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-   -   Quick compression question??? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/quick-compression-question-561942/)

RevUp13b Jul 23, 2006 10:18 PM
Quick compression question???
 
Compression tested out to be around 70ish with the engine cold on both rotor.
Does this need a rebuild??

pinkrx7 Jul 23, 2006 10:21 PM
110 good
90 getting bad
80 bad
you probably need a rebuild soon if not now

RevUp13b Jul 23, 2006 10:30 PM
if i warm up the engine and do another test, will it read fairly higher? or not neccesarily?

GoodfellaFD3S Jul 23, 2006 11:08 PM
Originally Posted by RevUp13b
if i warm up the engine and do another test, will it read fairly higher? or not neccesarily?
a warm engine will yield lower (worse) results. Your motor has very low compression.

Unholy FD3S Jul 23, 2006 11:12 PM
if a motor is around 90 to 100. anyone know how long it will last.

saying you drive it carefully.

Monsterbox Jul 23, 2006 11:43 PM
whats good in terms of 8.0, 9.0 etc?

RX7 RAGE Jul 24, 2006 12:28 AM
Mine was tested at 90 psi on both front and rear housings 20k miles ago but it still runs and starts up with no probs at all. :) Vacuum is a bit low at 12-13 but I'm not worried.

RevUp13b Jul 24, 2006 12:28 AM
hhhmm... so how long will it last with those kind of readings?

RevUp13b Jul 24, 2006 12:38 AM
Also, the compression check method was done with a normal compression gauge and sumwhat modified and itll blow off preassure each time, so not sure how accurate can it be... it can only be higher if it is off right? or no?

Mr rx-7 tt Jul 24, 2006 01:09 AM
Originally Posted by RevUp13b
Also, the compression check method was done with a normal compression gauge and sumwhat modified and itll blow off preassure each time, so not sure how accurate can it be... it can only be higher if it is off right? or no?
If the engine starts fine when warmed up and idles fine then your engine is fine don't worry about it.

RevUp13b Jul 24, 2006 01:24 AM
readings after warm up were around 80ish and slightly lower....will it at least last me 20k?

How much would u pay for this car?

BTW: all this info is given by the seller of the car im looking into

RevUp13b Jul 24, 2006 06:01 AM
Originally Posted by Mr rx-7 tt
If the engine starts fine when warmed up and idles fine then your engine is fine don't worry about it.
The owner did say the engine starts fine, idles fine, no hesitation, boost is fine (but at rare times it feels like the 2nd turbo doesnt kick in), never gave him any problems, never died on him, always starts.

GoodfellaFD3S Jul 24, 2006 10:04 AM
Originally Posted by RevUp13b
The owner did say the engine starts fine, idles fine, no hesitation, boost is fine (but at rare times it feels like the 2nd turbo doesnt kick in), never gave him any problems, never died on him, always starts.
Get the engine properly compression tested at a mazda dealership with a rotary compression tester. You're crazy if you buy the car without having done that. both 70 and 80 psi mean 'needs a rebuild.' anything under 6 bar (about 90 psi) is an old, tired motor.

tekno62 Jul 24, 2006 06:01 PM
If you in the SF bay area take it to RE and have Chuck to test it for you.. he has a rotory compression tester.

patriick Jul 26, 2006 12:44 AM
Did you hold the throttle wide-open while cranking? Leaving it closed will give false low numbers.

RevUp13b Jul 26, 2006 01:22 AM
not sure, the owner said he stepped on it, not sure about wide open though


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