny oil, let it idle till warmed up then change the oil again. the detergents in the tranny fluid will wash out most of the gunk. it wouldnt hurt to do the tranny fluid oil change then do another with sea foam…
Took the valve cover off after removing the oil fill and both vents and realizing no seafoam tricks were going to fix this. I honestly don’t know where to even start cleaning this. My guess is clean the valve cover and just leave the rest alone? The one picture with the screw driver shows how thick the coating is (at least 1/8th, probably 3/16ths) and the next picture shows the scrape on the valve cover.
looks like it’s never had an oil change … maybe once a year … becareful how much you clean out … you dont wanna open a can of worms … loosen up too much sludge and ya might end up wiping out a bearing
Yeah, no shit. I think I’m just going to clean the valve cover and leave the valve springs/top of the motor as is. Scrape off the old gasket, slap it back together, and hope that fixes the oil blowby enough that she gets home with it.
As it is some little part that I have no idea what it is broke while getting the valve cover off. 4 coolant lines about the diameter of my thumb all come together at this part and one side snapped off. Almost no force at all, just rusted to shit. I hate working on old POS’s, especially when they’re not mine.
I’m going to go take a picture of it and maybe someone can identify it before I head to the dealer tomorrow.
Heat control valve. 22.50 online. Dealer probably wants 50+. Oh well, ain’t my money.
EDIT: Normal stock @ autozone, $18.
Anyone bored tomorrow and feels like hanging out while I clean this bitch up and put it back together drop me a PM. Fridge is always stocked with Blue/Blue Light. Probably go parts shopping around 9 and be in the garage after that.
I was thinking that, but I’m afraid of how long the plugs have been in there. I’ve already broken two parts getting this valve cover off because it’s clear almost nothing has been touched under this hood since 91. All I need is to strip a damn plug. I’ll suggest she have one done when/if she makes it home.
