Compression on 3.9v8

RacingSnake · Feb 5, 2016

Right, I've done a search, so more seeking confirmation on this!!

As a result of my other thread (water pump), I had the garage run a compression test at the same time.
I don't have a cylinder by cylinder breakdown, but a note on my invoice:
All compression 80-100 psi

I read on here a couple of "target" pressures, from 160-180psi.
Couple of quick questions:
1) would this explain the sheer lack of performance (even though it's a defender!!!)
2) Other than general poor performance, is there an issue with driving it like this for a while - I'd like to leave this one as a summer job!!!

Thanks again!

jamesmartin · Feb 5, 2016

if its worn its worn already , it will explain some lack of performance as valves wont be opening fully,does it breath heavy from oil filler

RacingSnake · Feb 5, 2016

jamesmartin said:
if its worn its worn already , it will explain some lack of performance as valves wont be opening fully,does it breath heavy from oil filler

Is there a recommended test for that? or just open it up and stick my hand over it?! lol

jamesmartin · Feb 5, 2016

RacingSnake said:
Is there a recommended test for that? or just open it up and stick my hand over it?! lol

you can see it

RacingSnake · Feb 5, 2016

ok, I'll have a look in the daylight - I do recall looking in there when I first got it and noted it was very 'dry' in there.

norseman · Feb 6, 2016

I wonder if 'they' did the test with the throttle wide open & a warmed engine?
If so then with compressions like that you don't need a mechanic, you need a priest

RacingSnake · Feb 7, 2016

norseman said:
I wonder if 'they' did the test with the throttle wide open & a warmed engine?
If so then with compressions like that you don't need a mechanic, you need a priest

Doh!
tbh though, they're a LR specialist so I think they'd have done it correctly (whichever way that should be)

norseman · Feb 8, 2016

RacingSnake said:
Doh!
tbh though, they're a LR specialist so I think they'd have done it correctly (whichever way that should be)

Our father, which art in ............

waldamar · Feb 8, 2016

I've got a plan not to check my compression.............................. life is stressful enough!

Compression on 3.9v8

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