LEAKDOWN TEST

[normde2001]

Has anyone ever tried a "leakdown test" on diesel engines the way they do on small gas engines? It should work if you can inject air into the combustion chamber.

 

[RoyJackson]

A buddy of mine does it on Mercedes Benz diesels. Biggest difference is the fittings you use and you've got to pulll the injectors (that's where the cylinder is pressurized).

 

[polecat]

extrulate on this one guys???why and how???know my engines firly well but are u tryin to figure out if u have bad rings????or leaking valves??/..we used to always take comrression tester..test dry and then add a little oil in one cylinder at a tme and then do another compression test and figure out the differences...u r looking for an average ...or a particularly bad cyl...???/ /forums/images/graemlins/grin.gif

 

[normde2001]

Assuming the compression test is low, you crank the engine to TDC, valves closed, and pump 30-40# of air into cylinder via sparkplug hole or fuel injector. listen through air intake for intake valve leakage, exhaust for exhaust valve leak, crankcase vent for ring blowby leakage, (some expected at end gaps), check for bubbles in radiator or spray soap and watch for bubbles around head gasket. Never tried it but I would used a piece of tubing as a stethoscope. You can buy fittings for sparkplug holes, and I guess, get creative for diesels.

 

[polecat]

learn something everyday /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[SnowRidge]

</font><font color="blue" class="small">( extrulate on this one guys???why and how???know my engines firly well but are u tryin to figure out if u have bad rings????or leaking valves??/..we used to always take comrression tester..test dry and then add a little oil in one cylinder at a tme and then do another compression test and figure out the differences...u r looking for an average ...or a particularly bad cyl...???/ )</font>

Some of the small engines have automatic compression releases to aid in starting. This renders compression testers useless for qualitative purposes. A leakdown test is used instead.

SnowRidge

 

[Inspector507]

SnowRidge,
Look at the attached........looks close

 

[SnowRidge]

</font><font color="blue" class="small">( Look at the attached........looks close )</font>

Hmmm, Bubba's lookin' kinda glassy eyed. Too much catnip?

SnowRidge

 

[Inspector507]

He does well with catnip, but the female cat of the house, Bitsy, gets mean. We don't allow catnip anywhere her /forums/images/graemlins/grin.gif
Little Miss Priss who won't drink normally (see attached)

 

[SnowRidge]

</font><font color="blue" class="small">( Little Miss Priss who won't drink normally )</font>

Quite a coincidence, our female feline drinks the same way sometimes.

SnowRidge