White smoke from tailpipe (worse when hot) - opinions? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members

Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

LinkBack Thread Tools Search this Thread
Old 03-23-2015, 11:22 PM   #1
Thread Starter
Join Date: Dec 2012
Posts: 8
Total Cats: 0
Default White smoke from tailpipe (worse when hot) - opinions?

99 NB, 75K mi on stock engine, 5K on DIY t3 ebay turbo @ 8-10psi. Reverant MS2. The car runs and drives alright (for a beginner's tune, startup kinda sucks), has plenty of power and spools great. I called Savington this morning and he said my compression #'s were bad, but I need to perform due diligence before I eat ramen for 2 months during a rebuild.

How did this begin? Every couple of weeks i'd be stupid enough to get stuck in San Francisco traffic and after idling/barely moving for 15 minutes the smoke would start to pour out. Then driving off, it seemed to go away. I couldn't even reproduce the smoking by leaving my car idling in the driveway for half an hour then driving it up and down the block trying to simulate traffic and decel in gear trying to pull oil through vacuum (thought it was PCV or valve seals). Then a couple of days ago in traffic, it happened again and is now much worse:

Cold engine - no sadness

Cool engine w/ revs - some sadness

Warm engine revs - so much sadness that the camera falls over

Sometime between "occassional problem" and "undrivable" I did change the oil from castrol 5w40 synthetic to Rotella T6 5w40

I've replaced the PCV valve with the 323GTX unit and tried stock routing (vc to intake manifold and open drivers side port) and 'unhooked' (plugged intake manifold and both valve cover ports open.

I pulled the turbo compressor inlet and outlet and they were both dry, medium shaft play but no more than when the unit was new

Spark plugs all look dry

No fluids are low but it's smoking bad enough that I can't drive around for 1,000 miles to find out. Oil is at the correct level but I may pull out .5 quart to make sure of no turbo oil drain hose blockage.

Compression test today but no leakdown yet
Dry & Wet
#1 - 165 190
#2 - 162 180
#3 - 162 188
#4 - 180 188

The smoke is white but it doesn't smell sweet and headgasket-coolant problems I've seen in the past smoked more. And why would it go away after idle smoke for weeks, even when I boosted the **** out of it? Any opinions on whether valve stem seals could smoke as bad as the videos? There is no puff upon startup after sitting. Pull the head? Pull the motor?

Last edited by JoeWagon; 03-23-2015 at 11:33 PM.
JoeWagon is offline   Reply With Quote
Old 03-24-2015, 05:52 PM   #2
Supporting Vendor
iTrader: (31)
Savington's Avatar
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,367
Total Cats: 1,331

Pretty sure I talked to you on the phone yesterday. After our call, I recalled a customer with a locost who had a similar problem - random oil smoke from the exhaust after periods of idle. He tore his motor down and found major scoring in one of the bores. The wet test results you got are sort of what I expected you to see.

Time to pull the shortblock. It's done.
Savington is offline   Reply With Quote
Old 03-24-2015, 11:12 PM   #3
Join Date: Mar 2015
Posts: 2
Total Cats: 0

Mine had a similar smoke. Turned out to be brake fluid from a leaking master cylinder being sucked passed the booster into the intake. Mine did smoke constantly though. You would be holding brake pressure in that stop/go slow traffic.
Take off the booster line and plug it going to the manifold to prevent vacuum leak. See if the smoke goes away after a few minutes. It took mine about 10 minutes to burn clean.
It may be worth checking before you pull the engine because its easy.
nineteenhundred is offline   Reply With Quote
Old 03-25-2015, 09:55 AM   #4
Elite Member
iTrader: (5)
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19

With those compression numbers I wouldn't blame the brake booster
Stealth97 is offline   Reply With Quote
Old 03-25-2015, 10:02 AM   #5
Boost Czar
iTrader: (61)
Braineack's Avatar
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792

you need new ringlands.
Braineack is offline   Reply With Quote
Old 03-25-2015, 01:26 PM   #6
Elite Member
iTrader: (5)
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19

Time for the mad scientist to rip apart the block and replace the PISTON RINGS you fried
Stealth97 is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Raleigh: Fiberglass headlight scope, 1.6L ECU, AFM, Hardtop latches, more bigmackloud Miata parts for sale/trade 13 09-22-2017 01:34 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Mystery Engine Trouble. Halp, mt.net! vehicular General Miata Chat 12 09-14-2015 04:17 PM
New here, saying hi, here's what I'm workin with. SuperSneakySecretSquirrel Meet and Greet 5 09-06-2015 09:30 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 01:49 AM.