Cummins ISL oil leak while running

**timjet** · 10-23-2019

My motor home has a 2006 build Cummins ISL 400 HP with 94,000 miles. I last checked the oil level last month (2000 miles ago) and it was at the full mark. I changed the oil back in April.
I just noticed the oil level is about 2 qts low and oil has soaked the starter and the passenger side of the oil pan. Oil continues along the outside of the engine on the passenger side with some oil on the outside of the exhaust pipe.

I've developed a major oil leak some time within the last 2000 miles. It does not leak while sitting just when running. It has never leaked oil before.

Any suggestions?

I'm going to pressure wash the bottom of the engine and see if I can tell where the oil is leaking from.

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**watersupply189** · 10-23-2019

Originally Posted by timjet

My motor home has a 2006 build Cummins ISL 400 HP with 94,000 miles. I last checked the oil level last month (2000 miles ago) and it was at the full mark. I changed the oil back in April.
I just noticed the oil level is about 2 qts low and oil has soaked the starter and the passenger side of the oil pan. Oil continues along the outside of the engine on the passenger side with some oil on the outside of the exhaust pipe.

I've developed a major oil leak some time within the last 2000 miles. It does not leak while sitting just when running. It has never leaked oil before.

Any suggestions?

I'm going to pressure wash the bottom of the engine and see if I can tell where the oil is leaking from.

Welcome friend! Is it just at the bottom of the engine or is it leaking from the top side? Valve cover leaking?

2016 Ram Laramie 3500, G56, 6.7, Rough Country Leveling, HID headlights, Morimoto LED fogs plus a whole lot more!

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**timjet** · 10-23-2019

It is not leaking oil at the top of the engine. I just returned from a 12,000 mile trip to Alaska and am cleaning the dust off the top of the engine. No oil there.
Thanks for the welcome.

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**Polaraco** · 11-05-2019

Originally Posted by timjet

My motor home has a 2006 build Cummins ISL 400 HP with 94,000 miles. I last checked the oil level last month (2000 miles ago) and it was at the full mark. I changed the oil back in April.
I just noticed the oil level is about 2 qts low and oil has soaked the starter and the passenger side of the oil pan. Oil continues along the outside of the engine on the passenger side with some oil on the outside of the exhaust pipe.

I've developed a major oil leak some time within the last 2000 miles. It does not leak while sitting just when running. It has never leaked oil before.

Any suggestions?

I'm going to pressure wash the bottom of the engine and see if I can tell where the oil is leaking from.

Originally Posted by watersupply189

Welcome friend! Is it just at the bottom of the engine or is it leaking from the top side? Valve cover leaking?

2016 Ram Laramie 3500, G56, 6.7, Rough Country Leveling, HID headlights, Morimoto LED fogs plus a whole lot more!

Could be the oil filter, You have to be sure the old o-ring came out when you changed it. Look at the oil cooler and the turbo oil lines too

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**AnOldBiker** · 10-23-2019

@timjet

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**dodgemark** · 10-23-2019

Welcome and I agree.

Pressure wash to get road dust off and all excess oil.

Than start engine and let warm up.

Start looking with a light and when you see a oil drip shut down motor and try to get up close to motor and see hopefully starting point of leak.

Keep us informed.

Sent from my iPhone using Tapatalk

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**timjet** · 10-30-2019

OK, I got the engine cleaned up and took it for a 15 mile drive.

I can not see any fresh oil above the oil pan.

What you are seeing is the front portion of the oil pan with fresh oil clearly visible. This fresh oil was not there before I drove it.

I need to get an alignment tomorrow, so I'll clean the area again before driving.

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**watersupply189** · 10-30-2019

Originally Posted by timjet

OK, I got the engine cleaned up and took it for a 15 mile drive.
I can not see any fresh oil above the oil pan.
What you are seeing is the front portion of the oil pan with fresh oil clearly visible. This fresh oil was not there before I drove it.
I need to get an alignment tomorrow, so I'll clean the area again before driving.

Looks like the oil pan gasket is leaking.

2016 Ram Laramie 3500, G56, 6.7, Rough Country Leveling, HID headlights, Morimoto LED fogs plus a whole lot more!

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**timjet** · 11-05-2019

OK, I'm going to try and change the oil pan gasket myself. Any words of wisdom?

Question: how heavy is the oil pan? Will I be able to maneuver it or will I need to brace it somehow.

Question: If the pan does not disengage from the engine block, how do I get it loose?

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**CMB** · 11-05-2019

Drain the oil (obviously), break all the bolts loose but do not remove. Then remove the bolts in a criss-cross pattern leaving in 1 bolt in each side. Then loosen the remaining 4 bolts alternately. Once you have the bolts half way out the pan should drop down with a little tap(rubber mallet). If you choose, though not recommended, to put a screwdriver in between the pan and bottom of the block be very careful not to gouge either surface. Once the pan is loose you will be able to judge the weight. Slowly take the bolts out and your home free. Be prepared to have a few shop towels to clean the surfaces up before reinstalling.

Hope this helps- cheers!

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