Chrysler Repair: Chrysler engine shake, head gasket leak, spark plug wires

Question
89 Chrysler LeBaron convertible 2.5L turbo
The engine suddenly developed a severe shake.  Seems to be only running on three cylinders until it gets up to speed.  The engine ran great until one day I drove it, stopped the engine for about five minutes, started it up and that's when the engine started to shake.  At highway speeds the car doesn't shake as bad.  Maybe motor mounts or a head gasket?

Also the lights and dash lights go off when driving at night with the high beams on.

Thanks in advance.

Answer
Hi Nowell,
I would try to differentiate whether the problem is external to the engine (motor mounts) or internal (head gasket, fuel injector, or ignition). Why not remove the spark plug wires at the plug (gently twist off rubber cap, don't pull on the wire) one at a time, and see if the shaking is identical to your present situation at idle with any of the 4 removed, and of course much worse with the other 3 (might not even start) which would identify that one of the cylinders is bad (and if so then check the spark plug, the distributor cap and the wire for that cylinder, and maybe pull the plug and inspect and check the compression); or alternatively the shaking is equally bad with any one of wires disconnected which would at least eliminate the idea of a bad injector or head gasket effecting only one cylinder. On the head gasket, are you seeing more than the usual amount of white smoke in the exhaust pipe output, or are you loosing coolant, or is the oil milky colored?; any of those are diagnostic of the head gasket leak. You could also check the compression of the 4 cylinders to see if one is more than 25% lower than the rest. To test the injector function you could try cranking the engine with the center wire of the distributor cap removed and grounded so that no spark occurs, crank the engine for a few seconds, then pull the plugs and see if they look equally wet with gas, a dry one being suspect. The engine mount would cause the engine to move alot when you put it in gear or removed it from gear while at idle, but the engine itself would not be shaking whether in or out of gear at idle if it was the mount.  Finally, you could check the engine controller to see if it has noticed any malfunctions that could explain the shaking: Try using the ignition key: turn it "on-off-on-off-on" and leave it "on" (doing this quickly, no longer than 5 seconds). Then watch the 'check engine' light which will be 'on' for a few seconds then to begin flashing, then pause, flashing, pause, etc. Count the number of flashes before each pause and keep track of the numbers. Repeat the readout and verify the counts are correct. Then group them in pairs in the order that they came out, thus forming two digit numbers. You may notice that the pause is shorter between the digits of a given number, and longer between the numbers themselves. Then send me a 'follow-up' question telling me the results of your readout. By the way, 55 will be the last number (two groups of 5 flashes each) and that is the code for "end of readout".
I have the troubleshooting manual for the 2.5 4- cyl turboengine and we can look up the possibilities of what is wrong based upon what fault codes you show, if any.
There is also an essay on fault codes at the site:
http://www.allpar.com/fix/codes.html
which gives the meaning of the code numbers. But even then you need to get specific info for what exactly might be the diagnostic tests or parts to replace to complete the repair.
Roland  
P.S. On the lights and dash lights going off when using the high beams let me look at the wiring diagrams for an explanation.