Engine questions
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Engine questions
Hey guys got a few questions. What's the most common oil leak on 4.0 and I have a pulley noise and it sounds like a bearing but all my pulleys are new besides my Ac and power steering and harmonic balancer. But I wouldn't think the balancer would make a noise would it
Senior Member
Joined: Nov 2013
Posts: 616
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From: Vernon NJ
Year: 1998
Model: Cherokee
Engine: 4.0
Xjwonders nailed the oil leaks. The pulley sound could be the water pump, ac compressor, or the power steering pump. One way to narrow it down would be to remove the belt and spin each pulley by hand and see if you hear it. Another way to check would be take a can of WD40 and squirt a little on the back of each pulley were the bearing is an see if that stops it. Also check that the belt is not too tight or too loose.
Senior Member
Joined: Nov 2013
Posts: 616
Likes: 4
From: Vernon NJ
Year: 1998
Model: Cherokee
Engine: 4.0
Don't jump right on the rear main seal until you ruled out the rest of the oil leak areas that Xjwonders put in his post. Remember oil goes to the lowest part which in this case is the rear main seal. Do the other ones first then clean everything then see if the rear main is leaking.
CF Veteran
Joined: Jul 2013
Posts: 7,554
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From: Monett, MO.
Year: 1999
Model: Cherokee
Engine: 4.0
If in doubt refer to above and in this ORDER! The RMS is usually the last to go on these engines and the hardest to replace. I thought the same thing but was my oil filter adapter O-rings leaking.
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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
Member
Joined: Feb 2016
Posts: 209
Likes: 1
From: Thurston County, Wa.
Year: 1994
Model: Cherokee
Engine: 4.0 HO
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
Member
Joined: Feb 2016
Posts: 209
Likes: 1
From: Thurston County, Wa.
Year: 1994
Model: Cherokee
Engine: 4.0 HO