Rear Main Seal Leaking

Replaced the timing belt on my 2011 Acura TL and fixed the oil pump leak (replaced o-ring and resealed) and hoped that would fix my oil leak, but checked under the car today and found oil all over the bottom of the transmission underneath where rear main seal is. Unfortunately, it looks like it will need to be replaced to the tune of $1,600. Before getting it fixed, I put Mobil 1 high mileage synthetic in it today in hopes that could maybe help. Many other Acura owners said switching to HM synthetic slowed and even sopped the leaking completely. I'm hopeful but doubtful it will work. Worth a try though.

Question is, while the transmission is out, should I have them replace anything else?

Considering my engine burns oil (about a quart every 1,500 miles) and there is oil in the PCV passages presumably due to blow by, I'm assuming there is an excess of pressure build up in the crankcase. If this is true, what are the chances that the main seal will start to leak again after replacement?

 

how many miles is on this engine? about how much is it leaking

 

The type of oil wont have any effect on a leaking rear main seal but the viscosity might, it's just lost it's sealing capacity due to wear and age.

The real question is spending $1600 to fix what essentially a visual issue worth the money?

 

The car has 127k on it and I'm losing about a quart every 1,500 miles, but the engine also burns oil, which is "normal" for this car. I don't think my OCD can allow me to let it continue leaking 😄. Plus, I'll be selling it one day and want to be able to get top dollar for it when I do.

 

Wouldn't hurt to replace the input seal on the transmission (where the torque converter connects) while you have it out.

 

Through the seal?

That would be more than just a messy eng/trans case!

 

Sorry. I meant combined I'm burning and leaking about a quart every 1,500. Not sure how much I'm losing out of the seal. Despite there being oil all over the bottom of the transmission, I have never seen anything drip on the ground.

 

Most seals just weap oil, meaning a very small amount that gets blown over the case, making that mess but rarely drips, it's more a visual problem vs actual issue!

$1600 wuld buy a lot of cans of foaming engine cleaner. Once a month cleaning might satisfy that OCD!

 

Okay. I wasn't sure if it could get worse and end up being a catastrophic failure. Maybe I'll hold off then.

 

i would also check the rear cam plugs. they leak right on top of the bell housing making it look like a rear main. lot easier to do.

 

I wish that were it, but there is oil under the flex plate cover just below the crank so I'm pretty sure it's the seal. I'll take another look though.

 

MOST oil leaks down on the belly result from the leaks from the top. Hondas are notorious about valve cover leaks. You need, before making any financial decisions, to wash the belly clean, introduce UV dye into the oil, give it few days of driving anmd then scope with UV light. Unfortunately, as they crammed large engine into tiny engine bay, you have darn maze of what not.
You have stuck oil pickup rings on pistons, causing blow by into the crankcase. You could add catch can but that does not change the base problem - carbon deposit on rings. There are techniques of removing that buildup without pulling engine heads.
For a Honda engine, qrt x 1500m is quite a burn.
BTW, that engine is due rockers adjustment. No big deal DIY job.

 

I looked the engine over thoroughly when doing the timing belt, oil pump, and oil pan reseal. I had three leaks: the oil pump, the rear valve cover, and the main seal. There should be zero leaks once the main seal is replaced.