oil leak - suspect oil cooler line, difficult to pin down

[additive]

Hi,
Additive is still lurking at this site after all these years. I have nearly 200,000 miles now on my 96 suburban and it has been a great vehicle the past 5 1/2 years I have owned it.

Now I have an oil leak that I suspect is the oil cooler line, but I just can't see it to be sure. The leak is occurring between the plastic part holding it to the pan and the oil filter. The oil is dripping onto the front axle and then dripping down. Everything points to the oil cooler lines, but I can't pinpoint the exact location due to limited access. Has anyone else experienced this sort of leak? It leaks pretty steady, just that it hits the front differential cover and drips to the rear side. It doesn't appear that the oil line can rub against anything where the leak appears to be coming from. But maybe it has rubbed against the plastic part all these years then follows the line down before dripping on the front differential?? As far as I know, these are the orginal cooler lines and so I can't complain that they have lasted all these years, I just hate my usual habit of replacing parts until the right one is found.

Thanks to all who respond.

Additive

[ronniejoe]

The oil cooler lines on these are notorious for leaking. I put four sets of factory lines on mine, then upgraded to the DSG cooler and braided steel lines. Do a search here and you'll find all sorts of interesting reading. Also, look on the content side for articles as well.

Good luck.

[john8662]

Almost sounds like your leak could be originating from the oil filter adapter block (if you're burb is a 4x4), or possibly the o-rings on the oil cooler lines quick connect adapters. If it's the oil filter adapter, you'll just need three o-rings to fix that up, you can get them from the dealer.

Yep, Cooler lines are a real source of leaks.

[diesel65]

There is a possibility that the motor mount is bad and allowing the engine to drop, This in turn allows the oil cooler line to rub on the head of a bolt that is part of the front differential.
Pull the front shield and see if the cooler line is rubbing.
I have seen this happen. (Not to my truck)

[additive]

The other piece I failed to mention is that the leak occurred after an oil change. I have checked the oil filter, the drain plug and the dipstick but none seem to be leaking.

If it is the oil filter adapter, is it difficult to see? It looks like the leak seaps down the side of the motor and seaps on the top of the front differential before finally dripping off the back of the differential. For anyone who has had the adapter leak, does it leak towards the front of the adapter, or do you see it dripping near the filter?

I am going to start with changing the o-rings on the filter adapter, since the parts are cheap. Doesn't look like much fun to change though. Do I need to remove the cooler lines to get to the adapter?

thanks,
Additive

[joed]

I've had the adapter leak on my truck a couple of different times - it's pretty apparent as the bottom of the adapter around the bolt head is wet and it drips down onto the front driveshaft, similar to the mess you get when you change the oil filter.

As for removing the adapter, you don't have to remove the lines as they are above it. You may have to remove (or move to the side) the front driveshaft to get to the adapter bolt although I think I've been able to do it without removing it - it is a tight fit.

Hope that helps. Joe.

[jspringator]

I had an oil cooler leak. I guess the diesel vibration killed it.

[DennisG01]

I have noticed that because of the wind blowing things around while you're driving, it can sometimes be really hard to locate the source of a leak. I recently back traced a small leak and found that it was coming from the turbo oil return line. It's on the passenger side of the oil pan and towards the front of the oil pan. It's a metal tube sticking out about 3 inches with a rubber hose fitted over it and held in place with two band clamps. All I had to do was tighten the band clamps.
This may not be where your leak is coming from, but it's a good place to check, anyways.

[additive]

Thanks for the input so far. I am going to check out the turbo oil line tonight. THat may be it. I will update with my findings.

[additive]

As was suspected, it is the oil cooler line. I finally pinpointed it down to where it has been rubbing on a bolt head and finally wore through. Thanks again for all of the replies.
Additive