Re: R15 coolant and engine oil getting mixed... Engine overheating

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Re: R15 coolant and engine oil getting mixed... Engine overheating

Thanks Monk.

Another important thing. It takes 100-150 kms of testing to know whether actually coolant is eaten up and getting mixed with oil. On last two occasions tested for 20 kms and it was all well. Tested for 160 kms and all dreams came crashing down

Re: R15 coolant and engine oil getting mixed... Engine overheating

If you're getting oil in water or water in oil then it's internal leak hands down.

When you took the head apart from the half engine, did you align its face plate on CNC machine? Because whenever the bike overheats, head, being made of aluminium is likely to get deformed(Even at the miniscule level). Only very few times changing just head gaskets solves the problem and that's why CNC machine aligning is recommended. Secondly if faceplate and head gaskets are all good then it means head or bores have developed crack.

And you did replaced the engine oil every time you opened the engine for changing head gaskets, right?

There are coolant additives who seal the head gaskets, cracks which are hard to reach (sometimes temporarily) like K-Seal ST5501 Multi Purpose One Step Permanent Coolant Leak Repair : Amazon.com : Automotive, Bar's Leaks 1111 Head Gasket Fix - 24 oz. : Amazon.com : Automotive. I have utterly no idea how to obtain them in India, but I want to get one of those myself.

Once you resolved this issue then put 5k kms on the odo to check reliability and only then you should think about leh.

Re: R15 coolant and engine oil getting mixed... Engine overheating

Everytime we tested, we changed Engine Oil and Coolant. Gasket is not the culprit. We used rubber sealant and also aligned the head gasket properly. Changing the water pump(gasket and O rings that could be culprit). If these things don't work than I ll change bore.

Re: R15 coolant and engine oil getting mixed... Engine overheating

If you're getting water in oil then your engine is internally leaking. It has nothing to do with water pump as water pump is not a part of the engine. If the leak is big then white sweet smelling smoke(burnt coolant) will come out of your exhaust and if the leak is minor you would find it by regularly checking water level in radiator. Aligning head (not the gasket) is done only on dedicated CNC machine and only one or two such machines exist per city(Pune has only one). So generally speaking that job takes 3-7 days considering the load at CNC machine company (yes they work separately and no, no car/bike A.S.S. has them or can afford them). If this info wasn't told by your mech then my dear buddy he isn't much informed.

CNC machine alignment is nothing but cutting face plate (face plate: the part of the head which lies on gasket) of the head to make it flat or flush. Many local mech avoid this and opt for hand sanding of the head which doesn't do the job sometimes.

From what I can read from your writing, there is a possibility of the cracked head. Why I jumped right on that conclusion because R15 doesn't have coolant temp meter, So according international say, when 'check engine' or 'overheating' started blinking the damage has done already.

In case of internal leaking these are the small things which cause overheating. Ascending in the severeness order.

Head Gasket kaput.
Head deformed.
Head cracked.
head and bore cracked.

Re: R15 coolant and engine oil getting mixed... Engine overheating

So the lead changing the waterpump didn't help. Soon after 60 kms of testing, we found the froth after opening the water pump.


So the two probable issues- Busted Gasket and Faulty Waterpump(O rings, Gaskets, oil seal, impeller) didn't help.

Immediate plan of action. 1) Take the head to CNC machine for flat bed setting and test.
2) Switch to stock cylinder. This will be for cracked coolant cylinder jacket. And test.
3) Change the head and test.

Any pointers guys.

Re: R15 coolant and engine oil getting mixed... Engine overheating

Forget the CNC thing, just lap the chead on a pieces of glass. Lapping produces equally good if not better results as CNC. Trust me I have taken a machinist course and most of the mills I touched can't hold great tolerance. I suspect the bore as the RC kit for R15 has a thinner linear which may lead to premature crack in the bore. Try swapping it with the stock bore.

Re: R15 coolant and engine oil getting mixed... Engine overheating

That's the immediate plan. Swap the bore with stock one and check.

Re: R15 coolant and engine oil getting mixed... Engine overheating

i am not very knowledgable but won't the CNC machining reduce the swept volume thereby changing the CC and compression ratio..??

Re: R15 coolant and engine oil getting mixed... Engine overheating

Yes, it does but only miniscule.

Re: R15 coolant and engine oil getting mixed... Engine overheating

So finally took the head and bore to a renowned lathe shop and they did what they call "facing" to get rid of warped surface. Most probably tomorrow morning will get the bike for testing and will get to know whether the issue was because of warped head or warped bore.






Will get to know after testing whether this thing really helped. Next lead would be cracked bore and will swap RC bore with stock one.

Re: R15 coolant and engine oil getting mixed... Engine overheating

you didn't consider going to ASC...??

Re: R15 coolant and engine oil getting mixed... Engine overheating

The facing was not needed looking at the head I'd say, the facing is only done after the head gets opened many times, sometimes by stupid mechanics who pry it open with a screwdriver. Putting some lapping compound on a 2'x2' glass and lapping the head would do a better yet simpler job.

@princesirohi would ASC service his bike as it is Joel'd?

Re: R15 coolant and engine oil getting mixed... Engine overheating

[MENTION=28676]Juris[/MENTION]: I love your dedication towards your bike. You're leaving no stone unturned. With this speed to your bike's rectification you might able to get it leh'd in pre planned time.

For what it's worth I really really think that you should consider dropping some k-seal in coolant before starting your journey. It'll seal if any crack had crop open in unfortunate time and will let you complete your journey. I know an ebay seller who sells it around $25 with shipping. Today many american and jap car makers do add custome made sealers in their brand new cars.