"Should the leak down test be done on a cold or warm engine? Is this a test
most mechanics do or can do? Seems like a good test to routinely do.
thanks,
Linda"
Hi Linda,
Ideally, as in a compression test, the leakdown test should be done on an
engine at operating temperature.
However a warm engine is only going to have better piston ring sealing than
a cold one and a squirt of engine oil in the cylinder will remedy that.
Attached is a pic. of a leakdown tester I bought recently from an Ebay
seller in the USA.
Haven't used it yet, but for the $$ I couldn't make one any cheaper!
Very simple test to do, BUT, make sure the engine is physically locked at
TDC (compression) for the cylinder being tested.
Once you pump up the cylinder to ~100psi, the piston will want to move and
rotate the crank, VERY QUICKLY!
For a manual, in gear and e. brake on.
For an auto. jam the flex plate or crank nose to prevent rotation.
Normally only required to do this test if you suspect some sort of engine
problem i.e. blown head gasket or damaged piston rings.
I diagnosed two trashed pistons in a turbo car using a home made "inflatable
spark plug" attachment.
The dual gauge type is much more sophisticated and as mentioned, will give
you a % leak over time for all cylinders.
If you are looking at a multi-cam, multi-valve "head job", the more
information you have the easier it is to make the big decision.
Regards,
Graeme Suckling
1965 SP310
1971 P510
1972 PL510
1973 HS30
1993 ECR33 Skyline GTS25t
http://www.imagestation.com/album/pictures.html?id=4291195515
Adelaide
South Australia.
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.394 / Virus Database: 268.9.4/375 - Release Date: 25/06/2006
[demime 1.01d removed an attachment of type image/jpeg which had a name of
be_1.jpg]
|