Here you can find information regarding the assembly of the Ford 4.0L Cologne engine. In this guide we will
start from the inside of the engine including the
crankshaft, connecting rods, and piston ring installation and then move outwards all the way to the pulley belt
system. Along the way correct procedures and torque specs
will be given to aid in the assembly of the engine. Feel free to start from the beginning and work your way
outwards or skip ahead to your current position in the engine for what you may need.
Crankshaft Main Caps Installation
The 4.0L V6 Cologne engine block has 4 main crankshaft caps that hold the crankshaft into place. During assembly be sure to use new bearings
and apply the proper assembly lube to the bearings before installing. You can start by cleaning all bearing surfaces with a clean cloth and then
installing the bearings in to their proper places being the engine block and the main caps. Once installed you can apply lube and place the caps into there locations
on the crank and begin to hand tighten the oiled bolts. Once all caps and bolts are in place you can start from the middle and work outwards and torque the bolts to
72 ft-lbs.
Ford Explorer Crankshaft Main Caps Torque Spec : 72 ft-lbs
Piston and Connecting Rod Installation
To install the pistons and connecting rods you must first install the piston rings into each piston. Be careful
not to stretch the rings or break them during installation. Make sure to put the correct rings in the correct
positions, this can be determined by looking at
the instructions given with the new rings. Each ring manufacturer is different so be sure to check for your
specific rings. Once the rings have been installed you can now fit the connecting rod bearings into the end caps
and lube them up with oil or lithium grease. The piston can now be lowered into the cylinder, make sure the dot
or mark is facing the front of the engine and that you don't scratch the cylinder.
Once installed you can match the connecting rod caps with the correct rods and start to torque the connecting
rod bolts to 15 ft-lbs and then an additional 90 degrees. After all are done rotate the crank
to ensure all pistons move smoothly in and out of their cylinders.
Ford Explorer Connecting Rod Torque Specs : 15 ft-lbs + 90°
Balance Shaft Installation
The Ford 4.0 SOHC engine contains a crankshaft balance shaft within the engine block right next to the crank. This shaft can be installed with the
timing chain and marks as indicated in the picture. There are 4 bolts which hold the balance shaft into place. These bolts can be torqued down to
21 ft-lbs. The guide for the chain can be installed once the balance shaft is installed and the bolts for this can be torqued to 81 in-lbs or about 8 ft-lbs.
Ford Explorer Balance Shaft Torque Specs : 21 ft-lbs
Explorer Balance Shaft Guide Torque Specs : 8 ft-lbs
Oil Pump Installation
The oil pump on this engine goes right next to the balance shaft inside the bottom of the engine. There a a few bolts that hold the pump housing
itself to the engine block. These bolts need to be torqued to 15 ft-lbs. Make sure you lube up the oil pump prior to installing so that it is not dry
when the engine starts.
Ford Explorer Oil Pump Torque Specs : 15 ft-lbs
Cylinder Head Installation
The first thing you must do when installing cylinder heads is to ensure both the block and head surfaces are
completely clean from dust, oil, and any debris. The next thing you must to is
to set the camshafts to their correct positions to prevent any valves from hitting pistons during installation
and torquing of the head bolts. Much the same you have to set the pistons to their correct
locations, typically this means putting the #1 piston to TDC or Top Dead Center. Once everything is ready you
can install the head gasket onto the engine block by aligning the alignment dowels.
Something I usually do is spray down the head gasket with some engine copper spray from permatex which you can
find here, this ensures that any gaps that could be present between the 2 surfaces gets filled with the
spray. It
also helps to transfer heat between the 2 metals. With the gasket in place you can set the cylinder head onto
the gasket and block, if needed have someone assist with this process as the head can be heavy
and you don't want to scratch anything or drop it! Once the head has been placed you will want to start
installing the head bolts to make sure it doesn't move. Be sure to buy new head bolts as many manufacturers
use TTY or Torque to Yield head bolts meaning they stretch during torqueing and cannot be used twice. Also make
sure to lubricate the bolts in clean engine oil before installing them into the head.
Once all the head bolts have been installed and finger tightened you can start the torqueing process, almost all
head bolts have a multi-step process for torqueing. The 4.0L starts off with 25 ft-lbs and
then an additional 90 degrees then requires you to back them off a full turn. Then you must again torque them to
30 ft-lbs and add 90 degrees then an additional 90 degrees for a total of 180 degrees after the
30 ft-lbs but by going through each bolt with each step. After torquing the heads are completely installed and
you can now move to intalling the timing.
Ford Explorer Cylinder Head Torque Specs : 25 ft-lbs + 90° + 90°
Timing Chains and Guides Installation
The timing system on the Ford 4.0 SOHC is different from many other engines. It consists of a jackshaft
that runs through the middle of the engine and controls a timing chain in the front and in the back of the engine.
In other words each heads timing chain is located at a different side of the engine. This makes a timing chain replacement
much more difficult as you need to access the rear of the engine. For installation though you start by installing the rear timing
chain and sprockets into the engine block. There is a retaining bolt that can be tightened to hold the assembly into place. With
that installed you can now put in place the jackshaft sprocket and chain. The guides for this chain can be torqued down to 15 ft-lbs.
You can then move to the other side of the engine and install this set of timing chain and sprockets the same way as the other and tighten down the retaining bolt.
With both timing systems in place you can move to installing the cylinder heads and then return here to finish the timing chains.
Now that the heads are installed you can place in the oiled up rockers and lube up the camshaft journals. Once lubed place the camshaft into place
and install the camshaft caps and hand tighten. With all of them hand tighten you can begin to torque them starting from the inside and going out.
The first step is to 53 in-lbs and then the second is to 12 ft-lbs. Be sure to go through each bolt during each step. This applies to both camshafts.
With the camshafts down we can now tighten up the jackshaft bolt to 33 ft-lbs and then an additional 90 degrees. Now you need to position the camshafts to
TDC, this can be best done with a camshaft holding tool meant for the engine. With the camshaft at TDC you can then install the camshaft sprocket bolt and torque to
63 ft-lbs be sure you tighten the bolt the right way as it is LH threaded! You can then install the chain side tensioner into the head and snug it down.
Ford Explorer Cylinder Camshaft Bolt Torque : 63 ft-lbs
Ford Explorer Camshaft Cap Bolts Torque Spec : 52 in-lbs | 12 ft-lbs
Ford Explorer Jackshaft Bolt Torque Spec : 33 in-lbs + 90°
Timing Cover Installation
The timing cover on the 4.0L primarily covers the jackshaft rather than the actual timing components but is still an
important part as it holds most of the engine oil inside of the engine. For this reason it is important to use a good gasket
and silicon sealant to ensure the cover does not end up leaking oil down the road. When installing be sure to put sealant
where the oil girdle connects to the cover itself. All of the bolts can be tightened down to 15 ft-lbs.
Ford Explorer Timing Cover Torque Specs : 15 ft-lbs
Engine Girdle Installation
With the oil pump installed into the engine we can now prepare the block for the installation of the engine girdle. This is the part
that connects the oil pan and engine block together and creates distance between the crankshaft and the oil pickup tube. The girdle can be
installed very much the same as most other parts. Starting with cleaning both contacting surfaces and then using some silicon and the proper gasket to
ensure nothing leaks once complete. The girdle has two sets of bolts, one set being located on the outside of the engine and a series of bolts located
towards the middle portion of the engine. The outside bolts need to be torqued to 8 ft-lbs and the center bolts can be torqued with 2 steps. The first step
is to 11 ft-lbs and the second is to 24 ft-lbs. Once tightened the oil pickup tube can be installed and tightened down to 8 ft-lbs.
Ford Explorer Engine Girdle Perimeter Torque Specs : 8 ft-lbs
Ford Explorer Girdle Center Bolts Torque Spec : 11 ft-lbs | 24 ft-lbs
Ford Explorer Oil Pickup Tube Torque Spec : 8 ft-lbs
Oil Pan Installation
Much like the timing cover on the 4.0L the oil pan plays an important role in keeping the engine oil inside the
engine. For this reason I recommend using a new gasket as well as some silicone sealant
during installation. Using the same technique as before with the cover you clean the surfaces of both the oil
pan and the engine block and then install the new gasket onto the block and then follow
it up with some silicone sealant. Be sure to follow your sealants instructions to ensure you get the best seal
from your application. The oil pan bolts torque to 8 ft-lbs in a cross
pattern design.
Along with the pan is the oil pan drain plug, this gets removed and reinstalled quite frequently and can be
torqued down to 10 ft-lbs.
Ford Explorer Oil Pan Torque Specs : 8 ft-lbs
Ford Explorer Oil Drain Plug to Head Torque Specs : 10 ft-lbs
Valve Covers Installation
The valve cover installation is rather simple, there are rubber seals for each bolt hole and a silicon gasket
that prevents oil from leaking out of the engine. It is recommended to replace both the seals
and the gaskets although if they are in good condition you can reuse them. If you do choose to reuse them I
would use some silicone sealant along with the silicone gasket to ensure it does not leak.
The valve cover bolts torque down to 106 in-lbs or about 9 ft-lbs in a criss cross order. Be sure not to miss
any bolts to avoid having oil leak out onto the exhaust pipes and cause a lot of smoking.
Ford Explorer Valve Cover Torque Specs : 9 ft-lbs
Intake Manifold and Fuel Rail Installation
When installing the intake manifold you want to make sure you have all the surfaces as well as intake holes
cleaned out before placing the manifold into position. Once cleaned you can then place
the intake manifold gaskets onto the alignment pins. If you want you can also use a little bit of sealant on the
gaskets to help ensure there are no leaks. With the gaskets in place you can now put
the manifold down onto the gaskets and begin to install the bolts. The intake manifold bolts torque to 12 ft-lbs
and can be tightened starting from the inside and going outwards. The coil pack
for the spark plugs can be torqued down to 60 in-lbs or about 5 ft-lbs and the spark plugs themselves can be
torqued down to 15 ft-lbs, be careful not to overtorque these as they can snap and cause big problems.
When installing the fuel rail make sure that all the fuel injectors are in good condition and that all the
o-rings are in place and
are in good condition. If everything is good you can place the fuel rail into position and push the injectors
into their holes and start to torque the rail bolts to 90 in-lbs or about 8 ft-lbs.
Ford Explorer Intake Manifold Torque Specs : 12 ft-lbs
Ford Explorer Ignition Coil Torque Specs : 5 ft-lbs
Ford Explorer Spark Plug Torque Specs : 15 ft-lbs
Ford Explorer Fuel Rail Torque Specs : 8 ft-lbs
Exhaust Manifold Installation
The exhaust manifold can be installed by cleaning the surface areas on both the head an the manifold itself and
then by using the exhaust manifold gasket and putting it in place. Once the gasket is in
location you can put the manifold onto the heads and begin to torque the bolts to 16 ft-lbs. I always use some
copper spray from permatex on the exhaust manifold gaskets to ensure I do not end up with
any exhaust leaks once done. When you go to install the engine into the vehicle or if it is already in the
vehicle the torque specs for the exhaust manifold to the exhaust pipes is 30 ft-lbs.
Ford Explorer Exhaust Manifold Torque Specs : 16 ft-lbs
Ford Explorer Exhaust Pipe Torque Specs : 30 ft-lbs
Water Pump and Thermostat Installation
The water pump can be installed by using a new gasket and if desired some silicone sealant to aid it. Once
prepared the pump can be moved into placed and the bolts should be torqued to 20 ft-lbs.
The water pump pulley can be torqued to the water pump itself with 20 ft-lbs as well.
Ford Explorer Water Pump Torque Specs : 8 ft-lbs
Ford Explorer Water Pump Pulley Torque Specs : 10 ft-lbs
Front Dress and Pulley belt Installation
Most of what is left on the engine is just place and tighten objects such as the belt pulleys, belt tensioner,
throttle body, oil filter neck, crankshaft pulley, and motor mounts. If the items have a gasket and hold either
oil or coolant inside the engine then feel free to add some sealant along with the gasket. Always be sure to
inspect your gaskets and replace them if there is any deteriation or flaws with them. For the
belt system the crank shaft pulley gets torqued to 33 ft-lbs and then an additional 90 degrees. The belt
tensioner and idler pulley can both be torqued down to 20 ft-lbs. When installing be sure they
both turn smoothly and if they do not then replace them with new ones as the bearings can go bad. The engine
motor mount can be installed onto the engine block if it hasn't been already, the torques for
the mount to the block is 30 ft-lbs and then when installing the mount to the vehicle it can be torqued anywhere
from 95-125 ft-lbs. Finally the throttle body can be installed on top of the intake manifold
with a good gasket and some added sealant using 7 ft-lbs in a criss cross pattern. For installing the belt you
can use a tool to move the tensioner into its springed state and install the belt as shown in the
picture.
Ford Explorer Crankshaft Pulley Torque Specs : 33 ft-lbs + 90°
Ford Explorer Idler Pulley Torque Specs : 20 ft-lbs
Ford Explorer Belt Tensioner Torque Specs : 20 ft-lbs
Ford Explorer Engine Mount to Block Torque Specs : 30 ft-lbs
Ford Explorer Engine Mount to Frame Torque Specs : 120 ft-lbs
The Ford 4.0 SOHC engine contains a crankshaft balance shaft within the engine block right next to the crank. This shaft can be installed with the
timing chain and marks as indicated in the picture. There are 4 bolts which hold the balance shaft into place. These bolts can be torqued down to
21 ft-lbs. The guide for the chain can be installed once the balance shaft is installed and the bolts for this can be torqued to 81 in-lbs or about 8 ft-lbs.
