Sorry guys I didn't feel like searching to much... I have ran a few events in my Z and was wanting to do a compression test on all of my cylinders, the engine is a vq35de from a 03 Z, does anyone know what each cylinder should be registering?

 

That's OK. I don't feel like looking it up to much.

 

with all your posts, id say you wouldnt mind at all... Im assuming those are mostly helping others with questions instead of smart *** replies...

 

Skip the compression test and go directly to a leakdown test. A compression check really doesn't tell you anything and can give satisfactory test results when the motor would fail a leakdown.

 

I have never done a leakdown test before, how would I do that?

 

he probably got picked on alot growing up..trying to make up for it on the internet..

 

Yeah, he is an older guy. He's probably pissed off cause he has alzheimers disease & can't remember if he likes little girls or little boys....

 

It is a shame you lazy *** **** cant search though.

 

1. you need the have engine at operating temp
2. remove spark plugs
3. make sure the piston ur testig is at TDC at the compression stroke (so both intake and exhaust valve is closed)
4. install a tester into the spark plug hole
5. air from an air compressor will go through the leakage tester too see if you have any leaks.
-if you don't have one just hook up an air compresser, and put some air in it. (not to much); listen for any hissing coming from ur tailpipe, oil fill hole, and air intake. If you hear any hissing then u have a leak..

If you got more questions on what tool or how to do it read this http://www.aa1car.com/library/leakdown.htm

 

lol... be nice to davidv...

 

Actually a good topic and a couple good posts in here – I hope it goes more towards the beneficial and away from the silly.

So leak down is more critical than compression test, got it… but back to the OP – can someone give a little info regarding compression test…

 

i would like to know to.. subscribing

 

I'm not sure what the compression should be,but when you do a compression test the compression for all the cylinders should be relatively the same. For example if you do the dry compression test, and all the cylinders are around the number that it's suppose to be then your fine. If one is lower you wanna do a wet compression test by putting a little oil in the cylinder, so that it helps seal the piston rings. If the compression goes up then you probably a have bad piston ring. If the compression stays the same (meaning it's still low), you have some other problem (bad valves, bad cylinder bore, or the ring can be very bad and the oil couldn't seal it).

 

oh i found the compression specs. the compression standard is 185psi. the minimum that psi that the compression can be is 142psi, and the differential limit b/w the cylinders is 14psi. So to recap my above post :

● If compression pressure is below minimum value, check valve clearances and parts associated with combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head
gasket). After the checking, measure compression pressure again.
● If some cylinders have low compression pressure, pour small amount of engine oil into the spark plug hole of the cylinder to re-check it for compression.
– If the added engine oil improves the compression, piston rings may be worn out or damaged. Check the piston rings and replace if necessary.
– If the compression pressure remains at low level despite the addition of engine oil, valves may be mal- functioning. Check valves for damage. Replace valve or valve seat accordingly.
● If two adjacent cylinders have respectively low compression pressure and their compression remains low even after the addition of engine oil, cylinder head gaskets are leaking. In such a case, replace cylinder head gaskets.

I hope this helps some of you guys out.

 

Cool thanks for all the info guys, I have been real busy with work lately and the car has just been sitting. I will be doing the test this weekend and I will also be posting pictures for a DIY! Results will also be posted thanks!!!

 

Ngynnhu – thanks for the recent 2 posts!

Now I need to determine how detailed Cipher actually gets with “cylinder power testing”?... Gotta rid the glitch first, I cant get it to load