Bronco II 2.9L Heads Need Fixin'

Ask technical questions about your Ford Bronco II here. Technical write-ups on your axle swaps, engine swaps, chop tops, etc. are encouraged.
BroncoNoob
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Bronco II 2.9L Heads Need Fixin'

Post by BroncoNoob »

So I am working on fixing up a the Bronco that my sister abandoned at my house. It is a 1987 with the 2.9L V6 Engine. She overheated the engine several times and the car has had some work done on it previously. To my knowledge, the radiator, water pump, and intake manifold have been replaced. The heads have been rebuilt. I think the heads / gasket / block has failed again. The bronco has stalled numerous times and has barely any power. I am currently working on taking off the heads to see if they are warped or cracked. It would be a miracle if just the gasket was blown. My questions are:
1. Has anyone done this rebuild / inspection before?
2. If needed where can I get the new style heads that won't fail as easily?
3. If the engine block is cracked or warped, what other engines are easy swaps for this one?

Any input or advice would be greatly appreciated. I can post pictures on request and will do my best to answer questions you have for me. I am a fairly new wrencher and budget is limited. Thanks in advance.
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clem
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Re: Bronco II 2.9L Heads Need Fixin'

Post by clem »

I always like to know what I'm getting into, so i'd do a compression test or a leak down test. Up here we have a store called Princess Auto, it's a lot like your Harbour freight, tools to do these test should be available there. A 4.0L swap should be fairly easy and will bolt to your tranny. I toasted several 2.9L so I'm going to a 5.0L but it's a long term project. Good luck. -Jeff
'87 bII d44,9",np435/205and a 302 ( on hold)
'73 vw bug
'70 vw camper van
'98 jeep tj
2010 ranger
'56 international s110
BroncoNoob
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Re: Bronco II 2.9L Heads Need Fixin'

Post by BroncoNoob »

Thanks for your help on this one. I can ask a friend for help on the compression test, but I have never heard of a leak down test. What is this? You say the 4.0L is a fairly easy swap. What 4.0L engine should I use, like what cars should I look to get one off of? Thanks again.
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clem
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Re: Bronco II 2.9L Heads Need Fixin'

Post by clem »

'87 bII d44,9",np435/205and a 302 ( on hold)
'73 vw bug
'70 vw camper van
'98 jeep tj
2010 ranger
'56 international s110
BroncoNoob
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Joined: Sat Oct 10, 2009 7:22 am

Re: Bronco II 2.9L Heads Need Fixin'

Post by BroncoNoob »

thanks ill be checking those very soon, i already have a lot of parts off so it might be a bit.
Bills86e
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Re: Bronco II 2.9L Heads Need Fixin'

Post by Bills86e »

Spark plugs readings can tell you about the fuel combustion, and
compression is used for basic internal health, and LD can tell you if the coolant is leaking from hd gasket. Oil reading if water is
not going into cylinder but from head into oil cavities. All these
the tech uses to diagnose. What are you baseing the complaint
on? Air not bled from system will cause OH condition. Did you test the coolant for exhaust gas in it?
Dreded
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Re: Bronco II 2.9L Heads Need Fixin'

Post by Dreded »

clem wrote:I always like to know what I'm getting into, so i'd do a compression test or a leak down test. Up here we have a store called Princess Auto, it's a lot like your Harbour freight, tools to do these test should be available there. A 4.0L swap should be fairly easy and will bolt to your tranny. I toasted several 2.9L so I'm going to a 5.0L but it's a long term project. Good luck. -Jeff
the 5.0L is only as long term as you make it... aside from drive shafts I did mine in one day... from 6am to 12am.. so 18hours.... keep in mind that was carbed on a 1986 BII that already had a body lift. oh and about 50hours of research :p then I rolled that truck bought a new BII body and decided to do a 4" lift at the same time... 2yrs later it still needs a bit of work lol
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BroncoNoob
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Re: Bronco II 2.9L Heads Need Fixin'

Post by BroncoNoob »

5.0L is a bit much for my budget I think. If I was going the engine swap route, I would probably look for the same 2.9L and just not drive it dumb, or maybe go the 4.0L route. You still haven't told me what vehicle to get the 4.0L that you are talking about out of.. as for updating progress, I rented the compression test stuff yesterday and will test it very soon.
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Ranger Dave
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Re: Bronco II 2.9L Heads Need Fixin'

Post by Ranger Dave »

BroncoNoob wrote:You still haven't told me what vehicle to get the 4.0L

http://lmgtfy.com/?q=4.0+swap+in+a+Bronco+II
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clem
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Re: Bronco II 2.9L Heads Need Fixin'

Post by clem »

Sorry, I forgot that part, thanks Dave. As for my bii, I'm doing the sas, 5.0L and some other mods at the same time as well as keeping the other rigs running.
'87 bII d44,9",np435/205and a 302 ( on hold)
'73 vw bug
'70 vw camper van
'98 jeep tj
2010 ranger
'56 international s110
BroncoNoob
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Re: Bronco II 2.9L Heads Need Fixin'

Post by BroncoNoob »

In regards to the compression test, will the engine lube itself enough for the continuous cranking it will be doing? Keep in mind 3 years have gone by since the last time it started. I was thinking of putting a little motor oil in the cylinders to make sure they had oil.
BroncoNoob
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Re: Bronco II 2.9L Heads Need Fixin'

Post by BroncoNoob »

So now I am confused. The engine passed the compression test, it read 180psi for 1,2,4,5 and 150psi for 3 and 6. The repair manual calls out a 101psi minimum spec. Thoughts?
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tekatlarge
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Re: Bronco II 2.9L Heads Need Fixin'

Post by tekatlarge »

Your not actually looking for the highest numbers your looking for numbers close to each other. It there is over a 20lb difference start looking for problems.

Well the difference is 17 percent roughly. I get over 10% and start looking for problems.

Next step. Squirt some oil in the cylinders and run the test again. If the difference remains above 10% then it could be one or more items like cracked head, bad valves,Worn out, or maybe a head gasket.

If you were using a leak down tester the next step would be look in the radiator for bubbles and listen to the intake for leaking air and listen to the crankcase for air leaking and also the exhaust.

A standard compression tester just gives you the pressure in the cylinder at the moment.

A leak down tester allows you to actually see and hear the reason a cylinder is low on compression.

It looks like you will need to tear down the top end
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Ranger Dave
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Re: Bronco II 2.9L Heads Need Fixin'

Post by Ranger Dave »

it will run with that compression
BroncoNoob
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Re: Bronco II 2.9L Heads Need Fixin'

Post by BroncoNoob »

So I put all the stuff I took off the Bronco II back on and threw in brand new coolant, and a reliable battery and turned the key. I used the half tank of old gasoline (5 years at least) and made sure it had enough oil. The bronco roars to life, but then tries to catch on fire. No flames were present, but smoke came from the passenger side of the engine. It is tough to tell where the smoke is coming from, but its not oil, or trasmission fluid burning. It idled fairly high (no tachometer, and i havent heard it run in a long time to determine high revving), for about 1 minute on four seperate occasions. Each time I turned the
engine off due to the smoke issue. I noticed a large amount of rust coming out of the tail pipe. I am assuming this is due
to the fact that the vehicle was outside for so long. One more point, every time I barely press the accelerator, the rpm
drop drastically. I let off before it stalled, so I am not sure if the car will actually stall. I looked at Autozone for that leak down tester, but they don't have one. Any suggestions on where to find one to rent? Any suggestions on the smoke or accelerator issue?
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