UPDATE #2 Re: Misfire on cyl. 2

[Jim Jordan]

Hi Doug,

Yes, there is another source of oil for the #2 cylinder.  The head could
have a hairline crack that only opens when it gets to operating temperature.
When it's cold, the compression checks and leak down are virtually normal.
How do I know?  I had a head installed by a jackleg that had those
characteristics;  cost me tons before it was over.  

What I can't explain is how your engine suddenly started having this
behavior.

Cheers!

Jim Jordan 

>  -----Original Message-----
>  From: Doug Yoder [mailto:yoderw at msoe.edu] 
>  Sent: Tuesday, July 05, 2005 8:25 PM
>  To: Quattro List
>  Subject: UPDATE #2 Re: Misfire on cyl. 2
>  
>  Ok, after some experience driving this weekend, the car 
>  (1991 100, 2.3l NF engine) is still running very poorly.  
>  Significant loss of power (lose ~5mph going up hills on the 
>  freeway, can't accelerate) and fuel economy (~12 MPG!), and 
>  rough running - seems like cylinder #2 isn't firing, 
>  unplugging its spark plug wire doesn't change the idle.
>  
>  After about 300 miles since the new spark plugs were 
>  installed, I pulled
>  #2 to look at it again.  *Significant* oil fouling.
>  Picture here: 
>  http://people.msoe.edu/~yoderw/stuff/oiled_plug_small.jpg
>  (24kB, 640x480 JPG)
>  
>  So I started thinking how oil could be getting into the cylinder. 
>  Piston rings, head gasket, or valve seals.  Rings or head 
>  gasket would show up on the compression test I did last 
>  week, so that leaves valve seals.  Am I missing anything?
>  
>  Another question (somewhat rhetorical, but...) is "why did 
>  this happen all of a sudden when I changed the oil, plugs, 
>  and dist cap/rotor?"  I checked the oil level after seeing 
>  the fouled plug, and it was a quart too high!  Now, I know I 
>  only put in 5 quarts, because I only *had* 5 quarts... and 
>  there's only 5 empties in the garbage.  4.5 quarts came out, 
>  just like normal.  I drained a quart out, and it 
>  looked/smelled normal - no coolant or anything in it.
>  
>  This evening I tried pulling the ECU codes again, and had 
>  better luck than the last time I tried it.  One weird thing, 
>  though, was that once the blink output was activated, the 
>  idle became very rough and the engine died shortly 
>  thereafter.  Found one code: 2223 = altitude sensor. 
>    Anyone ever hear of an altitude sensor going bad?  I'll 
>  check the wiring on it tomorrow.  It seems, however, that 
>  the oil in cyl #2 and the altitude sensor would be 
>  *completely* unrelated problems.
>  
>  Any suggestions?  Thanks in advance,
>  -Doug Yoder
>  
>  --
>  *------------------*--------------------*--------------------
>  ----------*
>  |    Doug Yoder    |   wdy at zordok.net   |    
>  http://www.zordok.net/    |
>  *------------------*--------------------*--------------------
>  ----------*
>  |  Don't tell me the sky's the limit...                      
>            |
>  |                                  ...there's footprints on 
>  the moon.  |
>  *------------------------------------------------------------
>  ----------*
>  
>  

-- 
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.323 / Virus Database: 267.8.9/39 - Release Date: 7/4/2005