Oil Leak

[Takeshi]

Is this oil leak due to the water pump oil seal failure?
All I did was the following:
- Change the engine oil.
- Add the coolant (50/50) to an optimum level.
- Adjust the valve clearance.
After the valve adjustment, I checked the cylinder head cover gasket
to make sure there's no oil leak. (gasket sealant was applied to the
semi-circular rubber areas in front, and I detected no oil leak from cylinder head cover)
After all, my ST has 128k miles on it, and I've heard that it's a pretty common
issue among the high mileage STs.

I'd appreciate your input.

 

[BakerBoy]

There's a good likelihood that you pinched the under-throttle-body-heat dam under the valve cover. That hole is where such leaked oil will drain from.

 

[970mike]

From your picture it looks like a coolant leak coming from the "V" area and running down. Some have had good luck with tightening the clamps and others have replaced the clamps with constant tension type clamps. I have replaced my clamps and hoses as the hoses were weeping from the inside out. If you search this site on coolant leaks you will find several threads on how to repair the leak. Could also be an oil leak but the stains are coolant. Good luck.

 

[Mellow]

There's a good likelihood that you pinched the under-throttle-body-heat dam under the valve cover. That hole is where such leaked oil will drain from.

+1, it's highly unlikely the mechanical seal just happened to fail after your valve check so I'd double-check all the valve cover areas for even a small leak.

 

[Takeshi]

Thanks guys for such quick responses.
Yes, the leak is not from the weep hole but from the area I circled in red.
The oil leak was at an abnormal level. The coolant leak from there was minimal.
One thing I had not mentioned was that I detected the excessive oil leak from the right side cylinder head cover gasket for the first time,
so I redid the gasket seating. I don't see any oil leak from the cover anymore, but there must be some residual oil in the valley.

 

[970mike]

Pull the tank and throttle bodies off check your hoses and clamps. You may also want to reseal that threaded plug on the front right side of the motor as it could be leaking oil into the "V" valley and out that drain hole.

 

[OhioDeere]

This morning I moved my bike up to the front heated garage. After letting it warm up for 1/2 hour. I noticed about a pint of oil on the driveway.. after freaking out. I put it in the garage and commenced to take the tupperware off. I have the identical leak that the OP has. I had valve covers off 1000 miles ago and not a problem.

So, later I'll start to dissassemble and figure it all out.

 

[SupraSabre]

...
One thing I had not mentioned was that I detected the excessive oil leak from the right side cylinder head cover gasket for the first time,
so I redid the gasket seating. I don't see any oil leak from the cover anymore, but there must be some residual oil in the valley.

What's this "redid the gasket seating" you are referring to?

This morning I moved my bike up to the front heated garage. After letting it warm up for 1/2 hour. I noticed about a pint of oil on the driveway.. after freaking out. I put it in the garage and commenced to take the tupperware off. I have the identical leak that the OP has. I had valve covers off 1000 miles ago and not a problem.

So, later I'll start to dissassemble and figure it all out.

You both need to check the valve cover gaskets and see if the rubber dam has been caught in one of them. I had that happen when a stealer checked my valves. I had to replace the valve cover gasket before it would stop! Make sure you use a torque wrench on it for the proper seating!

 

[Blrfl]

Also make sure the retainer bolts are torqued down in the right order. Any other way and you run the risk of not getting a good seal.

--Mark

 

[Takeshi]

What's this "redid the gasket seating" you are referring to?

The valve cover gasket was not properly seated, thus there was an excessive oil leak from there.
I fixed the leak by seating it properly, but there must be some residual oil in the valley which caused the leakage in the picture.
This was my first attempt adjusting valves, and I should have been more careful.
It was a little hard for me to inspect the gasket seating, especially for the inner side of the right side cylinder.






You both need to check the valve cover gaskets and see if the rubber dam has been caught in one of them. I had that happen when a stealer checked my valves. I had to replace the valve cover gasket before it would stop! Make sure you use a torque wrench on it for the proper seating!

The last time I had a stealer check the valves, they didn't seat the gasket properly,
causing tons of leak. I decided to do it myself this time.

 

[SupraSabre]

Is this "stealer" you're talking about "Temecula Motorsports"?
They should be very familiar with STs as they do repairs for the police STs,
but the last time I had them check the valves, they didn't seat the gasket properly,
causing tons of leak. I decided to do it myself this time.

Yeah, I had the same problem with a Stealer up in Riverside...that was also fixing cop ST1300s. And yes Temecula Motorsports "should" be very familiar with the ST1300s, but I really don't trust them a whole lot...like I don't trust any stealers. The only time my bikes see a stealer, it is for warranty or in this case recall work! We will see how well they do! 4:

 

[Takeshi]

Pull the tank and throttle bodies off check your hoses and clamps. You may also want to reseal that threaded plug on the front right side of the motor as it could be leaking oil into the "V" valley and out that drain hole.

Could you be more specific which threaded plug you're talking about? I'd appreciate it.

 

[970mike]

Could you be more specific which threaded plug you're talking about? I'd appreciate it.

Here you go https://www.st-owners.com/forums/showthread.php?110233-I-Found-A-Picture-Of-The-Source-Of-The-Oil-Leak!&highlight=mystery+oil+leaking+plug+on+ST1300

 

[Takeshi]

Here you go

Thank you! Is this threaded plug accessible by just removing the air box?

 

[BakerBoy]

The red arrow in that picture [my picture] points at the cam chain release for the right bank. IF that bolt isn't installed, a small amount of oil could weep out (oil would have to flow uphill to get out). My money is still on the rubber dam being caught under the valve cover.

And, yes, you can see that bolt by removing the air box (including it's bottom half).

 

[Takeshi]

The red arrow in that picture [my picture] points at the cam chain release for the right bank. IF that bolt isn't installed, a small amount of oil could weep out (oil would have to flow uphill to get out). My money is still on the rubber dam being caught under the valve cover.

And, yes, you can see that bolt by removing the air box (including it's bottom half).

Thank you! The bolt for the right cylinder cam chain tensioner lifter shaft was there, but the sealing washer was missing.

 

[Takeshi]

Is the sealing washer for the right cylinder cam chain tensioner lifter shaft the Part#13 in the picture below?

 

[BakerBoy]

No. Item #11 is the neutral switch, so item #13 is not the washer you are looking for.

Related to oil leaks, it has been found on a few bikes that item #10 "SWITCH ASSY., OIL PRESSURE" is seeping oil around it's threads.

The washer you need is 90442-397-000 "WASHER, SEALING (6MM)" ... see here: http://www.ronayers.com/CAM-CHAIN-TENSIONER-C132486.aspx

 

[Takeshi]

No. Item #11 is the neutral switch, so item #13 is not the washer you are looking for.

Related to oil leaks, it has been found on a few bikes that item #10 "SWITCH ASSY., OIL PRESSURE" is seeping oil around it's threads.

The washer you need is 90442-397-000 "WASHER, SEALING (6MM)" ... see here: http://www.ronayers.com/CAM-CHAIN-TENSIONER-C132486.aspx

Thanks much BakerBoy! I am reluctant to remove the throttle body as "SWITCH ASSY., OIL PRESSURE" seems to require its removal in order to access.
I will first try the sealing washer and see what happens. As for the coolant leaks, I see the coolant seeps thru at the clamp locations, where they are connected to the water pump.
Is it possible to work on them by just removing the radiator? I'd like to avoid messing with the throttle body if I could.

 

[BakerBoy]

Yes, by all means, DON'T pull the throttle bodies for the clamp R&R...instead, do pull the radiator (and thermostat) and you'll have access from the 'front' of the engine to all the clamps. And you'll also get to see where the oil seep is coming from (I'm still expecting that you'll find it's the rubber dam pinched under the valve cover ).

You can see pics of mine in various states of service in My Galleries.