ok need some help on what i should do i have a 99 ram 1500 5.2 auto, i have continually had a cylinder 8 misfire that cylinder has low compression 90 psi compared to 160-170 for the rest. I am also slowly losing antifreeze it is not visibly leaking anywhere, so i am assuming i have a bad head gasket or cracked head. My problem is this is my daily driver and i cant have to much down time so im not sure if i should just try replacing the haed gasket, get a rebuilt head and just do the head and gasket at same time, just replace both heads and gaskets, or at that point just replace the whole engine with a rebuilt ??? btw engine has 99000 mi

 

Sounds like a blown head gasket. It needs to be replaced. As far as the head you won't know until you pull the head. If you don't have much time you change just the one head gasket and it would be fine. I don't see any point in replacing the whole engine. With only 99,000 miles on it. The 5.2 last up to 250,000 to 300,000 if taken care of.

 

+1 that you won't know for sure until you take it apart and inspect the head.
best case is the head is good and you only need a new gasket.
worst case is the head is cracked, and you need a new one.

to blindly buy a head from ebay is about $125 used or $175 rebuilt or $250 new. a little pricey.

have you got a local machine shop or engine rebuilder or junk yard ? ask them if they have good head on hand that you could get "right now". so you have this on standby. then pull yours off on one day and check it out. if you need a new head, then go get it. if you only need a gasket, then just put it back together.

if you've never fixed your plenum, then do this at the same time for about $150.

its unlikely you need a whole new engine or rebuild.


if time was everything and money was not an issue, i'd buy a new set of ebay heads, hughes plenum plate and just do it all at once. maybe also do water pump and timing chain while everything was apart and just be done with it.

 

well i just recently did the hughes plenum plate and the water pump, t-stat and all new hoses so back apart it all comes. I was hopeing that the plenum was my fix for the misfire which it was because i used to have multiple cylinders misfireing now im just down to the one. I have had plenty of issues I have been fixing and still have more, my tranny is also on its way out.... this thing is the never ending fixer upper lol