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I may be joining the trashed motor club....

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Old Jul 8, 2007 | 01:46 PM
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Default I may be joining the trashed motor club....

well the car is smoking..... quite a bit as of last night...

first things started as a little smoke on startup, that went away after 30 seconds or so.....

now it seems to just smoke any time I'm on the throttle..... hoping it's the turbo, but I pulled a plug and there was oil on the threads....

need to run a compression check today at some point, but it's *** hot out....

worst part is I have an autocross school tomorrow, and the miata is fucked up, looks like I'll be driving the 240 instead unless I solve the smoke problem today somehow.

oil level is fine, as is coolant level, and both look clean. The turbo's spoolup seems like it has gotten a bit slower lately (not that it was fast in the first place) it has a bit of up and down shaftplay, but no side to side or forward and back play in it.....

I'll also check the PCV valve, but then again it was fine a month ago or so....

any ideas? the smoke doesn't have a distinct smell of fuel, coolant or oil.... it's dark colored, and there is an oilyish residue (that's always been there) inside the tailpipe) Also, we put a test pipe on the car yesterday if you think that I might just be burning **** out of the exhaust......
Old Jul 8, 2007 | 03:07 PM
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do a compression check if it comes out ok then your motor is most likely good. still turbo rebuild is abit of a chore alot less work than a motor build
Old Jul 8, 2007 | 03:15 PM
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meh, I'd just change turbo's..... one of the reasons I think it may be a turbo issue is that I've been running a fleabay T3/T4 for a little over a year now.... it was bound to go at some time
Old Jul 8, 2007 | 03:33 PM
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You'd know if it was coolant. If it's dark at all it's probably oil or fuel. possibly oil is getting past the seals.
Old Jul 8, 2007 | 11:05 PM
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if it's turbo it would only smoke during vacuum... like sitting at stoplights or light cruise. that's when it'll suck oil through the seals and smoke like a bitch.

smoke under power and black oily soot is probably sadly rings. maybe valve seals depending on the compression test results.

Here's my guesses:
compression low dry, compression high wet: rings
compression low wet and dry: valve seats and possibly seals.
compression fine: valve seals
smoke like a SOB at idle: turbo seals
Old Jul 9, 2007 | 03:43 AM
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i dunno dude mine didn't smoke till the turbo went out.
Old Jul 9, 2007 | 11:25 PM
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yeah it smokes bad at idle, and just off idle at a stop. If I stall the car and re-start it, it smokes badly (only stall because the clutch is junk)

started it up today in hopes of a miracle before my level 2 autocross school, and the smoke is light in color, and increases with throttle input at a stop, but I didn't really throttle it up much because it was cold.

ended up using the 240 fopr the school today instead.....
Old Jul 10, 2007 | 09:26 AM
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I'd do a quick compression check at this point...

in the least pull the spark plugs and check for oil on the electrodes.
Old Jul 10, 2007 | 10:26 AM
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if it was JUST at idle, i'd say seals. but since it's idle and on the gas, i think you're fooked.
Old Jul 10, 2007 | 05:18 PM
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so i run a compression check (car is a 2000)

results are as follows.... from front of engine to back

Dry:
165
150
150
180

Wet:
180
160
170
190

The plugs had oil on the treads and were rather dark in color..... I assume piston rings at this point. Might have a leakdown done to confirm.....

Opinions????
Old Jul 10, 2007 | 06:06 PM
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you pulled all the plugs and floored it and cranked til it peaked and stopped rising right?

cuz that looks like rings and or valves and you name it.
Old Jul 10, 2007 | 06:59 PM
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well I pulled the plugs one at a time... but otherwise yes, cranked till the pressure peaked and stopped rising....
Old Jul 10, 2007 | 07:27 PM
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oh.... I didn't floor the gas.... big deal or no?
Old Jul 10, 2007 | 07:39 PM
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big deal, you have to do it wot
Old Jul 10, 2007 | 07:47 PM
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you're suposed to have all the plugs pulled when you do a test arn't you? Would you like for me to take a look at it, or if you need help with anything let me know, i live in MD and i'm free all week till sunday, i work in towson. but live in Odenton (arundel mills)
Old Jul 10, 2007 | 08:00 PM
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oh great, so much fun, have to do it again......

I'll let ya know if I need any help with it, unfortunately I have to work 7am-7pm the rest of the week
Old Jul 10, 2007 | 08:27 PM
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new results, with throttle wide open, and all plugs pulled....

210
185
185
210

also, a funny noise from the head as I was revving the car up a bit to look at the smoke and warm it up for the test.... kinda like a quick rattle around 4k on both the up and downswing of revs....
Old Jul 10, 2007 | 10:36 PM
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According to the service manual; 209-psi is "standard", 146-psi is minimum, and max difference between cylinders is 28-psi.
Old Jul 11, 2007 | 12:56 AM
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could still be the valve seals... dont think that shows up on compression tests. good to know it's not the rings though.
Old Jul 11, 2007 | 09:37 AM
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I vote "mildly blown" head gasket - oil from return galley



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