Engine Toro Recycler 20031 from 2004 leaking oil on top of deck

I have a 2004 model Toro Recycler mower model 20031. It has a Tecumseh LV195EA engine. The engine runs fine and is easy to start. I just recently see some smoke while it's running, but am not sure if that's coming from the exhaust or just from burning oil on the engine.

Lately, there has been a lot of motor oil on top of the deck, at the front of the mower. It looks like the oil is leaking from the front of the engine (well, the front being at the front of the mower, which is the cylinder and cylinder head part of the mower).

I cleaned off the oil and really can't see where it's leaking from, but it doesn't seem to be coming from up high on the engine, unless it's dripping. The oil seems to be coming from at the fins or base of the fins area of the cylinder.

It seems to leak only when the engine is running.

I searched the web and found others that had leaks. I checked the breather (part# 36557A) and there's no leaking around there. I did blow in the hose that connects the carburetor to the breather and blew oil out the top of my oil filler tube. I'm not sure if this part is bad or not, but it is not leaking oil around there.

I'm not sure where to go on this. I recently put $50 in parts into the drive system to get that working again (I worked on it myself, not taking it to a shop).

Most common oil leak on those engine is the seal on the dipstick tube. Easy fix, replace the seal, part number 37610, about $2.50.

Rivets said:

Most common oil leak on those engine is the seal on the dipstick tube. Easy fix, replace the seal, part number 37610, about $2.50.

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Thanks for the idea, though that's not where it's leaking. I haven't replaced an o-ring or seal in the 12 years I've had the mower, but there's never been oil pools or dripping back that far on the engine... well, back that far means away from the cylinder. If I have to order parts, I will get this seal and replace it anyway.

It seems to be leaking under the cylinder or not too far away on each side of it.

I've never replaced the breather assembly on the mower. Maybe it's plugged and building up pressure and forcing oil out when it's running?

But I don't see any oil running or collecting at or around the rubber plug on the breather. That is, unless it's leaking under the flywheel where I can't see it.

You must know more than I do, as there is only one place oil can leak under the cylinder and that is the sump gasket. If this is the problem, it will leak all the time, not only when the engine is running. You many have never replaced the seal, but as it gets old it will harden and leak, but what do I know? Oh by the way, did you ever think that the reason the oil pools under the cylinder is because the deck is tilted that way, just a shot in the dark? Read my signature and good luck.

I don't know if I know more than you do or not. I probably don't know more about mower engines.

I do know that there's never been any oil moisture around the bottom of the dipstick tube though. There's never been any oil on the sides of the deck - not running towards the front of the mower. It just appears at the front of the mower deck (and then drips down to the ground through the small hole in the mower deck)

I have seen oil dripping in the area of the arrow in one of the pictures of my original message. That's quite a bit away from the dipstick, but I guess - if the engine is also tilted at the same angle as the mower deck, it could be possible that the oil is running over there before it drips onto the deck.

I took the flywheel off today and found what may be the problem. It's really oily under the flywheel. Is the breather assembly plugged and need to be replaced? or could the top crank seal be bad? Can it be replaced w/o taking the engine apart?

Your mower cools by blowing thousands of litrers of air over the engine .
This will naturally blow oil all over the place.
There are 3 seals 2 on the crank and 1 on the dip stick
there are two gaskets one on the sump one on the breather. valve chest behind the carburettor

The oil level is at the top of the dip stick seal so that is the most common place to leak from particularly when the owner overfills the oil.

After cleaning all the gunk/oil off the engine, I put it back together and started it up again. There appears to be 2 places the oil is leaking from (one worse than the other) and I'm wondering if they may be related.

The first place I saw oil leaking was at the top rubber plug of the breather assembly. There was less oil leaking here. It would run down the back side of the motor (opposite the cylinder) and a little towards the starter side of the engine.

The other place is where the arrow is pointing in one of the first pictures in the first post. This area seems to leak more than the top of the engine area. It's right under the cylinder fins at the base of the engine. It appears to be at the gasket where the bottom of the engine meets the cylinder section.

Could a bad breather assembly cause both of these leaks? I hope so because I don't want to take the engine apart to replace that gasket. While I had the breather assembly out, I took it apart and it appears that the one-way valve 'sort of' works. I blew and sucked on the hose and did notice more resistance one way than the other (I don't remember which way). It also made a funny noise when going one way on the air/suction (again, I don't remember which - but it was on the 'easier' way that the air went through it).

Nothing except the air filter, oil and spark plug has been changed on the engine in 12 years.

Any suggestions?

Yes and something is creating excessive crankcase pressure such as worn rings or blown head gaskets or warped heads on OHV engines.
As noted earlier where you see the oil and where it is leaking from are usually 2 different places.

bertsmobile1 said:

Yes and something is creating excessive crankcase pressure such as worn rings or blown head gaskets or warped heads on OHV engines.
As noted earlier where you see the oil and where it is leaking from are usually 2 different places.

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The mower runs great and starts easily. It doesn't smoke.
Should I see excessive exhaust smoke if the rings are worn? Should the engine run poorly if the rings are worn or the head gasket blown?
Is it possible to check compression on a lawnmower engine like you can with a car? If so, what PSI should I see?