My check engine light came on a few weeks ago, P0304, and P0316. I cleared the code, drove 200 miles and the light came back on, same faults. Ran my compression today and it is what I figured. All my cylinders, were between 120-130psi, except 2 that was at 110psi, and 4, which is causing the check engine light, was at 90psi. This was warm, throttle open, oil made no difference. I Used my MAC tools gauge, and verified it with my Snap-on gauge, so the numbers are accurate. 120-130 seems really low whats the norm I would figure atleast 150? My plugs are perfect and clean, no oil fouling. My truck uses no oil at all between services, so I know my rings aren't my issue. I would have done a leak down, but I didn't have an adapter at the shop that would fit in the head. But given what I see with it not burning any oil, and clean plugs, I think the valve seats are gone. Any other advice before I order the set from Dover USA? After I do heads, I'm going to do stainless headers and high flow cats to free up the exhaust. Thanks guys!

BTW, truck has 100K on it.

Mike

 

120 -130psi for a motor with 100k plus miles is not bad at all. Cyl 2 @ 110psi would still be within specs but at the lower end. However, cyl 4 @ 90psi is definitely out of spec.

Ford OEM manual states that "compression pressures are considered within specification if the lowest reading cylinder is within 75 percent of the highest reading".

As a general rule of thumb compression pressure reading should be no lower than 100 psi and should not very more than 25 psi between your highest reading cylinder and your lowest reading cylinder. It’s more important that all cylinders read about the same plus or minus 25 psi rather than how high the readings are, given that none read below 100 psi. However, you will need to do both a dry and a wet test to help determine which components may be at fault.

 

Well, I ordered the head set today from http://www.doverusa.com/ I'm also going to do the water pump, thermostat, syncro shaft while its apart, and then stainless headers and high flow cats.

 

Got my heads, waiting on a box from Rock Auto with my water pump, t-stat, gaskets, oil filter and syncro shaft. All Motorcraft parts. I will get the heads done this weekend, and the exhaust work done this week or next.

 

Well, Heads from DoverUSA are on, along with a new Motorcraft water pump (the original was still there at 100K miles), t-stat, and syncro shaft. Another oil change with Mobil 1 too boot. Truck runs night and day better. It has all its power back, I would guess 20HP difference on the butt dyno of what it was missing and runs nice and smooth. Chalk this one up to another one of Fords crappy quality heads.

Now this week its off to get a set of custom stainless headers and high flow metal core cats. That leaves the only thing left hanging is my brake shimmy which I will tackle the week after next.

 

I own an 05 3.0 ranger that seems to have all the symptoms,but mine has 191+ on her.
Did comp test #3-80psi, 2-140, 1-190, other bank all had 165-170psi.only things that were changed was battery,pilot bearing,clutchmaster & slave cyl,release bearing,front brakes,tires. Oil every5000 thou.mobile1&motorcraft, i now use royal purple.
I was wondering what other gaskets ill need for the head swap.
Thanks.

 

The kit I got from DoverUSA came with everything, gaskets, seals, head bolts and all. I took the extended measure to replace my original t-stat and water pump that had 100K on them, and syncroshaft while it was apart for cheap insurance.

At 191K, if your truck doesn't burn any oil and your compression/leakdown test shows the rings are still good which seems like they are then I wouldn't hesitate to just do the heads.Everything I have read seems to indicate the bottom end of these motors, with proper care, are seemingly indestructible.

 

Thanks caliranger,what brand sycro did ya get? I heard of horror stories about some cheap ones and really dont want to buy something thats going to giveout on me.
How did yours look when u pulled it?
And was it hard to align up when reinstalling ur new one?

 

I went with motorcraft, $92 I think on rockauto.com. dorman is the bad one if I remember from researching. I would just buy a oem motorcraft rather then risk it since the price difference was small on a part that could ruin the motor. Mine spun freely when I pulled it out and feels ok but I replaced it anyway. Install is just like dropping a distributor. Make a mark where the metal tab is and drop it in until it lines up.

 

Im assuming that my 04 needs a head replacement as well after having the codes p0300 and p0316. I changed plugs,wires,coil and codes still pop up. How much of a pain was it to swap out the heads?

 

honestly, its not hard work doing them. Then again, I'm use to motors that look like the inside of a swiss watch with overhead cams, variable valve timing and lift controlled by an eccentric shaft and an electric motor (throttle stays wide open with engine running at all RPM). Its a simple motor though, about as easy as you can get. Just nuts and bolts, nothing to time, nothing too complicated if you know your way around a car.

You need to check compression and leak down though. I couldn't check leak down since my adapter wouldn't clear the head/exhaust manifold, but given my 90psi, no burning of oil and clean plugs, I knew mine was in the top end.

On a side note, this truck is becoming accustomed to me spending money on it. The belt tensioner did not like being moved, so now I have a hideous belt squeal. By hideous, think a high pitched noise, along with the whine of a roots blower. SO bad it was deafening inside the truck. It comes and goes, I put a grease/wax crayon on the belt and it shut it mostly up to a liveable noise like a loud cricket. My package from Rockauto got here today, new tensioner, idler, and a Goodyear Gatorback belt (I ran these on all the VW and BMW superchargers, great belts) which I will put on next week. My buddy pulled my manifolds and built jigs to make my stainless headers. Once those are done here pretty quick, its getting new metal core high flow cats too. I want this truck to last another 100K easy. Here is a pic. I washed and waxed it, and replaced the faded/chipping Ford emblems.

 

Caliranger
U have a supercharger on yours? If so which one, ive been looking for a whipple cause they're suppose to be bolt. I've heard the pcm had to be reprogrammed which is an extra cost.
Anyhow if u do thats a neat little sleeper u have there, she looks like a fleet truck, totally unassuming.
Nice little ride!

 

I dont think he says he has a supercharger

 

Nah, I wish. The tensioner sounds so bad it sounds like a whipple at times loaded full of angry crickets! Im changing that tonight though.

 

How difficult would it be for someone who has never been inside a engine to replace the heads? I've replaced a engine before, done water pumps, alternators, tune up, just never replaced heads. I still have to do my compression check. I've got codes p304 and p316. Do the new heads come with rocker arms and push rods? If not should they be replaced also? What other parts would you recommend replacing at the same time? I would think the water pump and thermostat, anything else? Thanks for your help. My truck is a 2006 Ranger Sport Supper Cab, 4 door. I've got a Chilton manual for it, but would perfer a dealer service manual.

 

Everyone has to pop their cherry sometime. If you have a manual its not rocket science so if you have done all that, you can do it. Take your time and go slow. No new rockers or push rods so those get reused.

For safe measure, I replaced my water pump, thermostat and the Camshaft synchronizer. I used all motorcraft parts since I don't like changing things twice that are critical, or hard to get too.

I replaced both the idler pulley, and tensioner and belt tonight. Went with Goodyear for all of it. I ran Gatorback belts on all the blowers I've used on BMW's and VW's, so I know they last and don't slip. No more noises up front. Knock on wood, my truck is almost new again and my receipt file is getting pretty fat.

I guess since this has turned into my build thread..... I'm going to find a spacer for my rear spring pac to bring the rear up a bit, still waiting on my headers to get built.

 

Thanks CaliRanger, I'm going to get this done this summer.

 

Well, my brand new Motorcraft water pump, that now has 500 miles on it is leaking from the weep hole..... This truck is wearing on my last nerve right now. Reason I bought a damn Motorcraft part is I didn't want to have these issues.

 

Wow that sucks, kinda makes me think twice about fords parts program.

 

Ford dealer will not warranty the pump and labor (which I did my self but for future peoples referance), nor would they even give me another one over the parts counter. They said I had to deal with who I bought it from, Rock Auto.

I called rock auto, they wouldn't just send me one. I had to either send them the defective new part, then they would ship out a new one upon receipt of my old one, or I could buy another one, and swap it and return my defective one. I chose the later option. I do have to pay shipping though. I think its shitty Ford wont warranty their own Motorcraft pump WITH receipt at a dealer. What happened if my truck broke down on the road? I was supposed to drive to northern California this weekend, but thats out now.

I will say, this truck is on its last chance with me. Its nickle and diming me to death and at this point, I have zero faith in driving it out of my AAA radius.

 

Nothing for nothing but u cant blame the dealership, rockauto would be the ppl i'd argue with, when u prove ur case with a faulty part due to manufacturing defect they might reimburst u for the shipping.

 

Well, I don't blame the dealer, and I don't blame Rock Auto. I blame Ford/Motorcraft for their crap warranty policy guidelines. I understand why the Ford dealer and Rock Auto can't just give one out to some guy who thinks his new pump is leaking when all he did was install it wrong. They give out a pump, and Ford/Motorcraft determines it isn't defective, Rock Auto or the Ford dealer would have to eat it. I do think the pump should be able to be warrantied at any Ford dealer across the country. Thats how we do it with BMW. Genuine BMW parts carry a coast to coast 2 year unlimited mileage warranty by any dealer.

 

Here are some pics. Got it pulled out, looks like the bearing walked out of the housing, and the impeller dug a good 10mm into the water pump housing. At least my timing cover wasn't damaged. Has anyone ever seen this before? Believe it or not, there is no axial or end play in the shaft/impeller assembly and it spins freely. It just decided it wanted to jump ship. Honestly, I expected better from Ford.





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And, this is the new one for comparison.

 

Well, damn... that'd prompt me to make a bearing retainer plate... keep that from happening again.

 

Hi. I recently bought a 2002 Ford Ranger and it had a cracked head. Even though it had a decent "miss" in it, it was still driveable. In fact I pulled my little boat across town with it and you couldn't even tell it was behind me going up a hill. Now I can go up even the slightest grade and the speed begins to fall off. How could I have lost so much horsepower by changing out the head? Any answers would be appreciated!