Oil leak

[Mariner Fan]

So, I have owned my bike since new. (2007 Venture) this year I’ve noticed a leak after the bike is parked. The oil is coming out of a vent hose. Everyone will say it is because I have overfilled the crankcase but it is not the fact. I have always filled it halfway in the window and the last time I filled it a quarter way up. This only happens when the engine is hot. I pulled the tank and sure enough there is oil residue in and below the air box above the carbs on the drivers side. Any ideas? I’m at a loss.

[vzuden]

The only time I have had oil in the places you describe is when the oil level is at or above midpoint on the site glass. You are checking it with the bike level and off the side stand, right?

[Mariner Fan]

Yes, the bike is level when I check the oil level. I’m taking it to the shop anyway but was hoping someone here would have an idea why this is happening

[videoarizona]

Yes, the bike is level when I check the oil level. I’m taking it to the shop anyway but was hoping someone here would have an idea why this is happening

 

Clogged crankcase vent?

[M61A1MECH]

Yes, the bike is level when I check the oil level. I’m taking it to the shop anyway but was hoping someone here would have an idea why this is happening

 

Oil fumes are supposed to get sucked up to the airbox with the idea that they will go into the carbs as vapors and be burnt during the combustion process, but during hard running at highway speeds the oil can be "sloshed" around and either more fumes than the system can handle or liquid oil can get sucked up to the air box. The excess fumes will eventually condense back to liquid and run to the low point in the air box where the hose is, and any liquid sucked up will immediately drop to the bottom f the air box and find its way to the drain tube.

 

Checking the air box periodically for liquid oil is a PM sort of thing, I would do mine maybe once a year or so, there was always some liquid oil present and I never over filled my crankcase.

 

If there is an excessive amount of oil then there may be a real problem some where, otherwise I would clean it and motor on and check it at some regular interval to monitor the build up.

[Marcarl]

I would think clogged air filters maybe, or did you change your air filters to another brand?

[Mariner Fan]

I would think clogged air filters maybe, or did you change your air filters to another brand?

 

I thought the same thing so I checked the air cleaners (K&N) they were clean. I may put factory air cleaners back on just for the heck of it.

[Mariner Fan]

Oil fumes are supposed to get sucked up to the airbox with the idea that they will go into the carbs as vapors and be burnt during the combustion process, but during hard running at highway speeds the oil can be "sloshed" around and either more fumes than the system can handle or liquid oil can get sucked up to the air box. The excess fumes will eventually condense back to liquid and run to the low point in the air box where the hose is, and any liquid sucked up will immediately drop to the bottom f the air box and find its way to the drain tube.

 

Checking the air box periodically for liquid oil is a PM sort of thing, I would do mine maybe once a year or so, there was always some liquid oil present and I never over filled my crankcase.

 

If there is an excessive amount of oil then there may be a real problem some where, otherwise I would clean it and motor on and check it at some regular interval to monitor the build up.

 

The strange thing is it seems to be heat related. The first time I noticed a puddle under the bike is when I backed it out of the garage last winter to run the engine and forgot about it for an hour or so. This week I was stuck waiting for a long and slow train on a hot day. Rode it into the garage and noticed it later on.

[cowpuc]

All IMHO and just that,, opinion here.. All 4 stroke engines have to vent the crankcase. The amount of oil "gases" being caught up in the vented can change for many reasons and HEAT causing vaporization is very common. Having answered the question of what level you are filling the case to has been answered so no since in doubling back on that = as long as your filling on the site glass while the bike is upright and level.

Years ago I sold numerous Chinese Scooters and had a couple catastrohpic failures come back due to long distance running at speed without checking oil consumption at each fuel fill = the case held less then 1 quart of oil and, under certain conditions (heat being one) the little 150cc 4 stroke would ventilate/aspirate the oil to the point the bike would burn down. After learning that some of my customers found checking the oil to be to much of an issue, I started experimenting with variety of oils to see if one brand/weight of oil would vaporize less then others and ended up scoring big time..

I am in the middle of putting together a huge wedding right now and dont have time to dig into shop notes from years ago to figure out which oil(s) proved the best results but can tell you that the answer to the issue may very well be found in just switching to a different oil platform. On my 1st Gens I always noticed a HUGE difference in this just by going to 20/50 weight when chasing the desert regions..

I would try this before defaulting to the thought that the engine needs a rebuild..

Hope ya figure it out

Puc

[Marcarl]

The strange thing is it seems to be heat related. The first time I noticed a puddle under the bike is when I backed it out of the garage last winter to run the engine and forgot about it for an hour or so. This week I was stuck waiting for a long and slow train on a hot day. Rode it into the garage and noticed it later on.

Soooo, when you let it run outside it was on the side stand, did you happen to do that waiting for the train as well?

[Du-Rron]

This only happens when the engine is hot. I pulled the tank and sure enough there is oil residue in and below the air box above the carbs on the drivers side. Any ideas? I’m at a loss.

 

Ok, RESIDUE is what you said. Not liquid oil right? "Residue" is ok. Liquid oil is not. If you have liquid in your airbox I am going with @videoarizona on this one as a blocked air vent. The oil is vaporizing and allowed to go up but when condensed, is slow to go back down. Check for a blockage.

I live in Texas so I know a little something about heat. I run 10W-40 and on long trips at cruising speed I will even get a hint of oil mist out the breather tubes to the airfilters and I notice this because I clean the air filters every oil change, (blow off the big bugs at least) . I am talking about "residue", a couple drops, mist that has condensed back to liquid in the tubes and on the foam blockers in the leg guards, when I go slower than warp factor 1. Nothing to write home about.

 

So... if you ride like a nut job in 100 degree heat at Warp 7 like I do, "residue" found inside the airbox every 5 or 10 thousand miles is perfectly ok. Here is how to check the breather.

 

 

In fact, on some bikes, you have to dump out the LIQUID oil from the airbox reservoir every 4K miles or so and this is part of regular maintenance and applies to bikes that have the correct oil level.

[Du-Rron]

The oil is coming out of a vent hose.

 

Which vent hose? Can you show us a picture?

[Mariner Fan]

Soooo, when you let it run outside it was on the side stand, did you happen to do that waiting for the train as well?

 

Yes, it was on the side stand last winter but not while waiting for the train. Of course it was on the side stand in the garage when it leaked.

[Mariner Fan]

Which vent hose? Can you show us a picture?

 

It’s the vent hose that is close to the kickstand when it is up.

 

 

The dark longer one. Posting with an I-phone is a pain! Lol

[Mariner Fan]

I have always used Yama lube full synthetic 15w-50.

[Mariner Fan]

TheInside of the airbox did not have standing oil in it, just a film. The carburetor inlets looked very clean

[Mariner Fan]

Ok, RESIDUE is what you said. Not liquid oil right? "Residue" is ok. Liquid oil is not. If you have liquid in your airbox I am going with videoarizona on this one as a blocked air vent. The oil is vaporizing and allowed to go up but when condensed, is slow to go back down. Check for a blockage.

I live in Texas so I know a little something about heat. I run 10W-40 and on long trips at cruising speed I will even get a hint of oil mist out the breather tubes to the airfilters and I notice this because I clean the air filters every oil change, (blow off the big bugs at least) . I am talking about "residue", a couple drops, mist that has condensed back to liquid in the tubes and on the foam blockers in the leg guards, when I go slower than warp factor 1. Nothing to write home about.

 

So... if you ride like a nut job in 100 degree heat at Warp 7 like I do, "residue" found inside the airbox every 5 or 10 thousand miles is perfectly ok. Here is how to check the breather.

 

https://www.venturerider.org/forum/attachment.php?attachmentid=116569

 

In fact, on some bikes, you have to dump out the LIQUID oil from the airbox reservoir every 4K miles or so and this is part of regular maintenance and applies to bikes that have the correct oil level.

 

Thank you for this information! This area on my bike looks pristine. I will pull the hoses and check to see if they are plugged

[Mariner Fan]

Just an update. I took the bike in for a service and they found that the oil leak was not a leak at all. I had a small amount of oil floating in the cooling reservoir. The hose that I thought was a vent hose is actually the overflow hose for the reservoir. I have read articles here that say that the cause could be in my water pump, head gasket, or the twinkie (still trying to figure out what that is). I have done the oil change and did not see any signs of water in the oil (the white foam). So, now I have to come up with a plan of action.

Have the cooling system inspected.

Inspect the twinkie and replace gaskets as needed.

If necessary, have the compression checked.

 

The bike has always ran very well so I'm not sure if the head gasket is the cause though I'm not ruling it out.

[M61A1MECH]

Most common problem that causes oil in the coolant is the water pump seals going bad, there is a vent hose for the chamber between the coolant galleries and the oil galleries that may show signs of coolant dripping that would indicate the seals, I had one fail but never had any weeping at the vent.

[Mariner Fan]

So the repair shop told me to just run the bike to see if there is still a problem.

 

I think they thought that I poured oil in the water reservoir.

 

Well, the problem still exists.

 

 

The water reservoir is full of oil

 

 

Has anyone here had this problem?

[M61A1MECH]

Yes, see my post #19 , I speak from experience it happened to me on my 98 Royal Star Tour Classic. You should start with the oil pump / water pump assembly. The seals on the common shaft can and do fail allowing oil to get into the cooling system.

 

It is a pain to get all of the oil out of the cooling system, some have flushed their cooling systems with a mixture of water and dawn dish soap followed by a couple of flushes of distilled water to remove the soap residue and minerals that the water may have left behind.

 

The twinky is the long oval sapped part that sits between the cylinders has a few hoses on it, it is actually a heat exchanger.

 

This issue has been reported by several here and also on the Delphi Royal Star forums.

 

Good luck , report back how you make out.

[Mariner Fan]

There is a drain hole in the water pump. Wouldn’t the oil drain out of it?

[Mariner Fan]

Steve, I’m taking your suggestion to the shop. Thanks for the input!

[N3FOL]

It’s the vent hose that is close to the kickstand when it is up.

 

https://www.venturerider.org/forum/attachment.php?attachmentid=116571

 

The dark longer one. Posting with an I-phone is a pain! Lol

I think it is just normal to have some oil at the end of that hose. Your hose does look a lot cleaner than mine. No worries there IMO.

[M61A1MECH]

You may have two different issues here.

 

First oil in the coolant overflow is bad, needs to be corrected as I noted above.

 

Second, there are three drain hoses as I recall under the bike on the left side near the side stand, one of them is a drain hose from the air box, it is quite normal to get some oil fumes up into the air box, that is what the crankcase breather does, suck fumes off the crank case and takes them up to the air box so the fumes can go through the carbs and out the exhaust pipes. If you over fill the crank case or run at high revs for a prolonged period of time the oil can splash around and liquid oil will be sucked up through the crank case ventilation hose and be deposited in the air box. The drain hose for the air box is on the left side so it is naturally on the low side of the air box when the bike is parked on the side stand. If there is an excess of oil accumulated in the air box over time it will run down the drain hose and drip on the ground.

Open the air box and clean out any liquid oil n there and dry the drain hose to remove any accumulated liquid, then monitor for further drips from that drain hose. Also make sure the oil is not above the line on the window when the bike is standing straight up.