Does flooding have an effect on compression readings?
Thread Starter
Joined: Feb 2001
Posts: 5,015
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From: San Diego, CA
Does flooding have an effect on compression readings?
I took readings on my engine which might be flooded and I got very low readings...4.2 in the front and 1.2 in the rear...does flooding cause this? I moved the car from the driveway to the street and shut it off right away. It was running fine before this happened so I might have to use the atf trick or push start it to get it to start right?
6502
Joined: Sep 2002
Posts: 151
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From: Houston
I did the same 3 weeks ago. Could not start it the next day. I left it for a week and used ATF. I used a syringe and put one squirt in each rotor. Started right away. Here are some instructions to fix it.
http://2ndgenrx7.freeservers.com/rp_unflood.html
http://2ndgenrx7.freeservers.com/rp_unflood.html
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Joined: Feb 2001
Posts: 26,664
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From: n
YES!
Dirty trick for used engine sales creeps is to pour ultra thick oil into the engine and then take a compression check.
It also helps if it's really cold!
Gas washes this oil away.
You make the connection.
-Ted
Dirty trick for used engine sales creeps is to pour ultra thick oil into the engine and then take a compression check.
It also helps if it's really cold!
Gas washes this oil away.
You make the connection.
-Ted
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I'm a boost creep...
Joined: Jan 2002
Posts: 15,608
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From: Auckland, New Zealand
The oil on the chamber walls seals the compression in. Excess fuel washes away the oil, so the chambers are no longer sealed and can't build enough compression to start the engine.
4.2bar and 1.2bar would be 61psi and 17psi respectively, which sounds like a cracked apex seal on top of being flooded...
4.2bar and 1.2bar would be 61psi and 17psi respectively, which sounds like a cracked apex seal on top of being flooded...
Thread Starter
Joined: Feb 2001
Posts: 5,015
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From: San Diego, CA
ugh..cracked apex seal just from moving my car from the driveway to the street? is this possible? those readings were from a mazda rotary engine compression tester by the way.
Joined: Oct 2003
Posts: 11,576
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From: Morristown, TN (east of Knoxville)
You can flood a car to show no compression. Dump some oil or atf into the chambers and start it up. Expect smoke, hold the rpm's up a bit until it clears out. I bet it isn't blown or anything.
dude, come on. 17psi? that is one ****** vicious flooding...
just unflood that bitch. drag it around a parking lot with all 4 spark plugs out and egi fuse out.
just unflood that bitch. drag it around a parking lot with all 4 spark plugs out and egi fuse out.
Last edited by jacobcartmill; Jan 14, 2005 at 02:41 AM.
Senior Member
Joined: Sep 2003
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From: Berthier, Quebec
Originally Posted by RX7 RAGE
those readings were from a mazda rotary engine compression tester by the way.
dunno if it's the same in the US, but in canada that's the way it's calculated
Joined: Oct 2003
Posts: 11,576
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From: Morristown, TN (east of Knoxville)
bar and kg/cm^2 is damn near the same thing...one is 14.7, one is 14.2 or so IIRC. using either one to calculate by, you won't be more than 5psi off on the other.
