Abbreviated:

New seals, springs, o-rings, housings, used rotors, used side housings.
Ran great for ~720 miles then started to smoke and foam oil from the dipstick instantly.

Unabridged:

I've never heard of this. I rebuilt a motor with all new OEM Mazda seals & new rotor housings. Motor was running great for about 730 miles when I developed an oil leak from the rear of the motor. I pull motor and replace rear main seal and stationary gear o-ring with new then put motor back in.

Now a week or two before the leak started, I noticed a noise from the front of the engine when it was started cold. I couldn't figure it out. After replacing the rear main and o-ring, I get motor back in car and hear that noise again.

I never saw oil foaming before I replaced rear seal. The smoking start almost instantly. I parked in my driveway to open a gate and look at the pipes to admire the nice beefy tone from my RB system and saw no smoke. I pull in past my gate and 20 seconds later, smoke is pouring out of the tail pipes. I pull dip stick and there was foam all the way up the stick and it sorta bubbled out the dip tube. WTF???

I looked at the oil closely and it had no water in it. The bubbles were oil bubbles and not coolant. The oil was very clean since I changed it a week before.

I don't understand how I can get enough blow-by to foam the oil. Can a messed up PCV cause this problem?
Perhaps the PCV was causing too much pressure and the increased pressure was pushing oil back into the chambers thus coming out the tail pipe. Maybe the turbo? Its a stocker that was rebuilt 1k miles ago.

Another though is a mis-torqued oil pump. Maybe its sucking air or something. I'm not too sure. I just know that it's frustrating to only be able to drive a car 1k miles in 2 years because of problems

 

Is the oil still oil colored or does it look more like a chocolate milkshake. If it's foamy and lighter in color, you have a coolant leak that's mixed with the oil.

 

The oil was very fresh. Maybe 60 miles on it. There is no discoloration. It's the clear brown color like any other oil.

 

I think I have improperly clearanced side seals causing blow-by. This was my first rebuild so I may have done it wrong. I stayed on the low side of the tolerance range though.

Also, I'm hearing a noise from the front of my engine when it's cold. The noise is not there for the first 5 seconds that the motor runs, then it comes in real loud then fades as the motor warms up. Here is a link to the video on you tube. It might be hard to pick out the noise, but it is a buzz/grinding noise that is the same as the rpms. As the rpms go up, the noise does too. Perhaps a bad or leaking oil pump, maybe a bad OMP pump drive shaft.

Also, I took some audio from the filler tube. I'm not sure how much bubbling noise is normal, but I don't think this is right. Link to the video here.

 

Do a coolant pressure check and see if your have a pressure drop, the other thing check and make sure that its not creating crankcase pressure as it would cause it to smoke like you said . does it smells like oil or coolant ?

 

That noise could be the thrust bearing miss installed, or could perhaps be the CAS or CAS gear, or as you said the oil pump or drive gear, or the OMP or OMP drive mechanism.

I had a similar issue that tuned out to be a trail spark plug wire corroded at the plug terminal. The arching to ground was really hard to spot, amazingly loud and somewhat intermittent.

 

foaming oil is sometime caused by mixing two lubricants, coolant in the oil wont cause it to foam. did you by mistake add a different kind of lubricant into your engine? use any kind of grease or lube that is not engine oil during your rebuild? that could be the cause of your problem

 

I used assembly lube and petroleum jelly when I assembled the motor, but after 3 oil changes and over 700 miles, the foaming won't just begin to happen from the assembly.

I'm going to take motor back out, remove front cover and inspect the front of the motor to see if I have an oil pickup or pump problem.

 

you don't have to pull the motor to take the front cover off........

 

Make sure you have the paper gasket between your oil pick up tube and block. Many leave this out and the pick up tube will suck air in and cause bubbles and eventually motor bearing failure. Also, make sure your oil pump sprocket is all the way down and on- sometimes the key will move when putting on and the sprocket will not be all the way down causing too much chain tension and pump shaft pressure and could be causing your noise.

 

I didn't replace the gasket for the pickup tube. It stuck on there pretty clean so I just re-used it. Was a stupid move since it's what, a buck or two? How much air can the pump possibly pick up? Enough to cause a hiss in the oil filter after the pump stops pumping?

 

are you loosing any water/coolant?

i'm asking because foaming is usually cause by some making it's way to the oilpan and is boiling and evaporating from there.



you need to seriously seal your pickup tube

did you seal you oil pump also

the two issues are unrelated to the water leak issue, they will cause oil bubbles.


it's not blow by, you issue is unrelated to side seal clearance problem.

PCV can mess things up, until you figure out your issue, i recommend unplugging PCV. make sure that the center plate air nipple located next to oil neck, pointing at the firewall IS UNCAPPED.

seriously, unplug the PCV.

from my experience.... 9/10 people do this mistake when installing their first rebuilt.

good luck

 

I know the foaming isn't from coolant or anything else. I changed the oil and inspected close. Nothing inconsistent since we know water and oil cannot mix without some serious detergents. Also, the bubbles I noticed on the dipstick when I pulled it out went away within seconds and the oil dripped down to the end of the dipstick and it is 100% oil for sure and not anything else.

I didn't seal the oil pump. I didn't know you were supposed to do anything except put the pump back on and torque it correctly. I will get a new gasket for the pick up tube and reinstall that.

I went back and compared the PCV routing to the manual and old rats nest and it is correct, but I removed it and stuck a tiny air filter on the upper nipple to see what would happen and it was not the fix.

True, I don't have to pull the motor to take the front cover off, but I do find it hard to take the oil pan off to get to the pickup tube and then reseal the pan good. It will give me a chance to inspect the front very close. I'm used to it now. I can have the motor in and out in 4-5 evenings with the lack of evening daylight.

 

With the help of a good friend, I removed the front over and inspected the oil pump. I saw some minor marks on the insides of the oil pump. One of the key ways for the inside of the pump was loose. I had some rotational play in it. A whole lot more that I would imagine there should be.

I rigged up a 17mm socket to my power drill to test the oil pump. I had the oil pan on so I filled pan with enough oil to cover the bottom of the pickup tube. I started to spin the pump and noticed tiny bubbles coming out in the stream of oil coming from where the little rubber o-ring is supposed to sit. I tried various rpms (10-200rpms) and still got bubbles in the oil. I also noticed some oil dripping down the inside of the drive gear that sits over the pump.

Upon removal of the turbo manifold, I noticed about a half ounce or less of oil sitting in the bottom of each rotor housing. Lets say that the pump is acting up big time, can that really cause the oil to make it into rotor housings or would it be possible that I have two separate problems?

I will attempt to take a video of my method for testing the pump and will post it on here.