Need help... blown head gasket on my ST1100?

[paulcb]

I'm just going to throw this out there for the debate: Delo is an oil made for diesel engines. Diesel transmission gears are not lubricated by the engine oil. Our bike's transmission gears are lubricated by the engine oil. Motorcycle specific oils have additives that help to prevent oil foaming caused by the gnashing it gets in the gear train. Diesel oil does not require such additive and may be why you see that foaming in your oil.

Other than being "cheap", I have never seen any good reason to use it, or literature that says diesel oil is recommended for use in a 4 stroke m/c engine.

Understood and good points Bush, but many have used this oil for many, many thousands of miles on motorcycle engines. Personally, I've got about 110k miles using it on my two ST100s and this is the first time in all those miles I've ever seen this foaming. I change my oil and filter every 5-6k miles. I don't mind a good oil thread, but if someone wants to discuss this, please start a new thread.

 

[W0QNX]

Well, I think I have the most definitive answer I can get without an oil analysis... I heated up some oil to ~300°F, and saw no boiling. Googling tells me that 50/50 coolant boils at around 225°F when not pressurized. So that tells me there's no coolant in my oil.

Smells like bacon!!

 

[dwalby]

if you have a bottle of coolant handy mix a little coolant, water, and motor oil in an empty water bottle, put the cap on, and shake it. Dunno if that will mix it the same way it gets mixed in a hot running engine, but if it does you'll see how its appearance is pretty obvious.

 

[John OoSTerhuis]

I’ve been following along and racking my brain... if it’s really not an oil overfill situation (sure looks like it), how does air get into the oil and foam...? JAWAG... could the crankcase breather somehow be involved?

John

 

[paulcb]

Well, I filled it with oil, closed the radiator cap and ran it for about 20 minutes. Fan came on/off 10 times or more, at it's usual ~12 o'clock position. Temp never got above ~12 o'clock just idling in the garage. Overflow bottle level rose about 1/2". I watched the sight glass while it was running and it looked nice and clear with fresh oil. Looked for oil/coolant leaks but found none. I shut it off and watched the sight glass... zero bubbles, nice and dark, was at the 1/4 mark after 1 minute and the 1/2 way mark after 10 minutes. Now, I'm going to wait a couple hours for it to fully cool, watching the overflow bottle and sight glass. I'll then pull the radiator cap and view the coolant for oil and open the oil cap and look for condensation. So far, so good, I think.

Am I missing anything?

 

[red one]

I guess you warmed it up with the cap off first? No bubbles? Other than that all you can do is ride it and watch and check. When I was fighting my heat problem on my bike I got tired of taking the Tupperware on and off to get to the radiator cap so I left the right hand gray pocket off my bike. Much easier.

 

[Davey1965]

I had a head gasket blow on my F150 a few months...That just doesn't look like my oil looked... for what its worth...hope you figure it out

 

[paulcb]

I guess you warmed it up with the cap off first? No bubbles? Other than that all you can do is ride it and watch and check. When I was fighting my heat problem on my bike I got tired of taking the Tupperware on and off to get to the radiator cap so I left the right hand gray pocket off my bike. Much easier.

I didn't warm it up with the cap off. I tried, but the water pump pushes a lot of water through the top hose and it comes into the housing neck pretty high up, so coolant shoots out with the cap off.

It's been cooling for an hour now and the overflow bottle level is back down to where it started, so I pulled the radiator cap. Coolant was at the starting level and no signs of oil after cooling for an hour. Oil in sight glass looks good (dark, no bubbles) and is just a hair over where it was at 10 minutes after shutoff, ~1/2 way between the marks.

So, I think I'm good... no oil in coolant, no coolant in oil and the cooling system is working as designed. Going to button her up and do my normal commute this week. I plan to check the coolant level Wednesday night before leaving for WinterSTOC on Thursday morning.

The foam is still a mystery to me... I've done 13 oil changes on this bike and pretty certain I've never overfilled it, but it's certainly not impossible... maybe I got distracted on the last change and added a little too much? How much extra would it take? We'll see how it looks at the next oil change. I'll try to remember to update this thread.

I think I'll do what Doug suggested (good idea!) and create an oil coolant mix. Thanks again to everyone for all the insight... I was pretty concerned and you guys helped out a lot!!

 

[paulcb]

I had a head gasket blow on my F150 a few months...That just doesn't look like my oil looked... for what its worth...hope you figure it out

Thanks. One more data point in my favor!

 

[paulcb]

As promised, I did a little coolant/oil mix experiment. I don't think it's equal to what happens in an engine at much higher temps and velocities, but it's interesting.

4 pics:
1) fresh oil straight out of the bottle, 2) ~10/1 oil/coolant mix, 3) freshly shaken vigorously for about a minute and 4) allowed to sit for an hour...
1 2 3 4

FWIW, I let a sample of my foamy oil sit all night and it never separated like that last pic.

A couple bonus pics. Some have wondered about the clearance of an automotive radiator cap on the ST1100. There is plenty of clearance, at least on my ST1100 ABSII. The first pic is the minimum clearance between the cap and the flange on the left. The second is the cap fully screwed on.

 

[paulcb]

Also, I had a nice long chat with our favorite ST whisperer Larry (Igofar). I believe the conclusion was that the most likely reason for the foam was me not letting the bike run long enough before I drained the oil, essentially not burning off any condensation. I only let it idle about 3-4 minutes before draining. And, it has been quite wet/humid around here lately. Maybe he'll chime in with more details. Thanks for calling Larry!

Pretty much what Raymond said earlier...

My first thought would be you have condensation whipped up by the crankshaft rotation not being boiled off. Based on you said no apparent coolant loss.

 

[dwalby]

Hey Paul, I think we discussed the little plastic shroud that normally attaches to that metal frame tab shown in your radiator cap photo a few weeks ago when I was replacing my cap. Looks like yours was removed by a P.O. Don't know if it makes much difference if its there or not, but yours is obviously missing from that photo.

 

[paulcb]

I kind of remember you mentioning something about that, but I’m not sure what part it is. What purpose does it serve? Pic?

 

[dwalby]

I kind of remember you mentioning something about that, but I’m not sure what part it is. What purpose does it serve? Pic?

here's the top view with it installed, the plastic nub is all that's visible from this angle. Its about the size of a 3x5 card and it sits vertically in front of the t-stat housing approximately. All I can figure is maybe it blocks ambient air from entering that area and cooling the t-stat housing more than desired.

 

[Bush]

What purpose does it serve?

I'm guessing it is a baffle, designed to redirect incoming air lower, towards the engine area and also to provide weather/bug/dust protection for the area behind it.

 

[paulcb]

Yes, I think I remember that on my other ST11, and I think I did have some problems with the automotive style caps. Thanks for the pic Doug.

 

[GreenZR]

I'm guessing it is a baffle, designed to redirect incoming air lower, towards the engine area and also to provide weather/bug/dust protection for the area behind it.

I agree, but there are two, one on each side. Parts #1 & #2.

 

[paulcb]

FWIW, I've continued to monitor my oil/coolant mix science project. The original 4 pics are below, from the day I started this on Jan 20.

1) fresh oil straight out of the bottle, 2) ~10/1 oil/coolant mix, 3) freshly shaken vigorously for about a minute and 4) allowed to sit for an hour...
1 2 3 4

Here are two more pics from Jan 27 and today, Feb 2. Note that little has changed in two weeks... much of the coolant is still mixed with the oil. The jar has just been sitting, not moved at all.
Jan27 Feb2

I think the suspended coolant bubbles are so small, their density is not enough to overcome the surface tension, so they never completely separate with the oil. And, I've been riding everyday since then with no oil loss/gain and my oil looks normal in the sight glass, so I believe everything's OK with my engine, relative to my original concerns. Note to self... fully warm the engine prior to oil drain!

 

[Bush]

Note to self... fully warm the engine prior to oil drain!

Or, just remove the drain plug on the cold engine and let it drain overnight. No need to run the engine first. Besides, where you live, the ambient temperature isn't that cold normally, right?

 

[paulcb]

Or, just remove the drain plug on the cold engine and let it drain overnight. No need to run the engine first. Besides, where you live, the ambient temperature isn't that cold normally, right?

Yep, that's what I've always done for the reasons you mentioned Bush, except not overnight, just for 30 mins or so, until it stops dripping. I think I'm going to go back to fully warming it up to make sure nothing sticks to the sides/bottom of the oil pan, and also releasing the clutch plates (thanks for the tip Larry) to get the extra dirty oil out of the clutch plates.