Leak down test results

[paulv]

Bala,

You're almost there. It is imperative that both valves in the cylinder under test are closed -- so TDC or BDC. It is better to test with TDC but some people have safety concerns and use BDC. I always go with TDC and leave the car out of gear (or in park). haven't had the need to do this with my Box, but helped out a couple of friends with their junk cars.

Here are the items required for your testing:

Throttle body open -- allows for hearing leaks from a bad intake valve(s).
Exhaust system (obviously open) -- allows for hearing leaks from a bad exhaust valve(s).
Remove oil dipstick -- allows for hearing leaks into the crankcase from blowby caused by bad rings.
Coolant fill cap -- allows for seeing bubbles in the coolant caused from cracked head/headgasket/etc.

Regards,
paul...

[Bala]

Originally Posted by paulv

Bala,

You're almost there. It is imperative that both valves in the cylinder under test are closed -- so TDC or BDC. It is better to test with TDC but some people have safety concerns and use BDC. I always go with TDC and leave the car out of gear (or in park). haven't had the need to do this with my Box, but helped out a couple of friends with their junk cars.

Here are the items required for your testing:

Throttle body open -- allows for hearing leaks from a bad intake valve(s).
Exhaust system (obviously open) -- allows for hearing leaks from a bad exhaust valve(s).
Remove oil dipstick -- allows for hearing leaks into the crankcase from blowby caused by bad rings.
Coolant fill cap -- allows for seeing bubbles in the coolant caused from cracked head/headgasket/etc.

Regards,
paul...

Have to do this again.

Did not leave the throttle body open for the hot test. But, for the cold test I could not hear anything from the throttle body.
Did hear air hissing out of Oil dipstick but manual says some leakage is expected.
No leak what so ever from coolant - good new I guess.
Nothing of significance from exhaust. Could hear a very faint echo like air noise.

Let's see how this goes again. Maybe I'll write up a DIY article on this while I'm at it.

Thanks Paul et all.

[The Radium King]

i thought compression test was the first step. if compression is equal across all cyls then you are ok. if it isn't then a leakdown test to try and determine why.

[paulv]

Originally Posted by Bala

......................... Maybe I'll write up a DIY article on this while I'm at it.
.............

You can use this guide (I forgot I had it) as a basis for your Boxster-specific DIY article.

Regards,
paul...

[Bala]

Did the warm/hot engine test again. This time with throttle body, oil dipstick and coolant cap open.

None of the cylinder showed any air noise from throttle body or the coolant fill (no bubbles either). Oil dipstick had a slight air hiss as before. I understand this is normal. Exhaust had a air noise echo. Very faint but could hear it like before.

Leak percentages were same as before but cylinder 2 and 5 were lower. This time the engine was much hotter than earlier though. Others were about same or lower. So am good? No engine teardown? I was reallt hoping for a drop and tinkering. Guess it has to wait for another day.

I guess i don't need to do a DIY. What PAULV attached is pretty straight forward.