Compression Test issues

[sp00k]

Right after my previous thread and the advice given i got myself a compression tester due to overheating under load and slight loss of water but sniff test didnt show a sign of a leak.The readings i got are

Cylinder 1-480 psi
Cylinder 2-440 psi
Cylinder 3-440 psi
Cylinder 4-420 psi

All of this was done when the engine was warm with a fully charged battery.According to the manual though its ment to me max 427 psi and min 356 with the max different between cylinders of 43psi.Can someone confirm if i got these figures right and also if there right why would it be do high :nenau

 

[sp00k]

Whilst i remember tappets where done a couple of months ago and the only mod ive done to the engine is an induction kit

 

[rustic]

Whilst i remember tappets where done a couple of months ago and the only mod ive done to the engine is an induction kit

You probably need to do the test say three times on each cylinder.

If they are fairly close, then average them then compare the readings.
If the readings for one cylinder differ too much, you might have to do the test several more times and disregard the highest and the lowest and then average them, then compare.

Also you don't know if the compression tester is accurate, or repeatable, ie same conditions should give same reading.

When you have more readings, then you can compare.

This is just statistical analysis, and should then give you an overall average result.

Hope it helps.

Rustic

 

[sp00k]

You probably need to do the test say three times on each cylinder.

If they are fairly close, then average them then compare the readings.
If the readings for one cylinder differ too much, you might have to do the test several more times and disregard the highest and the lowest and then average them, then compare.

Also you don't know if the compression tester is accurate, or repeatable, ie same conditions should give same reading.

When you have more readings, then you can compare.

This is just statistical analysis, and should then give you an overall average result.

Hope it helps.

Rustic

I get what you mean m8 and that's my plan :thumbs. Had a chat with R1cho about this who has helped out loads and after he's spoke to a m8 who restores motors he said try to do and oil change with an engine flush as well in case there's a blockage somewhere on it.Its due a change now which ill do as ive the stuff here to do it but like to ask on advice on the oil side as I got semi synthetic Castrol oil and this is ok to use as I read mixed views on stuff like this

 

[Sweety]

I use either mineral or semi synthetic depending on which is cheaper at the time:lol got semi in at the min & it's running fine:thumbs

 

[sp00k]

Right I think im on to something here.With the blowby valve the pipe that comes from the rocker cover I can blow not suck on the pipe at all going to the rocker cover,so is this right or am I on to something here :nenau

 

[Lazy-Ferret]

Right I think im on to something here.With the blowby valve the pipe that comes from the rocker cover I can blow not suck on the pipe at all going to the rocker cover,so is this right or am I on to something here :nenau

Which way are you blowing and from what point in the system? The blowby control valve has a valve in it to stop the turbo sucking the oil out of the engine.

Sent from my GT-I8160 using Tapatalk 2

 

[sp00k]

what I mean is if I took the pipe off the blowby valve that goes to the rocker cover then blow through the pipe its self to the rocker cover its self. Realised that the unit on the rocker cover unbolts so ive taken that off and soaked it in petrol and cleaned it all out,and now its unblocked so think it may help out now as there is circulation on the system.