Hi guys

I recently went to look at a polo 6n 16v. When we ran a compression test the meter read only 130psi (only tried one of the plugs, had just been for a 5 or ten minute test run), this seems a bit low? I've tried to find out what the readings should be without much luck, just wondering if anyone happens to know what it should be or what their valvers are running at.

Thanks

Nick

Edited 4 July, 200719 yr by welovegypos

My 23 year old mk2 engine managed 155psi all round, so yea it does seem low :(

Not much point in just doing one. You will need to do all four for a start.

Not much point in just doing one. You will need to do all four for a start.

Yeah i apprecaite that would have been wise. However, my query is still valid, it doesnt matter if its one or all of them that are low, its a problem either way surely? Would be nice to have an idea of what other people are getting or what vw expect me to be getting

Thanks

Nick

yeah i know that was just making sure you knew to do all of them mate.

yeah i know that was just making sure you knew to do all of them mate.

yeah sorry if i seemed rude. i dont know much about engines myself, had my dad do it him being a car nut and all. It did occur to us on the way home it was pretty amatuer not checking all 4 once we decided somethig might be not right. Doh!

Bump.

Surely someone has done a compression test on their 16v?!?!

i done it ages ago on mine using a gunson meter...i cant remember what PSI it was but it was in the green bit on the meter

EDIT: found a pic

i found a better pic on the gunson site...so mine were all reading 150-160 PSI

yeah i've got a contraption similar to that, so you're saying 150-160 for definate accross all 4? The reading of 130 i got was in the green on my meter, but only just! Hmmm i smell a problem :( Any ideas what it could be? Its been suggested the valves might have a problem, or the engine might just be very worn and needs a rebore. Any information anyone can offer would be very very helpful!

Thanks Tej.

Nick

Edited 5 July, 200719 yr by welovegypos

check to see if its burning oil...ie its giving blue smoke out the exhaust or the spark plugs are badly contaminated...then id suspect valve stem seals

if thats ok then check for excessive pressure in the engine breather...best place to look is in the airbox for lots of oil...there tends to be a fair bit anyway but pools of oil will probably mean piston rings

have a look in the header tank as well to see if theres any oily film in there as it could be a case of the headgasket being on its way out

thats all i can remember off the top of my head mate

hope it helps

nice one, saw no blue smoke from the exhaust, have to say the engine appeared to be in very condition, spark plugs looked ok, could just be new though i guess? i think they were recently changed.

Excuse the noobness, but i dont think it has an air box, got a bmc on it, or is that something totally different and I'm being retarded?

Will investigate what you said anyway, thanks again

Nick

when comparing results from compression tests you have to bare in mind the temperature of the engine.

a hotter engine will always give a better compression due to the rings and piston expansion.

and Tej get some work done instead of nobbing around on the internet!

when comparing results from compression tests you have to bare in mind the temperature of the engine.

a hotter engine will always give a better compression due to the rings and piston expansion.

and Tej get some work done instead of nobbing around on the internet!

thanks thats useful. unfortunately the car was warm when i did it, so that doesnt bode well! Any chance you remember what pressure yours was running?

Thanks

Nick

when comparing results from compression tests you have to bare in mind the temperature of the engine.

a hotter engine will always give a better compression due to the rings and piston expansion.

and Tej get some work done instead of nobbing around on the internet!

I'm not the one who keeps disappearin on training courses or holidays!!

@ welovegypos :- try doing the compression again, but put in just under half a tea spoon of oil in each cyclinder (spark plug hole ) and see if this improves the output...

I had a mobile tuning man do a test on my car and found the compresion to be from 212 down to 202 psi in all found cylinders so yours sound welll under