Recommend steps before fitting replacement engine

[onemanonelaptop]

Hi All,

Looking for a bit of advice. My 99 SOHC explorer has a broken cassette and has slipped timing (most likely) due to the popping/backfire sound when attempting to start.

I have a replacement engine on the way as it seems the easier route to take than fuss with installing a new timing chain set along with the possibility the valves took damage.

My question is what do you recommend i do to the replacement engine before fitting, what should i change/replace while i have it on the engine stand prior to fitting.

Thanks for your help

 

[C420sailor]

Depends on what you have coming.

I assume it’s a long block.

Gonna need to swap over the correct valve covers, knock sensor, fuel injectors and rail, intake system, exhaust manifolds and EGR, thermostat housing, engine mount plates, etc.

Change your motor mounts now. Install new gaskets as you go.

If a question pops up, ask us here.

 

[vroomzoomboom]

^^^ pretty much covered it.

 

[donalds]

X3^^^^^^

 

[Gary Crist]

If it is Auto, make sure the torque converter is all the way home!

 

[onemanonelaptop]

Ok so here is the engine that will be going in. Ill be replacing sparkplugs, oilfilter before fitting.

Ill be using the torque convertor from the truck instead of the one attached below.

Basically anything else i should replace with new parts while i have easy access.. (ill of course have to reuse all the hoses from the old engine for ones that were cut when this engine was taken out.)

 

[onemanonelaptop]

Depends on what you have coming.

I assume it’s a long block.

Gonna need to swap over the correct valve covers, knock sensor, fuel injectors and rail, intake system, exhaust manifolds and EGR, thermostat housing, engine mount plates, etc.

Change your motor mounts now. Install new gaskets as you go.

If a question pops up, ask us here.

Thanks for the reply appreciated. I think most of those are attached to the replacement engine already....

Ill add new engine mounts to the list, may as well replace all the belts while im at it.

 

[EB4X]

Water pump....
Unlikely, but if any of the freeze plugs look in subpar condition may as well replace them....cheap and easy.... I would replace any that are at rear of block / heads regardless - not sure if the SOHC has any back there....

 

[vroomzoomboom]

Oh! Another thing, also make sure to swap that flex plate from the one that came in your truck to the motor you are using. Some had a different bolt pattern going to the converter.
ask me how I know.

 

[fastpakr]

Oh! Another thing, also make sure to swap that flex plate from the one that came in your truck to the motor you are using. Some had a different bolt pattern going to the converter.
ask me how I know.

Ouch - that's a painful lesson to deal with.

 

[C420sailor]

Those flexplate bolts are external torx DO NOT use a 12pt socket.

What year and vehicle is the donor out of? Mileage?

When I did mine, I did the water pump while access was easy. Replaced both cam chain tensioners too (with Ford units).

I’d regasket what you can now. Valve covers, exhaust/intake manifolds, EGR, all that. It’s a little more time and money up front, but will keep you bone dry another 200k+ or whatever you get out of this thing. Depends on mileage, obviously. Ignition wires are easy to run hanging from the hoist, too. PCV is easy to get at. You can stand in the bay and change both upstream oxygen sensors.

Tip: put a piece of plywood or similar between the engine and AC condenser when you do the job. When my engine and trans unmated, the engine swung forward and hit the ply. Likely would’ve punctured the condenser had that not been there...

 

[onemanonelaptop]

Those flexplate bolts are external torx DO NOT use a 12pt socket.

What year and vehicle is the donor out of? Mileage?

When I did mine, I did the water pump while access was easy. Replaced both cam chain tensioners too (with Ford units).

I’d regasket what you can now. Valve covers, exhaust/intake manifolds, EGR, all that. It’s a little more time and money up front, but will keep you bone dry another 200k+ or whatever you get out of this thing. Depends on mileage, obviously. Ignition wires are easy to run hanging from the hoist, too. PCV is easy to get at. You can stand in the bay and change both upstream oxygen sensors.

Tip: put a piece of plywood or similar between the engine and AC condenser when you do the job. When my engine and trans unmated, the engine swung forward and hit the ply. Likely would’ve punctured the condenser had that not been there...

Thanks for the in depth reply..

The donor is from a 2000 explorer and has done 118k

The old engine is 1999 and only done 70k
Before i go down the donor route is there an easy way to tell if my valves are damaged as if they are not then i still have the option of replacing all the chains/tensioners and cassettes etc.... It is only my assumption they are damaged.

When i crank the engine it obv doesnt start and there is a loud pop/backfire periodically.

 

[C420sailor]

You could do a compression test or a leakdown test. You could also borescope the cylinders and look for any evidence of piston to valve contact.

I’d recommend all three, if possible...but I like to be very thorough.

With only 70k on the clock...if it were me, and the pistons/valves looked good, I would give strong consideration to removing the engine and fixing it. You know what they say...sometimes the devil you know is better than the one you don’t...

 

[onemanonelaptop]

You could do a compression test or a leakdown test. You could also borescope the cylinders and look for any evidence of piston to valve contact.

I’d recommend all three, if possible...but I like to be very thorough.

With only 70k on the clock...if it were me, and the pistons/valves looked good, I would give strong consideration to removing the engine and fixing it. You know what they say...sometimes the devil you know is better than the one you don’t...

Ok so ive done a compression test which ive asked a question about here: Compression testing advice / Help

Assuming ive done it correctly i have ZERO compression across the board.

 

[C420sailor]

Yeah, if it’s out of time a comp test won’t work. You could pull valve covers to verify when the valves are all closed on a jug, then do a leakdown.