How screwed am I?

Here is a picture of the plugs I just pulled off my 89 B2. I purchased truck for $500 bucks. It's a beater to say the least.



Can she be saved or so I need to start saving for a rebuild on her or just a new engine? She will crank but will die out quick without you pressing the gas. And you can smell burning oil.

I just replaced all plugs, wires, distributor and distributor rotor.

Looks like you got a bit of oil coming in.......................

Probably rings but you can do a compression test to confirm.
Leaking valve seals won't effect compression, leaking rings will.
Remove all spark plugs for the test
2.9l is 9.0:1 compression ratio so you should be 150psi+

Also disconnect coil to distributor wire and crank engine a few times, pull out a few spark plugs to see how bad oil intrusion is, look at spark plug tips

Valve guide seals can be changed by just removing the valve covers

Is the compression test something I can do at my house? Or have it done at a shop? I'm decent with my hands but this is my first project truck I want to do most the work on. I would think I can replace valve seals. But the rings? How intrusive is that?


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Compression test you can do at home. Make sure to have a fully charged battery.

Replacing rings means pulling the motor and tearing it apart.

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+1 ^^^

Compression test "Kit" can be rented at many auto parts stores or tool rental places
And can be purchased for $25-$50

Basic "kit" has a pressure gauge with release valve, a 1ft to 2ft hose, and 2 or 3 spark plug threaded inserts.

Walmart has this one: https://www.walmart.com/ip/Equus-3614-Innova-Compression-Tester/14644668

The insert screws into spark plug hole, the hose screws into insert, the gauge hooks to hose with "quick connect".

The gauge has a 1-way valve that lets pressure in but not out.
After gauge is hooked up to a cylinder you crank the engine with starter motor.
On each compression stroke of that cylinder it builds up pressure in the gauge.
After 4 or 5 compression strokes gauge will show highest pressure achieved
You write that number down, along with cylinder number
Release the pressure with the valve button and move tester to next cylinder.

You want all the spark plugs out so starter motor can spin the crank shaft as fast as possible, you will also be able to "hear" each time the cylinder being tested "hits" its compression stroke, crank slows down.
This is why you need good charged up battery.
Also while cranking the engine hold the gas pedal down all the way, this turns off the Fuel injectors but also allows better air flow into the engine


As alwaysfloored said piston ring replacement would require pulling out the engine, and at that point you would need to decide about rebuilding or replacing the engine.

A "Short Block" rebuild means new main and rod bearings, new cam bearings, new rings, maybe new pistons(they don't always need to be replaced), cleaned block, honed or bored cylinders, and new oil pump in most cases.
But no heads or head work is included

"Long Block" rebuild includes the head and valve work, and heads are installed on the block with lifters, push rods and rockers adjusted

You can pay for a Short Block rebuild then add the heads and other stuff yourself, although heads should be cleaned, surfaced and pressure tested at machine shop before being reused, and new valve guide seals installed.
Make some calls to local machine shops for pricing on short and long block rebuilds and head work, prices vary from shop to shop, also time frames, so ask.


A vacuum gauge is a good tool to have in the tool box, usually under $20
It works on any gasoline engine, no matter how many "do-dads" they add to an engine it is still basically a self powered air pump, so vacuum pressure can tell you alot about engine condition.
Good read here on using one: http://www.gregsengine.com/using-a-vacuum-gauge.html


Things you don't need to know, lol.
Engine compression is needed to heat up the fuel so a spark can ignite it, diesel engines ignite fuel just with compression heat.
You also get a "rebound effect" from compression, like winding up a rubber band releases more energy the more you wind it up.

Compression ratio is the difference in the volume in a cylinder when piston is at BDC(bottom dead center) and then at TDC(top dead center)
The head has a cavity and sometime pistons are domed or cupped.
If BDC has cylinder volume at 1,000cc and TDC has volume of 100cc then ratio is 1,000 to 100, or 10:1 ratio
BDC of 900 and TDC of 100 would be 9.0:1

Octane rating is a fuels ability to self-ignite when heated, 87 octane will self-ignite at a lower temp than 89 octane, and so on up to 93 octane for gasoline.
At about 9.5:1 compression ratio 87 octane will start to self ignite, self-ignition causes the pinging or knocking noise, and is bad for the engine.
87 octane gas and 93 octane gas have the same energy potential per gallon, Octane is strictly a temperature rating.
Higher compression engines MUST use higher octane fuel, but don't get more power from that higher octane, they do get more power from the higher compression though.
If you seem to get better MPG with higher octane fuel, with a 9:1 ratio engine, then you probably have some pinging going on and may not be hearing i.

To calculated expected PSI compression you can use 18 x (Compression ratio)
18 number comes from 15psi air pressure at sea level plus 3 for the mechanical compression of piston/crank movement
9:1 ratio x 18 = 162psi expected

Metal rings against metal cylinder walls are not suppose to be an air tight seal, same as metal valves and against metal valve seats are not an air tight seal, they leak even when brand new.
They are temporary seals, the faster the piston is moving the less time there is for air to leak out so the higher the compression numbers there will be
Which is why best starter motor/crank speed will give best compression numbers.

There is another test called a Leak Down test, it tells you how much the rings and valve are leaking.
You use an air compressor set to deliver 100psi of pressure
You put test cylinders piston at TDC
You hook up air hose with gauge to that cylinders spark plug hole and turn on the pressure
If gauge shows 95psi then you have 5psi leaking out or 5% leak down, this would be a fairly new engine.
If gauge showed 90psi then you would have 10% leak down, so older engine.
After this test and 90psi you would remove the hose from cylinder and add a teaspoon of oil to the cylinder via spark plug hole, then rotate engine a full turn back to TDC and retest that cylinder.
The oil will help seal the rings but not leaking valves
So if retest showed 95psi then rings are leaking the most
If test showed 91/92psi then valves are whats leaking the most
Called a dry and then wet test

You can do the dry and wet test using compression gauge to tell if it is a ring or valve issue on lower PSI cylinders

Thank you RonD. I'll have to read what you said a few times to take it all in. I'll get a kit from Walmart to do the self test. Then probably hit you up again to help me understand the results. Thank you for your time and knowledge. It is much appreciated. My mechanic can do rebuilds at his shop, but if it comes to a full rebuild depending on price I might just do a swap. Hopefully I can do test in a couple of weeks once life slow downs from Christmas.

Thank you again.

Elijah

Thank you

Used engines are a roll of the dice at best, last 2.9l built was 1992, 24 year ago, so all are very old now.
1989 to 1992 models will have the "good heads", which you have already
1988 and earlier 2.9l heads were prone to cracking so should be avoided unless you swap your heads over to the older engine.

4.0l OHV engine is a bored out 2.9l which will bolt to your existing trans and motor mounts, but does require computer and engine wiring swap
This page has info on 2.9l, and 4.0l engine swaps: http://www.therangerstation.com/tech_library/index-engine-fuel.shtml

But 4.0l OHV was discontinued in 2000 so 16 years old now and you would want a 1990 to 1994 4.0l for the 1989 B2 in any case, for best wiring and fuel system match up

Glad to know I at least got something good from the engine.

I'm your opinion should I stick with the 2.9l if I do a rebuild? I see a lot of people going to the 4.0l. But that would probably add in a lot more labor and cost for a transmission to fit it correct?


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2.9l and 4.0l share the same engine block so transmission from one will bolt to the other.

But changing engine size adds more labor and cost for sure, vs reinstalling same model engine.

And when considering an engine size swap you have to include the 5.0l V8


And yes, in my opinion, the 2.9l would be best long term for reliability and parts.
There never was a 4.0l B2 so parts ordering becomes more complicated, i.e. is it a 2.9l B2 part or a 4.0l Ranger part

Gotcha. Thanks again Ron. If I could afforded a 5.0l V8 I would. I also read about people dropping a 302 in them. Hopefully I won't need a rebuild and just a new valve seal or new valves. Might as well do both if a seal is need right? lol.


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The 302 and 5.0l are the same engine, just FYI, Ford renamed the 302 the 5.0l when things started going metric in the late '70s.
302 was first made in late 1960's, then in the late '70s early '80's it started to be called the 5.0l
Parts are interchangeable for the most part

Just for an idea, I asked a couple local shops about the 2.9L V6 to have one rebuilt. Both shops quoted close to the $5k mark. Another shop wouldn't even mess with it and said they'd drop in a crate engine...which I'm sure those other 2 shops would do as well. They gotta pull the engine anyhow, so they may as well start with a long block and then put everything back together from there.

Regardless though, I think I'd stick with the original engine. The 4.0 sounds cool until you get into the wiring and realize it actually gives you most likely less fuel economy plus the headache of never being able to just go to the parts store and get standard parts you'll forever be wondering if you got the right part because part of it is now a 4.0 rather than a 2.9. Stick with the right engine unless you forever want a headache.

I thought about a 4.0 swap when I am ready to have engine work done on my bronco 2, but I don't want to mess with the wiring, it just makes far more sense to put the right engine in to begin with. I could care less about 1/4 mile times I don't race and truthfully the 2.9L has plenty of power, it is NOT a race car.

A long block from Autozone, Orielly, etc is in the $2-3k range. That makes far more sense for myself rather than trying to pull the current engine and rebuild it right away, at least with the long block I can throw the accessories on, drop it in and hook everything up and be back on the road sooner...then take my time on the old engine.

Seems pricey to me but never shopped online for engines.

New bearings, cam, crank, and rods would be about $100

New pistons with rings about $200, just rings would be about $90

Full gasket sets about $150

New oil pump, new timing chain, new head bolts, about $90

You can have the block hot tanked and honed, by machining shop for about $150
You have to reinstall the core plugs(freeze plugs) it is easy to do, cost for plugs is about $10

They will also install the pistons/rings, cam, crank and rod bearings for you, usually $250 minimum charge for V6

Heads are up to you, machine shop charges about $100 per head to clean, surface and pressure check

It does add up but $2,000 to $3,000 doesn't get you a better engine, in fact it is worse from the stand point of a problem.
A phone number to call is the warranty
And "installation" mistake is often the first response, so "not our problem if you or your mechanic goofed up on the install"

I am sure people get good engines on-line all the time, so just a grain of salt

I hope compression comes back good so I don't have to decide on rebuild or replace. Maybe I can convince the wife for the compression test kit as an early Christmas present.......


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