Productive engine service tips

Being a specialized service, engine repair work challenges change every day.


Q: We keep hearing about stretch-fit belt technology on serpentine belts. Does that mean there aren’t any special tools required to install these new belts?

A: Stretch-fit belts are being used on at least some engines by almost all the most popular car makes. While some belt applications may not require any special tools, the overwhelming majority of stretch-fit installations require some sort of tool to safely and effectively route the belt onto its matching pulleys and idlers. When shopping for stretch-fit belt installation tools, line up some training as well so you’re properly prepared to service this new technology.

Q: When diagnosing a suspected faulty head gasket, we usually look for contaminated oil and coolant. Is there anything else we can use that’s more conclusive?

A: Yes, a combustion leak tester helps confirm and pinpoint the presence of combustion gases in the cooling system. First you add a blue-colored fluid to the tester, then insert the tip of the tester into the radiator to expose the tester to potential combustion gases. If the tester encounters any combustion gases in the radiator, the dye will turn yellow.

Q: We’ve heard that removing spark plugs on 5.4L Ford, 3-valve engines is a nightmare as it’s likely the spark plugs will break during removal. Are there any tools that can help save us when facing a “problem child” like this?

A: First, realize that removing plugs on these engines must be done with the engine cool and after soaking the spark plug threads with a recommended carbon cleaner. Still, some plugs break during removal, leaving the spark plug shell behind. When this happens, use a special spark plug remover kit, made specifically for removing the shell from the cylinder head. If the threads in the cylinder head need repairs, there are also inserts for this fix. Take your time and you should have decent success on these otherwise challenging spark plugs. (Check out this month's Tool Briefing on page 18 for more information on spark plug removal and repair.)

Q: When performing engine set-up, we need to easily identify when a cylinder is at top dead center. What tools are available for this?

A: A Top Dead Center (TDC) indicator works best for this purpose, which threads into the spark plug hole and positions a spring-loaded plunger against the top of the piston. As you rotate the engine slowly, watch the shaft of the indicator as it raises to its highest point. You can also use a “TDC whistle” to find top dead center. The whistle also threads into the spark plug hole, and produces a whistle sound as air being pushed upwards by the piston exits the whistle. The instant the whistling stops, you’ve found top dead center.

Q: We’re periodically tasked with owner complaints of low oil pressure. In some cases the oil light comes on and in others the gauge may read low. Is there a quick way to determine the source of the problem?

A: While there’s no quick way to get to the heart of the problem, perform the basics including confirming the oil level and ensuring that the connections to the oil pressure sending unit look OK. From there, consult service information for the oil pressure specification and the recommended access point to connect an oil pressure test gauge, using the proper adapters. With the gauge connected, take one or more oil pressure readings at the specified engine operating speed. Compare the readings to specs and go from there. If the pressure is OK, it usually means a faulty sending unit. Low pressure means you’ve got some further investigation to do, which may require some engine tear-down.

Q: We know warpage is the enemy of reliable head gasket installation, but what do we use to make sure warpage is kept within limits to ensure effective sealing?

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