Did I buy the wrong valve stem seals?

My 2002 protege5 is currently burning oil. It blows a huge cloud of blue-white smoke in the morning for a couple minutes then it goes away. I am pretty sure that this is from the valve stem seals being worn so I bought a set of valve stem seals from rock auto.

https://www.rockauto.com/en/moreinfo.php?pk=10895548&cc=1387447&pt=5800&jsn=9
It says they are intake and exhaust seals that work for the protege5 but I was just reading a thread that said the intake and exhaust seals are not the same.

Are certain valve stem seals interchangeable or did I make a stupid purchase? If so, can someone tell me where I can get the proper seals?

Thanks
 

pcb

The Diagram Dude
:
2002 MP5
My 2002 protege5 is currently burning oil. It blows a huge cloud of blue-white smoke in the morning for a couple minutes then it goes away. I am pretty sure that this is from the valve stem seals being worn.

It's almost certainly not the valve seals.

Our car has a specific problem of seized oil rings on the pistons.

There is a test to find out whether it's the valve seals or the oil rings.

Oil loss, possible burning oil

'02 Protege5 burning oil, white smoke on startup/post downhill acceleration
 

pcb

The Diagram Dude
:
2002 MP5
Bumping the thread back, with some god/bad news...

well, the good news is: I found the problem of cold start smoke.

Bad news: Well, it's the rings...
Worse news: The rings are fine, not worn out, not scored, not broken... So, what is it then?????

Ok, here's the details:

Mazda's pistons are crap! So f#"$%&ng bad, because they have one design flaw. The flaw that mazda jerks did not put any improvement in the pistons dept in 20 years!!!

The oil ring channel on the piston, has just 4 (four) tiny oil holes. Theese holes are used for the oil that was scraped off the cylinder walls while the piston was moving down to escape to the sump.

Naturally, more holes, bigger holes, the easier it is for the oil to sink down...

Ok, so, during time, oil and gasoline carbon deposits gradually plug these tiny holes up, preventing the oil from flowing down, and cooling the pistons, and bla bla...

The pistons overheat slightly, causing the oil that gets caught in the oil rings retainer to get sticky and guey and carbonised, turning it self into that hard -impossible to clean- resin / gunk / lacquer that sticks to your kitchen fry pans...

So, at the end you are left with the oil rings that are so badly stuck, glued, burned into the oil channel of the piston, that the oil rings do not even touch the cylinder walls.

The compression rings are a whole different story, and they are doing their job pretty good.

To make things worse, oil rings have sooooo weak initial tension, compared to the compression rings, that it is almost natural to have such a result.

take a look in this picture. Look at the gap between ends of the compression rings, and compare to the gap between oil rings... You will get the idea...
https://www.horsepowerparts.com/images/products/closeups/WSC/8550xx.jpg

Ok, so why does it only smoke on cold starts...

well, here's why:

Once you start up the cold engine, there is increased idle rpm, creating a huge vaccum in the intake manifold, as well as in the cylinders, as the pistons are trying to suck the gases in, but the throttle fully closed prevent thet from happening...

So, as the oil ring doesn't seal the oil, the vacuum sucks the oil past the compression rings ** and into the combustion chambers, and.... tadaaa! Bluse smoke. Now, the oil is fresh and cold, hence, there is no pale blue smoke, but thick white smoke, clearly smelling like oil.

As the engine runs, 10, 20, 30 seconds later, the piston warms up, the compression rings warm up, expand a little, close the gap, so does the crappy oil ring, that finally starts to touch the cylinder walls, and the oil stops sipping up onto the piston.

There is stil some run by, but not so noticable, so the oil consumption is pretty high.

The solution:

Rering the sucker, but drill some extra drain holes in the piston oil channel, and make the existing ones a bit bigger.


** compression rings are designed to hold the pressure, but not to scrape the oil of the flat surface. it is like your rain wipers on the windshield. They have to be thin, almost blade-like, to be able to scrape.

That is the reason why the compression rings do a perfect job of sealing the compression but leak oil past them like swiss cheese. And why oil rings are thin, blade-like!


I just wanted to bump this post...
 

pcb

The Diagram Dude
:
2002 MP5
This is a picture of a piston from my parts car that was burning oil like a MOFO.

Notice how the oil ring has no spring tension.


20210627_185134.jpg
 

pcb

The Diagram Dude
:
2002 MP5
There is an easy test to see of you have bad valve seals or seized oil rings.

Let your car sit overnight, then in the morning, remove your plugs and look down the plug hole to see if the pistons are wet with oil or not.

If they are wet then your valve seals are leaking.
If they are dry, put your plugs back in, start your car and run it for about 20 seconds then shut it off, remove the plugs again and check for oil on the pistons.

If they pistons are now wet with oil, then your oil rings are seized.
 
There is an easy test to see of you have bad valve seals or seized oil rings.

Let your car sit overnight, then in the morning, remove your plugs and look down the plug hole to see if the pistons are wet with oil or not.

If they are wet then your valve seals are leaking.
If they are dry, put your plugs back in, start your car and run it for about 20 seconds then shut it off, remove the plugs again and check for oil on the pistons.

If they pistons are now wet with oil, then your oil rings are seized.

I tried that and really didn't notice a difference so I went out and bought a compression tester. First cylinder 160psi, second 120psi, third 195 psi and the fourth 160 psi. Does this mean my pistons are fucked? If so, should I just try and sell the car or would I be able to dedicate a weekend to fixing the pistons?
 

pcb

The Diagram Dude
:
2002 MP5
Seized oil rings doesn't have any real affect on compression.
Everyone that has been burning oil has had normal compression.

Your compression isn't quite right though.


The normal compression on a new engine is 171 psi with a minimum of 119 psi and a maximum difference of 28 psi between cylinders.


20210709_081903.jpg



Screenshot_20210709-081823_Acrobat for Samsung.jpg




You probably have fouled combustion chambers that reduces the volume and increases the pressure.


Replacing your pistons is a HUGE undertaking.
It would be easier and probably even cheaper to replace the engine with a used one.

You're probably better off to just run it the way it is.
Lots of guys have done that and some needed a quart of oil every 250 miles.

Switching to 10W30 regular dino oil helps to reduce the oil burning.

Some guys have had some luck with freeing the rings with oil additives and using diesel engine oil.
There's information about in those links that I posted earlier.

Keep oil in your car and check your oil level frequently.
 

pcb

The Diagram Dude
:
2002 MP5
Does this mean my pistons are fucked? If so, should I just try and sell the car...

Your oil rings are most likely seized, but it's not that critical or a safety issue.

Your car isn't going to blow up or suddenly die on you.

It will run dirty, and that can lead to problems like fouled plugs and combustion chambers, fouled O2 sensors, burned out pre-cat, and a fouled EGR valve.

For the most part, it's just some smoke on startup and there are things you can do to help keep it from getting worse and maybe even stop the smoking by freeing up the oil rings.

The big thing is to keep a really close eye on your oil level.

If your oil level drops too low, you will suck air into your oil and wreck your engine in seconds.