Evo How Tos / Installations Post or link to your detailed how to / installation articles in here. If you have any questions regarding the how tos, feel free to post them in the Request sub-forum.

Compression Test How-To

Old Aug 3, 2005, 11:57 PM
Evolving Member
Thread Starter
iTrader: (3)
Ninj0x's Avatar
Join Date: May 2004
Location: California
Posts: 392
Likes: 0
Received 0 Likes on 0 Posts
Compression Test How-To

Compression Tester (can get from Autozone ect.)
Socket Wrench
Socket Extender
10mm socket (for spark plug cover)
13/16 Spark Plug Socket
Torque Wrench

From the shop manual:


1. Before inspection, check that the engine oil, starter and
battery are normal. Also, set the vehicle to the following

• Engine coolant temperature: 80 − 95C (176 − 203F)
• Lights, and all accessories: OFF
• Transaxle: Neutral

2. Disconnect the spark plug cables.

3. Remove all of the spark plugs.

4. Disconnect the crankshaft position sensor connector (located next to oil cap, a triangular connector).
NOTE: Doing this will prevent the engine control module
from carrying out ignition and fuel injection.

Keep your distance from the spark plug hole when
cranking. Oil, fuel, etc., may spray out from the spark
plug hole and may cause serious injury.

5. Cover the spark plug holes with a shop towel etc. Crank the
engine for a few seconds to clear debris from a round the
spark plug holes. After the engine has been cranked, check
for foreign material adhering to the shop towel.

6. Install the compression gauge to one of the spark plug

7. Crank the engine with the throttle valve fully open and
measure the compression pressure.
Standard value (at engine speed of 250 r/min): 1,128
kPa (163 psi)
Minimum limit (at engine speed of 250 r/min): 951 kPa
(138 psi)

8. Measure the compression pressure for all the cylinders, and
check that the pressure differences of the cylinders are
below the limit.
Limit: 98 kPa (14 psi)

9. If there is a cylinder with compression or a compression
difference that is outside the limit, pour a small amount of
engine oil through the spark plug hole, and repeat the
operations in steps 6 to 8.

(1) If the compression increases after oil is added, the cause
of the malfunction is a worn or damaged piston ring
and/or cylinder inner surface.

(2) If the compression does not rise after oil is added, the
cause is a burnt or defective valve seat, or pressure is
leaking from the gasket.

10.Connect the crankshaft position sensor connector.

11.Install the spark plugs (Torque: 18 ft/lb) and spark plug cables.

12.Use the scan tool (or disconnect battery for 1 min) to erase the diagnostic trouble codes.

NOTE: This will erase the diagnostic trouble code resulting
from the crankshaft position sensor connector being discon-

I got 175 on all cylinders, which is high (good). Good luck.
Attached Thumbnails Compression Test How-To-compression.jpg  

Last edited by Ninj0x; Aug 4, 2005 at 04:21 PM.
Ninj0x is offline  
Old Aug 17, 2005, 08:38 PM
Evolved Member
LancerEvoMR's Avatar
Join Date: Aug 2002
Location: New Jersey, USA
Posts: 2,088
Likes: 0
Received 0 Likes on 0 Posts
Discuss this thread Here!
LancerEvoMR is offline  
Related Topics
Thread Starter
Last Post
Evo How To Requests / Questions / Tips
May 24, 2018 07:40 PM
Evo How To Requests / Questions / Tips
May 10, 2018 04:56 PM
Evo General
Mar 1, 2017 10:08 AM
Evo General
Aug 12, 2016 04:16 AM
Lancer Engine Tech
Nov 7, 2005 12:49 PM

Thread Tools
Search this Thread
Quick Reply: Compression Test How-To

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.