can u guys tell me about 2.9 v6's

[Shran]

I don't think the 4.0 radiator is really necessary. I have put them in two Bronco II's now, and it is almost like they keep it too cool. My temperature gauge doesn't even go into the "normal" range anymore, just stays at or near the bottom after the radiator swap. My buddy's B2 did the same thing. I have a feeling that it has a serious effect on fuel mileage too since it will run richer when it's cold, and since it's always cold now...well do the math.

 

[4.0B2]

get a different thermostat??? so it stays closed longer

in all reality the 2.9 is a great motor, not a lot of power but still good stuff. i ran mine a long time and it NEVER overheated. idk why so many of them do but i know of 3 different ppl, myself included, that never had an issue with it. now the 4.0 fits like a dream and gives so much more power. its awesome, so if it goes bad, swap the 4.0 in and be done with it all.

 

[Shran]

get a different thermostat??? so it stays closed longer

Hottest thermostat you can get is a 195, and that is what I have in it. The 4.0 radiators are just so frickin big that by the time the thermostat opens, the water in the radiator is very cold and the thermostat just closes again.

 

[rusty70f100]

Well after having an '86 Bronco 2 in high school, and an '87 now, here's the advice I can give:

1. Run an OEM Ford thermostat. The aftermarket ones, for whatever reason, seem to make the engine run cold. I don't understand it, but that's been my experience.

2. The TPS (throttle positon sensor) likes to go bad. Hook up an analog multimeter, and set it to resistance. Go between the center and either the top or bottom pin on the sensor. Slowly open the throttle, watching the resistance. If it does not increase smoothly as you open the throttle, the sensor is bad. I find it's about a yearly replacement item. It will run a lot better, and get better mileage, with a good one.

3. If it doesn't want to start in the winter, suspect the starter. I learned this the hard way at -30F. It would crank over too slowly to start when it was that cold, but that was enough when it was warm. A new starter fixed it.

4. If, after you've taken a fairly long trip, there is condensation and / or snot on the bottom of the oil cap, you may have a cracked head. Every 2.9L I've seen that did not have a cracked head was dry as a bone inside the oil cap after a complete warmup.

5. I live in Iowa and I run 0w30 Redline synthetic oil in the winter. Not only does it crank over nice and fast, it keeps the engine cleaner too. The engine also doesn't tick on startup nearly as much as it did on conventional.

6. They like to leak out the back of the intake. Plan on putting that gasket in about every 60,000 miles. You can tell by the oil dripping off the bottom of the oil filter.

They're like anything else, you maintain them and they treat you good. My '87 gets 26mpg on the highway, and about 22 to 23mpg in town. The key is maintenance. Make sure you've got good plugs, plug wires, cap, and rotor. Make sure the O2 sensor is ok.

Just my suggestions. If I can think of anything else I'll let you know.

 

[disciplerocks]

I have the same problem with my 4.0 radiator, but I am not too worried about it.

 

[4.0B2]

Well after having an '86 Bronco 2 in high school, and an '87 now, here's the advice I can give:

1. Run an OEM Ford thermostat. The aftermarket ones, for whatever reason, seem to make the engine run cold. I don't understand it, but that's been my experience.

a lot of times if you are not careful, autozone will give you a 180 or 165 degree... or at least they will here, you gotta watch it and make sure you get what you want... my 195 from autozone worked great in the 2.9..
but i don't have COLD COLD winters either here in missippi

 

[85rx7_93ranger]

well i work at oreillys liek i mentioned earlier so ive aldready replaced the radiator hoses belts and used a oem premium 195 thermostat.

today i brought it back to the dealership and they did a warranty on the brakes for me and replaced the pads and rotors for free! yay

next thing is im gonna weld up my auto 4x4 hubs like i did with my old ranger for this winter )
liek this hehe

 

[RacinNdrummin]

The only reason to keep a 2.9 in anything is if you dont know how to swap an engine. The 4.0 is the best/easiest upgrade you can do to a Ranger or BII. The 4.0 is literally like a 2.9 on steriods, and the 4.0 SOHC (which really isnt that hard of a swap) is like a 2.9 x2.

In my opinion, its not even worth discussing the 2.9, its easier to swap in a 4.0 than to modify the 2.9 in any way that gains substantial power.

 

[4x4junkie]

My 2.9L has given me no problems (has about 170K). Runs quiet (has a slightly audible tick from the fuel injectors, no lifter tapping whatsoever).
I find it has adequate power (it's only 20 less than the 4.0L), though it does need to be revved to get that power (which is why tall axle gears with large tires suck big time with this engine).
However I would agree that there's little to be gained from modifying one, it's already pretty well optimized (at 48.3 HP per liter, it beats a lot of engines even 10 or more years newer). Swapping in a 4.0L is the way to go if more power is what you want.

I have the 4.0 auto trans radiator and a 195° t-stat on mine... No issues with temps being too low (the factory gauge does like to read low, though I think it's just the gauge), it consistently gets MPG in the low-20s. A 4.0L will likely replace it when (if) it wears out, but so far it's been doing pretty good.

 

[Shran]

The only reason to keep a 2.9 in anything is if you dont know how to swap an engine.

Oh.

Guess I should have scrapped the good 2.9 I had then and paid someone else for their 4.0 when I put an engine in my B2. My bad.

If you got it, use it.

 

[rusty70f100]

The only reason to keep a 2.9 in anything is if you dont know how to swap an engine.

Or if you like good gas mileage...

 

[Andres629]

I've got a 2.9 in both my Ranger and my BII', and both of them are awesome motors. Neither of them tick or eat anti-freeze, the rear main went on my Ranger, but fixed that when I did the M5OD conversion. 4.0 clutch for the win, so much nicer to drive. My BII has 3.45's in it right now on 33's, and honestly it's not nearly as bad as I thought it would be. Just watch your temps, install an aftermarket temp gauge and you'll be golden. If you're going to port the heads, port the upper and lower intake at the same time. They are terribly matched from factory. Also run an 86-87 throttle body to let more air through. The fuel mileage on these engines (when running proper) is awesome, much better than any of my 4.0's were.

Oh yeah, nice clean BII. Must be nice... lol.

 

[RacinNdrummin]

Or if you like good gas mileage...

Fuel mileage with the SOHC is better than the 2.9...and thats with 30" bighorns (not the most street friendly tire) over bald-ass 225/70-15's...

You gotta keep your foot out of the 4.0 to get mileage out of it

After having both of these engines and how little trouble it was to swap in the SOHC, Ill never have a 2.9 again.

 

[RacinNdrummin]

Oh.

Guess I should have scrapped the good 2.9 I had then and paid someone else for their 4.0 when I put an engine in my B2. My bad.

If you got it, use it.

Yes, you should have, and you still should... The 4.0 is a better all around engine...

I used to be a 2.9 fanatic... until I got a taste of the 4.0... and especially the SOHC. OHV 4.0's are a dime a dozen and are easy as pie to swap in, there is no drawback to putting one in a 2.9's place period, not even mileage.

So roll your eyes all you want....

 

[rusty70f100]

I've had both. Granted the 4.0L was in a '92 Explorer, and the 2.9L was in an '86 Bronco 2, but the best the 4.0L in the Explorer ever got was 16.5mpg. that was with the foot out of it going 55mph down the highway, with the wind. Both had an automatic transmission. The Bronco 2 got 20-22mpg consistently, and that was with a badly ticking engine and a high school kid driving it. The Bronco 2 I've got now, with a good running 2.9L, manual transmission, and a sane driver will get 23mpg in town and 26mpg on the highway. You can beat the crap out of it and you'll still get about 21-22mpg. Your SOHC 4.0L gets better?

I'm not calling BS, I just want a number.