Paint inside of oil pan.

I don't recall older engines having the inside of the oil pan painted, but a lot of newer pans seem to be painted on the inside.

Is the new oil PH so different the pans rot from the inside out?

The reason for my wonder is this, my cummins needs a new oil pan, the road salt has eaten the outside of it. The cummins pans are like tissue paper.
The OEM cummins/Dodge pan is over 1000.00 dollars in Canada with the updated bolt kit and gasket.
The aftermarket pans are way cheaper but then there is this out there.


Long story short, the aftermarket pans have an issue the paint coming off and wrecking the motor. I am thinking to buy the aftermarket pan and strip the paint off the inside, Just wondering if I am missing some magic science on why the inside is painted. The oem pans are painted on the inside as well.
It looks like the cost difference is the paint. Should I do something like glyptol to it after stripping it?

Can’t speak for everyone’s pan but at FCA they were E-coated.

We had issues with some of the trans pans back in the mid 2000-2005 time frame but that was due to improper rinse of the metal before the coating. A properly coated pan is pretty much bullet proof until or unless you puncture the e coat.

Problem is you don’t know if it was coated properly.

Thanks for that info, I've been reading up on E-coat, and that's probably where the price difference is between the pans. It's also interesting reading about moroso pans coating, it's too bad they don't make a Cummins pan.
I'm thinking the aftermarket pans are probably a powder coat, I'm going to buy one and strip it clean.

Diesel engine oil becomes acidic very quickly. There are no or few provisions for that neutralization. Manufacturers rely on strict oil change intervals. That's why diesel motor oil is not a good solution for older motors,ZPPD. Granted, gas engine produce acid from the combustion process but not as quickly as diesel. Just get a new factory pan clean the inside with acetone, water based degreaser, acetone again scuff 80 grit and use GE Glyptal. Should solve this problem.

Here's a Mopar one for $400.

https://www.facebook.com/marketplace/item/2295246177210987/

Kevin

is burning diesel fuel causing the diesel oil to becoming acidic quicker, or is it the oil itself ?
i knew of oil becoming acidic in gas engines, and figured diesel engines oil would do the same, but i never knew it [diesel oil] did that quicker.

I think the pans are made of crap to begin with. I had one on an N14 that perforated about 2" down from the pan rail. Very localized and the rest of the pan solid as a rock.

Ground the pinholes and brazed them shut. Ran the truck another 10 years with no further leaks.

Kevin

Hey buddy! In case you are still looking to buy, I know a website that offers a large number of aftermarket oil pans for diesel engine trucks. Everyone should check this page out. I hope this will help anyone!

I’ve installed quite a few aftermarket pans with no issues. Just did one about 2 weeks. Tons of the new stuff is coated inside.

Iirc those guys failed to mention that motor had an injector failure weeks before and filled the crankcase with fuel. Who knows how long they ran it that way but it did not help matters.

The pan on my 95 Cummins has not corroded. You see a lot of coated brake lines, fuel lines, trans and oil pans rust on newer vehicles. What ever the coating is seems to trap salt and dirt.
Doug

Not a chemist but I believe since a diesel ignites from the heat of compression, they form more oxides of nitrogen, due to the high combustion temperatures, and until recently diesel fuel had sulfur in it, so in the oil they formed nitric and sulfuric acids. They lowered the compression ratios on gas engines, in the 70's to lower cylinder temperatures, which stopped oxides of nitrogen. Then they invented the dual bed catalytic converters, which treated the oxides of nitrogen in the 90's and they started raising compression ratios up again, to make them run decent again. Also diesel fuel has more carbon atoms than gasoline which also changes the combustion chemistry as well. Diesel and gas have almost the same stoichiometric ratio around 14 to 1, but diesel has a much wider flammability rate, so they can run very lean like 40 to 1 The reason diesel makes more power but smokes so much when you dump extra fuel in them, is that when you get to stoichiometric, they make tons of soot, due to the extra carbon atoms in the fuel.

There is no way in the world I would paint the inside of ANY oil pan with store bought paint, even Glyptol
I might consider having it Teflon coated if I knew that coating would never come off

Its the sulfuric acid byproduct you mentioned that is in constant contact 24/7 with an alum oil pan that is a potential problem. I suspect Alum oil pans are also more favorable for OEM engine noise reduction, so pick your poison.With the move to lower sulfur fuels, I suspect the acid problem is much tamer today.

does anyone know what the coating is on the inside of factory pans ?
around here, it is common for front drive oil/transmission pans and differential side covers to rust through from the outside in, caused by the salt brine stuff used in the winter.
however, the inside of the pans look like new, and the coating will be still intact. so is it a hi temp powder coating or a teflon [type] coating ?

Like I mentioned much earlier in this post, E-Coat.

And the rust starts with either a stone chip or it was a bad coating to start with.

42RLE was known to have pan s rust through. We sold a ton of pans through Mopar because of this bad coating from the supplier.

i'm not disputing your answer, but on the front drive stuff i'm familiar with, it seems more like a powder or an epoxy type of coating. so
however, you are A #1 spot on about a tiny chip starting the rot process !
i have often wished i had kept several of the front drive pans and differential case covers i have replaced over the years that have rusted through from the outside in.
to say they were bad would be an understatement !

The first occurrence of this issue I became aware of was on the 42RLE.
While working on service parts I became aware of the most recent case which involved the NAG trans.

The engineer working on the issue gave me the background to both. E-Coat was mentioned being used and if I recall the acid wash used before the coating was not cleaned enough from the pan.

Geno's Garage has stainless pans available for the Cummins. $715.00