Car Repair Costs Explained: Engine Mounts, Rear Main Seal, Crankshaft & More

What these repairs actually are, what they cost, and whether extended warranty covers them - without the mechanic jargon.

See What an Extended Warranty Covers →

Component Guide: What It Is, What It Costs, Is It Covered?

Engine Mount / Motor Mount

Covered

What it is:

Rubber-and-metal bracket holding the engine to the frame; absorbs vibration

Symptoms of failure:

Clunking on acceleration/braking, excessive vibration, visible engine movement

Repair cost:

$250–$600 per mount (most vehicles have 2–4)

Warranty coverage:

Mid-tier and above

Crankshaft / Crankshaft Bearings

Covered

What it is:

Main engine shaft converting piston motion to rotation; bearings support it

Symptoms of failure:

Deep knocking noise, metal in oil, sudden engine failure

Repair cost:

$2,000–$8,000+ (often requires full engine replacement)

Warranty coverage:

All plans including powertrain

Rear Main Seal

Covered

What it is:

Seal between engine block and transmission; prevents oil from leaking at the rear

Symptoms of failure:

Oil puddle under the car toward the rear of the engine, burning oil smell

Repair cost:

$500–$1,200 (mostly labor - requires trans or engine removal)

Warranty coverage:

Mid-tier and above (seals & gaskets)

Chevy 5.3L Rear Main Seal (Gen IV)

Covered

What it is:

Same as above - particularly common on 2007–2014 GMC/Chevy 5.3 V8 engines

Symptoms of failure:

Oil leak from rear of engine, most visible on lower mileage AFM-equipped trucks

Repair cost:

$700–$1,200 independent / $900–$1,600 dealer

Warranty coverage:

Mid-tier and above

Neutral Safety Switch

Covered

What it is:

Prevents engine start in gear; located on the transmission housing

Symptoms of failure:

Car won't start, starts in wrong gear, intermittent no-start

Repair cost:

$150–$400

Warranty coverage:

Mid-tier and above (electrical/drivetrain)

Why Is My Car Sputtering?

Car sputtering - hesitation, rough idle, or misfires - has many causes. Some are covered by extended warranty; others are maintenance items on you:

Cause	Warranty?	Repair Cost
Faulty ignition coil(s)	Yes	$100–$400 per coil
Spark plugs worn out	No	$100–$300 (maintenance)
Failing fuel pump	Yes	$400–$900
Clogged fuel injectors	Varies	$200–$500 per injector
Faulty mass airflow (MAF) sensor	Yes	$200–$500
Bad oxygen (O2) sensor	Yes	$150–$400
Vacuum leak (cracked intake manifold gasket)	Yes	$300–$800
Catalytic converter failure	Varies	$900–$2,500
Clogged air filter	No	$25–$60 (maintenance)

What Causes Tire Blowouts?

Blowouts are one of the most dangerous sudden failures a driver can experience - and one of the few vehicle failures that extended warranty does not cover (tires are wear items excluded from all plans). Understanding what causes them helps prevent them:

Under-inflation (most common)

Under-inflated tires flex excessively at speed, generating heat that rapidly degrades the rubber structure. Check pressure monthly - especially in cold weather when pressure drops ~1 PSI per 10°F temperature drop.

Tire age

Rubber degrades from UV exposure and oxidation over time regardless of tread depth. Most manufacturers recommend replacing tires 6 years after the DOT manufacture date on the sidewall, regardless of mileage.

Overloading

Every tire has a load rating. Exceeding it - especially on cargo vans, pickup trucks, and SUVs with heavy rear loads - creates the same heat buildup as under-inflation.

Road hazards

Potholes, debris, and curb impacts cause immediate structural damage (impact breaks) that may not immediately deflate the tire but creates a weak point that fails later at speed.

Tires are universally excluded from extended warranty plans. For tire and wheel protection, look at standalone tire/wheel protection products offered by dealers or tire retailers.

Warming Up a Car Battery in Cold Weather

At 32°F, a lead-acid battery loses about 20% of its rated capacity. At 0°F, it loses up to 50%. Cold weather doesn't kill batteries - it reveals batteries that were already weak. Here's how to protect against cold-weather no-starts:

Park in a garage

Even an unheated garage keeps the battery significantly warmer than outside temperatures.

Use a battery maintainer

A $30 battery tender/trickle charger keeps the battery at full charge when the car sits for several days.

Drive regularly

Short trips don't fully recharge the battery. Drive 20+ minutes at speed to allow the alternator to top off the charge.

Replace old batteries proactively

Most batteries last 4–6 years. Replace batteries over 4 years old before winter, especially if slow to start in warm weather.

What extended warranty covers: A dead battery is a maintenance item - not covered. However, an alternator failure that caused the battery to drain is covered under mid-tier and above plans. If your alternator fails and the car won't start, the alternator replacement is covered; the battery replacement that follows may be at your cost depending on plan language.

Protect Against These Repairs with Extended Coverage

Most of the repairs on this page are covered - get a free quote

Engine mounts, rear main seals, crankshaft bearings, neutral safety switches, ignition coils, MAF sensors, and more are all covered under mid-tier and exclusionary plans. See exactly what your vehicle qualifies for at no cost.

Get a Free Extended Warranty Quote →

Provider	Coverage	Repair Network	Max Mileage	Cost/Mo	Rating	Quote
Chaiz	Powertrain/Major/Comprehensive	Any licensed shop	200K	$75-$180	★★★★★	Get Quote
Endurance	6 tiers	ASE-certified	200K	$90-$200	★★★★☆	Get Quote
CarShield	7 plans	20,000 shops	300K	$99-$150	★★★★☆	Get Quote
CARCHEX	5 plans	30,000 shops	250K	$100-$220	★★★☆☆	Get Quote
autopom!	19 plans	2,600 shops	No limit	$80-$190	★★★★☆	Get Quote

Frequently Asked Questions

What is an engine mount?▼

An engine mount (also called a motor mount) is a rubber-and-metal bracket that bolts the engine to the vehicle's frame or subframe. Its job is to hold the engine in position and absorb vibration so it doesn't transfer into the cabin. Most vehicles have 2–4 engine mounts. When a mount fails, you typically feel a thud or clunk when accelerating, braking, or shifting - because the engine is moving more than it should.

What is a motor mount - is it the same as an engine mount?▼

Yes - motor mount and engine mount refer to the same component. 'Motor mount' is more common in everyday speech; 'engine mount' is the more technically precise term. On hybrid and electric vehicles, 'motor mount' can specifically refer to the mount for an electric drive motor, which is a separate component from any combustion engine mount.

What is a crankshaft?▼

The crankshaft is the main rotating shaft inside the engine that converts the up-and-down motion of the pistons into rotational power. It runs the length of the engine block and connects to the transmission via a flywheel or flex plate. Crankshaft failure is rare but catastrophic - a spun bearing or broken crankshaft typically means a complete engine replacement at $3,000–$8,000+.

How much does a rear main seal replacement cost?▼

Rear main seal replacement costs $500–$1,200 at most independent shops. The high cost is almost entirely labor - the rear main seal is located between the engine block and transmission, requiring either the transmission or engine to be removed to access it. The seal itself costs $10–$30; you're paying for 4–8 hours of labor. Extended warranties cover rear main seal failure as a seal/gasket item in mid-tier and exclusionary plans.

How much does Chevy 5.3 rear main seal replacement cost?▼

The Chevy/GMC 5.3L V8 rear main seal replacement typically costs $700–$1,200 at an independent shop, or $900–$1,600 at a GM dealer. The 5.3L is notorious for rear main seal leaks - particularly the 2007–2014 generation (Gen IV LS platform). The Active Fuel Management (AFM) system's oil pressure fluctuations accelerate seal wear. Coverage under a mid-tier or exclusionary plan converts this into a deductible-only repair.

Why is my car sputtering?▼

Car sputtering (misfiring, hesitation, rough running) typically has one of several causes: bad spark plugs or ignition coils (maintenance/wear items, not covered), fuel delivery issues - failing fuel pump or dirty injectors (fuel pump covered in mid-tier plans), vacuum leaks from cracked intake manifold gaskets (covered in mid-tier plans), faulty mass airflow sensor or oxygen sensor (covered in mid-tier plans), or catalytic converter failure (covered in some plans). A diagnostic code scan is the first step.

What causes tire blowouts?▼

Tire blowouts are caused by: under-inflation (most common - under-inflated tires flex excessively, generating heat that breaks down the tire structure), overloading beyond the tire's rated capacity, road hazards like potholes or debris, tire age (rubber degrades after 6–10 years regardless of tread depth), and manufacturing defects. Tires are excluded from all extended warranty plans - blowout coverage falls under tire/wheel protection plans, which are separate products.

How do you warm up a car battery in cold weather?▼

Car batteries lose significant capacity in cold weather - a battery that's borderline in summer may fail completely below freezing. Ways to extend battery life in cold weather: park in a garage if possible, use a battery maintainer/trickle charger if the car sits for days, drive the car regularly (at least 20+ minutes) to keep the battery charged, and replace batteries over 4 years old before winter. A dead battery is not covered by extended warranty (it's a maintenance item), but an alternator failure that caused the battery to drain is covered.

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