Smoke on cold start

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2002 P5
So - I bought a used P5 w/ 100k last summer. it smoked a little on start up, but not bad. Figured I would do valve seals later.

About 2 months ago, it started consuming a lot of oil, and the smoking was becoming more regular.

I pulled the head and took it to a shop - they said that the valve seals were fine (but I had them put in new anyway). There are 2 head / block alignment pins. Someone had been in here as one of the aligment pins had cocked and deformed a little bit. So - I replaced them, new head bolts, timing belt, water pump - thought I had found the problem.

Now when the car is worse than when I started. Smokes bad on start-up (but only when cold. And by cold, I mean has sat for 8-10 hours. Also, I have 2 error codes (which are new) for random misfire and MAP sensor.

since it's only when cold, I am wondering if this has always been a cold start issue of some sort? Compression is good, all plugs appears to be firing.

Any help is appreciated.....
 

gozz

Member
Take a look at this thread, friend!!!

http://www.mazdas247.com/forum/showthread.php?t=123770221

I had the same problem...

Now I do not have as much smoke coming out on cold stars, only every other time, and just a small puff, like a puff of cigarette smoke... or so...

Before the seals were replaced, sometimes I had such a smokey startup that people were thinking I was smoking out mosquitoes...

I have to check the PCV valve, (I was suggested to) although I am not sure what does it have to do smoking on cold startups...


Oh, yes, and one other tip:

It is a long and unpleasant shot: but, maybe, JUST maybe, we got a crack in our engine heads, so when it's cold, the crack opens and some oil leaks, but as soon as the head worms up, the crack closes up...

Other thing is, maybe, the valve guides leak by the place where they go into the head, coz, stem seals are above that place...
So even the seals are doing a perfect job, the guides are not properly sealed into the head...

just my .02
 
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:
2002 P5
P-funk & gozz, thanks for the replies.

PCV valve is new. Valve seals are also new. I don't know if the shop that did the seals checked the guides - I thought that would be a standard thing? but am planning on calling them on Monday.

Usually plugs are white (across all 4) - after it has been running for a while.

Today, I only let it run 1-2 min (still smoking) and shut it off. Few hours later pulled the plugs and sure enough - black as midnight and still wet with oil.

Compression #'s today were 210 / 205 / 210 / 200. These are probably artificially high due to the oil, but they are at least consistent.

So it could be valve guides or a micro crack somewhere, but these both assume that significant amounts of oil are pooling in the head right? Is it possible that I have a drain path blocked somewhere in the block? I ran a can of seaform in the oil before I did the head, but maybe I got gunk somewhere?

Any additional thoughts are appreciated. I am planning on getting it hot and pulling the valve cover to see how much oil is there. Then, next morning see if it has all disappeared?

Again - I just want to say that the car runs fine after it gets up to temp.
 
:
2002 P5
Not sure how well the photo's came out, but after running the car and getting it hot I pulled the valve cover. There seems to be oil pooling around the valves. Any ideas of where the correct drain path is for this fluid? Or is this normal?
 

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2002 P5
I checked the car again this morning. Looks like the small pools of oil around the valves are about the same height- so I am assuming this is normal.

But, gozz - you said Intake and Exhaust valve seals are different? Do you know how? I just checked onlinemazdaparts.com and they are listing different prices for intake and exhaust seals. But I bought a full head gasket kit from Rock Auto (Felpro seals) and they were all in the same bag?

I trust the shop I took my head too, as they have done other engine work for my family and some of my co-workers and seem to be pretty good. But now I am starting to question the seals. Can anyone tell me the differences?

Thanks-
 

gozz

Member
I checked the car again this morning. Looks like the small pools of oil around the valves are about the same height- so I am assuming this is normal.

But, gozz - you said Intake and Exhaust valve seals are different? Do you know how? I just checked onlinemazdaparts.com and they are listing different prices for intake and exhaust seals. But I bought a full head gasket kit from Rock Auto (Felpro seals) and they were all in the same bag?

I trust the shop I took my head too, as they have done other engine work for my family and some of my co-workers and seem to be pretty good. But now I am starting to question the seals. Can anyone tell me the differences?

Thanks-

Hello there bontrager_steel

The exhaust valve stems are always under pressure and extremely high temperature due to the exhaust cycle (high overpressure impulses)...

The intake valve stems are always under vacuum, because of the intake cycle, especially when engine is under high RPM but the throttle is closed (coasting, etc)

This is why the exhaust valve seals have to be made of different materials and have to be more snug, (smaller hole),

and intake ones have to be a bit more loose, so that vacuum can get them snug, otherwise, excessive wear of seals would occur.

If you accidentally swap the intake/exhaust seals, they would leak...
 
:
2002 P5
Sorry - I was travelling for work.

I spoke to the shop that did the head work, they said the Felpro kit only has one seal in it. I confirmed standing there looking over his shoulder. They also stated that the amount of smoke I am seeing on start up couldn't be from valve seals (it's seriously like someone started a fog machine).

They also said that the valves were identical on intake and exhaust - so no need for unique seals.

This is all consistant with the experiment that I did previously where if I pull plugs after the car has been run for a while they are white, but if I run it for a few minutes and shut it down all of the plugs have oil on them.

They said that Mazda engines use low tension piston rings, and that since the problem goes away as the engine warms up it could be that I am on the low side of the tolerance band for the rings?

Which I would have had them check the block when I pulled the head, but am planning on pulling the engine again in the next few weeks.

Of course - this does not answer why Mazda dealerships want to sell you 2 different valve seals but felpro only sells one...
 

gozz

Member
Sorry - I was travelling for work.

I spoke to the shop that did the head work, they said the Felpro kit only has one seal in it. I confirmed standing there looking over his shoulder. They also stated that the amount of smoke I am seeing on start up couldn't be from valve seals (it's seriously like someone started a fog machine).

They also said that the valves were identical on intake and exhaust - so no need for unique seals.

This is all consistant with the experiment that I did previously where if I pull plugs after the car has been run for a while they are white, but if I run it for a few minutes and shut it down all of the plugs have oil on them.

They said that Mazda engines use low tension piston rings, and that since the problem goes away as the engine warms up it could be that I am on the low side of the tolerance band for the rings?

Which I would have had them check the block when I pulled the head, but am planning on pulling the engine again in the next few weeks.

Of course - this does not answer why Mazda dealerships want to sell you 2 different valve seals but felpro only sells one...

Huh, I recently did the oil change, and, same thing happens to me as well. It smokes as smoke bomb...

It is significant that the amount of smoke increases drastically immediately after every oil change, and reduces slowly, to a point where it almost doesn't smoke, but alas, the mileage forces you to change the oil again... so the loop continues...

Look, here's my point of view on the "blame it on the rings" issue:

I've seen bad and worn out rings on engines with more than 300 000 km on them. I've seen them smoke. they smoke on cold start, but smoke visibly bud discretely, they smoke after prolonged idling, visibly but discretely. They smoke cold, they smoke warm, to sum it all up, they smoke! sometimes, so bad that after driving behind the smokey one, you overtake it cursing the MOT station that "OK-passed" the sucker...

Again, the gravity does it's part (or Newton was seriously wrong there), and OIL CAN NOT get up past the rings when the engine sits over night, to be waiting next morning for you to smoke the entire neighborhood up!

Even so, if the rings do not seal all that well, they do not posses some magic powers to IMMEDIATELY start sealing after the engine has been running for 30 seconds or so... As it is case on my car... In that time, the pistons and cyl walls don't heat up to be even lukewarm...

I measured the blow by, it's normal, not to big, not to small... the blow by is the same on cold engine, as is on hot engine... In case of bad "temp sensitive" rings, that would not be the case...

the worst part is, my engine has only 90 000 kilometers on it, and it has been well maintained...

Ok, here are my toughs on this:

1. either the valve guide it self leaks, remember it is just pressed into the head, so nothing but the contact pressure seals the seam between the guide and the head.

2. There is a tiny crack in the head, so as the head cools down, the crack opens, oil drips down onto the pistons... Once you start the engine up, the heads warms up, the crack compresses due to thermal expansion, and closes up and seals....

3. Tiny crack in the engine block.

4. snapped ring.


Well, please, let me know if you'll take the head paprt, and please take many pics...

And, just for your benefit, please, let the car sit over night before taking the head off. Don't even start it up for a second. don't move the crankshaft.

After you take the in/ex manifolds, before taking the head off, look carefully (use a torch if you must) and check ALL the intake and exhaust valves (stems) for any fresh oil on them. And also the guide ends fr any fresh gunk or oil...

You will want to look for the leak between the stem guide (bronze gold on pic) and the head...

http://carphotos.cardomain.com/ride_images/2/3685/1061/21710530062_large.jpg


Take many pics...
Be careful and make sure to drain all the oil and coolant before taking the head off, because, after you take the head apart, look for any sign of oil, or coolant that might leak down from the head or the valves...

Do do the same on the cyl walls....

And then, rotate the crank a couple of turns, carefully observing the pistons, if they leave massive oil residue on the cay walls getting down to the BDC...

I hope you will have some more useful info on this issue...

I am planning to rent (oh it's gonna be a difficult task to do) a endoscope to look down the spark plug hole into the chambers for any sign of leaks etc...
But the important thing is not to move the car (start the engine at all) so the oil leak can be visible...
 
:
Lancer Ralliart Sportback
^Good post - he knows what he is talking about. I concur.

With the engine cold remove the valve cover. Is there oil covering the valves (a blocked oil return passage)?
 
:
Lancer Ralliart Sportback
Huh, I recently did the oil change, and, same thing happens to me as well. It smokes as smoke bomb...

It is significant that the amount of smoke increases drastically immediately after every oil change, and reduces slowly, to a point where it almost doesn't smoke, but alas, the mileage forces you to change the oil again... so the loop continues...

Look, here's my point of view on the "blame it on the rings" issue:

I've seen bad and worn out rings on engines with more than 300 000 km on them. I've seen them smoke. they smoke on cold start, but smoke visibly bud discretely, they smoke after prolonged idling, visibly but discretely. They smoke cold, they smoke warm, to sum it all up, they smoke! sometimes, so bad that after driving behind the smokey one, you overtake it cursing the MOT station that "OK-passed" the sucker...

Again, the gravity does it's part (or Newton was seriously wrong there), and OIL CAN NOT get up past the rings when the engine sits over night, to be waiting next morning for you to smoke the entire neighborhood up!

Even so, if the rings do not seal all that well, they do not posses some magic powers to IMMEDIATELY start sealing after the engine has been running for 30 seconds or so... As it is case on my car... In that time, the pistons and cyl walls don't heat up to be even lukewarm...

I measured the blow by, it's normal, not to big, not to small... the blow by is the same on cold engine, as is on hot engine... In case of bad "temp sensitive" rings, that would not be the case...

the worst part is, my engine has only 90 000 kilometers on it, and it has been well maintained...

Ok, here are my toughs on this:

1. either the valve guide it self leaks, remember it is just pressed into the head, so nothing but the contact pressure seals the seam between the guide and the head.

2. There is a tiny crack in the head, so as the head cools down, the crack opens, oil drips down onto the pistons... Once you start the engine up, the heads warms up, the crack compresses due to thermal expansion, and closes up and seals....

3. Tiny crack in the engine block.

4. snapped ring.


Well, please, let me know if you'll take the head paprt, and please take many pics...

And, just for your benefit, please, let the car sit over night before taking the head off. Don't even start it up for a second. don't move the crankshaft.

After you take the in/ex manifolds, before taking the head off, look carefully (use a torch if you must) and check ALL the intake and exhaust valves (stems) for any fresh oil on them. And also the guide ends fr any fresh gunk or oil...

You will want to look for the leak between the stem guide (bronze gold on pic) and the head...

http://carphotos.cardomain.com/ride_images/2/3685/1061/21710530062_large.jpg


Take many pics...
Be careful and make sure to drain all the oil and coolant before taking the head off, because, after you take the head apart, look for any sign of oil, or coolant that might leak down from the head or the valves...

Do do the same on the cyl walls....

And then, rotate the crank a couple of turns, carefully observing the pistons, if they leave massive oil residue on the cay walls getting down to the BDC...

I hope you will have some more useful info on this issue...

I am planning to rent (oh it's gonna be a difficult task to do) a endoscope to look down the spark plug hole into the chambers for any sign of leaks etc...
But the important thing is not to move the car (start the engine at all) so the oil leak can be visible...
All good points - BUT he has oil on all four plugs - so there can't be four identical valve seal failures or cracks in in the head...

This still puzzles me. i want to say worn oil control rings that expand as it warms up.

BTW:
The reason i ask about the PCV - it is a good inidcator of excessive blow by/low compression and is a source for oil into the intake manifold.
 

gozz

Member
All good points - BUT he has oil on all four plugs - so there can't be four identical valve seal failures or cracks in in the head...

This still puzzles me. i want to say worn oil control rings that expand as it warms up.

BTW:
The reason i ask about the PCV - it is a good inidcator of excessive blow by/low compression and is a source for oil into the intake manifold.

Hmmm, good point there...

But my car smokes like crazy when cold, and even then, I don't have any excessive blow by, nor my oil consumption goes on the fritz...

I haven't burned maybe 1mm of oil on the dipstick in the past 1000 km (approx 600 miles)

Well, here's what I did a few days ago:

The car was sitting over night.
Engine was stone cold!

Pulled the plugs out, all 4 were OK, perfect coffee colored, not a trace of oil, sooth, or any sign of trouble. Took a flashlight, looked down to the top of the pistons- all 4 looked dry, some carbon buildup, but no wet spots.

Put the plugs back in, started the car for 5 seconds, turned it off.

Took the plugs out: all 4 got black, soothed in oil.

Looked down to the pistons, 3 were COMPLETELY wet, not moist, but WET in oil, like a tablespoon of oil in each cylinder, and 4th one had some small wet spots, like someone sprinkled half a dozen drops of oil...

Put it all back in, started the car, fogged the mosquitoes in the city, and 100 meters (300 ft) and 30 secs later, the smoking stopped...

I put the oil catch can, and it does collect a tiniest amounts of oil, but not nearly enough to cause the smoking of that proportions...


One other funny but interesting thing I noticed:

If I cold-start the car in the morning, and IMMEDIATELY (1-3 secs after start-up) start driving, easy on the throttle, up to 2000 rpm as I live in the city I have to wiggle my way out of the lot, bunch of stop lights etc...

the car doesn't smoke!!!!!


If, on the other hand, I start-up the car, and LET IT IDLE for 10-20 seconds, all hell breaks loose!!! and the fog-machine kicks in...

If I kill and start the car again, and again, oh boy, do I solve the bug problem in my neighborhood... (cricket)

I just can not believe that oil control rings would seal so badly to pass a tablespoon of oil in each cyl ina matter of 5 seconds, next to the perfectly working compression rings, but then, 60 seconds later start sealing perfectly, while the compression rings do their job flawlessly the entire time...

Obviously, the issue has something to do with the intake manifold vaccum...

I am planing to soak the rings in something over night, but I am in a dilemma: Since I can't get the seafoam nor Marvel Mistery Oil here in Croatia, what to put down the cylinders???...

Injector cleaner? ATF? Engine Flush?

-ATF, I fear, isn't strong enough to brake the rings loose.
-Engine flush could do the trick...
-Injector cleaner works great on gas buildups, but how effective is it on iol lacquer and oil sludge buildup?
 
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darinb

Member
oil in all 4 cylinders too

Same issue exactly -change seals -- were all in 1 bag too -2 bad lifters replaced
new head gasket
-marvel mystery oil or seafoam down cylinder head overnight? -- which is better -- how would i know if it was intake manifold vaccum that was the issue -- can i adjust that down and see if it lessens--have a feeling its rings --but all 4?? maybe its the damn seals -4 on each cylinder so 1 is gonna be wrong size and let oil in from head --am going to get mazda seals and try that --let me know if any breakthru on info occurs --good luck
 
:
Lancer Ralliart Sportback
Not seafoam. It is a solvent.

You might try Restore [tm] (the 'high mileage' can o' stuff that seals rings)...

It helped on my [shudder] 1989 Caprice Brady-Mobile of a wagon...

Couldn't hurt...
 

Crazee D

Member
Contributor
:
White P5 go-kart
just joining the thread here,

I too have a regular oil burning issue. I am burning more oil faster on a regular basis.
My head is a FS02 from a 626 4cyl. (plugged disty hole ofc)
It was decked and lightly worked when I had it set up for my twiggy cams (new head gasket also done).
It was converted to Solid lifters and now back to HLAs since removing the twiggys.
(Still runnning kasman adj cam gears)
I blow a faint blue cloud on takeoffs after a cold start.
Leakdown tests were 5, 6's and a 7%

My current theory on my oil issue is a leaky valve cover gasket, got a new one sitting next to me here.
 

gozz

Member
BUMP ing the thread...

Anyone, any news?

Bontrager?

Mine now smokes on regular morning basis...

If I don't startup and drive immediately after startup, I make one hell of a smoke screen...