( UPDATE: Turned out to be a coolant leak ) Oil leak after riding ( with pictures )

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Hi ST owners!

I’ve always noticed a small ( water bottle
in pic for context ) oil leak under the bike that appears after riding. The leak in the picture was after a 90 minute ride, and I noticed it a couple of hours later.

I tried to mark where the oil is in one of the pictures, hopefully that’s a helpful start. I’d really like to get this fixed properly.

Thanks as always, hopefully someone can give me a starting point with this one.
 

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SupraSabre

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It looks like it's been leaking for a while.

It could be leaking from several different places.

You'll probably need to remove the fairings and check for leaking valve covers, which would be my first place to look.

if it is coming down through the square hole on the right side of the front engine cover, it could be the Oil plug near the right side of the valley.

But without removing the tupperware, no telling where it is coming from.
 
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The only thing one can see from those pictures is that it's at the front. You're going to have to either take off the lower fairings or get an inspection camera and go in there and find out where it starts. While there is oil dripping off those bolts, in picture 3 it looks like it is starting up higher, possibly around the pan gasket or even higher. Hard to tell with the lower fairings on.
 
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Looks like antifreeze or just water. Remove the 2 middle cowl on the right side. Start ur bike and look for leaks. Search the forum for removal.
 
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HondaInTheSun
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Thanks everyone, really helpful! Not sure how to tell if it’s water or antifreeze vs oil...any pointers there?

I actually do have an inspection camera...where would be the best place to start hunting with it without removing plastic?

Thanks again!
 
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Thanks everyone, really helpful! Not sure how to tell if it’s water or antifreeze vs oil...any pointers there?

Actually best place to start hunting with plastic removed

Thanks again!
I modified your post. Wasting time using a camera. Leak is a leak
Remove both side lower plastic. I like to start fresh by washing the front right side of the engine. I use a squirt bottle with soapy water, I also use a new paint brush to loosen the oil film. Then spray it off. Check reservoir on the left side. It's a white plastic bottle. If below min fill it up to max line with type II honda antifreeze. Start motorcycle and start looking usually on the right side for leaks. Find the square and round hole. Any leaks?

Report back
Isn't it nice to own your own motorcycle...
 
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It doesn't look like much of a leak, but it does look like you have had some seepage and grime build up for awhile, which makes it hard to find. If you aren't able to diagnose it the smart way, take the plastic off, clean everything well, and go for a ninety minute ride and then look for oil. Also, dumb question, but did you check that it's actually oil and not some other substance (e.g., brake fluid, final drive oil, coolant)?
 

Igofar

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Judging by all the crap on your lower front cowl, and all over the side of the engine, my guess would be that its not oil, but a pretty good coolant leak that is mixing with dirt, looking like oil.
 

CYYJ

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Keep in mind that if you have recently thoroughly washed the motorcycle, and in the process directed water from a hose into the area between the "V" of the engine, that wash water will drain out of the square hole - it's supposed to work that way.

If the valley in the "V" area is dirty, or if there is oil elsewhere on the outside of the engine, that oil residue and dirt will get washed out through the square hole. The water that falls on the ground will evaporate, but the oil won't, which might leave you thinking you have an oil leak.

This kind of false alarm is particularly likely to happen if the motorcycle was parked on a slightly up-sloping driveway (or coin-op car wash bay) when you washed it. If the bike was on a slight upslope, water will have pooled towards the rear of the "V", and will not escape until the motorcycle becomes level again.

I agree with @Tdinova 's suggestion: Take the two front fairings off the motorcycle (the fairings that wrap around the cylinder heads), wash the outside of engine thoroughly using Simple Green or similar to get rid of oil & dirt on the outside of the engine, especially around the two weep holes, the oil level sight glass, and the bottom of the engine, then put it back together and go riding. Once you have a clean engine, you can then use your borescope to monitor where the leakage is coming from.

Michael
 
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HondaInTheSun
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I had a very quick first pass, removing only some plastic. I’ve attached more pictures here of what I saw in case it offers any clues. I added a red arrow to a suspect area, and red lines to areas that appear “damp” with something.

I will say that there seems to be a green tinge to some of the areas which would indicate coolant vs oil?

Hopefully these pics help narrow down what comes off next...

Thanks as always!
 

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You can tell if its oil or aunt freeze pretty easily by sticking your finger in the goop. Oil is more slippery than anti freeze, which is 50% water. You can also smell it. Sure, with enough grime and road dirt it might be a bit tough, but you should be able to get a good idea.

Simple green is probably the cheapest and most benign way to go for cleaning. Auto parts stores sell a bunch of degreasers but many are noxious and you don't want them splashing on the fairing. Spray the loosened gunk w/ water, let it dry and dust w/ talcum powder. This will make ithe bike feel much better (like a baby) and show fresh oil immediately. Don't use Johnson's baby powder - it has asbestos in it. :rofl1:

Yup coolant will be colored. Most oil starts out honey colored and turns darker, eventually black when its past due for a change.
 

CYYJ

Michael
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Your slides 1 and 6 (the slides with the two parallel curved lines drawn on them) show conclusivly that the leak is coming down the drain path for the 'square hole', which means that the liquid is originating in the V of the engine.

Most probably, it is antifreeze that is leaking from one of the many cooling hoses located in the forward part of the V. This is a common problem with older ST 1300s, the solution is to replace the affected hoses (and at the same time, replace the clamps that hold these hoses in place).

Keep an eye on the quantity of antifreeze in the reservoir bottle near the left rider footpeg. If the leak is minor, you can defer the maintenance until it is convenient to do a major disassembly (up north, we call this a 'winter project'). If you need to frequently replenish the antifreeze, you might want to get the job done sooner rather than later.

Michael
 
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HondaInTheSun
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Thanks so much Michael!

So next steps...bearing in mind I am not remotely mechanically minded, but will try anything once...

Remove the side fairing panels. Both sides? Will this then give me access to be able to check the hoses and clamps we suspect are the issue?

Thanks again!

PS: I was going through the maintenance receipts for the bike and it had a 24k service done early, at 18k miles ( now 6k miles and 2 years ago ). The receipt mentions the cooling system ( attached ). I mention this as I don’t want to repeat things that have already be done as I’m not that confident to start with.
 

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spill some water on the floor where the leak dripped. If it beads up and doesn't mix, it's oil. Looks to me like it's oil coming from the timing cover. Cam,crank seal, just a guess, looks like oil maybe.
 
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If you id the juice as AF and not oil, then you will need to see where its leaking from. Yes, pulling the left n right middle cowls will tell you a lot, but not really give you access to the thermostat housing. My hoses were leaking at the large spigot on the left side of the housing (driver's left). Since I saw some corrosion on the housing, I replaced the hoses. While you are in there, you might consider swapping out the stat n o ring for new pieces, but I am getting ahead of myself.

You should be able to see the stat housing and signs of leakage from one or both sides. You will be looking with a good flashlight behind the radiator, and behind that cross brace just above the bottom of the V of the engine. Also check all the hose to radiator connections. To do significant work in this area you either need a trained pet octopus or you will have to pull the radiator OR go in from above. The latter gives you more room to work, but involves pulling the gas tank, air cleaner, air cleaner housing, and I think, throttle bodies. This gives you access to the whole area around the thermostat housing and you can replace any and all hoses and clamps if you wish. A less roomy alternative is to remove the front wheel, dangle the calipers from string or wire hung on the handlebars, remove the fender, pull the radiator, and take off the cross brace behind the radiator. Since your aunt freeze is 2 years old, and Honda recommends changing it every 2 years, this is the path I took and would recommend. At 17 years, your hoses should be carefully examined, but replacing the ones behind the stat housing is going to be difficult from the front (Larry says its possible - I don't disbelieve him but I do think it is beyond the capabilities of most of us mortals not blessed with his repertoire of incantations). Many guys who have worked atop the engine (@CYYJ, for one) have said the hoses last a long long time.

Now that I have bored you with background info, when I had a drip, I decided to replace some of the hoses. Unclip the fan connectors (small screwdriver prying up on the barely visible tiny tab to release the male n female parts), remove the big hoses from the radiator to drain the system, go change your clothes and clean up all the AF you spilled on the floor, remove the radiator mounting bolts, tip the radiator out at the bottom to unhook it from the top hangers, and carefully remove it from the bike. Now you can see that brace easily, remove it from in front of the stat housing and you can replace the two big hoses from the radiator and the thermostat and O ring.

It is very possible that all you need to do is tighten the hose clamps a bit. The OEM clamps are very narrow and can cut into the hoses if tightened too much. More than a few guys have gone the Breeze Clamp or Gates heat shrink hose clamp route. While I was in there I replaced the clamps I could reach and discovered that you have to be careful positioning the Breeze clamps because the spring assembly on them is so large it can get in the way of other components.

Should you decide to replace the clamps, PM me, I can give you some links to other threads if nobody posts them first.

If this is an oil leak, you are on your own. I had a trusted mechanic pull my clutch cover because I did not want to incapacitate the bike for as long as that would have taken me. Good luck!
 
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