1993 4.0L V6 OHV head replacement question

[93rangerxlt-ca]

On my 1993 xlt 4 liter v6 i have to replace the head and i was told i do not have to remove the timing chain . before i tear into it id like to have a second opinion since i have a rodeo to get to and dont have tim for unexpected set backs

 

[RonD]

1990 to 2000 Rangers used the 4.0l OHV engine, so no over head cams and timing chains to deal with.

You will need new head bolts, they can't be reused

4.0l OHV heads were notorious for cracking between valve seats if over heated, if you think you have a blown head gasket you may not, but do have a cracked head, they have exactly the same symptoms, best to have them pressure tested when having them surfaced.


In 2001 Rangers got the 4.0l SOHC engine which does have over head cams so you do have to deal with timing chains on those.

 

[93rangerxlt-ca]

My isssue is my 5th cylinder is dead (125psi) and my 4th or 6th i cant remember its the one on driver side closest to the front and its at 140 somthin an the rest tested at 175

 

[RonD]

If no over heating was involved then could be head gasket blown between adjacent cylinders or burnt exhaust valves.

Was engine ever "pinging" prior to the dead cylinder.
Pre-detonation/pinging can be caused by fuel injectors clogging up, even low fuel pressure, this Leans out the cylinders which causes the pinging, the pinging then causes head gasket ring to deteriorate, softer metal, and it causes extra heat which can burn exhaust valves.