SOLVED: CA18DET smokey after prolonged idle

[silvios]

Hi All

I have been noticing that my CA18 get a bit smokey out the exhaust when it has been idling for a while. Basically, i sit in traffic, and when i got to take off - smoke comes out of the exhaust then eventually clears when i get going again.
It is difficult to tell what color it is, but it looks white/blueish.

The car idles well normally, and this has only started to happen recently. I use a Synthetic 10w-40 (Nulon) oil with some additive that my mechanic added (not sure exactly what it is). I am thinking of going to a 10w-60 Castrol Sport next change with no additives. The idle does drop along with vac (slightly) but after i noticed this and take off then the car blows a puff of smoke.

I don't see smoke on startup. I don't see smoke on partial throttle / WOT.
I don't seem to see smoke on decel, although there is no large hills near me.

In order to troubleshoot this issue, i removed all the hot side piping to look for oil residue in the piping, to only find a little at the turbo intake, which i cleaned off. I also checked the spark plugs which looked perfectly fine to me. I then looked at the piston tops, to find that cylinder 1 was covered more than 2,3,4 with carbon/black deposits. The plug from cylinder 1 looked the same as the other plugs.

Some other things i have noticed
-Coolant is full
-Oil seems the same as it was 4000km ago

I am leaning towards a number of things which could be the problem:

-Leaky valve stem seals for cylinder 1
-Worn Rings on cylinder 1
-PCV valve gone?
-Turbo seal gone

I checked the turbo and it didnt seem to show signs of play or anything.

The mods are:
-Standard CA18DET
-T25 Turbo @ 14psi
- Exhaust
-FMIC
-Mines ECU

If anyone could shed some light on any of this, whether they have had the same issue. I am looking at getting a compression test done, so that will rule out rings? Will this tell if there are leaky valve stem seals?
Replacing valve stem seals - is this difficult?

Thanks in advance.

[boost_boy]

Go with #1 and/or #4 of the problems you suggested.

[silvios]

Thanks for that. I will look into it.

Could i try a thicker oil for the time being? Or a 'stop smoke' additive?

What would be the thickest i could go? 15w-50? or is a 10w-60 ok?

[float_6969]

Sounds like a failing turbine side oil seal to me.

[silvios]

Ok, what i don't understand is how dirty cylinder 1 looks compared to the others? I mean on cylinder 2,3,4 i can see numbers on the piston tops, but there is gunk build up on cylinder 1 so i cant see anything.
If the turbo seal is gone, that means it would smoke all the time?

Also, the smoke is not consistent. It happens once the car gets to operating temp, and then happens randomly, not all the time..The longer the car sits idling for, the worse the puff of smoke is when i go to take off.

What i may do is get some throttle body cleaner and spray into the cylinder to clean the piston top of cylinder 1.

I need a compression tester, ill be buying one today.

[boost_boy]

The engine is old and probably has been abused at some point in it's life. Those rubber seals on the entire engine is dry-rotted and hardened till the point of not being effective at all. Sounds like your experience with engines (at least turbo engines) is on the novice side, so I suggest you contact someone who has a little more knowledge on the subject. I can guarantee you that that engine of yours as well as it's components are in need of refreshening.

[silvios]

Thanks Boost_Boy. I will contact my mechanic today.

[Luchitosan]

To me is Valve seals, clean all the sparks, drive a week and re-check the sparks.
If they look dirty, brown, black, etc valve seals are gone.

If it's smoking just at first it's valve seal, if all the time (less but all time) can be the turbo seals.

Salute !

[float_6969]

Not necessarily true. The turbo on my Mazdaspeed Protege smokes like CRAZY at startup. After it warms up a bit, it quits smoking. It has brand new valve stem seals in it.

[silvios]

Just to let everyone know, i changed to a 10w-50 oil with a stop leak oil additive and it doesnt seem to be smoking as much as before.

I have spoken to my mechanic and he said either Valve stem seals or turbo.

I am yet to do a proper decel test - but will get to it.

[silvios]

I have been researching more and more about this issue.

The car does not smoke at all on startup.
The car does not smoke out the exhaust on deceleration.

The car smokes after idling for a prolonged period, and after this period if i take off it smokes then clears. When i boot it, it smokes a bit too. When driving normally, there is no smoke (had a friend follow me for a while). The plugs, after checking them multiple times, do not seem to have oil buildup on them.

I am leading towards turbo seal here. I am actually taking some time off work over Christmas, and i have just purchased a T28bb with no actuator which i can source, so i will get some help to fit that.

What i have not done is check the intake pipe for oil residue since the last time i cleaned it. There was a minor pool as mentioned before at the intake of the turbo. I cleaned all of this out, so i can pull the intake pipe off and check to see if there it more oil pooled there.

I do have a new exhaust parts (widemouth dump and 3 inch front pipe) plus there is a manifold > turbo leak so i may aswell take everything off and replace all gaskets along with the turbo.

Ill post up anything i find

[themadscientist]

If you have one cylinder that's nasty I would disagree. You may have a bad turbo seal. I know I do and mine does the same thing. Something strange is happening on that one cylinder. You need to figure out what that is. A compression tester is likely going to tell you bad things.

[dash]

this smokin didn't start right after u added your "exhaust", by any chance ?

[themadscientist]

[silvios]

I will now get a compression test. I have been talking about it but haven't done it yet.
I have not changed the exhaust yet. I actually ordered a T28 and i am waiting for it.

The car still idles exactly like it does before any smoke. The car is smooth as a hot knife through butter under WOT.
It doesn't hesitate at all. Power delivery is smooth. Would i be able to tell if one cylinder was down on compression alot?

The leak has gotten so bad now it sounds like a hair dryer under full boost. But when it hits full boost, the power is there, it just takes longer to achieve full boost. There is no misfiring either under WOT. The t25 turbo really sounds like it is dying.

It is an odd one...Again what i shall do is pull the intake pipe off and check for pooling oil (as mentioned earlier there was a small pool of oil at the intake of the turbo last time i checked, so i cleaned it all off).

[silvios]

I did a quick compression test last night. I didn't really have help, so i will do another one following correct procedure.

Cyl 1 : 138
Cyl 2 : 140
Cyl 3: 145
Cyl 4 : 122

Cylinder 4 seems lower than the others which is not too good. I did not have a battery charger hooked up nor did i hold the throttle open. I shall now get a professional opinion and also get him to run both Compression and Leak down tests.

As for my turbo - the leak has gotten worse and the turbo induction noise sounds so bad i barely even hit boost anymore cause it sounds like s***.

Great!

[Izento]

With those numbers I don't think it would affect your turbo or having smoke at idle. Those somewhat low compression numbers will affect power, but that's about it.

[boost_boy]

I did a quick compression test last night. I didn't really have help, so i will do another one following correct procedure.

Cyl 1 : 138
Cyl 2 : 140
Cyl 3: 145
Cyl 4 : 122

Cylinder 4 seems lower than the others which is not too good. I did not have a battery charger hooked up nor did i hold the throttle open. I shall now get a professional opinion and also get him to run both Compression and Leak down tests.

As for my turbo - the leak has gotten worse and the turbo induction noise sounds so bad i barely even hit boost anymore cause it sounds like s***.

Great!

If you're not ready to rebuild, at least change the turbo. You can live with those compression #s if blowby isn't that significant.

[silvios]

Ok cool. I have a T28 on the way. I will probably hook up a catch can on the exhaust side pipes (after checking oil buildup in the induction piping).

I will keep this post updated with results after the turbo change.

[float_6969]

If the engine was cold, you didn't have a good power source for the battery (I hook it up to a running car with jump leads), and the throttle plate wasn't open, those numbers don't mean much.

[silvios]

UPDATE:

I got a rebuilt T28 on my CA with all new gaskets and the smoke doesn't seem to appear after long idle anymore, even with Air con on.
Seemed that it was the T25 turbo.

Thank you to all who gave advice!

Thread Closed.