Friday, February 26, 2010

How to Fix a Flat

If you're slowly losing tire pressure, you may have a nail in your tire. Sometimes it may be difficult to locate the nail. Pour soapy water on the tire along the treads, and usually the leak will show itself.

Pull out the nail with a cutter or a pair of pliers.

Get a tire repair kit as shown. It's $10 from Pep Boys.

Use the the rasp tool to clean and roughen the hole. It may require some effort, so having some strength with your hands helps. :-)

Put one of the rubber strings on the needle tool, coat it with rubber cement, and insert it into the hole.

Pull the needle out, leaving the rubber string inside the hole.

Cut off the excess rubber string.

Pump the tire to specified pressure.

Thursday, December 10, 2009

BMW Fuel Filter Replacement (E46 2002 330Ci)

The fuel filter is a 60,000-mile maintenance item. Because this procedure deals with gasoline, be extra careful about safety. Make sure you have a fire extinguisher ready nearby. Wear surgical gloves and protective eye wear. Ensure that the work area is well ventilated. Also, you'll be working under the car, so make sure you put the car securely on stands. You absolutely do not want the car to fall on you!

To replace the old fuel filter, you'll need to get a new one. I got mine for $40, plus $10 shipping, for a total of US$50. If I had to do it again, I'd definitely get 6 clamps for the fuel line hoses, which will make the job much easier (see photo below).

Step 1: Depressurize the fuel system.

1.1. Open the glove box. Turn the two white tabs to open the fuse box.

1.2. Remove Fuse #54 to deactivate the fuel pump.

1.3. Open the fuel filler cap to release any pressure in the tank.

1.4. Start the engine and run until the engine stalls (no photo). The purpose is to empty out as much as possible the gasoline from the fuel line beyond the fuel pump.

Step 2. Jack up the vehicle and put it on stands. Locate the fuel filter guard, which is at the bottom side of the car, just under the driver's right leg. There are 4 screws holding the guard in place. Remove 3 of them, and push away the guard.

Step 3. The fuel filter is now exposed. Remove the fastener holding the filter in place, and unscrew the 6 clamps on the fuel inlet and outlet lines with flat-head screw driver. The rubber hoses may seem to be impossibly tight and stuck on the inlet and outlet, but they can be easily loosened by slight twisting using a plier.

Step 4. Disconnect the fuel lines, and use a metal container to catch the fuel spill. There will be spills, and the amount is quite substantial. Do not use a plastic container, as the gasoline will melt it.

This is a 4 quart cooking pot, and see how much spill there is. I was surprised how clean the gasoline was after 60,000 miles. This is a maintenance item, but in reality I didn't need to replace the filter.

Step 5. Remove the old fuel filter, and install a new one. Now comes the hardest part of the job -- tightening the screws on the clamps. Whoever designed the clamps should be taken out and shot. They cannot be tightened with a screw driver. They cannot be tightened with a socket of any size. Without the special tool, they can only be tightened little by little with a plier. It's a pain. I just don't see any reason for designing clamps that are easier to loosen than to tighten. If I have to do it again, I'll buy some new clamps so that they can be tightened with a screw driver.

Step 6. Put the fastener and guard back. Lower the car to the floor. Reinstall fuse #54 and fuel filler cap. Clean up, and you're done.

Sunday, December 6, 2009

Harbor Freight Tools

I love this place. I'm like a kid in a candy store whenever I go there. Sure, the stuff there aren't of the highest quality but they are very reasonably prices. Sometimes that's exactly what you need.

My most recent purchase is a portable air pump that plugs into a car's cigarette lighter socket and inflates the tires. For $18 it's very useful when you don't have access to a shop air pump and don't want to pay 75c every time at the gas station. Proper tire pressure is crucial for good handling and good fuel economy.

Thursday, December 3, 2009

BMW Ball Joint / Lower Control Arm Replacement (E46)

My car is a 2002 BMW 330Ci Convertible. Your car may be similar or different depending on the model.

The Lower Control Arms (LCAs) are an important suspension part that sets the position of the front wheels. Each LCA on this car has two ball joints and an end inserted into the bushing. If a play has developed at any of the ball joints, as is the case on the passenger side of my car, the wheel will have a play that can cause uneven wear of the tire (cupping) and the car pulling to the side when going over uneven roads or under braking (bump steer). It's easy to test the ball joints. Simply jack up the car so that the front wheel is off the ground. Rock the front wheel back and forth. If there is any play, there is a problem with the LCA or bushing.

Apparently the ball joints are a common problem on some model years of the E46 because a nylon lining is used for the ball joints which tends to fail at around 60K miles. Mine started having problems at around 50K miles.

The ball joints are pressed into the LCA and requires a power press to remove and install. DIYers need to replace the entire LCA assembly. LCAs need to be replaced in pairs, and alignment is needed afterward. This guide illustrates the steps for replacing LCAs. After the replacement, the car will go back to solid and firm handling, reminding us why we got these cars in the first place.

Allocate at least 4 to 5 hours for this job if you're doing this for the first time, even though it can be done in 2 to 3 hours if you're familiar with it. Then again, you wouldn't be reading this if you had done it before.

Step 0: Get a set (left and right) of Lower Control Arms. Mine are Lemförder, which I got for $336 plus taxes and shipping.

Step 1: This job is more about having the right tools and using them correctly than the procedure itself. These are the tools I bought specifically for this job.

- The pickle forks are $10 each from Pepboys. If I had to do it again, I would only need the bigger one -- it allows you to hammer on it without hitting the car's fender while trying to separate the inner ball joint.

- The KD ball joint separator, $20 from Sears, can be used to remove the outer ball joint and was probably not needed if I knew what I know now. But, it can come handy for other jobs, such as separating steering tie rods.

- The 8-lbs hammer, $24 from Lowe's, was definitely needed. Not sure if a 4-lbs hammer would also work.

- The 21mm wrench is needed to work the nut holding the inner ball joint. I got it for $7 from Pepboys. In hindsight, an 18mm wrench would also help working the outer ball joint nut.

Step 2: Put the car on 4 stands. I've done it several times, and I still find it tricky because the car is so low to the ground. First, use the jack that comes with the car to lift the car just enough so that you can slide a hydraulic jack under the car. Then lift the car by jacking on the frame reinforcement railing, after which you can put a stand to replace the car jack. When you do the other side of the car, you need to constantly check to make sure the car doesn't slip off the jack.

After the car is put on 4 stands, rock it back and forth to make sure everything is even and solid. No, the car won't fall from the rocking. If it does, it's much better that it falls now than when you're under it!

Make sure to loosen the wheel nuts first before putting the car on stands, as you'll need to take the front wheels off later on.

Step 3: Remove the plastic dust guard and the aluminum underside reinforcement. Both are easy. The only thing not obvious is the plastic retaining clip holding the dust guard to the front bumper. You'll need to pull on the center insert in order to remove the clips.

This is the step where you'll need to get under the car. After this step, you mostly work on the side of the car.

This is after the plastic guard and aluminum reinforcement brace have been removed.

Step 4: Remove the front wheel, exposing the access to the LCA ball joints and bushing. It is helpful to turn the steering wheel one way or another in order to have better access to the place you'll be working on.

Step 5: Use an 18mm socket or wrench to remove the outer ball joint nut. The ABS sensor is in the way of a socket as the nut rises. I didn't have an 18mm wrench. So I used an 18mm socket to break the nut loose and used a 19mm wrench to remove the nut completely.

Step 6: Insert a pickle fork around the outer ball joint, and start hammering. Hammer the fork in such a way as to insert it deeper. There is no point in applying any lateral force, as it's not going to help (ask me how I know). I believe you'll need a sledge hammer of at least 5 lbs. Mine is 8 lbs. Also, take out the nut completely before hammering (unlike being shown here) -- you don't want to deal with the situation where the nut is stuck and the ball joint rod rotates freely (you'd need an Allen key to hold the ball joint stud in that situation).

Make sure to wear protective eye wear when you do any hammering! Little things might fly under impact, and you don't want anything to hit your eye at high speed.

Another view of the outer ball joint (this is on the driver side), showing the ABS sensor.

An alternative is to use a ball joint separator as shown here. It's a bit tricky to use this type of separator because it doesn't go into position completely on the outer ball joint (it doesn't work at all on the inner ball joints), and you'll likely have to jack up the MacPherson strut to get enough grip. If you do use this separator, the outcome is quite spectacular, making a loud pop like a gunshot, when the ball joint rod separates. Also make sure to use protective eye wear.

Step 7: Use a 21mm wrench to loosen the inner ball joint nut on top of the frame cross member. You will need to use a rubber mallet to hammer on the wrench to break it loose. I used the pickle fork itself to transfer the force as shown here. Once the nut is turning, you'll have to use a lot of patience to remove it because there isn't much room at all, probably about 30 degrees before you have to reseat the wrench.

This is the view of the inner ball joint under the cross member. After using a fork, the boot will be damaged.

Step 8: Use the longest pickle fork you have to separate the inner ball joint. Again, hit the fork with a large hammer as if to drive it deeper. Be careful not to damage the car's fender when you swing the hammer. Use the fork only after the nut has been removed completely (to avoid the situation in which the nut is stuck and the ball joint rotates freely).

This is how it looks after the inner ball joint has been separated (driver side).

Step 9: Remove the LCA bushing by undoing two bolts (16mm) so that the LCA comes off the car completely.

Step 10: If you want to remove the bushing from the LCA, a good puller would be the best, but a C-clamp like this worked for me.

Putting a bushing on the new LCA requires very advanced material -- soap! With soap, it requires very little effort. Make sure it's installed the correct way (there are two possible ways for the bushing to go on the arm).

Here are the old and new LCAs side by side.

Repeat Steps 4 to 10 above to remove the other LCA. The only difference between the two sides is when you have Xenon lights, in which case there is a leveler on the passenger-side LCA.

Step 11: Now we need to install the LCAs. In order to install the inner ball joint nut, you'll likely need to use a jack to push the inner ball joint against the frame cross member. You have to put quite a bit of the car's weight on the jack to stop the ball joint rod from rotating while you try to tighten the nut. There is no way I can put my torque wrench there, so I simply tightened the nut as much as I could. You may also need to use the jack for the outer ball joint as well.

Step 12: Install the outer ball joint and the LCA bushing. This is after the new LCA have been installed.

Repeat Step 11-12 for the other side.

Put back the aluminum reinforcement brace and the plastic guard.
Put back the front wheels.
Lower the car to the floor.
Tighten the wheel nuts.
You're done for now.

The final step is to get the alignment adjusted. I went to a local shop specializing in German cars, and it cost me $94 cash (I was quoted $130 earlier by the same shop). They told me they needed to adjust the toe-in slightly.

Monday, November 30, 2009

BMW Thermostat Replacement (E46)

This is a Do-It-Yourself reference for replacing the thermostat on the E46 BMW engines. Mine is a 2002 330Ci Convertible, but this job should apply to all 1999-2005 BMW 3-Series vehicles.

The symptom leading to this repair was that the Service Engine Soon light on my car would come on after driving some distance on the highway, and it would go away after driving some distance on local roads. The error code was P0128 -- "coolant temperature below thermostat regulating temperature."

This job is about $300 at the dealer (some people got a quote for $400). I decided to do it myself and got a thermostat and housing assembly for US$57.70.

Here is how I hooked up a scanner to check the error code. I'm told some shops would do this for free.

This is a closer look at the OBD-II connector, which is standard on all cars manufactured since 1996.

Following the instructions of the scanner, I got the error code P0128, "coolant temperature below thermostat regulating temperature." What it means is that the coolant temperature is too low. One logical reason is that the thermostat opens up too early before the coolant reaches its designed operating temperature. It's probably not stuck open in my case because the light would go away after driving on local roads.

To replace the thermostat, you'll need to drain the coolant, which requires opening the drain plug at the bottom of the radiator, which requires removing the splash guard at the bottom of the car, which requires jacking up the car and putting on stands, at least the front end.

After removing the plastic splash guard, you can see the blue drain plug at the bottom of the radiator.

Open the coolant filler cap at the top of the radiator, and open the bleeding valve with a screwdriver.

Place a pan under the radiator and open up the drain plug.

Drain the coolant.

This is the coolant drained.

There are 4 screws holding the thermostat in place. It is possible to remove the thermostat without removing anything from the radiator. You just need an extender of the right length (a short one) on the socket wrench. In my case, it was a 3/4"-to-1/2" adapter. You'll also need to cut the nylon tie-down of the wiring.

This engine lifting bracket needs to be removed because one of the screws holding the thermostat to the engine also holds this bracket.

There are two hoses connected to the thermostat. Each can be detached by sliding the metal clip and pulling on the hose. This is the upper hose which is easier to detach. The bottom one may require some effort due to lack of working space. Also disconnect the temperature sensor connector. After that, the thermostat is free from the engine. It requires some Tetris skills to take the thermostat out of that space between the engine and the radiator.

Here are the thermostats, old and new, side by side. It appears that my old thermostat is not stuck open. I believe it just opens too early but I didn't test it (by putting it in a pot and heating it up...).

The more difficult part of installing the new thermostat is the bottom hose. There is just not enough space to apply any kind of pressure to push it onto the thermostat. Here I applied a little Vaseline on the o-ring which made it a lot easier.

Once the bottom hose is connected, the rest is easy. This photo shows that the thermostat has been installed onto the engine with the bottom and top hoses attached.

Reinstall the temperature sensor connector, and tie down the wiring which was cut loose when removing the old thermostat.

Now, close all drain plugs and bleeding valves.

The manual says to use 50/50 mixture of long-life ethylene glycol antifreeze and water. I got 100% antifreeze. For the water part, I filled with bottled water. I figure if it's good enough for me, it's good enough for the car.

Lower the car to the ground. Drive some and recheck the coolant level (after the coolant has cooled down, of course). My Check-Engine light came back on once again but went away afterwards and has never returned.