Oil in coolant

Hello! Looking for some advice here.

I just purchased a 2015 WR250R has about 13k miles on it. I decided to replace just about every fluid on the bike since I dont know the last time it was changed. So I swapped brake fluid, spark plug, oil, and coolant.

While I was flushing the coolant I filled the radiator with water and saw this...


In case you cant see the pic's there is a slight about of a brown bubbly substance in the radiator, and a similar film on the radiator cap. Im sure this is oil. It doesnt look like there is very much but regardless its still there. Ive looked all over forums for anyone with similar issues and have found a few things but not much.

Similar issues here : https://wr250rforum.forumotion.com/t4613-coolant-issues?highlight=coolant

Has anyone seen anything like this before? If so what was the issue? Many of the threads Ive seen never come to a conclusion on what the problem is. I changed the oil after finding this to make sure there wasn't any coolant in the oil and from what I could tell the oil was clean. Any advice you can provide would be helpful. I'm really just wanting to know if this is something I can just monitor for a little bit to see if it gets worse or if its something I need to try and figure out/ fix immediately.

Thanks!

I have the same issue with my 08 , I just change the coolant every 2 years also clean the over flow tank with carb cleaner.

OK glad to know I'm not the only one who's having the issue. How long have you had the problem? Have you had any issues with the engine overheating or performance issues? If anyone else has seen the problem please chime in, I'm curios how common this is.

A bit of searching led me to a forum topic on another site. I will post the important responses here. (this is from 2011)

TITLE OF TOPIC:
Oil in Radiator (08 WR250X)

Quote :

GreenHornet450

Posted July 2, 2011

Head gasket leaking would be my first guess.

Quote :

Yamaguy55

Posted July 3, 2011

that would be my guess as well.....or seal on water pump shaft. It wouldn't take a lot.

Quote :

Yamaguy55  

Posted July 4, 2011

If this were mine, I'd do the pump shaft seal first. It would be the easiest by far. Look at the Yamaha parts website breakdown: you'll need all the gaskets, the seal, I'd do the bearing if I were there so I didn't have to go back later, and check the shaft for scratches and such, where the seal rides. This and the head gasket are the two most likely points of antifreeze meeting oil, certainly not the only ones. Always start with the easiest first. I'd pull the head and cylinder last. I'd also drain the oil into a clean container, and really really check for antifreeze.

Think about it: if the oil is in the radiator but NOT the anti-freeze in the crankcase, then the oil pressure has to be higher there than in the radiator. The pressure is about 12-14 PSI for the oil, probably a little less for the coolant unless the bike is very hot. So depending upon what is leaking into what, you have a direction to check. The oil get to the cams up the left side of the cylinder and head, as you have that bolt they tell you to pull to check for flow each oil change. That is the ONLY pressurized place in the top end other than the actual head and cylinder castings where the oil is under pressure. Everything else is just run-back to the crankcase and splash lube. So it COULD be the head gasket, but rather than deal with all of that, stat easy and remove the clutch cover and check the pump shaft and seal, it is a lot easier to get at. Don't use silicone, but fresh gaskets and o'rings, seal, bearing, etc. If you must use gasket goop, either Yamabond 4 or 5 would be the way to go. Four is the same as some of the varieties of Three-Bond, since they actually make it. Five is made for gaskets, four for no gasket, but machined cases.

It isn't that tough. A shop should be able to do this in an hour or so, unless they're less than competent.

But......if is really really leaking, and NOT some odd-ball leftover from something else: flush the cooling system really really well, run for a few days with either straight water (my pick) or fresh motorcycle coolant, which isn't quite the same as car stuff, and check it again. If more oil, then we have a problem, Houston.

If not, then monitor and see how it goes. Either way, I'd still change the oil. Anti-freeze is a lousy lube.

Quote :

Yamaguy55  

Posted July 4, 2011

First: I wouldn't pull the engine, buy gaskets, or do anything until you can repeat the oil thing. For all we know, it somehow got in there another way. If it is REALLY leaking, it will come back. Once means nothing, twice does. You have to unbolt the subframe and lower the front to pull the head and cylinder.

I'd try one of the radiator flush things they sell for cars, just be sure to use a minuscule amount. For the quantity of coolant, you could fill it up with rubbing alcohol, run it for about 30 seconds, and drain it, then let it dry out. Don't use methyl alcohol, it eats rubber with gusto. I'd think some Cascade dish washer detergent would clean it very well also. ( again: maybe a tablespoon, if not less!!! don't overdo it.) You then have to flush and flush until clean. Remember to use motorcycle coolant (sold already mixed at bike shops) and not car coolant. The silica they put in car coolant is tough on motorcycle water pumps.

I'd be sure the last flush or any water added was distilled as well. Softened water like I have here at my house has traces of salt in it, not something to intentionally put in the engine. And you can guess what hard water would do for the radiator.

For a pictorial how to for the head: look up High Fives report either on here or over on the WR250R website: he shows a step by step to pull the cylinder and head, complete with photos. He was installing the 300 kit, but the concept and steps are the same.

Again: Don't pull anything until you flush it and have the oil come back. If it doesn't. who cares how it got there (factory, most likely) and if it does, time for action. be sure to drain the oil this time, don't wait.

Quote :

supermoturd  

Posted July 5, 2011

Yamaguy, your advice and tips are great. Thanks for taking the time to respond so thoroughly. I'm totally on board with not doing anything drastic until I can confirm that oil is actually being introduced to the coolant from the engine.

You mentioned using Cascade. I was looking on the box and I noticed that it had sodium and silicate in the ingredients. I'm assuming it will be ok to use it to de-grease the radiator as long as I flush several times with distilled water after I run the detergent through.

Quote :

Yamaguy55  

Posted July 5, 2011

I can't see why a reasonable cleaner (nothing acidic) followed by a complete flush, several times, would hurt anything. Leaving it in is another thing entirely.

Quote :

supermoturd  

Posted July 5, 2011

The oil appears to be normal. I drained it into a clean glass container. I'm not seeing any separation or layers. The oil has the same viscosity and coloration that it usually does.

I ran a tablespoon of Cascade through the cooling system for about five minutes. I then drained it and cycled about a gallon of distilled water through the system. That is, I filled the cooling system, ran the engine for about five minutes, drained the coolant and repeated about three times. There are almost no traces of oil now.

The plan now is to inspect the oil filter, replace the oil, fill the radiator with coolant, and put about 40 miles of good, hard, riding in before re-inspecting the coolant.

Hope this helps..

I have seen this problem on other bikes, but not on the WRR. Usually it's the head gasket that develops a leak, and the way to confirm this is to do a leak down test.

Thank you for your reply's, I think I am going to do a leak down test and see what the results are. Couple questions

1.If it is a head gasket failure is there a kit that anyone can recommend?
2.Also anyone know of a good write up on doing the job?
3.Any good sites you can recommend for aftermarket Yamaha parts in general or do you guys stick to OEM stuff?

Thanks Ill post my results when I finally get down to doing the test.

1. There is no kit, you only need to get the head gasket (Part # 3D7-11181-00-00)
2. Do you have the service manual? Besides it, you can follow any video showing the process on a 4T single-cylinder engine, you don't need a WRR-specific one
3. Do not go for aftermarket, get the Yamaha OEM stuff from either ServiceHonda or RockyMountain

No problems at all.

Well I performed a leak down test this week and am happy to report that it came back with no issues.

So at this point I'm just going to monitor it and change the coolant frequently. If I end up finding out its coming from another location ill post it here, but for now I dont think its hurting anything so ill just continue to monitor it and worry about it more if it gets worse.