Techs Helping Techs

Dec. 4, 2023
It's that time of year where readers share some of the tips and tricks they picked up from their own service bays. Thanks to all who submitted items to help educate the entire Auto Service Professional audience. Hats off to you!

It's that time of year where readers share some of the tips and tricks they picked up from their own service bays. Thanks to all who submitted items to help educate the entire Auto Service Professional audience. Hats off to you!

BAD COIL BRACKET GROUND

We recently had a 2014 Chevy Silverado HD2500 with a 6.0L engine with an intermittent/random misfire when cold, but the engine seemed to smooth out and improve as it warmed. During a lengthy diagnosis, we eventually discovered that this was traced to a bad/intermittent ground at both coil pack brackets. We cleaned all contact surfaces and even ran a separate ground wire to each coil bracket. Problem solved.

Rob Holland

Holland Auto

CLEAN THOSE PUSHRODS

If you’re servicing/rebuilding/cleaning an engine that features overhead valves and pushrods that have an oil hole running through each pushrod, and you plan to reuse the pushrods, it’s important to make sure that the oil passage is clean. A contaminated or plugged pushrod will prevent oil from getting to the rockers. Never assume (even with new pushrods) that the oil passage is clean. Use a small dedicated pushrod cleaning brush, solvent and compressed air to clean. The small diameter brushes are available from the performance aftermarket, from sources such as Comp Cams. You can squirt a brake cleaner solvent into the passage, scrub it with the small bristle brush, and blow dry with compressed air. Always wear safety glasses.

Dave Collier

State Road Service

ESCAPE PARK BRAKE HARNESS

If you encounter a 2017 Ford Escape equipped with 17-inch wheels, and the electric park brake warning indicator is on, check for DTCs. Codes C1034, C1A43, C2005, C2007, C2008 and/or U2002 may be present. If the vehicle has 4WD, you may also see the ABS warning on with DTC C003A or C0037 in the ABS module. If so, inspect the rear electric park brake/brake skid control wiring harness on both sides. Look for damaged wiring harnesses where the wheel(s) may have rubbed on the harness. If either or both harnesses are damaged, replace them, and use a tie strap to obtain adequate clearance between the harness and the wheel.

Paul Simmons

Bellview Auto

SEAL THOSE LS FLYWHEEL BOLTS

Here’s a tip for anyone unfamiliar with the GM LS series of engines. Some are unaware that the flywheel bolt holes on the crankshaft flange are open to crankcase oil. If you’re replacing or installing a flywheel or flexplate, be sure to apply a thread sealant to the bolt threads before bolt installation. If you fail to do so, you’ll end up with an oil leak that you may automatically assume is due to a rear main seal leak.

Brian Carmichael

Branson Automotive

REMOVING STUCK THREADED PLUGS

Here’s a tried and true tip for new technicians. If you encounter a stuck, rusted or frozen threaded plug in an iron engine block, instead of fighting with it and potentially drilling it out, try heat and wax. Use a torch, with acetylene only, and heat the plug until it’s glowing red. While still hot, apply a piece of wax to the plug edges. (This allows the wax to quickly liquify and get into the threaded area.) Then, immediately try to remove the plug using the appropriate wrench or bit. Usually, this will allow the plug to easily be removed. Caution: since you’re using a high level of heat, this is best done with the engine out of the vehicle to avoid the risk of a fire. And be sure to wear eye protection and heavy gloves — welding gloves are best. Avoid using just any cheap wax, such as candle wax. Use only a pure non-colored wax or paraffin. This type of wax is available from machinist supply sources.

Jody Holtrey

Mountain Motors

DON’T USE TEFLON FOR THREADS

You may encounter female threads that have rust or slight burrs that make it difficult to remove a bolt. After cleaning the threads, even using a dedicated thread chaser bit (never use a cutting tap), you may need or prefer to apply some type of thread lube to avoid the issue in the future. When a lubricant is required for threaded fasteners, use only the type of lube required for the application (engine oil, dedicated thread lube, anti-seize, etc.) Avoid using a Teflon spray lube, as tempting as it may be, simply based on the name “Teflon.” A Teflon spray lube can eventually work its way out of the threads and dry, resulting in potential metal-to-metal galling.

Clark Williams

Intercity Service

CLEANING OIL IN COOLING SYSTEM

If you encounter a condition of oil in the cooling system (coolant contaminated with oil or transmission fluid), naturally you first need to diagnose the issue to find out where the fluid transfer is taking place so you can repair the problem. But before putting the engine back into service, you need to clean the cooling system. Drain all coolant — including coolant from the block. Mix a 50/50 solution of distilled water and a degreaser such as Simple Green. Or make a mix of 75% water with 25% low-suds liquid laundry detergent. Add this mix to the system, and bleed the cooling system. Add only water if topping off is needed. Run the engine for about 30 minutes at operating temperature, revving to about 2,500-3,000 rpm intermittently. Then drain the cooling system (including the block). You may need to perform this procedure several times in order to properly clean the system. Once cleaned, fill the system with the appropriate coolant that is specified for the engine and bleed. 

Mitch O’Connel

Concourse 1

NO HEAT IN F-150

If you have serviced 2015-2019 Ford F-150 trucks equipped with the 3.5 turbo EcoBoost or 5.0L engine for customers who drive in extreme cold conditions (colder than minus 4 degrees, for example) and the engine is equipped with a block heater, you may have gotten complaints of poor or no heat in the HVAC system. This may be due to deposits from the coolant becoming trapped in the heater core. You may need to flush the cooling system (see the repair manual for the procedure for your specific engine,) replace the heater core and maybe the block heater. First, run the engine to operating temperature and set the temperature control to full warm, with the blower on medium setting. Measure the heater core inlet hose temperature — it should be above 150 degrees Fahrenheit. Then measure heater core outlet hose temperature. The inlet and outlet hoses should be within 10 to 30 degrees of each other. If not, drain and flush the system using a bottle of Motorcraft Premium Cooling System Flush or equivalent. Again, follow the flushing procedure for the specific engine, as procedures differ. Plan to replace the heater core. Inspect the block heater. If it’s a stainless steel unit P/N CV6T-6A051-AA or HL3T-6A051-AB, reinstall it. If it’s brass P/N 94BB-6A051-AA, replace with the stainless unit. Make sure the new heater has the correct connector for the wiring harness.

Dave Folsum

Avalon Motors

MISFIRING OPTIMA

A few months ago, a customer brought in a 2007 Kia Optima EX (2.7L V6 DOHC) complaining of engine running rough. When we scanned, DTCs P0300, P0301 and P0303 (all misfire codes) were found stored. After replacing the timing belt and associated hardware, the vehicle returned the next day with the same codes. We replaced the No. 1 and No. 3 coils and boots and all six spark plugs. The vehicle returned again with the same codes.

We performed the following tests:

  1. Checked the long and short fuel trim, after the codes are set, to see if Bank 1 is lean. If it is, swap the injectors bank-to-bank and see if the problem moves to Bank 2.
  2. If the miss is still on Bank 1, bench test the Bank 1 (right side) OCV (oil control valve). Energize the OCV and verify that it opens and remove the ground to verify that it closes again. Cycle it on and off several times to see if it sticks.
  3. Swap the OCVs from bank-to-bank and see if the problem moves to Bank 2. If it does, the OCV has likely failed.
  4. If the miss is still on Bank 1, unplug the OCVs and see if the trouble codes return. If they do, the CVVT (constant variable valve timing) actuator may be malfunctioning.

While potential causes include fuel injector(s), variable valve timing oil control valve and/or variable valve timing actuator sprocket, in this particular case, the fix involved simply replacing the variable valve timing oil control valve.

Greg Altman

Summit Auto Clinic

OIL SPRAY RESULTED IN MAF ISSUE

A longtime customer who has his fleet of plow trucks serviced at our shop brought in a 2017 Chevy Silverado for regularly scheduled maintenance. After doing an oil change, belt replacement, routine brake job and wiper replacement, the truck ran perfectly. About two weeks later, he returned, complaining about reduced engine power and engine stalling. When we asked him when the problem began, he said just after he had the truck oil-sprayed (he has his trucks oil sprayed before each winter to help protect against undercarriage rust). Knowing this, we began inspecting with the oil spray in mind. We quickly discovered that an over-zealous oil spray managed to enter the intake air system and contaminated the MAF. After cleaning the mass airflow sensor (using approved cleaner), all was well. It pays to ask the customer questions, as this saved a lot of diagnostic time that would have been wasted.

Gary Rittenhouse

Valley City Service

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