Can changing engine oil make leaks start?

[JeremyT101]

Hey guys,

I changed my oil last night on my 98 D1. Before doing it, there were some leaks here and there, the PS, and I believe a small coolant leak, but nothing that left anything noticeably different from the small drops on my driveway. I had Shell Rotella T 15w/40 in there before, and replaced with the same. Napa gold 6048 filter. No leaks around the drain plug or filter, but there appears to be clean engine oil slowly leaking (like enough to leave about a 2-3" wide dark mark on a large piece of paper under the truck after 5 hours) from the vertical plate just behind the oil pan, but before the transmission bell housing. I'm not sure if this is right where it meets with the transmission, but that is where the oil is coming from. This leak was definitely not there before and only started last night after letting the truck come to idle. The leak does appear to be slowing from last night. There are no new noises from the engine, and the oil level is just a hair below the full mark on the dipstick. Is it possible that since i let the oil drain out good and long before adding in the new stuff that some kind of leak was revealed? Anyone heard of the oil coming from that area before? Possible causal locations? (the whole frnt underside of the truck is COVERED in black residue from probably years of leaks so its neigh on impossible to read a flow pattern down the engine)

Thanks guys.

[MattScott]

Rotella T does have a more intense additive package than a standard oil. It's possible that with the flushing of the old oil that you broke a piece of sludge or something off that was actually keeping the oil in.

[Der Steppenwolf]

Coming from that area sounds like the rear main seal leaking. IF you want to dig in, degrease everything and get a bottle of oil leak detection dye. Run that for a while and then get a blacklight out and follow the trail. At the very least, degrease and keep a naked eye on it.

[FSU_Disco]

Had a similar issue when I went from Rotella to Chevron Delo (on sale). It began leaking a slight amount after the switch and then went away shortly after I changed back to the Rotella.

[tacr2man]

Is it a gas or diesel engine ?

[HOOLIGAN]

I run Dino oil in my Harley, and one time I switched to Royal Purple. It started leaking from several places. I drained it and put regular old Dino oil in and it hasn't leaked since. So, yes. An oil change can cause leaks.

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[owhiting]

check the easy stuff first. oil pan bolts will work loose over time so check them fist. If loose drop the pan and replace the gasket or use rtv. Rear main is the next stop but that will usually drip out the bottom of the transmission.

[Hill, Bill E.]

I run Dino oil in my Harley, and one time I switched to Royal Purple. It started leaking from several places. I drained it and put regular old Dino oil in and it hasn't leaked since. So, yes. An oil change can cause leaks.

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Switching from 'dino' to synthetic, especially in older or high mileage vehicles, will do that.

Back in '82, on my very first truck I bought myself (a '58 Dodge pick up) I changed all the 80W-90 in the diffs, trans and T-case.

All of a sudden everything was leaking! Little did I know when I changed fluid, my dad had put the bucket pump in a 5 gallon bucket of synthetic gear lube.

That stuff wasn't exactly cheap back then compared to regular 80W-90!


Seeing as the OP is using the same oil, I would start with 'owhiting's suggestions.

[Bergum]

Landys don't leak. They just mark they're territory... :-)

No. Changing oil can make engine leaks. New additives will remove old "cloggings" for good and for bad..

Better with a leak home than on the trail.

B4x4.no

[rover4x4]

probably a good idea to change the filter in about 500 to 1000 miles as the rotella will liberate all sorts of sludge and buildup from the engine, I like the NAPA 1452 it holds a quart of oil.