Worth Fixing Blown Head Gasket?


The blown head gasket is a real pain, some gaskets just fail with old age and others are provoked, either way, a blown head gasket means the vehicle can’t be used, or can it? I’ve been a mechanic for over twenty-five years and I’ll share some insider head gasket tips and advice.

A vehicle’s head gasket is worth fixing, so long as the vehicle was in good condition prior to head gasket failure. To help calculate if it’s worth fixing, follow this 3 step process:

  1. Determine the resale value of your vehicle if repaired
  2. Get repair cost estimates
  3. Vehicle worth repairing, if resale value greater than three times repair cost 

In this post you’ll learn how to figure out if your head gasket is worth fixing, you also learn some of the hidden costs of head gasket repair, hang with me and we’ll get this figured out.

1 Determine Your Vehicle’s Value

Having a head gasket fail is a real pain and it’s one of those types of problems that can’t be ignored. I understand your predicament, you don’t want to waste money and effort on a vehicle if it isn’t worth fixing.

Sometimes it is better to say goodbye to an older car and start again. But before we can make that decision we’ll need to gather some facts and consider them carefully.

Kelley’s blue book is a useful resource for pricing repairs, valuing vehicles, and finding local repair auto shops all from your phone.

We’ll need answers to questions about the cars general condition pre gasket failure, questions like:

  • Was the car reliable?
  • What is the mileage?
  • What is the bodywork like?
  • Was the car economical?
  • Did it have electrical faults?
  • Are the tires in good condition?
  • What about maintenance due?

Ok, some of these questions may be difficult for you to answer but together we’ll get through them. Getting these answered will start to build a picture of what general condition the vehicle is in and therefore how much money the vehicle is likely to cost you in addition to the head gasket repair. Make sense?

Let’s now consider each of these questions, in turn.

Was the car generally reliable?

If the car wasn’t reliable pre, replacing the gasket likely won’t change that, those issues will remain and will need investigation and repair.

Some common irritating issues like ABS warning lights, airbag warning lights, traction control warning lights, intermittent engine lights are often a simple repair but will still cost $100s to fix.

What is the mileage?

Cars with high mileage anywhere from 180,000 plus miles will start to require more maintenance and the likelihood of some major engine repairs becomes more likely.

How’s about brakes suspension and steering?

These are all components that require attention even low mileage cars develop braking issues from infrequent use. Consider if your car has shakes, rattles, knocks, or clicks while braking, driving on uneven surfaces or turning. If so it is likely you need some work, this type of work adds up to 100$ in repairs.

What about maintenance due?

Engine timing

Maintenance other than the oil and filter change is often forgotten about. Transmission oil changes, coolant changes, brake fluid change, power steering fluid change, and engine critical items like timing belt replacements need maintenance or they will lead to even greater expense.

Typically these items don’t cost a ton but do add up, maintenance items include:

  • Transmission oil and filter – $100 to 250
  • Coolant & thermostat changes – $120 to 200
  • Brake fluid change – $100 to 250
  • Power Steering fluid flush and change – $75 -to 150
  • Timing belt and water pump replacement – $450 to 1200
  • Serpentine belt – $50 to 120

What is the bodywork like?

Car rust

Bodywork is a minor issue you might say, scrapes, dings, and missing moldings will affect the value but won’t affect how it drives. However, if your vehicle suffers from corrosion, I’m talking bubbles of rust in the panels then I’d say there’s a very good chance the chassis, underpinnings, and exhaust system are also affected by corrosion.

Chassis corrosion changes everything, this type of vehicle isn’t worth fixing. Corrosion is too expensive to repair and will only cost you money into the future. In addition chassis corrosion is a safety issue.

Was the car economical?

Older cars aren’t known for their fuel economy and aren’t as environmentally conscious as newer models. If you do a ton of driving, this might be a great opportunity to own a more economical model.

Does it have electrical faults?

Faulty batteries can cause a ton of electrical issues, typical batteries last about three to four years and will cost about $150 fitting.

Battery testing

Other common electrical issues include faulty window regulators, central locking issues, alarm faults. Electrical issues are always expensive to fault find and fix.

Are the tires in good condition?

Tires are a running cost on all cars, a new set of boots can cost upwards of $300, so take that into consideration when evaluating your car’s true value.

Checking your vehicle value

To find an approx. value for your vehicle checks out the usual online used car portals.

www.kelleybluebook.com

www.cars.com

www.carmax.com

www.autotrader.com

I don’t look at dealer prices as those prices are often inflated, look at the private advisers only. There you’ll find a match for your make and model. I like to find the highest price and then the lowest price, the price in the middle is about fair.

That’s the pre-head gasket failure resale value of your vehicle.

2 Get Repair Cost Estimates

Head gasket costs will vary by vehicle, the severity of the damage, and by type of shop, you visit. Without a doubt, a local trusted mechanic will be a ton cheaper than a large main dealer shop.

Vehicle brand and engine size

Vehicle brand and engine size will obviously affect the price greatly. Higher-end vehicles and imports like Mercedes, Audi, VW, BMW, etc. will usually cost the most to repair.

Parts are imported and North American mechanics are less willing to work on imports, so you are forced in many cases to work with main dealers.

S class Mercedes

Similarly, many of the premium imports are fitted with larger engines; repairing a six or eight-cylinder engine will cost a lot more than a four-cylinder motor.

Severity of damage

How much damage the vehicle has sustained is obviously a large contributor to the final repair bill. When a head gasket blows it can cause a lot of damage.

Head gasket failure chart

A failing head gasket can for example manifest initially as a car that simply uses a lot of coolants. If ignored as is often the case, the coolant enters the oil system, combustion chamber damaging other components like turbochargers, O2 sensors, and Cats all expensive components to repair. (More on this later)

Repair shops

As said, shops often vary their price by how busy they are. Looking at it from the shop owner’s point of view, replacing a head gasket won’t happen in one day, it will take several days.

There’s the vehicle strip down, outsourcing cylinder head testing, parts ordering, and rebuild. On and off the clock, the repair could take a week to complete. That’s a vehicle occupying valuable workshop space unproductively.

In my experience, shop owners generally prefer smaller jobs, one to two hours, they can get a higher return from lots of smaller jobs. When the shop isn’t busy, sure they’d love to take in a head gasket job. 

Getting an estimate

Often a car owners club is a great place to ask about a trusted local mechanic that has experience with your brand of vehicle. Specialized tools or procedures are sometimes needed when replacing a head gasket, brand knowledge is valuable. 

A good shop will be able to give you a ballpark figure for your vehicle head gasket replacement. However, they won’t be able to guarantee that price, and the reason is simple. On strip down or testing, other issues may be found that will cost extra in materials and labor. Check kbb.com local auto repair shop finder.

Get at least two estimates for head gasket replacement. The cheapest price is often the dearest, best cross-reference the price with the shop’s reputation before selecting a shop.

3 Making The Calculation

This is the easy part, with estimates in hand and having a fair price calculated for your make and model, it’s simple, math. If three times the repairs costs equal more than the resale value of your car, it is indeed time to say goodbye.

If on the other hand, the calculation suggests the head gasket is worth replacing, great, but wow now we need to consider those questions we answered earlier, like maintenance due and tire condition, etc. These all play into this calculation also. 

Add the ballpark cost of these maintenance running repairs to the head gasket repair estimate bill. If three times the total repairs costs equal more than the resale value of your car, it is time to shop for new wheels.

But what to do with a nonrunning car? It still has some value, many dealers will still take a nonrunner as a part exchange. Your car has a ton of great parts, and some universal type parts like tires and batteries, and a local breakers yard will quote you over the phone and arrange pick up.

What Are The Hidden Costs Of A Head Gasket Job

Getting an estimate over the phone isn’t like a strip-down estimate. I’m a mechanic and I know sometimes things don’t go to plan, in fact, they rarely go to plan.

What this means, in reality, is a contingency should be built into your estimate, i.e. inflate it for unforeseen items or issues.

When things don’t go to plan, you could end up where you started. A strip down could reveal additional damage that you hoped it wouldn’t. Head gaskets can fail in seven different ways and each comes with risks for other components. 

Some hidden costs that could arise, issues include:

  • Warped cylinder head
  • Cracked cylinder head
  • Blown turbocharger
  • Damaged exhaust oxygen sensors (O2)
  • Damaged Catalyst 
  • Damaged camshaft

When a shop strips down an engine to replace the head gasket, it is common practice to send the head out to a specialist company for testing. Testing entails pressure testing the coolant passages for cracks and also checking that the head is true.

cylinder head

Cylinder heads can crack and warp when severely heated. A slight warping may be machined out but severe warping or cracking of the passageways spells the end for the head and blows the repair estimate.

The best route forward is a used but good cylinder head which will also need to be tested before being used. A good used parts supplier will at least guarantee it’s good or offer you a refund on the cost of the head but not the testing.

Finally, as a mechanic, I’m not a big fan of magic potions that guarantee results, but when your back is against the wall it may be worth a try. Several products on the market are designed to repair head gaskets by simply adding a bottle of chemicals to the coolant system. 

This as you can imagine is sacrilegious to a mechanic, I see the only correct repair is to replace the gasket. Saying that, if it gets you out of a tight spot it is worth trying, and it won’t cause any further damage to the engine. One of the better products is called Bar’s Leaks and you can check it out here on Amazon.com.

Check out the Mechanics tools page for a list of my favorite tools.

John Cunningham

John Cunningham is an Automotive Technician and writer on Rustyautos.com. I've been a mechanic for over twenty-five years, and I've worked for GM, Volvo, Volkswagen, Landrover, and Jaguar dealerships. My passion is cars. I use my knowledge and experience to write articles that help fellow gear-heads with all aspects of car ownership, including buying advice, maintenance, and troubleshooting.