Smoke on cold start

Bumping the thread back, with some good/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!
 
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Oh my gosh, I am so glad this is here. I recently acquired an 01 ES protege with high mileage and it has the exact same problem. Tons of smoke on start up, but quits within a minute. Mine is very bad though. With a 22 mile drive to work each day i went through about a quart of oil in four days. I also notice a random smoke cloud on take offs even after warm. Ive been so perplexed as to what the exact problem is and where to start. Im very glad to know theres more with the same problem.

Now im just not sure what all to do about it. are there any good aftermarket pistons with factory compression that have better oil drain holes, or do i have to modify my own? Does mazda know about this crap? Why dont all owners have this problem?
 
Well I found some aftermarket forged pistons by a few companies (wiseco, nippon) at stock bore size and compression. $550-$600 though. I just dont know if I trust myself to drill into my stock pistons or if a mechanic would know what i want and do it right.
 
Oh my gosh, I am so glad this is here. I recently acquired an 01 ES protege with high mileage and it has the exact same problem. Tons of smoke on start up, but quits within a minute. Mine is very bad though. With a 22 mile drive to work each day i went through about a quart of oil in four days. I also notice a random smoke cloud on take offs even after warm. Ive been so perplexed as to what the exact problem is and where to start.

Hello there.

Im very glad to know theres more with the same problem.
Yes, there are more of us with the problem...
Now im just not sure what all to do about it.
Well, depends how much you love your car... If you plan to drive it / own it for a longer period of time, it can be rebullt to last...

are there any good aftermarket pistons with factory compression that have better oil drain holes, or do i have to modify my own?

Yes, here in Europe it is harder to get some good aftermarket parts, but over in North america, the offer is better...
Does mazda know about this crap?

Well, yes and no. I am not familiar of any TSB (tech service bulletins) for sorting this problem out... but here's a c/p of some other web site where experts have said their part:

Smoking from the tailpipe has been a problem with the Mazda 626, MX-6, B2000 and B2200 with FE and F2 engines. These engines have a timing belt driving the camshaft. The problem is not often seen in the chain driven 2.0L engines. The customer's complaint is smoke from the tailpipe after starting a cold engine. This has been a problem since this engine came out on the 1983 Mazda 626. The smoke may be blue or white and it clearly smells like oil. The condition usually happens after exceeding 100,000 miles, but has been experienced with as little as 70,000 miles. The latter can usually be attributed to poor oil and filter maintenance.

After the engine has run a few minutes, the smoke usually dissipates. As the engine warms, the oil rings do a better job of sealing. Add a warm catalytic converter cleaning up what gets past, and very little smoke is then seen coming from the tail pipe. The actual amount of oil consumed is usually very low with this problem.

The problem is with the oil control rings. Either they become stuck in the groove or, more commonly, the ring is so badly worn that it won't seal well enough to keep the oil off the cylinder wall. If the oil rings are stuck because they are packed with carbon, the owner needs to do a better job of maintenance. In the case of the worn ring, it's still a re-ring job because the oil rings lost the friction battle with the block.

The cylinder block has a very high nickel and carbon content, which makes the cylinder walls very hard, so there is little wear on the cylinder. Rarely will you see a ring ridge or any taper to the cylinder. The honing marks may still be visible. In some cases, the oil control rings have been found to be worn so much that the oil control ring spacer/expander has been wearing on the cylinder wall.

To repair, clean the ring grooves (a used broken compression ring works great for this), deglaze the cylinders, clean and reassemble. You may want to replace the valve stem seals and do a valve job, if needed. Since the guides for the valves are bronze inserts, there is little wear. Smoking on start-up doesn't always mean valve seals ... in fact, these days it's almost always rings

Why dont all owners have this problem?

It depends, if you use good quality oil, if you run 1000 miles on a highway in one go, or 1000 miles with 100 cold starts, in start-stop city traffic...
 
I'm having the same issues but just recently started. I also noticed tht if I rev it up while its smoking it will miss not rediculous revs not past 3 but could this be from oil being on the spark plugs? I plan on doing an oil change with engine restore this weekend. I also noticed tht my oil is almost black I'm runing royal purple and not even 2k miles yet I checked it a couple weeks ago and it was just starting to lose its purpleish tint I.e. light brown. But it also doesn't smoke unless I rev it or I havnt noticed it yet
 
mine does it only in cold weather but now i gotta drive few miles in order for the smoke to go away so after all that i can rev the engine so hard and it wont smoke -___- i just dont know wtf is wrong i wanted to do the steem seals but now im not really sure about it

any help would be appreciated
 
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My car is doing the same thing. Just had the valve seals replaced but still smokes. Now I'm looking at selling the car or replacing the rings and what ever rabbit trail of problems they find once the engine is apart. How long would it take a mechanic to re-ring the engine?
 
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This morning i went to the car, take the spark plugs out and i saw a bit of oil on each piston so im think that my piston rings are not the problem. how can u tell is the valve seals are completely worn ? will the car smoke at all times? (before. the smoke used to go away with in a min or two and now i gotta drive couple of blocks in order for it to go away and this usually happens during the first days after every oil change) thanks!
 
quick up date on my car. Two weeks in the shop and two collapsed oil rings. They replaced all rings sent the head to a shop and replaced the rear motor mount, which he said took a good part of a day. Total cost $1475. Not to bad and a lot cheaper than finding a good used car. The check engine light is on but he said the code read O2 sensor, now I need to replace that, again.
 
Very interesting thread. Thanks for posting this.

I just replaced the FS9 head on my 2002 Protege due to 2 broken exhaust valves at 365K mi.
Replacing was "quicker" than sending it out for repair.

She smokes a lot on first start in the AM... then clears up. When I start it after sitting at work for the day... I make a quick escape so as to spread out the smoke.

Drinks oil worse with the new head... like a quart every 150-200 mi. Getting a little expensive... so I'm gonna take her apart again... Measure the cylinder walls (like I should have done the first time)... and go from there. If they are still w/in specs, I'll re-ring her and hopefully get another 100K out of her.

Should get to this in a few weeks.
 
Hey Folks. I recently bought a 2000 Protege w/ 226,000 miles. When I bought it, it was a warm day and didn't smoke noticeable a start up, but after a month the weather cooled, and I couldn't miss the huge cloud of smoke about 30 seconds after start up. In a public area, it was down right embarrassing! After warming up for a minute or two, it would quit. After reading this, I figured it was just the miles and the rings, and that I'd have to put up with it. A couple days ago tho I decided to clean out a few vaccuum lines and when I pulled off the EGR line, I saw the nipple was full of junk. I cleaned it out and then blew some carb cleaner and compressed air thru the hose and metal line and blew a bunch of black crud out. I didn't know what it would help, but for two days and cold starts, no smoke!!!!
 
Hey Folks. I recently bought a 2000 Protege w/ 226,000 miles. When I bought it, it was a warm day and didn't smoke noticeable a start up, but after a month the weather cooled, and I couldn't miss the huge cloud of smoke about 30 seconds after start up. In a public area, it was down right embarrassing! After warming up for a minute or two, it would quit smoking. After reading this, I figured it was just the miles and the rings, and that I'd have to put up with it. A couple days ago tho I decided to clean out a few vaccuum lines and when I pulled off the EGR line, I saw the nipple was full of junk. I cleaned it out and then blew some carb cleaner and compressed air thru the hose and metal line and blew a bunch of black crud out. I didn't know what it would help, but for two days and cold starts, no smoke!!!!
 
Update... She's back together and running.
A few months of sitting on jack stands, waiting for me to get around to everything that needed attention. I Did a little at a time as the budget would allow .... Rebuilt head, new rings, seals and main bearings in the motor. Replaced the spark coils, blocked off the EGR, rebuilt the transmission with new steels, friction plates, pistons, seals, replaced the torque converter, Installed new bearings on the front axle/steering knuckle, new left and right CV axles, new dust boots for the lower ball joints and tie rod ends, new sway bar end link connector rod thingy... and new fuel pump/filter.
367k miles and shes running like new... er. No smoking. Kind of an expensive fix, but way cheaper than a new car. I opted to rebuild it because I've had the car since new and know it's maintenance history... where if I bought a used one, there's no way to tell how it was treated.
 
The Mazda G6 engine in my Ford Courier started blowing a HEAP of smoke, mainly white, with a tinge of blue, when first started in the morning, every morning.
There was so much smoke that the entire street would fill up.

I discovered that I had put too much oil in.
Also, I park facing uphill on a slight incline.
Once the engine was warm, the smoke would reduce to nothing.
As a test, I reverse parked the car, so it was facing slightly downhill, and next morning, voila, no smoke.
By draining out some of the oil, it stopped smoking in the morning, regardless of which way the car was facing.

Several years after this, I had to replace the head - a faulty temperature sensor led to me missing the fact that the water had drained away... :(

So, new head, valves, gaskets, air filter, etc, and the white smoke has started again, so I suspect there is too much oil in it again.
The mechanic is going to drain some of the oil and I'll retest it tomorrow morning.

I am not sure of the cause of the issue, but I don't believe it has anything to do with the head, as it has since been replaced with a new one.
But either way, some oil must be making its way into the cylinders when there is too much oil in the system, and its facing uphill.
I'm not a mechanic, but thought I'd post a few observations I've made.
I also appreciate all the input made by others on this forum, interesting reading.

If anyone has any suggestions to the cause, I'd appreciate their input.
I suspect perhaps oil rings... but like I said, I'm no mechanic...
 
I know this is an old thread but wondering if someone could help me out?

What if my protege5 shows no signs of burning or leaking oil? Could stuck rings be treated with an engine detergent if caught early enough?
 
Great Thread Post and information for those who still have or have picked up one of the "surviving" P5s and want to keep them going into the future...Thanks :)👍
 
I noticed it once when I changed from Mobil1 (15k one) to Pennzoil (both synthetic). I switched back to Mobil1 and never had an issue since. I have also had really good results with Royal Purple. Use high quality oil and change your oil regularly and you will be okay. Must be the extra cleaning agents in the oil. (high quality oil filter is good too - Puralator Boss).
 
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Use high quality oil and change your oil regularly and you will be okay.


I agree, but some guys were using synthetic oil and running it for 10,000 miles.

Not a good idea.

They ended up with seized oil rings.

Cheap oil changed every 3,000 miles is a better idea, and it's cheaper if you change your own oil.

Just keeping an eye on the color of you oil is a good idea.
If it's looking dark or black, change your oil.
 
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