HunterGreenXJ

I have a fairly steady oil leak somewhere out of the crankcase of my '93 XJ 4.0L. I took it to my local mechanic and he said that my jeep isn't worth the labor cost of replacing the rear seal, where he says the leak is coming from. He said I could try replacing/cleaning the pcv./ccv valve to try to stop the leak. My oil level is dropping from full to add on the dipstick every 2 weeks or so.

My questions are:
1. would replacing the cCV/PCV help fix this leak?
2. How do you go about removing the valve. I have already broken the elbow on the back of the valve cover by trying to pry it out as my repair manual says.
3. Would switching to a heavier oil fix this problem? I am currently running 10w-30, Would 10w-40 help?
4. Any other suggestions for stopping this leak? I can't afford to keep dumping oil in!

jeep19xj91

Those valves are removed by twisting them like you would your oil fill cap. Im guessing the rear main seal is what he was talking about? If i had a shop tell me my jeep wasnt worth the parts i would give them a big FU and find a different shop, or do the work myself.

jeep19xj91

also check your oil filter adapter, mine leaks both there and at the rear main and between the two its losing a considerable amount of oil. Dont run a heavier oil, it only hides the problem and will cause more problems in the future

jakbob

if it is the rear main seal, it is easy as hell to do it. i know a guy who did it in a grocery store parking lot in under an hour... so go back to that shop and tell the guy FU... seriously...

ZINGGG

Yeah rear main seal isn't that hard to do and shouldn't cost that much. And to answer your question, if your rear main seal is leaking, changing out the ccv grommets and elbows won't help. Those are prone to leak too though but it wouldn't be enough to make the overall oil level drop a significant amount. And sorry but that second post is wrong. The elbows don't just screw off like an oil cap. There's more to it than that. You're gunna have to go at the elbow with pliers (get in between the elbow and grommet with them and GENTLY wiggle and lift upwards because those elbows are FRAGILE)

jakbob

x2

ZINGGG

Sorry and to add, don't use heavier oil, don't try any sort of stop leak additive. You're gunna need to bite the bullet and just change it. Spend the time and money cause when the rear main seal is shot, it'll leak A LOT. That is why your oil level is dropping so much. It'll be good to handle the ccv but you definitely need to do the rear main. Sounds like you need to find a better mechanic

aerojt

I did it a few months ago, the worst part is all the bolts on the oil pan. I found that the seal change wasn't too bad. I also have the race on the bottom of my crank, so that was like another 16 bolts...

I would say though labor could add up, depending on the shop.

ZINGGG

It's all about finding the right mechanic. I had a mechanic do all of the following: rear main seal, oil pan gasket, drain plug, both
motor mounts, serpentine belt, flush cooling system, replace thermostat and gasket... All for... Wait for it... $300. And no, I'm not missing a zero. My advice would be to find a new mechanic if you aren't up to doing the task yourself

captainofiron

rear main is really easy, the hardest part is trying to get your jeep high enough so you can easily drop the pan, haha.

if you have alot of blow by then yes the CCV can cause this to be worse.

those elbows on mine turn 90 degrees then pull out.

Another common leaking spot is the back of the valve cover, since that bolt is a pain to get to, I have seen them rarely torqued to where they should be. Also get the Permadry gasket, no cork.

HunterGreenXJ

I likely have alot of blow-by as i'm at 370000 km's (Sorry, Canadian model).

So I take it from being able to change the seal in a parking lot the engine doesn't have to be lifted at all?

captainofiron

nope, only obstacle is the front axle, with some wiggling (or removing the oil pump and pickup) it should come right out

cruiser54

VERIFY the source of the oil leak first. Rear of valve cover due to clogged CCV hoses? Oil filter adapter? Oil pressure sender? Remember, oil flows downhill and the lowest point for it to drip off of is the RMS area. Many other leaks can mimmick a RMS and they're way easier to fix. Have a closer look before you jump on the RMS train.

darknezz

i was gonna say something like this. If its been awhile you should just change the vlave cover gasket as it is even easier and like $7. And while the cover is off you can clean the inside of it where the ccv baffles are. pule the elbows out and spray with carb cleaner.

jeep19xj91

On my 91 they do, its a 90 degree twist to the left and they pop out, i would know because i removed them when i painted the valve cover