Hello, I have an 02 ranger 4.0 4wd. Just the other day I fired it up and it did a pop sound and was very rough running. I have one of those obd readers as it threw an engine light on. I get p0304 0305 0306 cylinder misfire...at this time. I have some plugs and wires to install but would like opinion of possible coil pack as well. It has about 250k on it and has what I think timing chain rattle as well. Is it possible it jumped time? Seems it would be doing backfiring sounds if so. It does start, I have to goose it a bit to keep it running but have not tried to drive it anywhere. Need opinion on that as well. I am trying to make it to a shop about 3 miles from my house either by attempting to drive it or having it towed.

thank you in advance

 

Welcome to the forum

Codes 304, 305, and 306 means the whole drivers side of engine is not working, so all 3 cylinders are dead

Yes, if you had a timing chain rattle then it reads like cam has slipped on that Bank of the engine, bank 2
And no, not the coil pack, 1/5, 2/6 and 3/4, each pair shares one coil in the 3 coil pack, if either set was not working, i.e. P0301 and P0305 then might be coil pack

I would FIRST test compression on 4, 5 and 6 cylinders, expected is 170psi, I think you will find them down under 100psi, a cylinder needs over 120psi to fire
It would only backfire it is was firing at all on that side
A spark can't ignite the air/fuel mix as is, it must be compressed to turn the liquid gasoline into a VAPOR that a spark can ignite, which is why compression is important

And test at least one cylinder on passenger side, as said 170psi is expected

I wouldn't drive it this way, if it slips more it could bend valves or damage pistons on that side, you can move it, just take it easy

 

Thanks for the reply
Curious what a timing chain job would cost?

 

Those symptoms sound very familiar to what I experienced a little over a year ago with my '02 4wd. I recall sitting in it at idle on a job site when all of a sudden I thought someone started to physically shake it from behind. Took it to Orielly's down the street and although I don't remember the exact codes it said I had cylinder misfires. "Rear timing chain". I ended up taking it to an engine rebuild shop and had a new long block installed. I shared in an earlier thread 4.0 SOHC Long Block what that cost me but pretty sure you can have it done for less if you can do it yourself. The labor alone was $1500.
Good luck popman.

 

Thank you
I have decided to have it towed to the shop this morning and have it looked at or setup a repair bill

 

Since there are so many miles and the truck is old maybe a used motor with less miles and change the timing chains on it might get a few more miles out of it. If I decide that is the path I want, what years of 4.0 will fit? Btw tranny was rebuilt last year.

 

You would want a 2005-2011 4.0l SOHC it will have the newer design,but I would still replace the 2 tensioners with new motorcraft parts

You just use the Long Block, swap over your upper and lower intake from the 2002 to the new engine so all wiring and vacuum lines will match up
2 other things you should change, rear main seal, and Knock sensor
Also inspect the thermostat housing they crack on the 4.0l SOHC

 

Working on a plan

 

The motor has to be removed and reinstalled and that will have a specific cost, get that as a separate cost

Then the cost of a used engine vs the cost of just doing the timing chains
Used engines come with their own set of worries, were they run low on oil or overheated, not even the seller(wrecking yard) will know that
Your own engine at least has some history you know about, but may have higher miles than a newer used engine