I need some help. I recently purchased this 04 ranger. It had a miss and I was hoping it was something simple. I was wrong.

Check engine codes said lean on both banks and cylinder 2 misfire.

I did a compression test and #2 was low. I put some oil in the cylinder. Pressure stayed the same. So today I spent the day taking the heads off.

Everything i I have read talks about the exhaust valves leaking. After getting the heads off I inspected everything.

Head gaskets look good with no signs of failure. I leveled the heads upside down and filled the chambers with fluid expecting #2 to start leaking out the exhaust.


None of the exhaust valves seem to be leaking.

On the intake valves
#2 is leaking heavy out the intake.
#1 has a small drip
#5 is leaking more than 1 but less than 2


What worries me is I haven’t read anything about intake valves leaking on the 3.0.

Will i I be ok replacing the heads or do I have something else I need to look at before ordering heads?


Thanks in advance.

 

 

From 2004 to 2006 the 3 litre had a problem with soft valve seats, so that fits the situation here, even more so if the intake valves are leaking.
I say that too because intake valves don't usually give problems because they are cooled from the fuel mixture on them and they are not subjected to the extreme exhaust heat.

Can't comment on Dover Heads.

I know my machine shop would simply put in new seats, valves and guides.

EDIT:
Looks like Dover Heads looks pretty reputable _ been there since 1941 _ no negative reviews on Facebook anyway.

And about the 3 litre, nice simple engine, very reliable with the exception of the soft valve seat problem.
They do suffer from leaky oil pan gaskets as they are getting old, but what engine doesn't. PITA to change which requires the engine be lifted off its mounts at the very least _ the trans needs to be dropped too.
If the coolant has not been maintained, the area where the timing chain cover mates to the block can and does corrode, so be aware of that. Leaks in that area.

 

 

Get a Ford water pump, after market ones may last less then a year or sometimes longer, usually garbage though.
Test the thermostat with the old one in a pot of water on the stove, it's surprising how many new thermostats are faulty.

The sensor on top of the synchro doesn't usually give problems.
What happens is the bushing wears and the trigger that passes in front of the sensor chews it up.
When you take the sensor off, look for what looks like rust; it's not rust, that's powder from the worn bushing.
If everything looks good and there is no side to side play in the synchro shaft, just leave it alone.

I spray some Tri-Flow down there once a year to keep in lubricated.
If you do need to replace it, get a Ford Motorcraft part, aftermarket ones are not good.

You will also need to remove the fan clutch, it's left hand thread.
Sometimes they come off easy sometimes not, there is a special wrench for the job.
Sometimes you can simply grab the serpentine belt to keep the fan from turning while you loosen the clutch, wear gloves.
Google "Ford Ranger fan clutch removal" _ lots of videos. Some good some bad.

https://www.rockauto.com/en/catalog/...ater+pump,2208

You may want to replace the timing chain and gears while you're in there, but they are good for 300k. That set up never really gave problems, it's very simple, no guides or tensioners to worry about.
Remember to replace the front crank seal too.

Put some sealant on the woodruff key on the front crank pulley so it doesn't leak oil in that area.

When you remove the timing cover, be carful not to damage the oil pan gasket.

 

 

The new heads will fix the problem, remember new head bolts.
I always use Fel-Pro bolts and gaskets.

 

 

 

I've always used Fel-Pro, my machinist uses them too _ I've known him for more then 20 years _ he's builds race engines.
I'm sure what ever brand comes with the rebuilt heads is fine.

When it comes to remanufactured heads too, I think they are better.
They are original castings that have been tested and repaired. (if necessary)

New heads can be Chinese, so quality control can be an issue.