31 replies to this topic

[liam1288]

hi guys, ive recently come to the comclusion that after being away and now im back driving that my car sounds louder and is less powerfull, i took it to get compression tested today because there was the concerning noise and was starting to overheat with my rad leaking...

it had good compression on all cylinders 2,3,4 but no compression on 1...

im hoping its just a head gasket blown between the water pump and number 1 but is this possible to blow there?

failing that im hoping a blown valve... deffinitely dont want to be taking the engine out for a rebuild!

any ideas?

[KernowCooper]

No compression ! did they do a wet test with oil in the bore? headgaskets go between cylinders usually as its the narrow part of the gasket, could be a burnt out valve or more serious like a holed piston, do you have lots of crankcase pressure when running with the oil filler cap off?

 

Remove the head and check the gasket/valves and investigate from there.

Edited by KernowCooper, 23 May 2013 - 09:15 PM.

[liam1288]

no i just popped in and asked for the test as a favour...

not sure about the pressure with the cap off, how would i check?

yeah im hoping its the valves... ill whip the head off tomorrow and see

[liam1288]

Bump

[lrostoke]

Whatever the problem the heads got to come off.

 

So easiest is just get on with it. The possibles have already been mentioned could even be a snapped ring.

[liam1288]

Would that cause smoke out of the exhaust though?

[Fast Ivan]

Would that cause smoke out of the exhaust though?

 

oil being burnt

[Fast Ivan]

with a compression reading like that, or in fact not even as bad as that requires the head to be removed for investigation.

 

You could try a compression test with a drop of oil in the offending bore to see if this helps compression, if it does then it points to piston ring/bore problems, but this would be nothing more than getting some more information, ultimately the heads coming off.

 

Hopefully it will be head related, gasket/valves. Worst case is rings/pistons/bores and a rebuild of the bottom end.

[liam1288]

The valve clearances weren't checked before... It was just a favour I asked to do...

[Fast Ivan]

worth a shot checking them for sure, it will also give you a chance to check the springs as it could be that one has failed.

[lrostoke]

And if its a spring the heads ideally still got come off :)

[liam1288]

Yeah good suggestions! How much oil do I pour in the cylinder to do a comp check? Or shall I not bother and just remove the head after checking valve/springs

[Fast Ivan]

a teaspoon

[liam1288]

Had a look at the valve clearances and on the offending cylinder side number 1 was closed shut when it was meant to be open!
Adjusted that and checked the compression and it read 12 so all was fine! Driving it feels a lot more responsive and smoother as expected but its always nice to have a quick fix!

[Fast Ivan]

Well that's brilliant news