Oil leak possibly Dip stick

[Georgia Mike]

So I am on a trip at a campground and noticed oil droplets on the the back of the motorhome. I opened the rear hatch and found oil sprayed on the left side of the engine. I went to check the oil and the dip stick was partially out. I then noticed that all the oil seems to be around and below the dip stick opening. Can oil come up the tube like that? I checked the oil before I left and I always make sure the dip stick is seated back on. Now when you try and tighten the head of the dip stick it won’t seat it just comes out real easy. I guess something is wrong with the rubber grommet at the end or something. I assume as you tighten the head of the dip stick it’s supposed to wedge the rubber grommet?    Btw Merry Christmas 

[donbouv22]

I’ve had this problem too. If you don’t get the dipstick down tight it’ll blow off and soak your engine compartment, rear engine cover and tow vehicle. I fought it on a road trip and finally used a couple of cable ties to hold it in place, but it’s only a temporary fix. When I got home I got a new dipstick and it’s been fine. Anytime you check your oil always drive a few miles and make sure that dipstick is still tight. It happened to a buddy’s coach, too. 

[96 EVO]

I can't see oil making it's way up the dipstick tube 🤔!

Well, after reading the previous post, I guess it can!

Edited December 25, 2023 by 96 EVO

[cbr046]

Positive crankcase pressure?

- b

[96 EVO]

2 minutes ago, cbr046 said:

Positive crankcase pressure?

- b

Would have to be.

Pulled many dipsticks in my gas jockey days, and the stick wasn't covered in oil to the top!

[Hancoman]

Yes had the same problem. I probably got sidetracked and for got to screw down the cap. Oil all over even outside engine compartment and up the back  

[Robert92867]

Are those oil lines crossing over the alternator?

[Georgia Mike]

5 hours ago, Robert92867 said:

Are those oil lines crossing over the alternator?

No, they are hydraulic lines for the fan. I’m getting two ways of thinking on this issue. Some are saying that if the oil dipstick cap came off that oil will come out and that’s normal others are saying it’s positive crank case pressure from a blocked breather tube. The weather has been raining here so I haven’t been able to check any further but hopefully today I will be able to look further.

[Joint Venture]

I had the exact problem with my dipstick and as a temporary measure I secured the dip stick with a couple of tie wraps so it wouldn't come out and spray oil over everything.  After replacing dipstick handle and grommet the problem was solved. Cost me less then $20. I verified that the PCV filter was in good condition as well.

Edited December 26, 2023 by Joint Venture

[Georgia Mike]

1 hour ago, Joint Venture said:

verified that the PCV filter was in good condition as wel

I thought it only had a breather tube so where is this PCV filter located. I would like to change it.

[diplomat don]

Cummins engines will force the dipstick out a little followed by the oil. That is why they have the rubber grommet that you tighten when replacing the dipstick. Later models have catches similar to how the sewer hose connects. Seen this more than once in my 43 yrs of driving truck. Makes a big mess. Don

[96 EVO]

Good to know 👍!

Mine has the catches you mention, and can be a PIA sometimes getting the stick in the last inch in order to lock it in place!

[Ivylog]

2 hours ago, Georgia Mike said:

I thought it only had a breather tube so where is this PCV filter located. I would like to change it.

It’s in a he top of the valve cover if you have a 425 ISL… 400 doesn’t have one.

[96 EVO]

1 minute ago, Ivylog said:

It’s in a he top of the valve cover if you have a 425 ISL… 400 doesn’t have one.

My 400ISL has one, but, it's a '07 built engine.

[Joint Venture]

I can't speak about the ISL series as mine is the ISM and has the filter on the valve cover and is accessed thru the access hatch in the bedroom next to bed.

[dl_racing427]

On 12/25/2023 at 4:01 PM, 96 EVO said:

Would have to be.

Pulled many dipsticks in my gas jockey days, and the stick wasn't covered in oil to the top!

As long as the seal on the dipstick is good, oil won't migrate up the tube.
Diesels are turbocharged, and normally have some blowby.  Under high boost, it can be enough to push oil out the tube.
Boosted gasoline engines can do the same.

OP:  Check to see if you threaded the handle out too far, and the threads are tight, causing the inner part to spin instead of the plug tightening up.

Edited December 27, 2023 by dl_racing427

[Twomed]

For the non-believers just leave yours loose,   1) run down a western mountain Jake on high   2) post the pic, cleanup mess.   Carabiner and a tie wrap snugged up will  keep it from a second event.

OR...just travel in the East and call the hills mountains and you will be fine. 😁 😃

[Jeff sams]

Had same issue zip tie to that little bar

[Gweedo]

My isl400 has the filter. Sits on top of rocker cover black box.  

Edited December 27, 2023 by Gweedo

[Georgia Mike]

So I cleaned up the oil that was all over the rear engine compartment and zip tied the dip stick so I couldn’t move and I had a clean oil free engine when I arrived home. Now, about the breather system I found a black box on top of the valve cover is this the breather and is there a filter in there? This is a 400 Isl built in 2005

[Bill R]

@Georgia Mike There is no filter in mine.  It is just open with some baffles.  It is easy to open up and find out.    The small line at the lower left of the pic is a drain line that goes back to the crankcase with a check valve in line.  The larger line at the bottom is the crankcase blowby tube that OEM installed goes down to in between the starter and engine.  My 2006 400 ISL was there and there was quite a bit of oil build up.  I rerouted it to a location away from the engine with a catch can.

[Gweedo]

Yes. Careful removing the hoses. 

[Georgia Mike]

I changed my oil yesterday and the oil dipstick rubber grommet just won’t expand enough to tighten up. I have looked online and found the entire dipstick for over $100 but can’t find just the grommet. Others have posted that they changed the grommet but didn’t give the source. If anyone knows where to find it please let me know. I found this on Amazon but I don’t think it will fit.

Dorman 65113 Dipstick Tube Rubber Grommet Universal Fit

[Ivan K]

You can try to reuse the rubber piece from appropriate size expansion plug looking like one of these

3 Sizes (6pcs) Rubber Expansion Plug, Fit Hole Size: 3/4"~1-1/8" (19mm~28mm) Automotive Rubber Freeze Plug

[Georgia Mike]

Thanks Ivan, I was trying to find the exact one but I’m going to go with your line of thinking.