[Nikon1234]

Hi.

Recently I found out that the engine shakes excessively. At first I thought the spark plugs, I changed all 4, not resolving the problem. I then thought of the engine (transmission) mounts, 4 of them, I changed 3 out of 4, only the rear transmission mount was left, not changed. All three changed mounts, left, right, and the front mounts, after out of the car, looked good. I also got down to the car and looked, inspected the rear transmission mount, it looked good too.

Now I think it might be the engine missfire. My reasoning is, while the car is idling, it has a small, but noticeble shaking. While I am driving, giving the hard gas, down shift stick shift, the car vibrates much harder. However if I drive it in ease, cruising along without pushing too much gas, the car shakes, just a little. The vabrition increases when push hard on gas.

I am thinking to get a scan tool to diagnose the car more, anyone can suggest me a descent scan tool?

Thanks for the help.

Dan

 

[17Hatch6MT]

Compression test?

 

[Thebigzeus]

Could be torque converter slipping or not locking up and shuddering also.

 

[Nikon1234]

what could a compression test guide me to? Is there a precedure to do the compression tests? My mechanic level is on change out engine and transmission oil, do the brake job. In other words, my car lever knowledge is at an primary level.

thanks.

 

[17Hatch6MT]

I am not an expert either, but to me a hard misfire like that suggests maybe a bad valve or piston or something. The compression test might not be the first thing to do. You've changed plugs but maybe there's something wrong with the coil or the transistor (computer) that runs it. Or what about the fuel injection. These would all set codes & the engine light, I'd think, but maybe not. A compression tester is a pressure gauge that records maximum pressure when you spin the engine over with the starter. It mounts in the spark plug hole. Gives an idea of general wear (if all cylinders are a little bit low) or a specific problem (if one cylinder is low and the others are normal).

 

[Cruzing12]

I recently had my coil pack go, and while yes the engine ran it was quight rough, shaking hesitation followed by a lack of power.

One thing that gave it away was when I checked the spark plugs one plug was wet looking. A simple swap of plugs would help diagnose, having changed them all a re check would do.( wet looking- injecters working but no spark, dry - no fuel getting in) As for the coil pack I'm not sure if it can be tested with an ohm meter but that would give it away the dead coil if it is the coil pack.

As for a plug tool computer a basic one would do, I went with the innova. Just check out the features. As "live data" will show which cylinder is missing as the engine runs. And cheaper ones will just read the check engine light codes.

All it will do is tell you what's happening but you'll still need to diagnose.

 

[snowwy66]

Of all 4 plugs fire and all 4 cylinders have 200 psi compression the engine runs fine. Rough example.

Knock one cylinder down on compression and now the engine runs rough. It becomes out of balance.

You should have a code if a cylinder is acting up.

It's also my understanding that the flywheel is a dual mass. If one or both comes loose. That would make the crankshaft vibrate. Felt throughout the motor.

Start with a compression check first.

Is your engine light on?