Compression & Leakdown Tests

I saw my shop do it....some meter was used that screwed into the spark plug socket i believe

It didn't seem too complicated.

Sorry my answer sucks but that's all I got.

 

Carbon it is not hard to do the tests you just need the correct tools

For a leakdown test

http://buy1.snapon.com/products/diagnostics/eepv309a.asp

for a compression test Snap on has a kit p/n EEPV503

that will do the job

The key to doing the leakdown test you have to turn the engine over to top dead center compression and an air compressor to get a reading

the general rule of thumb is compression on the lowest cyl needs to be with in 10% of the highest cylinder IE Highest compression reading 180psi lowest no lower than 162psi

on leakdown no more than 10% leakage on any cylinder. if it is greater than 10% locate the source of the leak

out the exhaust = exhaust valves
out the intake = intake valves
out the crankcase breather = piston, rings, cylinder
radiator coolant = head gasket, crack in head or block

 

Just step away from the toolbox.

Each cylinder needs to be set exactly at TDC on the compression stroke to do the test. Some cars are pretty easy to do this on, some not so much. Guess which ones we're talking about.

 

It ain't hard, just need the right tools and time to do the job properly.

Some people really mess up the leak down tests because they do not do it properly. But once you know how to do it, it's easy.

You wind the engine over manually by putting a socket and bar on the front of the crank pulley bolt.

Or place the car in 5th gear and push forward till you acheive TDC.

You can 'flick' the key till it comes close then place in gear to "rock" engine to get TDC.

As you can tell, there are a few ways to get TDC.

+1

 

Lol, all good man.

Yep, TDC is top dead centre.

I performed these tasks sooooooooooooooooo many times, I could not tell you a number sorry.

It's not hard, I am sure there would be a procedure you could find on the net and print out which shows you how to do it etc.etc.

You will need a compression tester. Cheap and easy to find from a local auto parts shop. Thread sizes are mostly universal these days, but you may need one or two adapters to suit. Simple stuff.

A leak down tester was linked back there. A Snap On one. They are A LOT more expensive than a compression tester, but still reasonable if you use it often. You could make your own if you knew what you were doing. Again, I am sure there are guys on the net that have made their own and put pictures up etc.etc.

Both are easy procedures when you have done a few. Try and find some procedures on the net man, you will soon see what is involved. Hopefully there are pics too so you can really understand the process.

 

lol

Tim, which ones?

 

Carbon:

It might help if you explain what you intend to do and why you want to know. These tests, in theory, are not that difficult to perform. However, to do them correctly and then correctly interpret the results, can be very difficult, depending upon the specific situation. I'm quite mechanical, but on a Ferrari engine, I would feel much better having an experienced, qualified Ferrari Tech perform the tests, with me hanging around.

 

TDC is essential otherwise the compressed air will turn the engine, SO pushing the car in gear to find TDC is a bad idea should you forget to put it back in neutral AND don't forget to remove whatever tools you are using to turn the engine before applying the air. 100 psi into the cylinder at anything other than precisely TDC will give the crank a swift half turn flinging tools into, A; the most expensive component within reach B; your skull.
A leakdown test is far more telling than a simple compression test but a bit more complicated and time consuming.
There are plenty of inexpensive testers that for your purposes will serve just as well as the uber$$ Snap-On model. If you don't have an air compressor it's a moot point.