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

Water in oil. compression still ok

Thread Tools
 
Search this Thread
 
Old Jul 4, 2011 | 06:52 PM
  #1  
muoto's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2008
Posts: 414
Total Cats: 69
From: Finland
Default Water in oil. compression still ok

Last Saturday when I was driving on track my car start to hesitate. I wasn’t overheating (water was 220F and oil 230F). When I open the hood I notice that my catch can was overflowing with oil.
  • I check the compression. 173-170-169-175. Stock 8.8:1 pistons 100K miles driven. I got same compression result year ago.
  • Oil-stick is full of milky cream
  • Top of the catch can is full of (condensed?) water
  • I fill up my radiator 500miles ago and look like there's about half a gallon shortage now
  • I’m using 250cc/min water-injection but sounds odd if that water got past the rings

Sounds like head gasket has gone bad. But why my compression results looks the same as when i didn’t have these problems?
Old Jul 5, 2011 | 08:18 AM
  #2  
muoto's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2008
Posts: 414
Total Cats: 69
From: Finland
Default

If oil is blowing out it has to be high pressure in cylinder head right? Compression seems to be ok. And only 5-10psi higher with drop of oil so I assume that rings are ok.

So that leaves the head gasket or loose cylinder head bolts. Guess I can re-torque those bolts or maybe better, change ARP bolts there.
Old Jul 5, 2011 | 01:50 PM
  #3  
hf-mx5t's Avatar
Junior Member
 
Joined: Jun 2005
Posts: 286
Total Cats: 235
Default

check your cylinders for cracks mine had good compression, and oil/water mix
Old Jul 5, 2011 | 03:55 PM
  #4  
kaboshe's Avatar
Junior Member
iTrader: (15)
 
Joined: Apr 2010
Posts: 403
Total Cats: 1
From: quebec,canada
Default

Originally Posted by hf-mx5t
check your cylinders for cracks mine had good compression, and oil/water mix
mine HAD good compression, and coolant in my oil.
also founded that ''water/coolant'' in my catch can.
cracked cylinder head for me
Old Jul 6, 2011 | 10:37 AM
  #5  
muoto's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2008
Posts: 414
Total Cats: 69
From: Finland
Default

Well let’s hope that isn’t the case. I just bought that head and had that checked for valve leaks.

I did compression test again with drop of oil. Wet results were about 8-12PSI higher so it is probably the head gasket. Why can’t my car run even a month without problems
Old Jul 6, 2011 | 05:13 PM
  #6  
kaboshe's Avatar
Junior Member
iTrader: (15)
 
Joined: Apr 2010
Posts: 403
Total Cats: 1
From: quebec,canada
Default

dont be that disapointed, changing it takes about 3-4h

i installed a 150$ cometic head gasket with 100$ worth of bolts after going to make sure my head was straight. it sure was straight....and cracked.
Old Jul 7, 2011 | 04:57 PM
  #7  
muoto's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2008
Posts: 414
Total Cats: 69
From: Finland
Default

Cylinder head is off and I didn't found cracks or anything unusual. Guess if I want to be sure I have to get that leak-tested again. But I’m almost sure that cause of all this is my old head bolts which I been re-using over 6 times by now

Here’s a picture of water injected head: http://www.miata.fi/kuvat/head070711.jpg
Exhaust valves is covert with that “hard white stuff”
Old Jul 10, 2011 | 05:42 PM
  #8  
muoto's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2008
Posts: 414
Total Cats: 69
From: Finland
Default

Originally Posted by kaboshe
mine HAD good compression, and coolant in my oil.
also founded that ''water/coolant'' in my catch can.
cracked cylinder head for me
Did you found that crack looking it? Or can those cracks be so small that eye can’t see it
Old Jul 10, 2011 | 07:22 PM
  #9  
kaboshe's Avatar
Junior Member
iTrader: (15)
 
Joined: Apr 2010
Posts: 403
Total Cats: 1
From: quebec,canada
Default

could not find anything just by looking at it, i did not extended my search too long since b6 are so cheap i ordered another one for next-to-nothing.


I went to a shop that did a leak down test, told me i had a cracked head, and i drove home just like if i stole it.i'm curently getting the engine out
Old Jul 19, 2011 | 02:12 AM
  #10  
muoto's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2008
Posts: 414
Total Cats: 69
From: Finland
Default

A little update: I change the HG and replace those old bolts with ARP stuff. Start the car. Had it run 15min. Tested compression again and it changed from 173-170-169-175 to 195-190-185-175 PSI
Old Jul 23, 2011 | 09:21 AM
  #11  
kaboshe's Avatar
Junior Member
iTrader: (15)
 
Joined: Apr 2010
Posts: 403
Total Cats: 1
From: quebec,canada
Default

while installing the new engine i founded the ***** who was ******* everything up
Attached Thumbnails Water in oil. compression still ok-dsc00606.jpg  
Old Jul 25, 2011 | 06:47 AM
  #12  
muoto's Avatar
Thread Starter
Junior Member
 
Joined: Jun 2008
Posts: 414
Total Cats: 69
From: Finland
Default

It’s probably safe to say that this problem is now gone. It was bad head gasket or the head bolts..or both.
Coolant level has stayed the same and same goes with oil And car pulls hard
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
Apr 12, 2021 04:21 PM
Quinn
Cars for sale/trade
6
Oct 23, 2016 07:58 AM
shooterschmidty
Engine Performance
8
Sep 30, 2015 10:28 PM
zephyrusaurai
Meet and Greet
2
Sep 28, 2015 10:59 PM




All times are GMT -4. The time now is 10:58 PM.