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-   -   Tell me why my car is smoking at start up idle... (https://www.miataturbo.net/diy-turbo-discussion-14/tell-me-why-my-car-smoking-start-up-idle-26735/)

rmcelwee 10-04-2008 12:20 AM

Tell me why my car is smoking at start up idle...
 
If I start up my car and let it idle it will start putting out a ton of smoke. I'm talking serious Spy Hunter smoke screen. It will continue smoking forever (AFAIK) until I start driving it and then the smoke will go away and won't come back (AFAIK). I don't drive it often so I haven't tested it much. Any ideas?

1.6L with a T25/28, IC, and an oil restrictor in the feed line. DIY catch can does not have any oil in it. This problem existed before but went away for a while when I put the restrictor in. The turbo manifold may have a slight leak if that makes any difference. Other than that the car is a rocket...

paul 10-04-2008 12:29 AM

rings or valve seals?

TURNS101 10-04-2008 01:01 AM

Is the turbo draining well enough?

the last 2 times that happened to me my turbos were shot. The seals were smoked.

My car with a new turbo did it the other day 1 time when I started it up. Then it didnt do it again.

I think my drain line isnt straight enough..

So check those 2 things out also..

y8s 10-04-2008 09:20 AM

bad turbo seals can smoke like a bitch at idle. can you plug the oil feed to the turbo at idle (wire the WG open I guess) to verify that it is or is not the turbo seals?

rmcelwee 10-04-2008 09:27 AM


Originally Posted by y8s (Post 315692)
bad turbo seals can smoke like a bitch at idle. can you plug the oil feed to the turbo at idle (wire the WG open I guess) to verify that it is or is not the turbo seals?

The turbo would still spin a bit wouldn't it? I would think that this would ruin the turbo if it wasn't bad already, but what the hell do I know <G>...

I just don't understand why it will smoke for 5 straight minutes (massive amount of smoke) until I step on the gas.

wes65 10-04-2008 11:04 AM


Originally Posted by rmcelwee (Post 315695)
The turbo would still spin a bit wouldn't it? I would think that this would ruin the turbo if it wasn't bad already, but what the hell do I know <G>...

I just don't understand why it will smoke for 5 straight minutes (massive amount of smoke) until I step on the gas.

With the wastegate open, you can probably hold the turbo still. Dont quote me on that though. I feel like i remember people talking about doing that on the first startup on a new turbo. Hold the compressor wheel in place while starting to allow the oil to feed to the dry turbo before it started to spin.

Thucydides 10-04-2008 11:10 AM

Here are a couple of thoughts; ok, more like complete guesses.

At idle, the level of oil in your oil pan is higher because your oil pump is spinning slower. If you slightly overfilled your crankcase perhaps your turbo oil drain us submerged. When your driving, besides more oil being in your cylinder head, the oil in your pan is sloshing around. When the sloshing exposes your turbo drain it can drain more effectively.

So the easy thing to do is check your oil level with your dipstick. If it's over filled perhaps that's your problem. Poor draining + a bad seal = smoke.

The other obvious difference between idle and running is that at idle you have a constant manifold vacuum. While driving the manifold pressure goes up and down. So, if the engine doesn't smoke under load, but smokes under deceleration, perhaps your problem is related to manifold vacuum, though I like the oil drain theory much better.

Braineack 10-04-2008 11:41 AM


Originally Posted by wes65 (Post 315708)
With the wastegate open, you can probably hold the turbo still. Dont quote me on that though.

my turbo wont spin at idle with the wastegate open. and yes you can hold it in place with you finger.

My guess is valve seals. But why don't you get up to 6k or so in 2nd, and let go of the gas and pull a shit ton of vacuum, smoke trails then?

rmcelwee 10-04-2008 11:47 AM


Originally Posted by Braineack (Post 315717)
My guess is valve seals. But why don't you get up to 6k or so in 2nd, and let go of the gas and pull a shit ton of vacuum, smoke trails then?

It takes me about 30 minutes to get my car out of storage but I'll try that the next time I get a chance. Thanks!

y8s 10-04-2008 11:56 AM


Originally Posted by rmcelwee (Post 315720)
It takes me about 30 minutes to get my car out of storage but I'll try that the next time I get a chance. Thanks!

do the turbo oil line test too. it's trivial once the car is warmed up.

btw, it's saturday, go out and get to work! stop playing your 10 xboxes

TURNS101 10-04-2008 01:09 PM

y8s and brain

So you are saying to have the waste gate open so you can hold the turbo in place.

I get that. Even though my waste gate is in the biggest pain in the ass spot in the world.

Anyway, now doing that will prevent oil from going to the turbo correct??

That way you can see if it is the drain or the seals.. In my situation anyway. I dont think I have any other issues..

Am I correct?

Thanks everyone..

Braineack 10-04-2008 01:17 PM

you can hold the wheel in place without the wastegate open. In my case, my wastegod rod popped off the arm...when i was trying to figure out wtf just happen, i pulled the intake tube off to inspect my turbo, at idle it would not spin. gave it some gas and it barely would spin....i got scared, but then i noticed the wastegate was open.


otherwise, while the turbo is spinning at idle, you can press your finger on the lock nut and it will stop easily.

TURNS101 10-04-2008 01:20 PM

Yikes, even with the WG not open you can stop it??
Man, sounds scary stick your finger in there LOL

Was I correct in the turbo not spinning there for no oil going into it to see if its the seals??

y8s 10-04-2008 01:39 PM


Originally Posted by TURNS101 (Post 315746)
Yikes, even with the WG not open you can stop it??
Man, sounds scary stick your finger in there LOL

Was I correct in the turbo not spinning there for no oil going into it to see if its the seals??

green jim apples on the fresh tomorrow????


disconnect / plug oil line
stop turbo from spinning so it doesn't fuck up the bearings
see if there's smoke.

does that answer your question (whatever it was)?

because it sounded like you were asking if JUST stopping the turbo will prevent the oil from entering the turbo. and no, that is not the case.

rmcelwee 10-04-2008 01:50 PM


Originally Posted by y8s (Post 315723)
do the turbo oil line test too. it's trivial once the car is warmed up.

btw, it's saturday, go out and get to work! stop playing your 10 xboxes

Actually I am trying to get Win98 installed on my new computer. Having one heck of a time doing it - I'm on my second day trying right now...

TURNS101 10-04-2008 01:53 PM


Originally Posted by y8s (Post 315751)
green jim apples on the fresh tomorrow????


disconnect / plug oil line
stop turbo from spinning so it doesn't fuck up the bearings
see if there's smoke.

does that answer your question (whatever it was)?

because it sounded like you were asking if JUST stopping the turbo will prevent the oil from entering the turbo. and no, that is not the case.

Thanks for that.
I am not so sure what the green apple thing is about.

I only like apples in pie and/or apple Crisp.. Ahh well now that I am not in NY anymore I miss fresh hot apple cider donuts..

I apologize I am not so up to speed on all of the turbo knowledge.

I did all of the work on my car myself, but I am still learning the ins and outs of the turbo itself.

Now I understand what you meant.

Is it best practice to be holding the turbo before the car is started?

Now if you have the the oil feed disconected and holding the the wheel still and it does not smoke. It is likely the seals..

If it does smoke you need to look elsewhere.

yes no maybe so

y8s 10-04-2008 02:25 PM

if it doesn't smoke with the turbo oil feed disconnected, it's the seals. if it does smoke, it is something else.

TURNS101 10-04-2008 03:02 PM

Cool deal.

Now if I can just find the time between the kid's diaper changes.. LOL

Toddcod 10-09-2008 06:53 PM

Does the car only smoke after it has set a while? If so, sounds like valve seals to me. I wouldn't put my finger anywhere near that turbine. lol


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