2002 Jeep Wrangler TJ 4.0 oil leak help / questions

[ds53652]

Hi All,

recently new (new to me) Jeep owner - 2002 Jeep Wrangler 4.0L w/ 107K miles. I've been cleaning it up and making it mine over the last couple of weeks. It was very evident that there was a previous oil leak from the valve covers and the rear main. And from what I had read, that's pretty common with the 4.0L engines. But the seller said he had those fixed (had receipts/invoices of the repairs as well) and at least on the valve cover I can see a pretty, new blue gasket. I also didn't see any oil drops on his driveway where he parked the jeep and I haven't seen any oil drops in my garage since I've been parking it in there for the last few weeks.

One of the things I wanted to do was to degrease the engine, which I did last week. There was a LOT of built-up oil and grime all over the place. After the degrease with 2 cans of degreaser and a power washer, it looked MUCH better!! And I was hoping that it would stay oil-free... Well unfortunately, it hasn't. It looks to be leaking oil from the head gasket (see attached pics from the passenger side). Is this also a common place for these engines to leak oil from? Is this a major concern? How hard is it to replace the head gasket? What should I expect a shop to charge to replace it for me?

It also looks like the two grommets on top of the valve covers are leaking a tiny, tiny bit. Is this common? I see that some online Jeep parts websites have the rubber grommets in stock. Do I have to take the valve cover off to replace the grommets? Is it worth it to replace the grommets?

Any other insights and recommendations would be very much appreciated.

Thanks very much, Roger

 

[Steel City 06]

If the head gasket is leaking oil, it should be replaced as soon as you have time. A bad head gasket can cause oil and coolant to mix, which can destroy the oil, in turn causing engine damage and even failure.

Check your dipstick frequently to ensure your oil is not becoming cloudy, milky, or like a milkshake. Search Google images for "oil with coolant in it" to see some examples of what to watch out for. If you see that, stop driving as soon as possible. Otherwise, a leaking head gasket isn't as big of an issue, for now.

 

[01CuHed]

I'm going to follow this thread...my 2001 Sport has an oil seepage (very small amount) in the same location Roger pointed out. Seems like I have read in the past that is not too uncommon on 4.0L? I read a post some time back where a guy cleaned up (degreased) that area well and ran a bead of high-temp RTV to stop the seepage.

I replaced those 2 grommets and fittings on my valve cover which will stop that oil seepage there and no you don't have to remove the valve cover. Just be very careful removing the two old ones or you may wind up having to remove the valve cover to recover the broken pieces. Seems like youtube may have a video on how to properly remove those valve cover fittings.?

 

[ds53652]

Thank you Sir, very much appreciated.

If the head gasket is leaking oil, it should be replaced as soon as you have time. A bad head gasket can cause oil and coolant to mix, which can destroy the oil, in turn causing engine damage and even failure.

Check your dipstick frequently to ensure your oil is not becoming cloudy, milky, or like a milkshake. Search Google images for "oil with coolant in it" to see some examples of what to watch out for. If you see that, stop driving as soon as possible. Otherwise, a leaking head gasket isn't as big of an issue, for now.

 

[ds53652]

Thank you Sir, very much appreciated.

I'm going to follow this thread...my 2001 Sport has an oil seepage (very small amount) in the same location Roger pointed out. Seems like I have read in the past that is not too uncommon on 4.0L? I read a post some time back where a guy cleaned up (degreased) that area well and ran a bead of high-temp RTV to stop the seepage.

I replaced those 2 grommets and fittings on my valve cover which will stop that oil seepage there and no you don't have to remove the valve cover. Just be very careful removing the two old ones or you may wind up having to remove the valve cover to recover the broken pieces. Seems like youtube may have a video on how to properly remove those valve cover fittings.?

 

[01CuHed]

I "googled" to refresh my memory regarding oil seepage on 4.0L engines passenger side between the block and head. The following was the general consensus...the usually small seepage is on the push-rod gallery side of block (passenger side) and does not interfere with compression. They talked like the coolant gallery was on the driver's side of block which makes sense cause that is where the 0331 heads are known to crack. Some say their Jeeps have been seeping oil for years on passenger side with no issues.?

 

[ds53652]

Thank you for the additional info. Everything you shared here sounds like what I'm seeing. Oil looks good, antifreeze looks good and level is rock steady. And it is a very small seepage...so small that it has yet to drop a single bit of oil on my garage floor (in a month). No overheating and engine performance is fine.

Any insight as to the cause and fix(es)? Does it mean my head is warped? Or maybe just a gasket has aged and needs to be replaced and should be good for another 100K miles?

Thanks again for the additional info.

I "googled" to refresh my memory regarding oil seepage on 4.0L engines passenger side between the block and head. The following was the general consensus...the usually small seepage is on the push-rod gallery side of block (passenger side) and does not interfere with compression. They talked like the coolant gallery was on the driver's side of block which makes sense cause that is where the 0331 heads are known to crack. Some say their Jeeps have been seeping oil for years on passenger side with no issues.?