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Discussion Starter · #1 ·
So i just recently got a used 2018 Kawasaki Ninja 400 and noticed a white milky substance in oil.. any ideas? Also should temp be that high?
BTW im new to riding.
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The milkiness in the oil viewing window indicates either that:

1. the oil has a lot of water in it due to prolonged condensation caused by too many short trips in cold weather, which were insufficient to warm up the engine enough to vaporize the water. If so, just ride it at least 10 miles each time you start it up, and this will clear itself up

OR

2. You have a coolant system leak that is leaking coolant into the oil. Longer rides will NOT cure this if this is the real problem. You'll need to have a motorcycle dealer do a diagnosis and repair since you are a newbie. If this is the problem, continuing to ride the bike will cause great damage, so don't. Get it looked at very soon.

The temperature gage reading being high (5 bars) MIGHT be confirming problem no. 2 above. But, it is also fairly common to see 5 bars on the Ninja 400 / Z400, especially when riding a lot in city traffic or other low speed environments.

Jim G
 

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Discussion Starter · #4 ·
The milkiness in the oil viewing window indicates either that:

1. the oil has a lot of water in it due to prolonged condensation caused by too many short trips in cold weather, which were insufficient to warm up the engine enough to vaporize the water. If so, just ride it at least 10 miles each time you start it up, and this will clear itself up

OR

2. You have a coolant system leak that is leaking coolant into the oil. Longer rides will NOT cure this if this is the real problem. You'll need to have a motorcycle dealer do a diagnosis and repair since you are a newbie. If this is the problem, continuing to ride the bike will cause great damage, so don't. Get it looked at very soon.

The temperature gage reading being high (5 bars) MIGHT be confirming problem no. 2 above. But, it is also fairly common to see 5 bars on the Ninja 400 / Z400, especially when riding a lot in city traffic or other low speed environments.

Jim G
Coolant leaking into oil, could that be because of blown head gasket? The bike doesn’t smoke or anything except in the morning being that it’s cold but other than that no smoke and seems like it runs and idles really good.
 

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Coolant leaking into oil, could that be because of blown head gasket? The bike doesn’t smoke or anything except in the morning being that it’s cold but other than that no smoke and seems like it runs and idles really good.
A blown head gasket is a possibility, BUT unlikely if the engine is running well as you say. The most common cause for coolant getting into the oil, or to the outside of the engine, on the Ninja 400 / Z400 specifically, is apparently a design weak point in the coolant system passage gasket on the front of the engine. I am not familiar with that specific failure point, but I THINK it manifests as an external leak, not an internal one. But others with experience on that specific weakness might be able to give you better information on it. But again, if the engine is running welll, and if the fluid level in the coolant overflow tank is normal, then this is unlikely to be occurring on your bike.

Jim G
 

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Do you have any coolant stains around this spot on the front of the motor?
 

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That temp gauge reading is normal, and has been the cause of a 1000 questions. I can't really tell what's going on with the oil sight glass pic, it's not detailed enough.
 

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I had the same milking white substance in the viewing glass when I first started riding. It was from the condensation built up in my oil pan from short riding since I was just starting to learn. You could drain some oil to see if there’s coolant in there and that would confirm if you have a coolant mixing with oil. But it’s most likely condensation if you’re riding in cold weather. Oil viewing glass has milky substance
 

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Discussion Starter · #11 ·
Do you have any coolant stains around this spot on the front of the motor?
Do you have any coolant stains around this spot on the front of the motor?
I didn’t see anything
 

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Discussion Starter · #13 ·
You don't see "anything" because the entire viewing window is filled with the milky appearing oil! Again, usually, this is a result of trips too short to fully heat the oil to force the condensed water to boil off.

Jim G
No I mean I don’t see any coolant stains or signs of coolant leaking on motor or anywhere
 

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I've been waiting for this thread to go sideways. :LOL:

More seriously, I'm not mechanically inclined, but the simplest approach to ruling out mystery problems always appeals to me. Occam's Razor, or maybe inherent laziness? As suggested, an oil change and monitoring for a while, or even just several longer rides to heat out condensation, is better than ripping everything apart looking for an unknown leak. Do you know when the oil was last changed?
 
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So i just recently got a used 2018 Kawasaki Ninja 400 and noticed a white milky substance in oil.. any ideas? Also should temp be that high?
BTW im new to riding.
View attachment 21037
View attachment 21038
Not sure if you know this but you can contact Kawasaki and change the warrenty if your bike still has one over to your name from whoever bought the bike you just need pink slip. Looks like you have got a. Blown headgasket mine looked like that when I blew my last 250. Hoping for the best for you just hope u don't need a 3000 repair like they wanted for mine. Good luck man
 
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