How bad is this oil leak?

[al07]

I noticed that my newly acquired 2004 Sahara has an oil leak. How bad is it?
The stain on the floor has been accumulated since Thursday.
I'm new to Wranglers, so this concerns me.

 

[al07]

Comes from here:

 

[pagrey]

Not bad at all. An old mechanic once told me, don't worry about dirty oil leaks, worry when the oil has washed the dirt away. High mileage oil can help if it's a rear main seal. It could be a valve cover leak so you might take a really close look at the back end of the valve cover. Mine has leaked off and on for 100k at times worse than that, I don't loose sleep over it. Don't forget to check your oil.

 

[AndyG]

Not bad at all. An old mechanic once told me, don't worry about dirty oil leaks, worry when the oil has washed the dirt away. High mileage oil can help if it's a rear main seal. It could be a valve cover leak so you might take a really close look at the back end of the valve cover. Mine has leaked off and on for 100k at times worse than that, I don't loose sleep over it. Don't forget to check your oil.

Perfect response .

I lost a lot of coolant in a 7.3 diesel once at the top of a mountain- really got concerned- the tow driver is an old salt, very practical minded- he said that is a good sign- you had some to lose, and didn’t lose it til you got here. He was right.

The back valve cover leaks are common, gently tighten the bolts , a 1/4” drive is best.

Don’t forget Wednesday is Sahara day at our local restaurant- bring a Sahara owner and eat free- make him pay for it.

 

[Jerry Bransford]

That's a rear main seal leak which is not inexpensive to change. It was likely caused by the continued use of synthetic engine oil. The same thing happened to my BMW that had lived on nothing but synthetic engine oil.

The cure for my leaky RMS was nothing more than switching to a HIGH "High Mileage" CONVENTIONAL engine oil like a 10W-30. High Mileage engine oils have additional seal restoration products that will help to get the seal restored back to its original consistency and thickness. Switch to that and my bet is your RMS leak will be gone forever if you stay with the same oil. NAPA High Mileage 10W-30 would likely do it fine, it's made for NAPA by Valvoline.

I've never had a RMS leak in either of my two TJs because I've never run a synthetic engine oil in them. I run a synthetic ATF+4 in the transmission, synthetic ATF in my transfer case, and a synthetic ATF+4 in my power steering but I won't run a synthetic in my engine (or axles).

 

[AndyG]

That's a rear main seal leak which is not inexpensive to change. It was likely caused by the continued use of synthetic engine oil. The same thing happened to my BMW that had lived on nothing but synthetic engine oil.

The cure for my leaky RMS was nothing more than switching to a HIGH "High Mileage" CONVENTIONAL engine oil like a 10W-30. High Mileage engine oils have additional seal restoration products that will help to get the seal restored back to its original consistency and thickness. Switch to that and my bet is your RMS leak will be gone forever if you stay with the same oil. NAPA High Mileage 10W-30 would likely do it fine, it's made for NAPA by Valvoline.

I've never had a RMS leak in either of my two TJs because I've never run a synthetic engine oil in them. I run a synthetic ATF+4 in the transmission, synthetic ATF in my transfer case, and a synthetic ATF+4 in my power steering but I won't run a synthetic in my engine (or axles).

Thanks Jerry, @Chris, please remember how quick he responds when we do reviews. May be time for a raise.

 

[al07]

Perfect response .

I lost a lot of coolant in a 7.3 diesel once at the top of a mountain- really got concerned- the tow driver is an old salt, very practical minded- he said that is a good sign- you had some to lose, and didn’t lose it til you got here. He was right.

The back valve cover leaks are common, gently tighten the bolts , a 1/4” drive is best.

Don’t forget Wednesday is Sahara day at our local restaurant- bring a Sahara owner and eat free- make him pay for it.

Haha something tells me I need to get used to Sahara jokes...

 

[al07]

That's a rear main seal leak which is not inexpensive to change. It was likely caused by the continued use of synthetic engine oil. The same thing happened to my BMW that had lived on nothing but synthetic engine oil.

The cure for my leaky RMS was nothing more than switching to a HIGH "High Mileage" CONVENTIONAL engine oil like a 10W-30. High Mileage engine oils have additional seal restoration products that will help to get the seal restored back to its original consistency and thickness. Switch to that and my bet is your RMS leak will be gone forever if you stay with the same oil. NAPA High Mileage 10W-30 would likely do it fine, it's made for NAPA by Valvoline.

I've never had a RMS leak in either of my two TJs because I've never run a synthetic engine oil in them. I run a synthetic ATF+4 in the transmission, synthetic ATF in my transfer case, and a synthetic ATF+4 in my power steering but I won't run a synthetic in my engine (or axles).

I doubt this Wrangler has been running on synthetic oil. It's been maintained on the cheap, I don't think the previous owner has spent additional money for synthetic oil if it was not required. I have his number, I will ask.

Noted the advice on high mileage oil. I'll make sure to switch to that at the next oil change.

 

[Jerry Bransford]

I'd switch to the high mileage now, odds are very good it will seal that RMS leak within a week or so.

 

[OldBuzzard]

I doubt this Wrangler has been running on synthetic oil. It's been maintained on the cheap, I don't think the previous owner has spent additional money for synthetic oil if it was not required. I have his number, I will ask.

I bet it has. Almost all oil, anywhere, is now synthetic or a synthetic blend. You have to work really hard to find a completely conventional oil now. I only know of two, the NAPA High Mileage 10W-30 which Jerry mentioned, and Super Tech High Mileage from Walmart.

 

[Kaptainkid1]

I'll put money it is a Valve cover gasket. Start from the top and work your way down the block. I replaced my RMS at 170k and it turned out to be the valve cover gasket. I also was advised it the RMS but that wasn't the case after changing the RMS 3 times and another TJ owner advise me start from the top and work your way down.
After doing the RMS 1st it looked strange that the RMS didn't look like it was leaking after dropping down the oil pan. I would say the RMS was still in good condition and could last another 20k easily had I not decided to replace it anyways.

 

[Vinman]

Also check the torque on the oil pan fasteners, my last 4.0 leaked almost as bad as yours and after re-torqueing the pan bolts the leak stopped.

 

[OldBuzzard]

Oil pan bolts get 105 in. lb. (about 9 ft. lb.) — not very much.

 

[al07]

I bet it has. Almost all oil, anywhere, is now synthetic or a synthetic blend. You have to work really hard to find a completely conventional oil now. I only know of two, the NAPA High Mileage 10W-30 which Jerry mentioned, and Super Tech High Mileage from Walmart.

...and you were right. Quaker State conventional oil, which is a synthetic blend.
Would a high mileage synthetic blend or high mileage full synthetic also do the trick? Or it has to be completely conventional?

 

[al07]

I'll put money it is a Valve cover gasket. Start from the top and work your way down the block. I replaced my RMS at 170k and it turned out to be the valve cover gasket. I also was advised it the RMS but that wasn't the case after changing the RMS 3 times and another TJ owner advise me start from the top and work your way down.
After doing the RMS 1st it looked strange that the RMS didn't look like it was leaking after dropping down the oil pan. I would say the RMS was still in good condition and could last another 20k easily had I not decided to replace it anyways.

Forgot to mention that the Wrangler has 109k miles. Too early for the RMS?

 

[eastbloc]

How bad is it?

That looks like 1qt of oil loss per 1000 miles of highway driving.

 

[Kaptainkid1]

Forgot to mention that the Wrangler has 109k miles. Too early for the RMS?

Could depending on oil maintenance and age of gaskets. I would say 109k is an earlier if the engine was kept in regular oil changes and maintenance records show good history. Driving very little or lack of driving for long periods can also dry out rubber gaskets too. So back of engine block of the 4.0l by the firewall. I would put a paper towel and rub the block and see if you can feel a little oil drip. It's very minor drip from the valve cover. All most to point it's not very noticeable at all. Any oil back there means needs you should change the Valve cover gasket. It's the cheapest and easiest to change.

 

[eastbloc]

I'll put money it is a Valve cover gasket. Start from the top and work your way down the block. I replaced my RMS at 170k and it turned out to be the valve cover gasket. I also was advised it the RMS but that wasn't the case after changing the RMS 3 times and another TJ owner advise me start from the top and work your way down.
After doing the RMS 1st it looked strange that the RMS didn't look like it was leaking after dropping down the oil pan. I would say the RMS was still in good condition and could last another 20k easily had I not decided to replace it anyways.

Haha i was in exact same boat, changed my RMS 3 times before realizing it was valve cover.
But now my RMS is really leaking, so not much of haha now.

 

[al07]

Just so I get mentally prepared, how much are we talking (ballpark) for RMS change and how much for valve cover gasket?

 

[Kaptainkid1]

Just so I get mentally prepared, how much are we talking (ballpark) for RMS change and how much for valve cover gasket?

Valve cover $15 gaskets and 30 mins labor time max. RMS $30 plus oil pan gasket $40, oil change $40 and 5 hours of labor.