Not 100% sure if my rear main seal crapped out on me or not. I have a slight oil leak dripping from the rear exhaust side of the engine. I plan on replacing the rear main plug and valve cover gasket. If the leak doesn't stop there then I guess I'll have to suffer and do the rear main seal. I can't really tell which seal is bad due to all the crap and grime on the engine. When and if I do the rear main, should I drop the transmission or pull the engine? Which is easier? Thanks for any advice!

Why has it become so common to EXPECT THE WORST and/or Picked the most difficult-to-fix solution to what cud be a Minor/Easy fix.

You Wrote: "I have a slight oil leak dripping from the rear exhaust side of the engine"

Do you have Manual Trans on this 200 --- you neglected to say what year and how many miles on it. The worst thing that can happen with a "slight leak" is some of the oil will get on the flywheel and contaminate the clutch disc causing slipping when you try to accelerate, esp going up a steep hill...with a Manual Trans.

I rather clean the engine with a tooth brush(LOL) and then inspect for the leak source than pull an Auto Trans, only to find no leak at the seal.

Any leaking from the Front seals. Have they been replaced. New seals on the front and a clogged system could force oil out the rear seal.

As suggested. Clean the Flame Trap Crankcase Vent system first. Then clean the dirt off the engine.

1989 AW70. My mistake sorry about that!

Have you checked for pressure arising from your engine's breathing system?

I would clean up all the various hoses and connections - don't just look at them, remove each piece to see if any are clogged with dirt and oil. A tiny hose or elbow might just be your problem.

It would be possible to clean the bottom and rear of your engine with a pressure washer without getting water in any of your electrics - this might find your leak and if not, working on your engine would be a lot easier.

Thinking out of the box - is there a place that you could drill a 1/4 inch hole to check for rear main leakage? - you could always plug the hole.

Yeah I've already gone through this debacle of having to manually blow through the pcv hoses. With the oil cap off I could breathe easily through all the hoses. With my oil cap on, I could barely breathe through it.

Follow Sousa’s counsel - check crankcase ventilation system first. Excessive crankcase pressure can force oil past a brand new rear main seal, and past aged cam cover gaskets/seals.
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82 242-6.2L; '17 Mazda3; '16 Crosstrek

And if you go with transmission removal, make sure you disconnect heater hoses. There was one of the heater hoses that developped a pin hole after a clutch replacement on my 1982. Hoses where left in place and I know they were stretched with the engine lowered against the firewall.

Afterward there was loss of coolant once in a while and I never was able to locate the leak, because it would stop or dry before I look for it as the polythene holding tank was low level.

Check what is suggested in the other posts above before going with rear seal replacement. I had good results with stopleak added to engine oil 15 years ago and that made me delay that work until a clutch job was required.

Good luck.

a rear main seal job as you know is major job and is to be avoided at all costs until it can not.

i have done half dozen and have always done this first before concluding no other choice was possible. for every one done 3 have not had to be thanks to this liquid

look for a bottle of AT-205 re-seal and follow the directions exactly.

https://www.ebay.com/itm/ATP-Re-Seal-8-oz-AT205/132373012185


you will know within a few hundred miles if it is going to help you. it is very effective if the seal is largely in place and not physically damaged but merely dried out and a bit worn. this liquid helps to swell old seals and does a first rate job.

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if you are forced to do the seal and do not have a lift it is a tough job.

you choices are these:

1. pull the engine WITH the transmission attached and reinstall same. much more work and much much longer but oddly enough less stressful since its a one step out and one step in after all the stuff is detached

or

2. drop the transmission alone. this is not hard on the removal but can be VERY difficult to align the bellhousing with the back of the engine on the install and extremely hard if you do it alone. the difficulty stems from the fact you have insufficient clearance without a lift to do the job efficiently as you will see if it comes to that.