PO used "Stop Leak" - any concerns?
Thread Starter
Junior Member
Joined: Nov 2015
Posts: 36
Likes: 0
From: Denver CO
Year: 1998
Model: Cherokee
Engine: 4.0L
I recently found that the previous owner kept records of all oil changes in the manual. Most of the oil changes in the past couple years mention that he added "stop leak" - not sure which product. The jeep does leak a lot of oil and I am about to start replacing gaskets, starting with the valve cover gasket and working my way down. Also not sure if relevant, but I switched to using Rotella T6 5W-40 as soon as I bought the jeep.
Is there anything I should be worried about with regards to the "stop leak"? Is there a cleaner product I should use before I change the gaskets in case the stop leak has gummed things up?
Is there anything I should be worried about with regards to the "stop leak"? Is there a cleaner product I should use before I change the gaskets in case the stop leak has gummed things up?
CF Veteran
Joined: Jul 2013
Posts: 7,554
Likes: 17
From: Monett, MO.
Year: 1999
Model: Cherokee
Engine: 4.0
Stop Leak is used in the radiator to stop small water leaks in the cooling system, not used in the oil at all. In fact GM installed a sealer at the factory in all their new cars for many years, others may have done so IDK.
CF Veteran
Joined: Oct 2013
Posts: 5,924
Likes: 203
From: Greenville, SC
Year: 1999
Model: Cherokee(XJ)
Engine: 4.0
not 100% true they have some stop leaks at the auto parts store for other things like trans I know for sure. Supposed to stop slipping too.
Moderator CF K9-unit
Joined: Apr 2012
Posts: 5,842
Likes: 12
From: Alaska
Year: 2000 sport
Model: Cherokee (XJ)
Engine: New 4.0l from s&j engines
I recently found that the previous owner kept records of all oil changes in the manual. Most of the oil changes in the past couple years mention that he added "stop leak" - not sure which product. The jeep does leak a lot of oil and I am about to start replacing gaskets, starting with the valve cover gasket and working my way down. Also not sure if relevant, but I switched to using Rotella T6 5W-40 as soon as I bought the jeep.
Is there anything I should be worried about with regards to the "stop leak"? Is there a cleaner product I should use before I change the gaskets in case the stop leak has gummed things up?
Is there anything I should be worried about with regards to the "stop leak"? Is there a cleaner product I should use before I change the gaskets in case the stop leak has gummed things up?
CF Veteran




Joined: May 2012
Posts: 7,965
Likes: 964
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Whether any of them are any good or not is another discussion.
Here is one that I have used and it works very well.
rwhealey, I wouldn't worry about it. Your regular oil changes will clean out anything that needs to be cleaned out.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
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. "$hit flows downhill".
Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.
Revised 02-26-2013
Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking.
Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?
A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.
Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.
First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$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
As long as you have good oil pressure and no knocking or odd sounds from the engine it should be fine.Find all your oil leaks fix them and just do a normal oil change on it.I will give you a heads up the valve cover is a good leak point if its leaking take it off and make sure its mating surface is prefectly flat.Some people will over tighten them which warps the edge causing leaks.
Trending Topics
CF Veteran
Joined: Jul 2013
Posts: 7,554
Likes: 17
From: Monett, MO.
Year: 1999
Model: Cherokee
Engine: 4.0
Read the OP's post he said " Engine OIL" changes not other things.
Fred, there are dozens of stop leak products on the market for auto engines, and for transmissions, and for power steering, differentials, you name it. Walk into any parts store and you'll find probably a half dozen different brands on the shelf, or more.
Whether any of them are any good or not is another discussion.
Here is one that I have used and it works very well.
rwhealey, I wouldn't worry about it. Your regular oil changes will clean out anything that needs to be cleaned out.
Whether any of them are any good or not is another discussion.
Here is one that I have used and it works very well.
rwhealey, I wouldn't worry about it. Your regular oil changes will clean out anything that needs to be cleaned out.
Again he said "OIL" and no one makes a stop leak for engine oil, it would cause more problems than it ever could help before it blocked the oil galleys. You are correct on one thing most are a bunch of "Snake Oil" for sure that are sold for other things.
Leaks need to be repaired and none are that hard on the 4.0.
::CF Administrator::





Joined: Feb 2011
Posts: 14,479
Likes: 805
From: Blunt, South Dakota
Year: 97
Model: Cherokee (XJ)
Engine: 4.6 stroker
Senior Member
Joined: Nov 2014
Posts: 603
Likes: 1
From: Hacienda Heights
Year: 1990
Model: Cherokee
Engine: 4.0
Read the OP's post he said " Engine OIL" changes not other things.
Again he said "OIL" and no one makes a stop leak for engine oil, it would cause more problems than it ever could help before it blocked the oil galleys. You are correct on one thing most are a bunch of "Snake Oil" for sure that are sold for other things.
Leaks need to be repaired and none are that hard on the 4.0.
Again he said "OIL" and no one makes a stop leak for engine oil, it would cause more problems than it ever could help before it blocked the oil galleys. You are correct on one thing most are a bunch of "Snake Oil" for sure that are sold for other things.
Leaks need to be repaired and none are that hard on the 4.0.
CF Veteran
Joined: Oct 2013
Posts: 5,924
Likes: 203
From: Greenville, SC
Year: 1999
Model: Cherokee(XJ)
Engine: 4.0
Read the OP's post he said " Engine OIL" changes not other things. Again he said "OIL" and no one makes a stop leak for engine oil, it would cause more problems than it ever could help before it blocked the oil galleys. You are correct on one thing most are a bunch of "Snake Oil" for sure that are sold for other things. Leaks need to be repaired and none are that hard on the 4.0.
I recently found that the previous owner kept records of all oil changes in the manual. Most of the oil changes in the past couple years mention that he added "stop leak" - not sure which product. The jeep does leak a lot of oil and I am about to start replacing gaskets, starting with the valve cover gasket and working my way down. Also not sure if relevant, but I switched to using Rotella T6 5W-40 as soon as I bought the jeep.
Is there anything I should be worried about with regards to the "stop leak"? Is there a cleaner product I should use before I change the gaskets in case the stop leak has gummed things up?
Is there anything I should be worried about with regards to the "stop leak"? Is there a cleaner product I should use before I change the gaskets in case the stop leak has gummed things up?
My 2013 JKUR10A and 2016 Red Rock has stop leak in the resevior...
You can buy this at the parts department...
.
Last edited by M998; Apr 13, 2016 at 04:04 AM.
CF Veteran




Joined: May 2012
Posts: 7,965
Likes: 964
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0



