2.9L compression question

[Four0Sport]

i acquired a 1989 bronco II that uses antifreeze like a fiend, its deffinetly going into the oil. when i pulled the dipstick out 3/4 of the stick was covered in a milky coffee colored mixture of antifreeze and oil. pulled out the old compression tester and started doing some diagnosing. here is what each cylinder read:

3 -120 6 -120
2 -135 5 -105
1 -120 4 -120

front of engine

i know that like 4.0s their predecessor the 2.9 is known for warped/cracked heads and head gaskets going out. my question is whether the low side or high side is where the leak is occuring. just seemed odd that cyl 2 is over the exact amount cyl 5 is under. hmm. im not the greatest and engine work or engine diagnosis but projects like this keep me from being bored.

if anyone has any input or ideas id appreciate it. just thought id get some responses b4 i get into tearing the heads off. deffinetly not looking forward to that.

 

[410Fortune]

You may consider the cost of new heads for that 2.9L vs the cost of just replacing it with a low mileage 91-94 4.0L, its almost a bolt in conversion, you just have to convert to the DIS and MAS 4.0L computer

I am no expert either but I do know that water in the cylinder can mess up your compression test

 

[Four0Sport]

yeah.. there is some bottom end noise too. im afraid the water has already washed out the rod and main bearings as well as the cylinders. i have priced a couple used 4.0s but wasnt sure of how much work you had to do, i.e. replacing the computer, running MAF and DIS. did you document your 4.0 swap like you did your 5.0 conversion? would make for some good reading.

 

[410Fortune]

I did not, I did the 4.0L conversion A LONG time ago, however I do have wiring charts that may help
With your 2.9L being a 89 it already has the big white round wiring plug near the brake booster, almost identical to the 91-92 explorer making your job even easier.

there are like 16-20 wires that talk to the truck from the engine/trans and computer... the rest you can pretty much get from a donor and bolt in

in fact in late 90 or in CA the 2.9L was EFI for a few years, I think they even offered a 2.9L in the ranger until 91, that 2.9L was MAS and EFI but it did still have a distributor...

So you can either gut your engine bay of all the 2.9L stuff or some people have actually taken the 2.9L wiring and piggyback the required wires for MAS and DIS on top of it, then make it all plug into the 4.0L computer... they are VERY similar engines.

Once you have a OHV 4.0L in a Bii you will wonder why the hell the 2.9L was ever used... the 2.9L is great in a Merkur car (Scorpio) but not in a heavy 4x4 IMO 4.0L = hell yes

 

[Four0Sport]

yeah.. a guy that comes in work did the 'piggyback' method to add MAS to his late 80s mustang 5.0 and said it was relatively easy. its something i will deffinetly consider as 4.0s are more common and easier to find than a 2.9

 

[410Fortune]

and they actually make enough torque to motivate a BII!