So my moms car has 140000 miles. Never had many major issues. But the other week as we exited off the interstate from doing a steady speed of 65 (mds was active) and as we stopped at a light the car felt like it had a warped torque converter or something, very off balance. So we pulled over and turned it off And when we cranked it back there was a loud POP then back to the rough shaking idle. We took it to get the codes read and it said misfire on cylinder 1. We put in New plugs and swapped out the #1 coil pack for another to see if the misfire moved. Well when we cranked it up the same loud pop and idle. Now the code read #1 Mds solenoid was stuck. So we replaced that as well. Still didn't fix it. And just in case put a new #1 coil pack. This time when we cranked it there was a huge pop and it sounded like something was loose near the #1 cylinder inside the motor. Loud clanking ticking knocking noise. Now when we try to crank it it will act like the battery is dead (New battery) then will spin over freely for a few seconds then will drag again. We have taken off both valve covers and all the rocker arms are moving as they should and with all the spark plugs out it spins over freely and everything looks to be in working order, although we cant tell whether or not the engine is on time. I've looked on basically every forum and found nothing. Does anyone know what this could be? So far I have came up with a bad sensor (no idea where to start), broke rod, timing chain stretched or broken, bad lifters, etc etc. Any help would be greatly appreciated!!

 

*UPDATE* Timing cover is off. Chain is tight with no play in it.

 

*UPDATE* Timing cover is off. Chain is tight with no play in it.

 

Bro when you finally find out whats the cause please post. I wish I could help

 

Do a compression test.. If all is good , it's a bad sensor . I would start with cam and crank sensor then to 02's , and cat converters..

 

Finally got it started and it seemed to be perfectly fine. After driving it for a day the misfire came back. We are going to take it to the dealership to see what they find. I think regardless we are going to replace all the mds solenoids and put msd coil packs and Taylor wires on it.

 

Sorry it's been so long I completely forgot about this. It ended up being a bad mds wiring harness. Took 20 minutes to put on and the problem was fixed.