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

:
Mazda Protege5
I've noticed in the last 6months to a year that my PR5 has been burning oil and smoking sometimes on a cold start after sitting for 8+ hours. This usually lasts for the first 5mins of driving then goes away. I've also noticed that when I drive downhill and use the engine compression for braking, once I accelerate after this, I'll get a big puff of white smoke, even if the car is warmed up. My coolant levels are fine, so it's nothing related to that, but I'm adding maybe 1-2 quarts a month. I'm not getting any check engine lights, but I have installed the O2 sensor trick which is popular for the PR5.

Any suggestions where to start?
 

pcb

The Diagram Dude
:
2002 MP5
Switching to 10W30 regular dino oil can slow down the burning as well as save you some money.

Some guys opted to replace the engine with a used one but that is still kinda expensive.
 

JazzySP20

Madaz
:
AUSTRALIA
:
BJII Astina SP20
I have had somewhat success fixing this issue on a friends GF FSDE 626. His 626 hatch had over 300'000 km's and would blow smoke at start up, hard acceleration from lights, and he had to top up the oil every few days. He was going to dump the car and I said let's try something and see what happens. He agreed as it was a nothing to lose situation anyway. If it doesn't work the car is going to be scrapped anyway.

We removed the old oil and put in oil designed for diesel engines only (not oil designed for diesel or petrol) and about 500ml of diesel mixed into the crankcase. He ran like that for about 50km's. We then changed the oil (was black as night) and oil filter and did the exactly the same again. Diesel only oil with 500ml diesel into crankcase with new oil filter. About 50 kms later he said it was getting better, so changed the oil and filter again but this time we put diesel oil only. Another 50 km's like that and we changed to 10W 30W normal petrol oil with new filter. The car hardly blows smoke at start up now, but a slight hint of blueish smoke when he guns it off the line every now and then.

This was done in October last year, and he is still driving it today with hardly any smoke from the engine anymore. So it worked for him. No guarantees this will always work and is something I would hesitate do on my engine if ever the issue was to arise on my FSDE. But there yo go. He spent a few $$'s on the oil and filters yes, (almost AU$400 all up) but it did improve the engine smoking issue.

I have read of people having success filling the crankcase entirely with diesel only - and running engine for 30 min or so, then doing oil and diesel mixture into crankcase, then finally oil only. But I was not game to try that.
 
Last edited:
:
protege5
You may have a couple things going on. Or it may all be caused by the valve stem seals. Smoke for a minute at start-up is almost always caused by valve seals. AS the car sits overnight, the oil in the head will pool in the lowest position (valves) and seep into the combustion chamber. When you first start the car, it burns off the oil that has seeped in. Also during deceleration (engine braking) the vacuum created is increased, and sucks oil in through dried out valve stem seals. This is a pretty common problem, and while it may be inconvenient, it's not really going to hurt anything short term. long term you'll be looking at a cat converter, maybe fouled out plugs but it's not going to do any major damage. I'd bet your valve stem seals are pretty bad from the sounds of it.

It is possible that you've got a problem with the rings, but my experience would put my money on valve seals if I were a betting man. But to be safe, I would Check compression, you can "rent" a compression tester from autozone for free.

If compression is good, the engine has a lot of life left in it and it's probably just the oil control rings sticking, causing the smoking. This isn't uncommon to have great compression and smoke. There's 2 sets of rings on the car...
-oil control rings - these distribute oil to the piston and cylinder wall
-compression rings - these are what give the cylinder compression and allow the combustion process to occur.

If compression is low, then compression rings and/or cylinder wall likely has significant wear and scoring. Best bet would be to rebuild the motor or replace it. Probably not much life left to it (I wouldn't take any long trips).

If compression is good, then it's probably either valve seals, or the oil control rings stuck and probably sludged up. Using Diesel, ATF, or a wide variety of other detergents mixed with the oil pre-oil change is something that's been tossed around for a while. Really, the only TRUE way to de-sludge an engine is to take it apart and clean everything, replace what's worn, and put it all back together. However, it wouldn't hurt to put a quart of ATF or whatever detergent in the oil, let it idle for 30 minutes and change the oil. Maybe get a few gallons of cheap oil and repeat the process a couple times. AFter 30 min of idling it will likely come out black as night like you hadn't changed the oil in years. Keep doing this until after the 30 min it comes out looking clean, then put your good oil in and run it. (I wouldn't change your oil filter until you're ready to put in the good oil at the end)

Also just to note, depending on how much your motor smokes it may continue to do so for a while until it burns off the caked oil out of the exhaust pipe.
 

Natey

Moderator
Contributor
Patron
Oil rings would make black smoke, no?

White smoke = water or coolant related.
 
:
protege5
Oil rings would make black smoke, no?

White smoke = water or coolant related.
unless you look closely, or familiar with engines and seen the different kinds of smoke, 99% of people can't tell the difference between blue/black/white smoke. IT's just "gray" lol

Plus he said he's using 2 qts of oil per month. And the coolant levels are fine... IF the oil was going into the coolant it would be obvious (not to mention the coolant levels would keep increasing).
 

pcb

The Diagram Dude
:
2002 MP5
You may have a couple things going on. Or it may all be caused by the valve stem seals.

It is possible that you've got a problem with the rings, but my experience would put my money on valve seals...
Our specific engine has a problem with oil ring seizing.

The link that MrGiggles posted covers it.

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.
 

n2stox

Jeff
:
2003 MP5, 2000 Audi S4, 67 Mustang (hers)
I was also burning a quart or so per month...dealer had no idea (compression was fine and all the plugs looked normal) and a 2nd mechanic had no idea except he said there is a lot of gunk in there.

So, I ran an engine flush detergent (liquimoly) in a warm engine at idle for 15 mins before changing the oil. Smoke in startup was down about 90%. And I had serious spy vs spy smokescreen before...I could fog half the neighborhood. 2 weeks later I did it again....smoke is gone and that was 3 weeks ago.
 

pcb

The Diagram Dude
:
2002 MP5
I was also burning a quart or so per month...dealer had no idea (compression was fine and all the plugs looked normal) and a 2nd mechanic had no idea except he said there is a lot of gunk in there.

So, I ran an engine flush detergent (liquimoly) in a warm engine at idle for 15 mins before changing the oil. Smoke in startup was down about 90%. And I had serious spy vs spy smokescreen before...I could fog half the neighborhood. 2 weeks later I did it again....smoke is gone and that was 3 weeks ago.
Kool !!!
You're the first one I'm aware of that has fixed this problem without an engine rebuild or replacement.

That means there is hope for the others who are burning oil, and there's a lot others.
 
:
2003 Mazda Protege5
I hate to bring back an old thread so my apologies.

JazzySP20 what diesel-only oil did you use? Also what weight?
 

JazzySP20

Madaz
:
AUSTRALIA
:
BJII Astina SP20
I don't remember exactly what weight. But it was Penrite brand and it was the cheapest thing going at the time.
Honestly though, I think there's better and cheaper ways of flushing out the sludge build up inside the block. And I think the type of oil had we used had little effect. I think the 500ml of diesel mixed with the oil was the key. Some of the guys here have got the same result using different methods. There's also off the shelf engine flush stuff which should do the same if not better. THIS one from Liquid Molly for example

Sorry, I cannot be more helpful as it was a while back now, and I cannot remember exact details.
And also, the 626 is still going strong with zero smoke.
 

pcb

The Diagram Dude
:
2002 MP5
Hey Jazzy, ...

Can I ask why you used diesel engine oil??

Is there more detergent in it or something?
 

pcb

The Diagram Dude
:
2002 MP5
" Also what weight? "

I would assume the thinner the better. It would be more like a solvent.

You'd burn more of it though.
 
:
2003 Mazda Protege5
I did try the liqui moly engine flush.

I'll probably just use 10w30, I don't want to go too thin and deprive the engine of proper lubrication.
 
Top