compression test results help please.

[robdf2]

I had a compression test done on my car today with the following results :

when cold, the compression test  on cylinder  number 1 measured 12.5 bar , cylinders 2,3,4 measured 11.4 bar
however when warm cylinder number 1 was reading 14.4 bar andcylinders 2,3  were on 11.5 and number 4 was on 12.4 bar. 

anyone know if this is normal?
i would expect maybe a small difference but im no expert but these results look a bit odd to me?

leon cupra mk2
cheers

      Rob.

[PDT]

Did the engine have a stabilised power supply to the battery throughout the test?

Did you try a wet and dry test (by adding a 5ml syringe into the cylinder) ?

Was fuel still entering the cylinders during the test?

[robdf2]

The test was done by a seat dealership under the instructions of seat technical , so cant answer any questions on their method 

if the test was done in the way you descibed , what do you think of the results that they have found?
thanks

[PDT]

Firstly they should be measuring in PSI as it has a greater degree of resolution when using a decimal point of accuracy.

You cant rely on the test results or interpret them unless you know the conditions they were tested under, I see so many posts on forums where compression tests were carried out incorrectly.

Ideally you need to ask them if:

Cranking voltage was stabilised?
Was fuel entering the cylinders?
Was a wet and dry test carried out?
Was throttle open or closed?
 

[robdf2]

thanks for the replies
i dont ever think i will find this info out.
i think its bad news tbh , they have told me they want my car for another 2 weeks to investigate :-(

i will try my best to find out
incidently i had a new cylinder head on my car at 4,000 miles this was diagnosed as high comprssion on cylinder 3.
since its been fixed (supposedly fixed) i have had high timing pull -6 or -7 across all cylinders , my exhaust pops on tickover , crap fuel consumption and it struggles to make power , missfires loads , oh and spark plugs only last about 8 k if im lucky !

as a standalone figure is 14.4 bar a little high?
thanks for your help.

[robdf2]

I had an email today from the dealers , my cylinder head is coming off again for investigation 

[Tfsi_Mike]

Fingers crossed for you mate.

[Saint Steve]

its known, that piston damage will increase the psi on a compression test. Purely because the rings can become stuck due  to the aluminum melting and causing them to give such a difference.

Keeping fingers crossed its not as bad as it sounds, but the dealers are doing the right thing by removing the head.

[robdf2]

Fingers crossed for you mate.

cheers buddy

[robdf2]

its known, that piston damage will increase the psi on a compression test. Purely because the rings can become stuck do to the aluminum melting and causing them to give such a difference.

Keeping fingers crossed its not as bad as it sounds, but the dealers are doing the right thing by removing the head.

if only you knew the history steve
i had a new cylinder head after 4,000 miles
and its never been right , 3 years i have been battling with SEAT to get my issues resolved and now its come to this , the car has been a dog since day 1 , i have been telling them for 3 years that my timing is being pulled constantly , and i might as well been talking chinese for all the good it did me.

will see what they report back to me.

[WILLZIE]

Could there be any bent valves? or is that something you would now about through compression test and driving?

[robdf2]

it could be bent valves , a compression test test will just tell you that something is wrong with the compression of the cylinders.
the only way to find out whats causing the issue is to remove the cylinder head.

mine should be off or definatly off by tomorrow , so should be able to post up with whats wrong 

[Tfsi_Mike]

 

[robdf2]

thought i would post a mini update on this.
A new cylinder head is being fitted 

my second cylinder head in 3 years not bad going ! 

[yin]

Rob i have been following this over on cupra.net since the beginning. You must have the patience of a saint.
 I would have drove it through there front window by now.