Hey all, looking to pick up a decent compression tester and wanted some input.

My thought was to spend a little more and get the one that remembers the high/low, etc. Sears has one: http://www.sears.com/sr/javasr/product.do?cat=Mechanics+Tools&pid=00947043000&vertical=TOOL&subcat=Automotive+Testing+Equipment&BV_SessionID=@@@@1396345915.1162233225@@@@&BV_EngineID=ccecaddjemilefecefecemldffidflk.0

Any thoughts?

I've got a couple of older Snap-On units. I think the part number is MT308 with some additional letters on the end. About $215, much less if you buy used from eBay. The gauges are accurate, and the adaptors fit nicely. There are separate adaptors for the various thread sizes and sealing methods (taper seat vs. gasketed plugs.) So that's my recommendation.

The Sears item you link to seems to be much too nice for only $100. It's imported from Taiwan. If you're satisfied as to the guesstimated service life and the gauge's accuracy, it seems like a reasonable deal. First thing I'd do when I opened the box would be to check the gauge against regulated shop air pressure. That'd be a way to verify the head unit to about 130--175 psi depending on your shop air supply, and depending on the accuracy of the pressure gauge on the shop air regulator.

There's a phone number at the bottom of the Mity-Vac info sheet. Call 'em and ask about build quality. http://www.mityvac.com/info_sheets/MV5532.pdf

I got a "almost new" Mac compression gauge from the snap-on guy for $100. It was only $135 or so new and it works great. I haven`t tried it on cars yet so I don`t know if I got the right adaptors but it works grat on bikes.

I also have a digital Mac compression tester, has memory for each cylinder and even averages out when your finished with all the cylinders. Mine was a killer deal at about 150 dollars brand new off the Matco truck of all places. Guy had a bunch of stuff from a guy that retired. Does everything from Diesel to gas and it was never used.

But personally. The traditional compression tester that places like Sears sell that comes with 2 different hoses and fittings at each end for the popular sized threads will do just fine. They last for years. Most of the ones I see come in a plastic pouch instead of a molded case. Perfect for home use.

Bear in mind, its not the precise accuracy of the tool that you are looking for. If it is within reasonable calibration it should be good for a compression test. What you are looking for is equality across all cylinders. The guage needs to be fairly accurate but more importantly it needs to be consistant.

Most gauges you can buy at the average auto parts store will be accurate enough for your purposes and will also be able to reproduce simlilar numbers from similar cylinders.

I purchaced a NAPA gauge that cost me $35 and it works perfectly. :)

Good info, guys - thanks!

buy or build a leakdown tester (which will also work as a compession tester if so desired)...theyre much better and useful than a regular compression tester...heres a good link and a good quote from it.."The cylinder takes in air and compresses it, and the tester traps it. The maximum is reached when the gauge holds more pressure than the engine can produce. The weakness of this test is that throttle postion, engine temperature, ambient air temperature, and a host of other factors can make the results vary considerably." ...mostly, i assume, being fuel and oil conditions, if a bad ring or scored cylinder wall is temporarily sealed by oil, what good is a compession reading?

http://www.xs11.com/tips/misc/misc3.shtml