head removal
#1
#2
RF Veteran
iTrader: (1)
If the timing chains have not been replaced then you would need to pull out the engine.
Rear timing chain can only be replaced with engine out of the vehicle.
Google: ford 4.0 sohc timing chain replacement procedure
Explorers got the SOHC engine in 1997, Rangers got it in 2001, the old design and materials used in the timing chains/cassettes were faulty, the newer design and materials are better, they were installed starting in about 2005 on the 4.0l SOHC engines
Explorer how-to will be the same as Ranger how-to
As far as just fixing the spark plug threads
Google: spark plug helicoil thread repair kit
and
Google: time-sert spark plug inserts
This can be done with head in place, although you will need to remove(or cut out) inner fender and maybe remove exhaust manifold on that side for best access.
If you cut out part of the inner fender you can go to a wrecking yard and cut out a larger section from an inner fender there and use it as a patch
Rear timing chain can only be replaced with engine out of the vehicle.
Google: ford 4.0 sohc timing chain replacement procedure
Explorers got the SOHC engine in 1997, Rangers got it in 2001, the old design and materials used in the timing chains/cassettes were faulty, the newer design and materials are better, they were installed starting in about 2005 on the 4.0l SOHC engines
Explorer how-to will be the same as Ranger how-to
As far as just fixing the spark plug threads
Google: spark plug helicoil thread repair kit
and
Google: time-sert spark plug inserts
This can be done with head in place, although you will need to remove(or cut out) inner fender and maybe remove exhaust manifold on that side for best access.
If you cut out part of the inner fender you can go to a wrecking yard and cut out a larger section from an inner fender there and use it as a patch
Last edited by RonD; 08-15-2016 at 10:57 AM.
#3
#4
RF Veteran
iTrader: (1)
The newer design timing chains and cassettes have been great, so once that is done engine should be fine for many years.
Replace front and rear main seals(crankshaft) when engine is out, that applies to any engine.
Also replace Knock sensor, under lower intake, the wires tend to get brittle and break, and it is hard to get to once intake is back on.
Check upper and lower thermostat housing, these tended to get brittle and crack as well.
If they look good then don't change them, it is obvious if they are starting to leak somewhere.
Good how to on that one here: How To Replace the Upper and Lower Thermostat Housing on a Ford 4.0L V6 SOHC Engine
Replace front and rear main seals(crankshaft) when engine is out, that applies to any engine.
Also replace Knock sensor, under lower intake, the wires tend to get brittle and break, and it is hard to get to once intake is back on.
Check upper and lower thermostat housing, these tended to get brittle and crack as well.
If they look good then don't change them, it is obvious if they are starting to leak somewhere.
Good how to on that one here: How To Replace the Upper and Lower Thermostat Housing on a Ford 4.0L V6 SOHC Engine
#5
#6
RF Veteran
iTrader: (1)
The 4.0l SOHC engine runs 9.7:1 compression ratio, this is how Ford got most of the extra horse power from this 4.0l, the older 4.0l OHV had 160HP(9.0:1 ratio), SOHC 200HP.
When compression ratio is 9.4:1 or higher an engine can start to ping/knock when using regular gas(87 octane).
Compression adds heat, Octane is a heat rating, lower octane number means a fuel will self-ignite at a lower temperature.
Pinging or Knocking is when a fuel self-ignites just before spark plug fires, the noise is caused by the 2 or more "explosion" wave fronts meeting inside that cylinder.
This will cause damage to a gasoline engine, valves and pistons are not built to withstand this.
Google: piston damage from pre-detonation images
Diesel engines are built to withstand this, they don't use spark plugs, the heat of compression(often 20:1 ratio) ignites the diesel fuel, and it often ignites in more than 1 place in the cylinder, this is why diesel engines sound "pingy".
Anyway since most people prefer to run Regular gas, and 4.0l SOHC will ping/knock on Regular gas Ford had to add a Knock sensor to prevent engine damage.
The Knock sensor can detect ping/knock before you even hear it, when it does the computer will advance the spark timing so fuel is ignited by spark plug BEFORE it can self-ignite.
This change in spark timing does reduce engine power, so not optimal, but better than engine damage, lol.
When compression ratio is 9.4:1 or higher an engine can start to ping/knock when using regular gas(87 octane).
Compression adds heat, Octane is a heat rating, lower octane number means a fuel will self-ignite at a lower temperature.
Pinging or Knocking is when a fuel self-ignites just before spark plug fires, the noise is caused by the 2 or more "explosion" wave fronts meeting inside that cylinder.
This will cause damage to a gasoline engine, valves and pistons are not built to withstand this.
Google: piston damage from pre-detonation images
Diesel engines are built to withstand this, they don't use spark plugs, the heat of compression(often 20:1 ratio) ignites the diesel fuel, and it often ignites in more than 1 place in the cylinder, this is why diesel engines sound "pingy".
Anyway since most people prefer to run Regular gas, and 4.0l SOHC will ping/knock on Regular gas Ford had to add a Knock sensor to prevent engine damage.
The Knock sensor can detect ping/knock before you even hear it, when it does the computer will advance the spark timing so fuel is ignited by spark plug BEFORE it can self-ignite.
This change in spark timing does reduce engine power, so not optimal, but better than engine damage, lol.
Last edited by RonD; 08-17-2016 at 01:03 PM.
#7
#8
RF Veteran
iTrader: (1)
Just 1 on the 4.0l SOHC, or any engine I have seen, metal of the engine block conducts sound quite well, so "ping/knock" is easy to detect.
Diagram of location here: http://www.autozone.com/repairinfo/r...96b43f8036de4d
Diagram of location here: http://www.autozone.com/repairinfo/r...96b43f8036de4d
#10
#11
RF Veteran
iTrader: (1)
Hard for sure but not impossible
Couple of way mentioned here: 1 SOHC V6 Engine Removal Procedure | Page 2 | Ford Explorer and Ranger Forums - Serious Explorations
Lots of pictures in that thread.
I have long extensions so I use that method on most vehicles
On some vehicle you can lift engine off motor mounts then remove motor mounts to lower engine down a bit more for clearance.
You want to loosen and remove the hardest to get at bolts first, then loosen the easier ones.
If an automatic, make sure to disconnect torque converter from flexplate before separating engine and trans
Couple of way mentioned here: 1 SOHC V6 Engine Removal Procedure | Page 2 | Ford Explorer and Ranger Forums - Serious Explorations
Lots of pictures in that thread.
I have long extensions so I use that method on most vehicles
On some vehicle you can lift engine off motor mounts then remove motor mounts to lower engine down a bit more for clearance.
You want to loosen and remove the hardest to get at bolts first, then loosen the easier ones.
If an automatic, make sure to disconnect torque converter from flexplate before separating engine and trans
#12
Does any one know the name or part number for the rear timing chain guide bolt that's in the head? not the bolt that holds the guides in but the upper bolt that gets cradled by the guide.
Also what bolts need to be replaced (other than head bolts) like camshaft sprocket bolts and harmonic balancer bolt?
Also what bolts need to be replaced (other than head bolts) like camshaft sprocket bolts and harmonic balancer bolt?
Thread
Thread Starter
Forum
Replies
Last Post
Tanker3278
DOHC - 2.3L Duratec / Mazda L Engines
33
02-14-2016 01:19 AM