Dark Regent

I'm having issues with a rear main seal leak on my F24 engine, and I'm hoping you all might be able to provide some insight.

It started with an oil leak that I first thought was the pan itself, as the leak kept showing up at the right rear corner of the oil pan, along the seam.



So, I thought maybe there was an issue with the RTV on the oil pan, even though it was a brand new build. So, I dropped the pan, resealed it, and put it back. The same thing happened again. So, I thought maybe I suck at running an RTV bead, too, and resealed it a second time. Again, it leaked, but now I was thinking it had to be something else, like a cracked oil pan or something. I still wasn't thinking bad rear main seal since it was a new build. I also noticed that oil appeared to be collecting between where the engine block, the timing chain cover, and the oil pan meet. So, I dropped the pan for a third time to do a more thorough inspection. I also bought a new pan just in case there was a crack issue.

It seemed like oil was repeatedly collecting in this right rear corner of the pan (which I now know is indicative of a RMS leak):



When getting ready to reseal the oil pan for a third time, I finally did see indication of oil leaking from the RMS itself, which I did not see the second time:
(looking at the snout under the crank shaft, with the flywheel to the right)


As far as the "oil leak" where the engine and timing cover meet, I believe that was actually coming down the side of the block from the stock oil cooler, as I noticed a shimmer on the cooler itself and wiped it with my finger, which came back and clearly showed oil collecting. I thought maybe it was because, when I dropped the oil pan, it looks like somebody dropped the engine block when building it and rounded off those corners where it meets the timing cover, but I figured the RTV should fill that in anyway. So, I replaced that $3 o-ring and it definitely was bad (rigid and flat spotted), so that was kind of annoying that Inline Pro just put the 2007 seal back and didn't replace it, but it was an easy fix.

I replaced the oil pan for peace of mind, since I had it and was now relegated to pulling the transmission again.

After doing so, sure enough, the RMS is indeed leaking:



I cleaned the seal off and could not see any obvious damage to it. After letting it sit a week while I waited for parts, it's obviously still leaking/weeping:



So yesterday, I drained the oil and pulled the RMS out. I tried using the @Billman250 method but couldn't pierce the RMS. I ended up using a 3/32" drill bit and going very slowly to get through the metal in the RMS, then threading in the tip of the screw and pulling it out.

After getting it out, I did find some minor damage on the RMS, but I don't know what caused it. There is some feathering on the outside edge of the seal including at the bottom where it was weeping, so I'm guessing that's what's causing the leak:



I will say that I originally received this engine in January 2018 and didn't finally get to start it up until April of this year. So, I don't know if it sitting for 5 years is the cause of this, but it's a possibility. It has been inside a climate controlled building the entire time.

The other curious thing to me is that it's not an S2000 RMS, nor is it a K24 RMS. I purchased a new S2000 RMS (91214-PCX-003) as well as an Acura TSX RMS (91214-RNB-A01, which replaced 91214-PL2-004), neither of which matched the seal Inline Pro used. Based on the markings on the seal I took out itself, it appears to be a 91214-PL2-003, which is meant for an Acura NSX or Legend. All the seals are the same dimensions, and the Acura seals seem to have essentially the same construction, but the S2000 RMS is different, with a full C-channel of metal inside it as opposed to the L-shaped metal inside the Acura seals.

So, I'm trying to understand if it really matters which seal is used and which I'd be better off putting back in. I don't know if Inline Pro use the RMS they did just because it was readily available to them or if there was a specific reason. I plan to talk to them this week, as well. I'd also like to know what caused the damage on the RMS that I'm seeing. Is this normal and indicative of poor lubrication or something?

I am a bit paranoid after seeing the other threads talking about issues with IP builds and my engine was built right around the time Jeremy supposedly left. I've dropped the oil pan three times now and every time I do, I find more debris in the oil, which I'm hoping is just normal break-in material. You can see the black streaks in the photo below, which are magnetic, so I'm guessing it's just piston rings bedding in:



I'm not quite up to 500 miles on the break-in, so fingers crossed this will be the end of the "little" teething issues, and I'm hoping everything is actually okay otherwise.

noodels

No debris on crankshaft causing issues,did you clean contact area ? could use Very a fine sanding paper using oil to smooth if not done already .

Dark Regent

After getting the RMS out, I cleaned out the groove around the crankshaft. I sprayed brake cleaner on a paper towel and wiped it all off. I ran my finger around the end of the crankshaft and didn't feel any issues, but I will take a closer look before reassembling.

One thing I'm also not sure about is how to prep the new RMS before installing it. The Honda shop manuals don't mention anything other than just putting it in at the right depth. I did notice that the new S2000 RMS I received does appear to be pre-greased.

S2000 shop manual:



Acura TSX shop manual:

noodels

How far is your crank sticking out ? or what dimensions are you doing yours,is your end float measured within spec,as its worth checking?

Dark Regent

I did measure the depth of the RMS before pulling it out and the lower left edge was in 0.265" from the end of the crankshaft and the upper right was inset 0.235". So, it wasn't in totally straight, but it was within spec.

I actually bought both of the Honda seal tools for the S2000 (07VAD-P8A010A) and TSX (07ZAD-PNAA100) in preparation for installing a new seal. They were delivered yesterday. The TSX tool looks like it will index off the end of the K24 crankshaft and perfectly inset the seal when I install it, to be in spec. So, that is what I plan to use. The S2000 tool looks like you have to be a lot more careful, as the depth is not controlled by the tool. I originally was going to use a PVC 3-inch sewer cap, but it also wouldn't control straightness and depth.