Tech Stuff

7th Annual ‘Tips From Techs’

Our industry is made up of dedicated people who share a passion for all things automotive. Technicians who service vehicles on a daily basis routinely discover solutions for various repairs that go beyond what a service manual provides.

One of the great things about our industry is that rather than being selfish and keeping those tricks to themselves, technicians are willing and eager to share information with each other. Automotive technicians nationwide are brothers and sisters, and brothers and sisters help each other. It’s what we do.

With the BMW transmission plate removed, you’ll find a 6 mm x 1.0 bolt on the left side.
<p>With the BMW transmission plate removed, you&rsquo;ll find a 6 mm x 1.0 bolt on the left side.</p>

CLICKING DUE TO BAD HALF SHAFT JOINTS

If you’re dealing with a vehicle that has an independent rear suspension that’s equipped with universal joints, and you hear and feel a clicking/ratcheting sound as soon as the vehicle starts to move under its own power, you might initially suspect a problem with the differential, when the issue is likely dry or worn-out rear half shaft joints. This can occur if the vehicle has been stored and not driven for a long period, where the grease in the U-joint bearings has dried up.

You can try to heat the joints using a heat gun, which might help to loosen-up the dried grease, and/or try to lube the joints, if they feature grease fittings. But most likely you’ll need to replace the joints.

Consider servicing the joints before you dive into the differential gears. If you do decide to replace the U-joints, be sure to place match-marks on the inboard and outboard flanges so that they are re-installed in the same position, to avoid an unlikely but potential vibration.

Edward Currie

Landslide Hills Automotive

On BMW X3, X5 and some Series 7 models that are stuck in gear, this bolt can be fully tightened to place the transmission into manual neutral, thus allowing the vehicle to be moved.
<p>On BMW X3, X5 and some Series 7 models that are stuck in gear, this bolt can be fully tightened to place the transmission into manual neutral, thus allowing the vehicle to be moved.</p>

STUCK BMW

In case you don’t work on BMW vehicles much, and the vehicle won’t move because of the electronic shift lock system fault, here’s a handy tip: First take the transmission plate off. Just beside the pan bolts on the driver side, there is a 6 mm hex bolt that you have to completely tighten on the X3, X5 and some 7 Series BMWs. This will put it into manual neutral so that it can be moved.

Jake Vance

ASE Master Technician with L1, L2 & L3

American & Import Auto Repair

MALIBU SHORT TO GROUND

If you’re dealing with a 2004-2007 Chevy Malibu and you find the Park light fuse open, don’t bother replacing the BCM, since this won’t solve the problem. A short to ground in Circuit 8 (output dimmer circuit) can cause the Park light fuse to blow.

The circuit #9 (brown/park lamp fuse) wire goes to the BCM and is converted to Pulse Width modulation for the output on illumination circuits (#8 gray wire). Check for a short to ground on the #8 gray circuits in the doors, around the center console and near the driver-side front seat track. The BCM circuit does not protect the #8 illumination circuit and will cause the Park light fuse to blow if a short occurs.

Rob Holland

Holland Auto

BUSTED STUDS

Some 2010 F-Series Ford trucks with a 6.8L engine feature stainless steel exhaust manifold studs. One or more of these studs may be broken due to improper tightening. Remove the exhaust manifold(s) and remove not only the broken studs, but remove all exhaust manifold studs and replace with new stainless steel studs, P/N W703902-S403. Replace the exhaust manifold gasket(s). Install the exhaust manifold and tighten the studs into the head at a mere 71 to 115 in.-lbs. Install new stainless steel nuts, then tighten the stud nuts to 204 to 239 in.-lbs. Do not over-tighten the studs where they thread into the heads. Applying too much torque when installing the studs can cause the studs to splay, making it difficult to reinstall the exhaust manifold.

Matt Swenson

Larson Auto & Truck

In order to improve oil drain-back on General Motors’ LS-series engines, carefully drill a 5/16-inch hole in the outboard side of the lifter guides, just above the floor at each lifter location.
<p>In order to improve oil drain-back on General Motors&rsquo; LS-series engines, carefully drill a 5/16-inch hole in the outboard side of the lifter guides, just above the floor at each lifter location.</p>

LS LIFTER BUCKETS

GM LS series of engines (LQ4, LQ9, LSI, LS6, LS2, LS3, LS7, LS9, etc.) feature hydraulic roller lifters that are guided in place with plastic lifter guide buckets. The plastic guides feature inside flats that mate to flats on the sides of the lifters in order to keep the roller lifters in plane with their respective cam lobes. The lifter guides tend to allow engine oil to collect and puddle above the top of the lifters, not allowing oil to drain back to the sump quickly enough.

Push the lifters into the guides fully until they snap into place.
<p>Push the lifters into the guides fully until they snap into place.</p>

If you tear down an LS engine or just pull the heads off, here’s a tip. With the heads removed, rotate the crankshaft two full turns. This will cause the lifters to move up into the guides, “locking” each lifter into a high position where they are held up in the guides. Each lifter bucket is secured to the block with a single 6 mm screw. Remove the screw and pull the lifter guide along with its four lifters. Pop the lifters out of the guides. Drill a 5/16-inch hole in the outboard side of the plastic lifter guide, just above the floor of each lifter location. The outboard side is the side of the lifter guide that faces the exhaust side of each bank.

Note that a single 6 mm mounting screw secures the plastic lifter guide to the block, torqued to 106 in.-lbs.
<p>Note that a single 6 mm mounting screw secures the plastic lifter guide to the block, torqued to 106 in.-lbs.</p>

Deburr the holes and thoroughly wash the plastic guides. Reinstall the lifters into the guides, pushing them up until they each “click” into a held position. Reinstall the guide and its four lifters, tightening the 6 mm screw to 106 in.-lbs. These holes will allow oil to drain back to the sump instead of being held inside the lifter buckets.

Larry Ritz

Smitty’s Car Repair

Be sure to re-use the original lifter guide screws. They feature a shoulder under the screw head that properly centers the lifter guide. Do not substitute a generic 6 mm bolt.
<p>Be sure to re-use the original lifter guide screws. They feature a shoulder under the screw head that properly centers the lifter guide. Do not substitute a generic 6 mm bolt.</p>

STINK REMOVER

When a customer’s vehicle has a bad odor, such as tobacco smoke, food odors, body odor, a mildew smell, etc., try using an ozone generator. Place the tool inside the passenger area, at a location above the floor area, such as on the dash or on top of a center console. Run all window glass all the way up, except for one window, which should be about 2 inches open. This allows you to run the ozone generator’s power cord out of the vehicle, and allows an air exchange.

Leave the tool on for about an hour, and then check for odor. You’ll notice an initial metallic smell, which will dissipate in about 20 minutes.

If the unwanted smell isn’t gone yet, run the tool for another hour.

An ozone generator is a useful tool to remove unwanted odors inside the passenger compartment.
<p>An ozone generator is a useful tool to remove unwanted odors inside the passenger compartment.</p>

Ozone is an oxidant that contains three atoms of oxygen as opposed to the two atoms of oxygen that we normally breathe. The extra oxygen atom in ozone attaches itself to other molecules, which results in non-offensive, or “neutral” molecules. In layman’s terms, ozone soaks up the stink and neutralizes it. Depending on the degree of odor, it may take multiple treatments, but it does work.

We’ve had customers who have said they’ve tried “everything” to get rid of bad smells, including washing surfaces, spraying over-the-counter odor eliminators, to no avail. After one or more ozone treatments, we’ve been able to get rid of offensive odors in every vehicle that we’ve treated. The metallic smell that is created (you’ll notice a metallic flavor on your tongue, kind of like you sucked on a handful of pennies), but that goes away in short order.

Brian Dalton

Grand River Auto

CHEWED WIRES

We’ve all run into vehicles that have shorting issues on various circuits, due to wires being chewed by small rodents.

Recently we heard of a special electrical tape from Honda that is impregnated with a chemical that’s similar to what’s found in super-hot chili peppers. When a mouse or chipmunk starts to taste this tape, they back off immediately.

After you’ve repaired wires, wrap this tape around the harness. It will deter future chewing. Just don’t rub your eyes after handling this tape.

Honda’s part number for this tape is 4019-2317. I think they call it rodent deterrent tape. There might be other brands out there, but we used the Honda tape and it works. This is a great preventive measure for cars that are stored for long periods, too.

Bob Wilwood

Pete’s Import and Domestic

LET IT BLEED

We recently had a Chrysler PT Cruiser in for an overheat problem. The owner had replaced the radiator hoses and complained that the engine overheated since his repair. He assumed that he maybe needed a new radiator or electric fans.

At the base of the fill tube, below the thermostat in the cast aluminum lower housing, there’s a small air bleed valve.

With the engine running, open the bleeder using a 10 mm wrench and let the coolant spit out. Once you see a clear stream of coolant, close the valve. Then top off the coolant. If you don’t bleed the system at this bleeder, you’ll never get the air out of the system.

Cooling system bleed valves are fairly common, but some folks, especially do-it-yourselfers, are not aware of this.

If you don’t bleed the system properly, you’ll have air pockets that will prevent the heat from being transferred. This is a common and simple task, but some overlook this.

Mitchell Blankenship

Destiny Automotive

BLEEDING ACURA BRAKES

If you tried bleeding the brakes on a 2007-2012 Acura MDX and have a low pedal, you could have air trapped in the VSA modulator. Instead of replacing the master cylinder or the VSA modulator, here’s a procedure to bleed air from the system.

1. Make sure the battery is in good condition and fully charged.

2. Raise the car on a lift and remove all four wheels.

3. Connect your HDS PC and MVCI. Go to ABS/TCS/VSA and go to Functional Tests, and follow the screen prompts.

4. Click on Left Front VSA.

5. Press and hold the brake pedal and click Enter. Keep the pedal depressed until the test is complete.

6. Next, click on Right Front VSA and repeat the previous two steps.

Next, you’ll want to bleed the VSA modulator.

1. Connect one end of a clear hose to the left front caliper bleed valve and place the other end of the hose into a container, keeping the container higher than the caliper.

2. Open the bleed valve.

3. Click on Left Front VSA and follow the screen prompts. Do not press the brake pedal while running this test.

4. Repeat this test four times. You don’t need to turn the brake rotor during the test. Click on Enter when prompted.

5. Close the left front caliper bleed valve.

6. Repeat steps 1 through 5 for Right Front VSA, Left Rear VSA and Right Rear VSA.

7. Top off the brake fluid.

Next, perform a normal brake bleed, twice on the front calipers and five times at the rear calipers. That should do the trick.

Roger Plumley

Ace’s Garage

Here’s a torque wrench extension that’s 2 inches long. Add length, and you’re adding leverage.
<p>Here&rsquo;s a torque wrench extension that&rsquo;s 2 inches long. Add length, and you&rsquo;re adding leverage.</p>

TORQUING WITH AN OFFSET WRENCH

When using a torque wrench, if you’re faced with wanting to apply the correct torque value to a bolt head or nut that’s hard to access, sometimes you need to use an offset wrench that basically makes the torque wrench longer.

Because you’re adding length, you’re adding more leverage. If you attach an extended wrench to the torque wrench and tighten with the torque wrench set at the specified value, you’ll over-tighten. You need to compensate for the added length to avoid this. Torque wrench extensions are usually 2 inches long.

There’s a simple formula to follow in order to adjust the torque wrench to achieve the correct value.

T = Desired torque value (the published torque spec)

L = Length of the torque wrench (from center of the grip to center of the head)

E = Length of the extension

Y = The value that you need to set on your torque wrench

The formula to be used is as follows:

T x L divided by L + E = Y

Measure the length of your torque wrench, from the center of the head to the center of the grip handle. This is Length E. Once you know Length E and the length of your extension, figuring out what to set your torque wrench to is easy.

If the 2-inch extension is added to a torque wrench that’s 14.5 inches long from center of handle to the center of the head, you now have the leverage of a 16.5-inch torque wrench. You need to adjust the torque wrench to a lower setting in order to apply the desired torque value.
<p>If the 2-inch extension is added to a torque wrench that&rsquo;s 14.5 inches long from center of handle to the center of the head, you now have the leverage of a 16.5-inch torque wrench. You need to adjust the torque wrench to a lower setting in order to apply the desired torque value.</p>

Here’s an example: Let’s say you want to apply a torque value of 35 ft.-lbs.

Let’s say that your torque wrench length is 14.5 inches. This is your length L.

Let’s also say that your wrench extension is 2 inches long. This is length E.

35 x 14.5 (T X L) = 507.5

14.5 + 2 (L + E) = 16.5

507.5 divided by 16.5 = 30.75 (Y)

So, in this example, in order to achieve 35 ft.-lbs., you would adjust the torque wrench to 30.75 ft.-lbs., or just round it off to 30.5 or even 31).

Steve Walker

Sunshine Auto Repair Specialists

The Ford stamped steel thermostat housing is very prone to rusting, and the thin base distorts when tightened, so it should not be re-used.
<p>The Ford stamped steel thermostat housing is very prone to rusting, and the thin base distorts when tightened, so it should not be re-used.</p>

POWERSTROKE THERMO HOUSING

Ford 7.3L Powerstroke diesel engines are great, except for a few common issues. One worth noting is the thermostat housing on 1999-1/2 – 2003 7.3L engines. This thing is terrible. It’s made of thin stamped steel, and is very prone to rusting, to the point where it looks like it’s going to rot off and spew coolant. Also, due to the thin 3-bolt base, the base distorts when tightened, so re-using it is not a good idea. The cheap OE housings are one-time-use and should be replaced whenever you service the cooling system, or when it begins to look nasty and you’re concerned about failure.

Instead of replacing the housing with another OE stamped steel unit, a popular fix is to use an aftermarket housing that’s machined from 6061 aluminum billet stock. It won’t rot, and the base and neck wall thickness is substantial, so it’s not going to warp or distort. It seals with a nice thick O-ring, and it’s anodized to reduce surface corrosion. This type of replacement thermostat housing is available from a number of sources. They cost around $48 to $67. Yeah, it costs more than the original, but the swap is definitely worthwhile. They even include the O-ring and stainless bolts. ■

Bobby Young

Bobby Y Truck & Automotive

Aftermarket billet aluminum housings are a good upgrade. They won’t distort, and the anodized aluminum won’t rot.
<p>Aftermarket billet aluminum housings are a good upgrade. They won&rsquo;t distort, and the anodized aluminum won&rsquo;t rot.</p>

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