TJGriffin23

My Cherokee's gas mileage has been slowly dropping and when it sits in idle for a bit before its driven away it looks like a scene from what the "smoke on the water" music video would have looked like except bluesmoke, and the smoke is sitting on the pavement, not the water. I think I have a leak somewhere, well I know I do cus there is residual oil all over the place and has been for the last 10,000 miles (it has 248,000 almost)
So I got some ring sealer to throw in with my next oil change. Im sure it will make the problem less bad than it is now, if not completely fix it. Has anyone ever personally used that kind of product and it mucked up the engine?
If it doesn't work can some one point me in the direction of how to's on replacing rings and other things that keep the engine from leaking oil and a time estimate on how long that sort of project takes... more than 8 hours?

Looking forward to hearing from everyone.

codykrr

Blue smoke tends to be two things.

if you say your gas milage is dropping then it means its probably running rich. try an injector cleaning and check your fuel pressure.

thats why once its idling the smoke is worse. its "loading up" on excessive amounts of fuel. some blue smoke is normal(ish) but lots of it is not good. Id go buy a can of seafoam and put that in a half tank of fuel and run her almost dry. see if that helps. if not then an injector cleaning is in order.

its not hard, to clean injectors. you will need a 5cc syringe all of your injectors out, and brake or carb cleaner. a 12 volt switched source or you can even get buy with a couple AA batteries and a switch.

there are videos on youtube on how to clean injectors.

Now that being said.

it could also mean you are buring oil. this would most generally be cause by bad valve seals. which is more involved than cleaning injectors. more like a weekend project(or a case of beer- I rate jobs by about how many beers one could enjoy before the jobs done) But to add, most generally vehicles I have seen with wore valve seals tend to smoke primarily on start up. so thats why Im leaning to running rich. but do not rule out the possibility of a needed head job.

it could also be as involved as needing new valve guides or valve seats.

I would try the fuel system first.

change fuel filter(if its not in the tank) check fuel pressure, and then clean injectors.

if you do all that and its still burning blue smoke..time for a head job.

TJGriffin23

Today I mixed some ring sealer in with my new oil that I just changed. I hope thats not something I will have to do every time that I change my oil. Im gonna get on the fuel filter and injectors sooner rather than later.

belvedere

Which product exactly did you use? How many miles are on this engine? Have you done a compression test?

TJGriffin23

it was just called ring sealer. it was see through but super thick like honey. I have not done a compression test, where can I get that done for free? it has 248xxx.

I think the reason it is leaking oil is cus the crank case seal is bad or loose. Where the engine meets the crank case there is a lot of built up oil residue. I should probably get on that right away, it shouldn't be too difficult, its right on the top of the engine!

cruiser54

Here's how to diagnose the oil leak and it keeps you from automatically assuming it's the rear main.

　
I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.
Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking.
Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?
A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.
First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.
Revised 02-26-2013

salad

No amount of blue smoke is normal. Check what cruiser54 suggested. Leaks being an obvious suspect as oil hitting a hot exhaust burns into blue smoke. Then do a compression test to see if the problem is rings or something like valve seals. Products like RESTORE will help with rings for a bit but won't do anything for upper cylinder problems.

Sometimes you can rent compression testers, otherwise you can buy 'em. I picked up my testing kit for $15 or so on sale.

belvedere

Just a Band-Aid, then. Real thick oil might burn a little slower. Don't use it in cold weather.

Probably nowhere. DIY or pay a shop for an hour's labor.

TJGriffin23

I watched some videos and have learned a lot about possible areas for oil leaks. Now I need to get under my jeep and check with my knew Cherokee knowlege.

TJGriffin23

Thanks all, espeacially cruiser 54, I learned a lot from the information you gave me. So if me rear seal was to be leaking wouldn't my garage have oil spots where the leak is occuring?

There are no signs of leakage on the ground. only some minor build up around certain areas under the hood and the bell housing.

cruiser54

With my hokie write-up, you are now fully equipped to diagnose the leak yourself.

TJGriffin23

no more blue smoke. thanks all

cruiser54

And why is there no more blue smoke?

TJGriffin23

because of the thick stuff i threw into the oil to seal her up

kennzz05

dream on it will be back as mentioned thats not a repair but a patch up, yes oil leaks will leave spots. burning oil is something completely different