16th Aug 2008, 16:59

I own a 90 Ford Bronco II 2.9 2wd that now has 603,000 miles on the original engine. Paint is faded, dash is cracked.

But my old lucy keeps kicking along.

28th Aug 2008, 23:32

My Bronco 2 also just started ticking, close to 300,000 miles on it though. My mech says "Put some thicker oil in it and don't worry about the engine, one day it will puke itself and then you walk away." Is this bad advice? I have had the Bronco 2 forever and it's definitely not a money pit.

10th Oct 2008, 03:24

I too am a fan of the Bronco II, can't beat the turning radios on them, but I too have experienced everything you all have.

Mine is an 88, speedo says 197,000, it's got the 3rd engine in it now, went through 2 automatic over drive trans, and now is a manual 5 speed.

Had the CV drive shaft problem, fixed it with the u-joint conversion.

The 1st engine had a cracked head and spun cam bearings when I bought it, thought it was an oil pump so I changed it, the head and put a gasket kit in it, through it back in the truck, still ticked, but some times it would stop for about 5 miles and ease back into tickin.

The engine in it now is an 89 out of a Ranger; it's OK but just seems gutless, so I've recently bought an 89 engine from a junk yard, and plan to rebuild it as a mod. Going for 200+ whp. I know it's possible cause the Merkur Scorpio's was hitting around that. I intend to play around with the 2.9 for a bit, just because not many do.

The 5 speed manual is like day and night to the auto, I'll never go back. I get rubber in 1st and 2nd gears, and if not careful it will go sideways too, with a stock no mods 2.9.

As for oil pressure, I pay it no mind. I like the power it has at 3500-5000 rpms; hang there all day!

Can't wait to set this other engine in it, I'm shooting for a 6000-6500 rpm range power band with the same ECM, but who knows, I might have to even upgrade to a reflashable one.

Going with ignition upgrade, free floating rockers, port and match plenum, intake, and heads, 20-30 over bore, maybe even some longer rods, balancing the short block, weight re-ducting the crank, going to lighter flywheel and performance clutch, mill the heads and deck the block, debating on a cam profile yet, oh and bigger injectors, do something with its breathing process for cooler and more air, headers (to save those well known cracking heads), and maybe even electric fans...

Will see how that works for me, and in the mean time start to plan the off road version as a 351 or 390 conversion on 44's after the rust process becomes impassable in PA.

And no I'm not crazy, a 390 will fit, just need a bigger shoe horn! Might all seem insane, but I'm just not ready to give up my Bronco II just yet, I'm sure some of you understand!!!

30th Oct 2009, 14:43

I don't know what to say. I have a 1990 Bronco II with a 2.9L V6 and I love it, but I had to do a engine swap with a new water pump, cam and crankshaft seals, new oil pump and oil scream also a new gas tank because it had bad gas. After the engine swap it had no problem running. But one day the fuel pump just wouldn't work. Well I fixed that problem. But for some reason my Bronco II won't idle at all, and when I give it gas, it just bogs down. And I'm stumped.??? If anyone can help, please do.

Thanks.

31st Dec 2009, 19:31

I have a 1987. I know, engine is worn out, lots of noise after some highway trip and maybe low mileage, but I love this truck. Never let me down, and is perfect for the Baja desert roads.

1st Feb 2010, 00:20

I have been a Bronco2 fan for many years. I have owned 11 of them, only have 2 now, fixing to buy another.

I have an 89 with the 2.9, it's the first 2.9 I have owned that has been so noisy. I still love it, so I will spend the money and fix it. I hope an oil pump and aftermarket heads will help.

My other one is an 86 with a mean little 302. I would have a yard full of them if I could, but my wife would shoot me.

12th Oct 2010, 21:59

Getting ready to go look at a 1990 Bronco II with the 2.9L fuel injected V6. I've read all the comments here and I am fairly comfortable around the engine. What should I look for and check to see if it has any of the aforementioned issues?

I plan on checking the coolant and oil for any signs of cracked heads, driving it and listening for any loud noises and ticking. It's been in storage for years and looks in very good shape. Is there anything else I can check without taking it apart?

I appreciate any help from 2.9 lovers out there!

27th Feb 2013, 09:52

I just pulled a 4.0 from the local junkyard to rebuild for a project vehicle I'm working on.

It has some of the same valvetrain issues as the 2.9, but with the additional "feature" of fixed rockers so the ticking can't be adjusted out of the assembly. There is also a wear problem on the valve end of the rocker. This may be due to poor lubrication, poor materials (or a combination), or it may be that once the pushrod end wears to the point that the lifter can't compensate, the resulting gap on the valve side causes the wear.

I've read that the 2.9 pushrods and rockers will fit the 4.0. I have a single set ordered from Rockauto, and I'm going to compare them against my 4.0. If they fit, I'm going to use the 2.9 rockers and pushrods.

On the 4.0, the pushrods are hollow and there is an oil passageway to the pushrod cup. But they still wear. According to an engine builder article, the suspicion is that all the oil that gets to the pushrod cup in the rocker, drains down the pushrod rather than oiling the cup.

This is why the 2.9 system is so attractive. The pushrods aren't hollow, so if I drill the 2.9 adjusting bolt (as the scientist suggested) - and drill the rocker (if required - the 4.0 rocker already has this passage), oil will then get to the pushrod cup without draining away, and should solve that lubrication problem. That cup should always then have a puddle of oil trapped in it, that is constantly flushed clean. Wear should be drastically eliminated as long as the valvetrain remains adjusted. Drilling the adjusting bolt should be easy enough. Drilling the rocker will be a bit more complicated, but a simple fixture should suffice. However, it will probably be necessary to provide some sort of oil relief in the threaded area of the rocker, so that the oil that gets to the adjuster bore still feeds into the adjuster itself. Once I have one in hand, I'll be able to tell what's required.

However, I hadn't yet considered air bleedoff from the lifter as mentioned by the scientist. I have not seen that mentioned elsewhere in my researching.

One solution would be to drill the ball of the pushrod, and then drill a relief hole elsewhere on the pushrod to bleed off any lifter air. Perhaps a very small hole in the cone at the top of the pushrod would bleed off air, but still keep enough oil in the cup to keep the adjusting ball lubed up. Another might be to machine a slight groove in the pushrod ball where it meets the lifter - again to bleed off any air. Could also potentially modify the lifters themselves to bleed off air, although they are probably hardened and difficult to machine.

I'm leaning towards a large hole in the bottom of the pushrod (same diameter as the 4.0), but a significantly smaller hole in the cup at the top of the pushrod.

5th Mar 2013, 01:43

I have a 88 Bronco II EFI 2.9 4wd automatic. Just passed 60k miles, has had a lot of little problems, but probably the only vehicle I'll ever have as a daily.

Recently just took a 450 mile trip, taking it easy and ran great through the hills. Should have continued designs on the Bronco II.

Just ran into a problem code 21, but replaced the ECT sensor on it. Also replaced the fuel pump relay, fuel pump regulator, TFI, PCV valve alternator, cap, wires, but recently it decided to die on me while at operating temperature. Can't get up to speed after 20 minutes of driving, but I'm suspecting the map sensor. Haven't received the ticking yet, but when I do, swapping to a 4.0 sounds good.

12th Feb 2016, 10:04

My 89 Bronco II engine has just been freshly rebuilt. Just did the timing on it. It has not been on the road as of yet. It has a slight ticking noise seemingly from the passenger side. I suspect lifter ticking.

After reading quite a bit from other websites, it seems to be a design problem common with the 2.9 engine. Use a high volume high performance oil pump. Change oil when recommended & use a oil filter with an anti-drainback valve. Not sure if a thinner oil like 5w20 or 30 would be better or a thicker oil. The thinner stuff would flow faster I guess.