1986 ford ranger 2.9 won’t rev past 3k

[Noah44]

I bought a 1986 2.9L 2wd ranger a little while back and it needed some work as it sat in a field for probably 10 years or so I was told so I replaced every single brake line front right hose both front calipers new pads and I cut the rotors. Everything’s good there but now I’m stuck. The truck in neutral used to rev and bounce at 7k and if I was I’m gear with the clutch in it would do the same but that was only when the engine was somewhat cold and I mean like the first 5 minutes running after that it will not go above 3k and the engine sounds like shit and starts piping when it does. The truck overheats really quick to it was gettting so bad that just moving it around it would overheat so I took the thermostat out and it goes good for probably 10 minutes now until it gets to normal operating temps so somewhere around 200 degrees and at that point it dosnt want to run past 3k. And now like within the past 2 days it won’t go past 2800 even right when u start it. The truck idled at 2000 when I first got it so I put a idle control valve in it and now it idled between 700 and 1000 I’m so confused with this thing right now has anybody had a plroblem like this or have any advice?

 

[black_demon69]

Have to ask why would you want to Rev it to 7k in the first place?
Sounds kinda like a blown headgasket too me

Check spark plugs, compression, fuel pressure, etc...

 

[evintho]

Sounds kinda like a blown headgasket too me

Check spark plugs, compression, fuel pressure, etc...

Cracked heads are a common problem on 2.9's.

 

[Dirtman]

I think the problem is that it sat in a field for 10 years...

 

[black_demon69]

Cracked heads / blown headgasket is probably why it was parked for 10 years....
Still pulling plugs etc can be very telling. Probably should also do glove test

 

[alwaysFlOoReD]

My understanding is the computer won't rev past 5500. That's the limit on my 4.0l.
Yes, you need to do some investigation. -Check the rad fluid. There is a tester you can use to make sure it is at the correct percentage for your area. Plain water is BAD. Rust forms and clogs the rad and heater core.
-Do a compression test. There should be even compression on all cylinders, within 10%.
- Do a glove test. That will tell you if head gasket is gone. Search on site there is a good description that RonD gives.

Get back to us with results.

 

[Noah44]

So I decided to pull the valves covers off it it was just disgusting what they had in them it was like what u get on your stove after something burns all charcoal and chunky bits so i decided to pull the heads off it to still working on that thoughbut I got the intake manifold off it had like a black mud between the gasket and manifold everything is just nasty. I refer it that high just to see if it was having the problem all the time since it wouldn’t rev once warm. Hopefully by tomorrow I can get the heads off and then gonna take everything and clean it and put new gaskets and put it back together as long as nothing is broken or cracked. If the heads r cracked and the motor needs work what would be the best swap I want something diesel I was kinda thinking a tdi because it would have the torque and still have enough power for the truck to move good plus it would get good fuel mileage had anybody done that before?

 

[Noah44]

The antifreeze I’m the truck no matter how many times I flush it and put more in it comes out brown and boils away so even though I know it’s bad I’m using just straight water to try and get any of whatever is in there out that’s also why I’m taking the heads off hopefully cleaning some stuff can get something out that could be blocking some of the passage ways

 

[PetroleumJunkie412]

2.9 rev limiter is 5600 on 88+.

J&C Enterprises in Fairmont WV builds stout fully dressed replacement heads for the 2.9. They won't crack.

Did you pull KOEO/KOER codes yet?

2.9s are severely allergic to heat. Don't overheat it. You will break expensive parts if it overheats.

Clean out your rockers. You'll kill the new heads or your old ones if yout don't.

Install a catch can.

Change oil, run a can of liqui moly engine flush and a spray can of sea foam intake cleaner, change oil again afterwards. Use full synthetic (Walmart generic is fine), a Motorcraft FL-1A filter, and run 20% lucas synthetic oil Stabilizer.

It also sounds like either your coolant temp sensor or IAT sensor is shorted, dead, or both of them are. They're cheap. Consider replacement.

Check timing by pulling your SPOUT connecter. If it walks around on its own +/-2 degrees, your hall effect sensor is dead.

Just throwing the generic crap out there. Cleanliness is king with 2.9s.

It's a 2.9. If it's kept clean,cool, and well lubricated, they don't quit.

 

[black_demon69]

Might also pull water pump and check impeller, also while heads are off I would clean carbon from cylinders and you can use some compressed air to agitate debris in the bottom of the block to make it easier to flush out using water hose. Just protect cylinder walls from rust by coating with Vaseline and clean up water from cylinders then remove and clean Vaseline just prior to putting heads back on then coat with a thin coat of clean oil.

 

[alwaysFlOoReD]

Yeah, I had a 4.0l water pump impeller loose on the shaft. It moved enough water at idle but as soon as you started moving the temp gauge went up.

 

[Jay11]

2.9 .....

Thank you for this information. I just got a 4.0 and this will be handy.

 

[PetroleumJunkie412]

A

Thank you for this information. I just got a 4.0 and this will be handy.

A 4.0 is:

Good boat anchor for a large boat.

Makes a great counterweight for a trebuchet.

A source of some 2.9 parts

Worth around $100 as shredder scrap

Not a 2.9.



If you own a 4.0, I'd recommend sand and vinegar in leiu of oil. Works great!

?

 

[Jay11]

A



A 4.0 is:

Good boat anchor for a large boat.

Makes a great counterweight for a trebuchet.

A source of some 2.9 parts

Worth around $100 as shredder scrap

Not a 2.9.



If you own a 4.0, I'd recommend sand and vinegar in leiu of oil. Works great!

?

Say what? Is a 4.0 4x4 such a crap pile?

 

[sgtsandman]

Don't mind Petroleumjunkie. He just loves the 2.9 so much that all other engines are inferior.