Engine Compression Testing Question

[Growser]

So I bought this compression tester from Harbor Freight. I'm comfortable in using this on a SOHC car with the exposed plugs. What do you do on a DOHC with limited access? Do you just screw it in through the top of the engine and hope you get it screwed down far enough??

[quantumech]

I plan on getting this guy, or maybe their other one with the other attachments on Monday.

Is the hose long enough so that you could prop it up between the hood and windshield and watch the gauge as you crank from the drivers seat? I thought I would try doing that so I could see the compression numbers with each crank to see how long it takes is build-up. The whole building up on fewer cranks the better thing.

Don't you just screw it on until it stops though?

[Tiger]

I borrowed a newish one from AutoZone with a deposit that looked something like that. A trick to keep from cross threading plugs is to attach rubber hose to the end of the plug to gently get the plug screwed in. With that in mind, I just straitened the hose on the compression tester and then threaded it in where the plug goes until it stopped turning. It seemed to work. It was sweet that my car came with an aftermarket remote starter. Made the testing much easier.

[Growser]

You do just screw it in, but wondering if you can get it twisted in enough. I guess I won't know until I try it,

[madpogue]

I've got a cheapo HF gauge like ^^^^^, and an beat-up Sun gauge that's older than half the members here. They both go into a DOHC just fine. I think most personal-use compression testers are designed about like this.

[Growser]

Thanks madpogue. That's exactly what I was wondering. I have a DOHC Saturn I'm looking at buying this afternoon but it isn't running. I want to do a compression check, but being it's not my car don't want to get the tester stuck.

[OldNuc]

They work fine. The o-ring makes the seal and you can get it tight enough to squirt the ring out. Gently hand tight works fine.