4.0 Engine rebuild – quick and dirty

Quick and Dirty Engine Rebuild
Jeep 4.0

Jennifer’s Jeep had a sudden severe clacking sound. With the head removed, there was no evidence of a problem. However with the oil pan off, parts of the piston skirt were found.

A quick internet search found several reports of broken piston skirts. Many of the pictures looked just like hers. The original idea was to replace just the one piston and put the engine back together. However, closer inspection of the other pistons revealed cracks in the same area of the skirts.

Due to the cost of replacement pistons, we elected to use pistons from an older engine we had in storage. The engine currently in her XJ is a 96 4.0 removed from a Grand Cherokee. The older engine was her original 92 model. The block was worn but the pistons were fine.

We noticed a major difference between the way the skirts were made on the older pistons. The older ones are much thicker. The older pistons use different rings so we had to order a ring set for the 92 engine.

We obtained a gasket set and a set of rod bearings as well. We elected to retain the original main bearings and not remove the crank or main caps.

We left the 92 pistons on their original rods and installed new rings and rod bearing inserts. The pistons ring grooves were carefully cleaned before the new rings were put in place.

We used a ridge reamer to cut the small ridge out of the top of the cylinders. The ring end gap was a few thousandths over spec but we felt was close enough; much lower than the gap on the original worn rings.

We used a cylinder hone to lightly scuff the cylinder walls. They looked smooth even in the hole with the broken piston.

We fitted a ring compressor over the piston and tapped it down into the cylinder bore. Rubber hose was placed over the rod bolts to help guide it over the crank and to protect the crank while driving the rod into place.

When the rod made contact with the crank, there was a notable change in the sound made when tapping the piston top. We would then move to user the Jeep and install the rod cap. While difficult, it was possible to find a position to place the crank so that the rod bolts could be accessed with torque wrench.

Once all six pistons were in place, we set the head back on. While the head was off, I installed the new valve seals that came with head kit. I used a KD tool valve spring compressor and carefully removed the retainers. I then pried off the old seals and tapped the new ones in place using a deep well socket as a driver. I then replaced the springs and keepers.

After start up, she drove about 500 miles before the first oil change. The engine seems to be running fine now. And it is much quieter.

Jeep Lifter replacement

Jennifer’s Jeep has had a loud lifter tick for a while. We finally decided to pull the head and replace all the lifters and push rods. We used the following procedure from Jim Alton to work with:

Mike,

Jen sent me a message and said her lifters need replacing. The head needs to come off unfortunately. Before going that deep, just to eliminate a longshot (but much easier fix), remove the pushrods and make sure they are straight. If any get bent slightly they will be too short and make noise. They have to come out to remove the head anyway, so its easy to check them before getting too deep.

Procedure for lifters (coming from my head…hopefully I don’t miss anything):

-Remove the valve cover.
-Remove the rocker arm bolts. I leave them right in the rocker arms and remove them as an assembly in pairs. Put them somewhere so you can keep them in order. Lined up on a clean bench or table, or even in a divided container like muffin pans.
-Remove the pushrods. Inspect them to make sure the ends aren’t worn. Roll them on a flat surface to check for straightness. If they are even slightly bent replace them. If any are more than slightly bent, this could be your problem- replace them and reassemble, and see if its quiet again. (just a very slim chance this is the problem…most likely, its lifters)

If the pushrods aren’t the problem-

Have new head bolts handy. They are supposed to be “one reuse allowed”, but I always install new. Most part’s stores will have them. They cost a little, but easier and cheaper than ending up with stretched bolts.

-Remove intake manifold. Remove remaining 3 fasteners to loosen exhaust manifold if you didn’t already. Pull the exhaust manifold away from the head slightly using a bungee cord or similar.
-Drain coolant, then remove upper radiator hose & both heater hoses from the engine.
-Remove belt
-Remove 4 bolts holding the A/C compressor top the mount. Don’t disconnect AC lines. Lift the compressor up, flipping it to the passenger side of the Jeep. It should sit over there upside down still attached to the hoses.
-Remove a couple bolts attaching the A/C bracket to the head. You don’t need to remove the whole bracket, just the bolts going into the head. Removing the whole bracket involves removing the alternator.
-If the head has never been off before there is a spot on the firewall that could keep the driver’s rear head bolt from being removed. Bending this over slightly will give clearance.
-Remove the head bolts.
-Lift the head from the engine- straight up, then out. Its HEAVY! This is old American engineering cast iron! Get someone to help if your back isn’t good, or use an engine crane.
-Use a pick to pull the lifters out. Some may be somewhat stuck. I have found letting them drop low, then a quick pull up helps get them past the dry ridge that builds up. You may have to try several times up and down.

Once they are out check the cam lobes for wear. Look for scarring, obvious wear signs. It would be best to have a dial indicator to check for lobe lift, to eliminate cam wear from a possible noise cause, though that would usually lead to a misfire code as well.

While the head is off anyway, I would use a straight edge to check for flatness. Check the length of the head in a couple places, then check corner to corner. If you can put anything larger than a .003″ feeler gauge between the straightedge and the head, the head is warped. Very rarely does this happen on a 4.0, especially earlier years. Also take the time to clean the oil return passages in the head. They are very small, and often have casting flash left making the holes even smaller. Gunk builds up and keeps the oil from draining back as well as it should. I feel this is one cause that leads to blowby in the earlier engines. Just make sure the passages (near where the pushrods go though) are clear.

If everything looks good, lube the new lifters and drop them in. Reverse the removal procedure.

-Clean the block surface and head. I use an air powered scuffing wheel, but a razor blade followed by a Scotch-brite pad will work also. Do the same for the intake & exhaust manifolds and their surface on the head. Clean coolant out of the cylinders and clean up the block as well as you can.
-Set the head gasket in place, then the head, being careful not to damage the head gasket.
-Torque the head bolts, then reassemble everything.
-At the end have 5 extra quarts of cheap oil ready (plus the 6 you will be using), and a filter. Drain & change just the oil before starting the engine, then start up, and run several minutes. Then change the oil & filter. While shops won’t spend the money to do this, I like to. Changing the oil right off gets the coolant out that ends up there during the head removal. Starting it up circulates the new oil and picks up more coolant that is in the block, as well as the material that dropped in while cleaning up the block and head. Changing it a second time gets rid of this. Overkill? Maybe…but it only costs a few dollars for cheap oil, and it makes me feel a lot better.

Jim

VW Passat Glove Box door repair

VW Passat Glove Box door repair

The glove box door on the 2000 VW is a rather complicated affair. It seems really sturdy with a heavy metal layer sandwiched between the two plastic parts. However, the handle and the inner workings are actually quite fragile.

The common failure points are the plastic supports for the hinge pin on the handle and the hinge supports of the two bell cranks inside the lid.

The first task to making the repair is to get the box open. If just the handle is broken, you can reach in with a finger and press down on the two tabs of the bell cranks. This will release the lock pins. On this example however, the bell cranks were also off their pivots. I had to reach in and grab the detent in the slider and pull the pin out. Pushing in on the glove box door reduced the tension making it easier to pull the pin out.

With the lid open, the two halves are separated by removing the torx screws. Two required a short bit and a ratchet while most could be removed with a standard screw driver style torx tool. The outer cover will still be attached to the base but it can now be opened enough to make the repair.

I began by putting all the parts back where the belonged. I discovered that none of the parts were actually broken just the bell cranks had come off the pivots. I used two sheet metal screws to secure the two bell cranks on the pivots.

Next I focused on the broken handle. There are two pins that com in form either side. The small recesses in the handle were completely broken away. I made a new pin by cutting a 3 inch long piece of 3/32 welding rod. I then drilled a 1/8 inch hole all the way through the handle. I then threaded the welding rod through all the holes making a more secure mount for the hinge.

I carefully pressed the two halves of the cover back together making sure to properly align the tab on the handle with the hole between the bell cranks. Once the screws were replaced the repair was done. The door now opens and closes smoothly and will be much stronger than in original form.

Considering the door s sell for $200 new and even used ones are going for over $60 this was time well spent. And since I used material I already had, there were no material costs.

Heater Treater Blend Door Repair

Heater Treater Blend Door Repair

1999 Jeep Cherokee XJ

Janice’s Jeep Chreokee has had trouble regulating the temperature in the cabin. Eventually the warm / cool knob made no difference at all. It was cold all the time.

I remembered the previous experience of pulling the HVAC box to replace the heater core. That was a job I do not care to repeat. I also remembered that I had a lot of trouble getting the blend door to sit properly in its hinges when I reassembled the box.

I first checked the actuator and saw it moved in response to the knob on the dash. I had had trouble with my GMC Suburban that turned out to be the HVAC controller. Since the actuator was moving but the temperature was not changing, I knew something had to be wrong with the blend door.

A quick Google search showed this to be a common problem on the 97 to 01 Jeep Cherokees. The door is plastic and will break. Once I got mine out, I found it was indeed broken where the drive actuator engages it.

While searching for solutions, I found HeaterTreater.com. They offer a metal replacement blend door along with a procedure that allows the door to be replaced from the foot well without removing the box. At first, I thought the $119 price was high but it sounded better than removing the box again. Especially since the Freon has to be removed to pull the box.

I put the kit on my Paypal account and waited. It was shipped the same day I ordered but it did not arrive until the following Monday. So much for Priority Mail.

I borrowed my Dad’s Dremel kit as recommend in the instructions. The kit came with a cutting blade that looked like a drill bit. Dad’s kit had one similar but shorter so I used his instead.

I removed the passenger seat to get access. I was surprised that it is held in my SAE fasteners rather than metric. Janice had previously removed the actuator. That was the most time consuming part of the job. The actuator is held in place by three screws with 8mm heads. (Not two Phillips screws as stated in the instructions.) Two are almost impossible to access. I used a short socket on a ¼ inch drive ratchet. Even with that I had to pull the carpet back to get enough room.

I cut out the template from the instructions. It is a nice pattern and well thought out. I would not make the hole any different after seeing inside. At first, I could not find a way to transfer the pattern onto the black box to make the cut. It was very difficult to see in the dark floor board and then was little room to get a light in there with me.

My final solution was to transfer the pattern onto a piece of the provided silver tape. They sent plenty. I then stuck the tape to the box and used that as a guide to cut along.

I had not used the Dremel before or used a drill bit as a cutting tool. It was very messy and I would advise goggles or a face shield. Regular safety glasses don’t provide enough protection as the plastic chips fly everywhere and there is not much space between your face and the cutting. After some experimenting, I found it best to make several shallow cuts rather than trying to plunge in and make the cut all at once.

I made a pretty messy cut but was able to get the section cut out properly. As they note in the instructions, it does not have to be neat as it will be covered by tape when you are done anyway.

With the section removed, I could see my blend door hanging at an odd angle. It was not seated in the upper pivot point. At this point I considered putting it back in place and returning the Heater Treater Door. However, upon closer inspection I saw where it was broken. I was able to get it out without making the additional cut noted in the instructions. I guess I was lucky as they said.

Next I took a close look at the replacement door and compared it to the original. There are some minor differences in the shape. The major difference is in the material of construction however. The original is flimsy plastic and the replacement is metal covered in foam. The replacement also has a removable axle to allow it to be inserted and removed without separating the box halves. All the stressed parts are made of steel or aluminum. It looked very strong.

Putting the door in place took me several tries. The top has to fit in the pivot point at the top of the box. The instructions describe the procedure but it took me several attempts before it popped into place. Then it promptly fell out and I had to do it all over again.

The most difficult part of the whole procedure was then putting the little nylon washer in place. I had a very difficult time finding a way to position my hands to get the washer placed under the shaft and over the hole without letting the door slip out of the upper pivot. I am not sure how I eventually did it, but I finally got it all in place.

The axle shaft will fit in two ways only one of which is correct. I hooked up the actuator to the wire again and rotated it to the centering mark on the actuator by turning the hot cold knob on the dash. I removed the wire again and slipped the axle shaft into the actuator. I then carefully raised the actuator and shaft into the hole and wiggled the door to let it slide down on the axle.

I then rotated the actuator to align the screw holes and put in the one screw that is easy to get to. I reattached the wire and tested the actuator. The door moved nicely from one end to the other.

I then sealed up the hole. I tore two pieces of tape and placed them on the bottom of the cut out piece. I then pressed the cut out into the hole and pressed down the tape on either side. It does not look perfect, but you can’t see it unless you lay in the floor anyway.

I then let Janice put back the other two screws holding the actuator. I then reinstalled the seat. She will now have heat for holiday traveling. She now just has to clean up all the black plastic shavings. I even had them in my ears.

Overall, I found the Heater Treater well worth the price. The instructions were very clear and easy to follow. The template was just the right shape to make the repair. Cutting the box sure beats removing the box. See www.HeaterTreater.com for more info. Allow about two hours to make the repair.

Transfer of Ownership

Transfer of Ownership

Beginning today mikestrawbridge.com will be owned and managed by Jennifer Bryan. I will not go into the reasons behind this change but trust that the site is in good hands.

From this point forward, Jennifer will be responsible for the content of the site and will collect the commissions it generates. She will also be answering the questions you send via the “Contact Mike” form. If you need any Crown Parts, she will be able to get them for you.

Thank you for your support and I hope you will continue to support this body of information by supporting the advertisers here. They pay for the web hosting and other expenses associated with running the site.