7.3 idi dripping oil

[Andre3MC]

I noticed an oil spot on the shop floor after moving the bus, I wasn't able to investigate further but I want to know what to look for the next time I am working on it. The drips were near the front of the engine, the oil level is fine and it is running well. Where should I start looking? Is this fairly common?

It is a high mileage (~250k) southern bus that I had serviced before we drove it home from GA. Drove 1,100 miles in about 20 hours with zero issues, it seems to run and drive well.

[Dead pirate]

All deisels are seives

[Booyah45828]

Clean the underside of the engine off with some degreaser and a hose. Then start it up and check for any oil drips.

There are of various leak points from seals, to gaskets, to broken components. Simply saying you have an oil leak up front doesn't tell us from what.

On the idi engines, you can occasionally have oil cooler gasket and o-ring leaks, which could have drips from front or rear of the engine.

[Ronnie]

Does not hurt to check as Booyah has suggested. But must say if you drove more then 1100 miles and do not need to add oil, that is great.

[cadillackid]

its a 7.3 if its not dripping then its out of oil
or wait was that a Detroit 6-71

[EastCoastCB]

Could be hpop seepage, or just slobber coming out of the blowby tube. Never seen a 444 that didn't slobber.

[Andre3MC]

Okay I will clean it up and report back, it sounds like it’s not something to be terribly concerned with which is relieving.

[BeNimble]

Unless you go camping where 'leave nothing behind' is the rule. Dripping oil into the campground would be frowned upon. And people wonder why campgrounds don't like Skoolies.

[Andre3MC]

Originally Posted by BeNimble

Unless you go camping where 'leave nothing behind' is the rule. Dripping oil into the campground would be frowned upon. And people wonder why campgrounds don't like Skoolies.

Solid point, I’m not a huge fan of dripping oil either, I’m new to diesels so not sure what to expect.

[Beirdo]

My plan would to be bring one of these along:

https://www.amazon.com/dp/B00DXZVL6G

I figure 5'x8' should suffice for small oil drips. Now if it's pouring out, that's different.

[Andre3MC]

I got some pictures of the leaks:








It looks like the only one that is leaving spots on the floor is the trans cooler (?) line shown. The differential is weeping also, I am not sure if that is normal on these.

[Booyah45828]

I would say that you're on the right track.

The first 4 pictures look to be a valve cover gasket, but it looks like more of a weep then a leak. Maybe check that those bolts are snug tight on the valve cover.

5th is the cooler line, and it looks to be coming from the crimp, so I'd say a new line is in order. Those can be fabricated at certain auto parts stores, most truck shops, and 99% of tractor/ag dealerships.

6th has the oil cooler in it. They are known leakers, but yours looks to have oil from the valve cover all over it, so it might be fine. Wash it off, start it up, and recheck it.

6th is the pinion seal. They get dirt and crap all over them which ruins the seal and starts to weep like that. Make sure there isn't any radial play there or you might need pinion bearings too. You'll have to remove the rear joint of the driveshaft, remove the pinion nut and yoke, and then the seal. Inspect the surface of the yoke that it isn't grooved where the seal rides or has anything else funky going on. If it is, you might have to install a speedi-sleeve or new yoke depending on availability.

I've replaced my pinion seal already, it isn't a hard job, just requires the right tools to do.

[Ronnie]

The trans cooler line I would replace, if it does fail it will leave you stranded.



The rest I am not concerned about. Checking the pinion bearings is a good idea and if sloppy then take care of the bearings and seal at the same time. If not sloppy let it go.

[Andre3MC]

Thank you I will look into getting a replacement cooler line and check the fluid level. For the diff do I need to remove the rear joint of the driveshaft to see if there is play in the bearings?

[Ronnie]

You should be able to leave the driveshaft on to get a check on bearing slop. There must not be any tension on the driveshaft, so if there is a parking brake on the driveshaft that needs to be released, and wheels chocked of course. If you have air brakes then the parking brake is likely on the rear wheels not the driveshaft.


So just lift up and down on the shaft and see if there is movement. Ideally you would use a dial indicator and measure the amount of movement and then check the book for the acceptable amount of radial play.