Coolant Spitting Up Out Of The Cap

[Mr_Schexy]

I need some input on my 12 Busa spitting out coolant when I get in it. I just replaced the head gasket and it started spitting p
out coolant so I replaced the thermostat and the problem continues. So I thought the radiator may be clogged so I replaced it, and still the same thing. I haven't replaced the waterpump yet but why would it build so much pressure if the pump was bad. Any help or idea is greatly appreciated.

 

[notright]

Just replaced head gasket? Hate to be doom and gloom but, sounds like gasket blow by.

 

[notright]

Curious, why did you replace the head gasket? Did you check the head? I hope not but there could have been a problem with the head. Cracked warped etc. Because you said it happens when you get in it it sounds like compression is leaking into the cooling system.

 

[Hayabusa Wannabe]

What was the reason for the head gasket change? Was this motor overheated?

 

[turbojonny]

What was the original reason for the head gasket replacement? The is typically caused by the coolant system being pressurized by a bad head gasket. It can be (but usually not) a bad radiator cap.
When my head gasket let go it would lose coolant and I could see bubbles in the overflow.

When the bike is warm take off the overflow cap. Run the bike and rev it a bit while you shine a flashight into the overflow radiator. If you can see bubbles...bad. You will also be able to see the coolant flowing as you rev the engine, which will tell you that your water pump is working and that the thermostat is likely open.

 

[dadofthree]

Ruh Roh

 

[Mr_Schexy]

The original problem was the head gasket started leaking oil from the timing chain port when I took the head off I noticed cracks in the ceramic

 

[Mr_Schexy]

I checked for gas leak in the crack in the block with the little device with the liquid in it in the liquid state blue which indicates there's no gas escaping into the cooling system

 

[Mr_Schexy]

Let's try this again. I used a little device with a small psiphon pump on it with a blue liquid in it to detect gases leaking from the block into the cooling system which came out negative. Could timing be causing this if it' a link off?

 

[mjl3truck]

Try a new cap before you go too crazy pulling stuff down.

 

[Mr_Schexy]

Try a new cap before you go too crazy pulling stuff down.

A new cap came with the new radiator and the new one and the old one still does it.

 

[dave s]

Sounds like head gasket/ warped head etc.If the coolant pipes are rock hard you know the system is pressurised

 

[GIXERHP]

Do a Leak down test, and a compression test
Also make sure there is no blockages, in all of the coolant hoses
If it's blowing out of the cap, the cylinder is pressurizing the coolant system,
I agree with a warped head.
Or a hidden crack under the valve faces.
Does blow when the motor is cold, or only as it gets hot?