Pesky oil leak/starter issue on a 96 Grand Cherokee

[damionm]

Hello fellow Jeep lovers,

I am the second owner of a 96 Jeep Grand Cherokee, 4.0 liter/6 cylinder that has given me great service with minor repairs on occassion (replaced water pump, radiator, catalytic converter and an oil sensor thus far), but like all machines,..is now in need of more 'intricate' engine repair. I have about 235,000 miles on this Jeep, and have yet to have any serious engine problems,..until now,..but I'm not sure if my problem is that serious yet. Back in December of '07, I started to experience infrequent "non-starts" and she would hesistate to start,..eventually she wouldn't turn over and crank up. Immediately my first thought was the starter was dying/finally dead, and I needed to crawl underneath it and yank her down and get a new one,..no big deal. I wasn't experiencing any issues with how she drove or the engine, so I figured that's all it was. Well, I took the starter off, and took it and had it tested at a local parts house, to make sure it was dead. They tested it and the selinoid kicked and the starter performed flawlessly..so this left me kinda baffled at this point. The only other thing that was odd was the fact that the starter was rather drenched in oil,..so I cleaned it off with some carb cleaner,...let it dry out,..cleaned my terminals where the battery cable connects,..bolted it back on the block,..gave it a go and low and behold,..she cranked like new. So with that,..I figured I was starting to have an oil leak somewhere that made its way down to the stater. Well, I've had my Jeep parked up until a few months ago, and low and behold,..same deal,..she won't crank at times,..and I've had to crawl back underneath her and clean the starter off,..specifically where the battery cable connects to the terminals. So now I'm at a point of wanting to fix the obvious oil leak,..but not sure where to start. With the kind of problem I've described,...where should I consider looking as a source of this pesky and annoying issue? Thing is, I never know when the starter is gonna get shorted out due to the oil leak,..leaving me unpredictably and temporarily stranded at any given time (I keep a change of oil clothes in this thing just in case I have to crawl underneath it at any time lol). With that, I do need to get the core problem addressed as soon as possible. I don't know how much more of this my ol' starter can and will take before I have to replace it and fix the oil leak. I'm already having to give it a few 'love taps' with the hammer, along with cleaning it off,..just to get it to crank back up when she gets oil soaked lol. I've been told it's likely a combination of a bad and leaking valve cover gasket, and good ol' gravity causing this issue,..but I'm not sure...please help and advise if you can,..thanks!

 

[MudderChuck]

I've had the stater off of my 96 XJ half a dozen times. I replaced the brushes once, they wear and get short, as they get shorter the springs for the brushes don't push as much.
The starter needs a little spin for the solenoid to seat all the way and for the bendix to work right. If the brushes are making iffy contact, you sometimes won't get the spin you need.
I've also cleaned the oil out of my starter on numerous occasions, the oil leaking onto mine from the oil filter adapter "O" rings managed to leech into the starter and coat the brushes. I've gotten good at removing the starter, the end cap from the starter and cleaning the brushes. I use spray brake cleaner. A new set of oil filter adapter "O" rings are on my to do list.
GoJeep has a good writeup on starter R&R. Cleaning the starter motor
I rarely have to rebuild the whole starter, brushes or brush cleaning are usually what's needed. Though I have sprayed the mud out with hot water and regreased the planetary gears and bendix on occasion.
Sand or mud left on the brushes can wear them down fast. I sure don't know exactly how the sand, mud ot oil gets in there, but it sure enough does.
Last time through I sealed the end cap and the wire grommets with a very small amount of silicon, which seems to help somewhat.
I still have the original starter out of my long dead 87 XJ, on it's third set of brushes. I keep a spare rebuilt junkyard starter in both of my XJ's and another spare on the shelf in the garage.