4.0 SOHC Engine

[BigPip]

I am about to go pickup a used SOHC engine to put into my explorer and wanted to get some input about what you suggest replacing before putting the used motor in. I am for sure going to change the timing chain and guides as I have read alot about them. My hopes are to find a wrecked truck in the bone yard and pull the valve cover off to see what it looks like in there.

Thanks for any suggestions.

 

[Stang65fst]

I always wonder about doing the head gaskets when you have the motor out.

 

[scdix50]

Replace rear main seal, check all freeze plugs and make sure you have a good thermostat housing, if you are already in salvage yard, look for one that has been resently replaced. While your there grab some spare bolts, for upper intake, lower intake, valve cover and any other loose bolts.

 

[Joe Dirt]

add 2 more cylinders...

 

[joecrna]

Look for leaks at the primary oil pan. Can't get to this with it in the truck. PCV valve, hard to access in the truck and cheap to replace. As you said, timing chains and balance shaft if its a 4x4 engine. Id replace/upgrade those no matter what unless its a newer engine. T-stat housing frequently cracks but is easily replaced. If you want headers (waste of money) do it now. Nothing much elase goes bad, so just fluids, belts, hoses, plugs, wires, filters. The standard replacables. Id put in a new fuel filter too.

 

[BubbaFL]

add 2 more cylinders...

+1000

If you have the time and money, find a V8 donor truck and do a swap. Toss the POSohc.

 

[BigPip]

I have heard the SOHC was a good engine... My Continental has the v8 (4.6) and with its new pipes I am happy with it.

What I am trying to do is put the original engine back in the car, someone put an OHV in the SOHC truck and I am tired of chasing problems. I found someone that pulled their engine already to replace the timing chain but decided it was too much $$ so he agreed to sell the motor for $100.

Thanks for all the advice! I am now leaning towards pulling the heads and having them dipped and grind all the valves down. I didn't even think about freeze plugs, that's a great suggestion. I was thinking about borein' it out but that's just getting crazy. I will measure the cyl walls to make sure they are still in range.

 

[BubbaFL]

I have heard the SOHC was a good engine...

Somebody's pulling your leg. Probably the worst designed engine in modern history with such a long production run. It should have died on the drawing board.

I rebuilt mine just to see how cheap I could be and still come out with a good running engine.

For the price of "doing it right" (valve job, new bottom end, buying a good quality timing kit instead of the chinese ebay one), I'd just buy a donor V8 truck (or just buy a new truck) and never have to worry about that stupid-%^* chain on the back of the motor again.

Good luck whichever way you go!

 

[fordnut71]

i have a 99 sohc. we got it with140km on it an the truck now has 300km on it now.
iv only have run castrol syntech in it sense we got it an it doesnt burn any oil at all. the death chain rattle an chain are still the factory parts. motor has only been opened up for a t stat i had to replace last winter. so in my books the 4.0l sohc is a great motor

 

[albi1cnobi1]

99 SOHC V6 204,232 miles. Keep the oil changed, do the tensioner TSB, and she'll run a long time. If you have the engine out changing all the chains and cassettes is a smart idea. Do that and she'll run forever.

 

[BigPip]

add 2 more cylinders...

what engine (v8/302) will bolt up in there? do I have to get one out of an explorer?

 

[BubbaFL]

what engine (v8/302) will bolt up in there? do I have to get one out of an explorer?

That's the easiest route - get a V8 Ex, move over the engine / tranny /exhaust / front dress / computer etc.

 

[htrdlncn]

My SOHC engine started the timing chain death rattle at just over 100k miles,(so noisy I have had people ask me if it was diesel!!! ) I bought a replacement low milage SOHC from a newer Mustang for $500, I figured I would wait till the engine blew up to change it, well its been 60k miles and two years now (has 160k) I have beat the crap out of it, has been to the dragstrip three times now, has towed a 4000lb BMW on a car trailer across the state, has pulled my 6000lb boat around, and I floor it at least once a day running it up to almost 6000rpm daily and the the engine has NOT blown up, Im getting tired of waiting and trying to blow it up on purpose so i will probably swap to the newer engine this winter but the SOHC has impressed the crap out of me!!

 

[BigPip]

My SOHC engine started the timing chain death rattle at just over 100k miles,(so noisy I have had people ask me if it was diesel!!! ) I bought a replacement low milage SOHC from a newer Mustang for $500, I figured I would wait till the engine blew up to change it, well its been 60k miles and two years now (has 160k) I have beat the crap out of it, has been to the dragstrip three times now, has towed a 4000lb BMW on a car trailer across the state, has pulled my 6000lb boat around, and I floor it at least once a day running it up to almost 6000rpm daily and the the engine has NOT blown up, Im getting tired of waiting and trying to blow it up on purpose so i will probably swap to the newer engine this winter but the SOHC has impressed the crap out of me!!

When they wouldn't die for me, I used to drain the oil, brick on pedal and start taking bets on how long it would last before it would die. Also a good way to earn a few bucks for the new motor install.