leakdown tester question

[mixwhit]

Does a leakdown tester also measure cylinder pressure (like a compression tester), or does it just give you a relative value to compare against other cylinders?

Also, has anyone used the Harbor Freight $30 tester?

 

[Roadkill]

It is used to tell you how much pressure you are losing on a per cylinder basis as well as where that air pressure is going. You can listen at the oil dipstick tube for air leakage and watch the rad for bubbles.

Lots of air leaking into the oil pan area = bad rings/seal.
Lots of bubbles in the rad = bad head gasket/cracked head.

There is a certain psi leakage amount that is considered acceptable. Remember this isn't a quick test like a cylinder pressure test. Each cylinder MUST be at TDC. If not and you pressurize the cylinder you could get a nasty surprise.

 

[mixwhit]

thanks roadkill. it sounds like the first logical step to gauging engine health might be a compression test. then perhaps a leakdown test after that if the readings warrant it.

 

[coffee]

Don't forget intake noise means intake valve and exhaust noise is exhaust valve.

 

[mentalbreakdown00]

Do compression check first, it will give you an idea of engine health. Remeber to use a bat chager, hold throttle open and pull all plugs though. Now if one cylinder is down a little the leakdown will let you diagnose the prob with that cyl.