Compression test on 6A13TT

[Hotwire]

Question for those in the know:

I'd imagine a compression test on the legnum/galant (6A13) a manifold off job as to test compression you have to remove the spark plugs (duh) BUT my question is then - What about when your cranking it over to get the compression? Wouldn't it be a rather bad idea to crank it over with the inlet manifold off? would nasty things potentially be sucked straight into the engine?

I want to compression test my engine to ensure its worth spending the $$ on new lifters, timing belt change, water pump etc and would get a workshop to do it, but Im curious to know about the method, and what the cost (hours) is likely to be to me.

Cheers
Lee

 

[Guest]

i did a compression and leak down test on mine.

inlet manifold off, basically every you would do to change the plugs.
when you do it though, unplug the 2 plugs on the same bracket that attach to the timing belt side of the plenum, these are for the crank angle sensor, and cam angle sensor, and will stop it pumping fuel in when you crank it.

just make sure there is nothing around the inlet manifold and you'll be right.

 

[bradc]

Or if you are really concerned put a thin layer of cotton (read: tshirt) over the 6 holes.

 

[Guest]

ummmm, no.

cause it will get sucked in.

 

[bradc]

I've done it before with it being held down by a bolt in either corner and didn't have problems, but yeah I probably should have said that!

 

[Guest]

So what comp did u guys get across the cylinders and show your milage.
Mine was 4 cylinders at 12psi I think 1 at 10.5 and 1 at 11 and a bit. 85kms on the clock.

 

[Kitty's VR4]

WTF...... 10.5psi to 12psi, I hope you mean bars and not psi, otherwise I think you need a new elastic band

 

[Guest]

what kat said... sounds like you had 10.5 - 12 bar, which is 152 - 174 psi

i had 180 - 182 psi across all 6 cylinders, 105,000km

anything up to 10% variance is fine (so yours is all good)

 

[Guest]

Sorry must have been in bars. My wife already hits the fan that I talk car shop all day long so if I start to get even more clued up and say the right thing then she''ll divorce me so I will stick to making the odd mistake and talking less.
By the way what is the comp for a brand new engine vr4.

 

[gorgath]

Thread mine!!!

Does anyone know what is the standard compression pressure on every banks?

 

[Guest]

Thread mine!!!

Does anyone know what is the standard compression pressure on every banks?

142psi

 

[naughtika]

just a stupid question.. what if the compression i'm getting is higher?! I know its higher doesn't always mean its good..

 

[bradc]

What is the actual figure?

 

[wesleyong]

Hey guys,

The rear middle cylinder of mine is 110psi!!!

Is this a serious problem?? :-O

 

[bradc]

That is a bit on the low side, what are the other cylinders?

 

[wesleyong]

I don't have the figures with me here at work, but the other 5 were mainly around the 180 mark. The lowest being 170 and the highest 190.

 

[bradc]

That does sound a bit worrying to me.

 

[wesleyong]

So what does this mean? Do I need to act immediately on this? Or will this indicate a short lifespan...?!?!

 

[bradc]

You probably don't need to act immediately. Do a few searches on google for low compression. It could be something like a weak valve spring or bad piston rings.

http://www.google.co.nz/search?hl=e...in+one+cylinder&meta=&aq=2&oq=low+compression+

 

[whats_doing]

Holy old thread revival batman.

Did a compression test on my car last night. It was still warm to the touch and was a dry test only.

Rear bank:
All 180psi on the dot.

Front bank:
155psi, 150psi, 160psi.

Is this going to be an issue at all. The pressures are similar on the same bank but differ by 14% from one bank to the other.