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-   -   Compression Test Results...? (https://www.miataturbo.net/engine-performance-56/compression-test-results-42000/)

MGrissom Dec 12, 2009 02:15 PM
Compression Test Results...?
 
Sooo fouled my plugs.. cars still running rich..

Decided to check compression while i had the plugs out.

Results were from front of car to back:

190
175
150
150


Look ok?


-Michael

magnamx-5 Dec 12, 2009 02:43 PM
the 150s look kinda low Was the car warm? try a dab of oil in the lower compression cylinders.

MGrissom Dec 12, 2009 02:48 PM
Originally Posted by magnamx-5 (Post 494700)
the 150s look kinda low Was the car warm? try a dab of oil in the lower compression cylinders.

was not warm.

hustler Dec 12, 2009 05:03 PM
Originally Posted by MGrissom (Post 494703)
was not warm.
Steven Hawking in the house!

Braineack Dec 12, 2009 05:50 PM
do it fully warm, and do a wet test as well

y8s Dec 13, 2009 10:15 AM
in case the above weren't clear...

warm up the car

do a DRY compression test first.
then add the drop to teaspoon of oil to the spark plug holes and re run the test.

from the factory service manual:

COMPRESSION INSPECTION

Warning
• Hot engines and engine oil can cause severe burns. Be careful not to burn yourself during removal/installation of each component.
1. Verify that the battery is fully charged.
2. Charge it again if necessary. (See 01–17–2 BATTERY INSPECTION.)
3. Warm up the engine to the normal operating temperature.
4. Stop the engine and allow it to cool off for about 10 min.
5. Perform “Fuel Line Safety Procedure”. (See 01–14–3 BEFORE REPAIR PROCEDURE.)
6. Leave the fuel pump relay removed.
7. Remove the spark plugs. (See 01–18–3 SPARK PLUG REMOVAL/INSTALLATION.)
8. Disconnect the ignition coil connector.
9. Connect a compression gauge into the No.1 spark plug hole.
10. Fully depress the accelerator pedal and crank the engine.
11. Record the maximum gauge reading.
12. Inspect each cylinder as above.
• If the compression in one or more cylinders is low or the compression difference between cylinders exceeds the maximum, pour a small amount of clean engine oil into the cylinder and inspect the compression again.
— If the compression increases, the piston, the piston rings, or cylinder wall may be worn and overhaul is required.
— If the compression stays low, a valve may be stuck or improperly seated and overhaul is required.
— If the compression in adjacent cylinders stays low, the cylinder head gasket may be damaged or the cylinder head is distorted and overhaul is required.

miata2fast Dec 13, 2009 12:41 PM
/\ That is a good post.

curly Dec 13, 2009 01:42 PM
Originally Posted by y8s (Post 494919)
...and overhaul is required
...and overhaul is required
...and overhaul is required
Owned.

y8s Dec 13, 2009 04:50 PM
Originally Posted by curly (Post 494966)
Owned.
they know how to make a trap feel like a choice.


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