Citroen AX cyl 3 no compression

[jsp]

I am having a problem on my Citroen AX 10E.

Last year it had a blown Headgasket before I put mine to wintersleep. and I replaced the head,HG, gasket set and H.bolts and now cyl 3 wont get a compression at all almost.

cyl 1: 150psi
2: 145psi
3: 15psi
4: 145psi

all tests are done with wide throttle open.

Is a valve seat gone or piston ring?

[ekjdm14]

First thought if water had been leaking into #3 is that the rings could have stuck and a dose of oil additive may help. First though I would check the obvious, that the cooling system isn't vastly pressurising and that the valve clearances are correct.

Also, have you done a "wet" test? note the compression readings & then drop 5-10ml clean engine oil down the spark plug holes and repeat the test. A huge increase in readings then would suggest rings/bore whereas little to no increase points to valves/head/gasket.

(Another check to pinpoint quickly is to connect an air supply to the offending spark plug hole & listen for where the air is escaping. Hissing at the exhaust or carb obviously is valve whereas through the oil cap would say rings/bore/head)

HTH

[jsp]

First thought if water had been leaking into #3 is that the rings could have stuck and a dose of oil additive may help. First though I would check the obvious, that the cooling system isn't vastly pressurising and that the valve clearances are correct.

Also, have you done a "wet" test? note the compression readings & then drop 5-10ml clean engine oil down the spark plug holes and repeat the test. A huge increase in readings then would suggest rings/bore whereas little to no increase points to valves/head/gasket.

(Another check to pinpoint quickly is to connect an air supply to the offending spark plug hole & listen for where the air is escaping. Hissing at the exhaust or carb obviously is valve whereas through the oil cap would say rings/bore/head)

HTH

Ok will try that.

[Gibbo2286]

A rough test is to put a couple of teaspoons of oil down the spark plug hole then test again, if the pressure comes up some then it will be the rings if it doesn't it's almost certainly a valve.

Check the valve clearances make sure the gaps are set correctly.

[Gibbo2286]

Beat me to it jsp we must have been typing at the same time but I got a damned ppi phone call before I clicked submit.

[jsp]

Turns out to be a valve adjustment. Adjusted it correctly and no leak anymore. Topic can be locked thanks all.

[Zelandeth]

Nice to hear it turned out to be nothing sinister! Thanks for letting us know.

[jsp]

lucky me otherwise redoing the HG would be a second time in one week XD.

[ekjdm14]

Ouch, yes that would have been a pain! Glad it's sorted & an easy fix for a change. Nice when something simple/free sorts a potentially large problem

[CitroJim]

That's a relief Delighted it was a lovely simple one

[jsp]

Need valve adjustment still. Engine idles very rough sometimes.