3.0 valves AGAIN

[rurouni20xx]

the fuel and air that passes over them cools the valve faces, and im sure the tops are pretty toasty. the valves are made of stainless steel which dissipates heat better as well. the seats are stationary and since they are cast iron and not aluminum they dont dissipate heat that well and cook.

 

[crf250r6]

I have an outer where on the filter. By now I know its running lean, I know they come running lean but why is it so lean now, I'm sure the intake didn't help but the first time it did it I didn't have it on their, and 2 of my buddys rangers were bone stock when theirs did it too. I'm just wondering if something starts going out causing it to run lean around 50k miles cause it seem on every truck that it happens to does it at 60k, and since whatever the problem is didn't get fixed it happens again 10k miles later, like mine and my buddys truck, I just don't want to start buyin all these sensors and have it not be that and then have to do my heads for a third time. I just want to know if anyone has had this problem and knows how to make sure it stays gone ands it doesn't lean out again, and also is it cause ford changed the heads or did they for some reason make these years run more lean.

 

[rurouni20xx]

to be honest id look into a programmer and richen it up if you want to keep the truck. i hate to say this but after about 2000-2004 year models nothing was built to last longer than 100k miles, at least ive never heard of a newer model truck going further than 150k without a rebuild, whereas my 93 3.0 is still running (uses a qt of oil every 1000 mind you) at 280k miles. see what you can do man.

 

[stmitch]

It can't hurt to double check the cats like I said. If one's clogged or even partially restricted, the heat build up can do lots of damage similar to what you've run into already.
The programmer is a good idea too.

 

[Big Jim M]

Well... Not really!

the fuel and air that passes over them cools the valve faces, and im sure the tops are pretty toasty. the valves are made of stainless steel which dissipates heat better as well. the seats are stationary and since they are cast iron and not aluminum they dont dissipate heat that well and cook.

Actually when thinking about the valve cooling one must think in TIME events.
Although things are happening very quickly one must think of how long the valve is OPEN compared to how much time it spends against it's seat closed.
One will find that by far the valve is resting and COOLING itself by conducting it's heat into the coolant cooled SEAT.
Although the incoming mixture may have some cooling minor effect on the intake valve it has no effect on the exhaust valve.
In fact it is the coolant in the engine that is taking the heat out of both valves.. as hard as that may be to comprehend.
Big JIm

 

[crf250r6]

ive thought about a tunner but they dont make one just a chip, and i am going to get my cats tested, but what ever it is a common problem on the 04 to 07 3.0s. i think im going to buy new heads but im almost thinking of getting heads for maybe an 01 or 02 and maybe it wont happen, cause i know the years this happens they changed the heads.

 

[stmitch]

For a tuner, I'd go with an SCT X-Cal or livewire. (chips and modules don't work as well on obdII trucks) They'll hold three custom tunes plus your stock tune. Doug @ Bamachips, or Fred @ Rogueperformance both have lots of experience with tuning 3.0's, and can hook you up. Just google either one.

 

[rurouni20xx]

tuning devices are abundant for the 3.0 you just have to look for them. the sctflash tuner is probably the best one, and the guy at rogueperformance.com is a dealer and 3.0 enthusiast. hell the website gave me a lot of formulas for fuel and injectors when i was on paper building a turbo 3.3 stroker. you have a lot more options than me with a 93 obd1/eec4 computer system as far as tuning is concerned.

 

[crf250r6]

ill check those out, but what does everyone think, is it cause ford changed the heads or changed something diffrent to cause it to run lean?

 

[rurouni20xx]

both heads and tune for emissions purposes. the fuel system was also changed in 99 up for the standard and flex fuel models. my older system has a twin fuel line (return style) fuel system with a vacuum actuated fuel pressure regulator. the 99 up is a returnless (single line) fuel system with the regulator built into the fuel pump. much more expensive (parts wise, your fuel pump is a lot more expensive) than my setup but better for evaporative emissions. you also have more cats and o2 sensors than the older models, and more sensory of the motor for that matter. its all for emissions, squeeze more readings from the engine so you can adjust the tune that much further. in this case however they are squeezing the tune so lean that the engine doesnt last as long as it used to, then again the engine wasnt designed for all this stuff either. its simply retrofitted from an older design, which usually creates a lot of problems.

 

[crf250r6]

So it sounds like the 04 and so on heads can't handle the newer fuel system, but I just can't figure out why it happpened again after only 10k miles.

 

[rurouni20xx]

the 99 and so on engine, they did the changes back in 99 that are currently being used all the way up to 2010. its not that the heads cant handle the fuel system. its the fact that they tweaked the piss out of it and leaned it down so far to please the federal government and keep an older design. just cheaper on ford than going to a newer more efficient design that will easier pass emissions. most other vehicles they dropped a newer style engine in, why they didnt do so to the 3.0 in the ranger im not sure. i guess to make $$$ or the simple fact of if it aint broke dont fix it came around. i stand behind the 3.0 100% its an awesome engine dont get me wrong, but the 2 valve ohv arrangement isnt very efficient and has trouble passing emissions or producing peak power. thats why chevy went to smaller bores, the v8s went from 2 valve ohv to 3 valve sohc with variable valve timing in fords, the 4.0 ohv to an sohc 4.0 with better valve angles/chamber design, and the 2.3 lima to the 2.3 duratec. they simply breath better and can take the tune better. even your engine building manuals show for general purposes of calculating volumetric efficiency: ohv 2 valves 80% ve, 4 valve/multivalve 90% ve, and variable valve timing multivalve 95% ve. there is a lot of wasted fuel in the old 2 valve ohv engine like the 3.0, and to make emissions happy they had to lean it way down. this in turn lead to engine longevity problems, something that is inevitable from lean mixture. my question is why havent they redesigned the engine or use a different version of one that is the same displacement (older 3.0 taurus sho v6 or duratec 3.5 v6) for example.

 

[stmitch]

Yeah. I doubt the heads are the main culprit. They haven't changed the design in FOREVER. If they changed something on the newer trucks, it wasn't anything in the basic engine design, so it would more than likely be some aspect of the tune.

 

[crf250r6]

Theirs another forum on where someone had the same problem and they talked to ford and ford said they had changed the heads in 04 putting beefer valves in them and that's when the problems came up. I have a few friends with 99 2000 and 02 and don't have this problem.

 

[rurouni20xx]

they didnt change the valves they are the same part number, they went to beehive shaped valve springs. now if the valves are staying on the seats longer because of stiffer springs allowing for more time to transfer heat to the head that may have something to do with it. i credit big jim for correcting me on the seat issue but the airtime also has a lil to do with it as well. the purpose of titanium intake valves in your dirtbike is to dissipate heat better, they dont heat up as fast and last longer. also since the valves are cooler it doesnt affect the temperature of the intake charge. your exhaust valves are steel in a honda head (honda mix their valves yamaha uses all titanium in the 5 valve designs but the newer 4 valve designs they are going back to tit intake/steel exhaust) so they will absorb the heat and transfer it to the exhaust, this in turn heats up the exhaust port a little more to help burn any excess fuel. a lil more fuel can be used to "water down" the cylinder head temperature but creates an incomplete burn and fouls plugs a lil quicker. personally i would add a lil fuel change my plugs every 12k miles rather than 16k miles lose about 1 mpg and not worry about valves for the rest of the engines life. all in the tuning. the cats stopping up can back up your system as well like a few others have mentioned but when they do youll notice a drop in fuel economy. my cats stopped up at 220k i went from 23 mpg to around 18 and wondered what was going on, threw a cel then my mileage went to 8mpg. had a high flow converter installed, dropped the factory one on the floor and 3/4 inch of soot piled where i dropped the dam thing. i can tell you for fact that was caused by rich mixture and a tad bit of oil usage. as hot as that cat gets though i doubt the little bit of change in your tune would affect any of the rest of the system.