trrbo_tc

Does anyone here know where i can find a basic guide to doing a compression test on my 2007 tc ?

i found many compression test guides but most are for other cars,

specifically for the tc what i need to know is what to disconnect to prevent fuel from spraying into the chamber when i crank the motor for the actual test itself.

a fuse maybe ?

i hear and read about everyone doing compression tests on there tc's but no one posts how it should be done "properly"

maybe im missing something, can you guys point me in the right direction please ?

thanks !

yamaha16bw

I havent done a compression test before but I'd think you'd just unclip the injector harness.

Schuller

Pull out the all the coils and plugs. Pick a cylinder and screw the tester into the plug hole You test one cylinder at a time. Now turn over the engine like your starting the car while holding the gas pedal down all the way for 3 seconds. Now check the reading. You should get about 180 psi. It should be even in all the cylinders. If one cylinder is low test it again. If your getting any low readings you should take it in for a leak down test.


Why do you think you need a compression test?

rhythmnsmoke

Even if the lowest reading cylinder is 75% of the highest reading cylinder, you are good. You will not read the same PSI across all 4 cylinders.

trrbo_tc

ok guys .. thanks .. ill try that ..

trrbo_tc

COMPRESSION TEST READINGS / RESULTS !

alright here are my readings from my compression test.

i did 2 tests.

the first test i cranked the motor about 8 - 10 times

the second test i cranked the motor about 4-5 times


Here are the First Test Readings

From Left to Right as you face the engine compartment -

Cyl1 : 200

Cyl2 : 197

Cyl3 : 210

Cyl4 : 200

that was test 1 where i cranked the motor about 8 - 10 times
---------------------------

now for test 2

---------------------------

Test 2 Results / Readings :

From Left To Right as You Face The Engine Compartment

Cyl1 : 190

Cyl2 : 185

Cyl3 : 184

Cyl4 : 182


iv'e been running a f*cked up turbo install for about 3 months now, i'd say compression is pretty good. i just cant get anyone to tune my bastard car properly.

anyways.. those are my readings

Mr_Meaty

Hey...could you do a step by step on how to do a compression test along with what I need to buy from the store?

I may be showing my ignorance here, but where are the coils?

TCpete

coils phil are the black caps above our motor that connect to the spark plugs and provide spark to the spark plugs... their new modern name for the spark plug wires is called coil packs....

and yes a DIY with pics or video would be good!!!!

Mr_Meaty

Thanks pete So you would HAVE to remove the coil packs to get the spark plugs out anyway, right?

So what do you disconnect to prevent fuel from spraying when you crank the motor?

kikcaffine

^ Pull the EFI fuse out.

TCpete

yea u need to take out the coil pack to get to the fuse..

rhythmnsmoke

Your Compression is good. So, no problems there.

rhythmnsmoke

Now that I'm not sick anymore, I was planning on doing a DIY (video style) on how to do a compression test.


Side Note: You only need to remove the coil packs (Plug wires), and spark plugs from the motor to do your compression test.

TCpete

travis DO ET!

Danger_Darren

Dont forget to disconect the ignition. and you dont need to remove any fuses.

satoman44

i just removed the efi fuse. btw, your comp test numbers look good. according to the repair manual for 05-06, compression should be no less than 165, with a difference of no less than 15 psi.

Schuller

Do no more and no less than what I stated in the my post. Don't fall prey to misinformation guys. The coils are those thingys that plug down onto you plugs.

Now go to the track and put down some 13.....

satoman44

can i ask you why you held down the gas pedal?

Schuller

Should open throttle body for air. Its standard procedure really and I have not heard it does not apply to a Scion.

Mr_Meaty

So, by "Pulling the coils" you mean completely removing them from teh car? Or just disconnecting them from teh spark plugs?
And there is nothing else you need to disconnect to prevent fuel from spraying everywhere?