Car smokes on start up only!!!

[801SlowestSt]

Car started to smoke on startup it would throw a big puff of white smoke smelling like oil. After warming up smoke will clear up and stop. Car drove fine no smoke while drive but it always throws a puff a white smoke on start up. A few days later did a compression test cylinder one won’t hold compression gets up to about 130 but slowing goes down. Cylinder 2 - 4 hold fine at 150. Where should I start on fixing my problem need help. No coolant lost. For the couple days I drove it before compression testing it it drove fine no issues no codes but it did seem a little under power but nothing to noticeable. Is it rings or a gasket or valves???

 

[Coyote Chaser]

What kind of condition is spark plug 1, compared to spark plugs 2 - 4?

 

[SteveS]

Traditionally smoke on cold startup only is valves (valve guides leaking)

 

[Mycooking]

Since compression is down I'd use a bore scope to check cylinder wall condition and also look at the condition of spark plug 1(is it extra dirty compared to any others) the puff of smoke like stated above me is usually due to worn valveguide seals but could me a piston ring also letting just a little bit of oil blow by until all warmed up and the rings expanded. Good luck on finding and fixing the issue.

 

[Sam4]

Am I wrong thinking oil is getting into the turbo? I think that was the cause in my/ higher mileage Mazdaspeed3s?

 

[TyphoonFiST]

Mileage? Has the car ever been overheated?

 

[Dialcaliper]

Am I wrong thinking oil is getting into the turbo? I think that was the cause in my/ higher mileage Mazdaspeed3s?

Low compression suggests it’s in-cylinder and not the turbo or elsewhere.

I’m going to echo, check the plugs for oil residue after letting it sit. If that is vague or inconclusive, give the car a quick crank with both the clutch and throttle fully depressed to jostle things up. (which should crank the engine with fueling cut off, normally used to clear a flooded condition)

There are only so many ways to get oil into the cylinder - valve guides or a crack in the head, head gasket or piston rings. This car has oil squirters, so a small amount could be leaking around a ring that’s not sealing well when cold.

You can also try removing the intake and exhaust manifold to check the valve guides, but that’s a non-trivial job.

If the oil smell is vague, it could also be a rich condition, probably as a result of poor cylinder sealing. Check your ECU for misfire around the time of startup.

White smoke is usually steam from water (mixed with exhaust or coolant - oil and fuel tend to make grey/black smoke. So depending on where you are, it could be condensation in the exhaust pipe from the last run. And the poor compression snd Does it do it on all starts (like stopping at the grocery store), or just cold starts?

 

[the duke]

Traditionally smoke on cold startup only is valves (valve guides leaking)

It could also be the turbo, IE drain/leaking at the CHRA or seals. This was a typical problem in the MZR motor in the Mazdaspeed 6 and 3s.

With that said and his leakdown on cylinder 1 failing, I agree. Rings or valves are not sealing.