Head gasket

[97mazda]

I got a 97 Mazda b4000 4.0 got white smoke coming from the exhaust but the oil isn't milky. I'm loosing antifreeze. Any suggestions

 

[RonD]

You have a cracked head(common issue on 4.0l) and/or a bad head gasket.
The heads don't just crack, usually there is a water pump or blown hose issue that causes overheating, but it doesn't take much overheating on these engines for the head to crack.

Coolant in the oil is when there is a sever leak in cooling system from blown head gasket, reads like yours hasn't got that far yet which is good since bearings will not be effected.

Best bet is to pull both heads and have them tested(pressure test) and surfaced(made flat)
Get a head gasket kit/set and new head bolts(can't reuse this type of head bolt)


There are a few ways to confirm a cylinder leak
Block test: this is a chemical test to determine if there is "exhaust" gas mixed with the coolant in the radiator, you can buy a kit for this test or call a shop to see how much they would charge for this test.

If you trust your nose, open rad cap and smell, if it smells like exhaust then confirmed

Pull all the spark plugs and inspect the tips, super clean tip means it was being "steam cleaned" by coolant(which is what makes the white smoke)

Glove test:
cold engine
remove rad cap and overflow hose
disconnect coil wire, you want a no start

Place latex glove over rad cap opening, use rubber band to seal it tight to rad
Block overflow tube, vacuum cap from upper intake works or if you have some one else to crank engine use your finger to block opening.

Crank engine
If glove bounces then you have a leak from a cylinder into cooling system, confirmed.
If you want to find out which cylinder, remove 1 spark plug at a time and crank engine, when glove stops bouncing that last spark plug removed was in the leaking cylinder.
Put spark plug back in to confirm.


There are "head gasket sealer" products available, these are temporary fixes at best, but can work, but not on 100% of the leaks, so IMO best to just get the problem fixed, but if it would be a better time in a month or two then spending the $25-$40 on the "sealer" might be something to consider.
No, there is no "best one", they all pretty much work the same way.
And no, they won't clog up the rad or heater core, that is not how they work.

 

[97mazda]

I took the intake off and gasket is bad and checked the plugs, They all wasn't super clean as u said. It wasn't over heating. The smoke don't do it all the time.

 

[RonD]

You can get a intake gasket to leak coolant into the air passage, so coolant is sucked into the engine, but it is rare.

 

[97mazda]

I put a new intake gasket on it, so far it quit smokeing and aint loosing antifreeze.

 

[enjr44]

Can't ask for better than that!