More often than not, a blown head gasket is amongst the more serious of problems that a car can suffer, and in some cases it can be enough to turn it into a write-off or salvage car (some of which end up in our own online vehicle auctions here at RAW2K). That means spotting and diagnosing the problem early can sometimes be key to saving the car in question - so here’s everything you need to know about a head gasket, and how to tell when you’ve got one.
What is the head gasket?
Your car’s head gasket is a key component that’s situated between the cylinder head and the engine block. Its primary job is to keep the combustion chamber sealed, in order to maintain enough pressure for your engine to function smoothly.
To elaborate, if your car has a combustion engine, it’s essentially powered by explosions. A pressurised atmosphere is required for those explosions to happen, so your head gasket keeps compressed air and fuel inside the cylinder so that it can be effectively ignited and turned to energy that propels your car along. At the same time, it prevents coolant and oil from entering the combustion chamber so that it doesn’t contaminate the ignition process (and crucially, so that your car doesn’t lose precious fluids).
Now, since your head gasket is the first defence against these incredibly hot gases and liquids, then yes they are known to fail occasionally. So, how can you tell when this has happened?
How to tell when you have a blown head gasket
Unlike certain issues that can arise with your car, a head gasket may not necessarily immobilise it right away. True, sometimes this can happen, but often these sorts of issues develop slowly over time.
Your oil is contaminated
One of the most reliable signs that you’ve got a blown head gasket is a white milky substance appearing in the oil in your oil cap. Mechanics sometimes term this ‘mayonnaise’, or ‘milkshake’. (Let’s be honest, there are much worse potential names for it!) Coolant or antifreeze getting into the oil is a very bad sign, and antifreeze in particular can have a detrimental effect on your engine bearings. Repairing this issue often involves an engine oil flush at the very least, and a replacement of the engine oil filter. It can sometimes require complete disassembly of the bottom of your engine.
There’s white smoke coming from your engine exhaust
This is an issue that’s probably not going to escape your attention for a terribly long time; clouds of sweet-smelling white smoke billowing from your exhaust. This is generally caused by antifreeze seeping past your head gasket into the cylinders, where it then gets vaporised into steam. That’s what you’ll spot billowing out of your exhaust. There’s another undesirable side effect, too - namely in that it allows combustion pressure into the cooling system, which can again have a serious knock-on effect on how your car runs.
External fluid leak
Sometimes, an issue with your head gasket might manifest as a simple oil or coolant leak. While at first this might not seem like it’s such a serious problem, if your coolant gets too low, it leads to very unhealthy running conditions for your engine. It poses other dangers too - namely in that if leaking oil drips onto your hot exhaust, it can cause dense smoke and possibly even fire.
You notice problems with your engine
How your car ‘feels’ accounts for a big part of driving, so it’s a skill that even new drivers don’t have to take that long to settle into. That means if a problem develops with your engine, it probably won’t take you that long to notice. If it’s running poorly, skipping, underpowered, or ‘hesitating’ - that is, taking a bit longer to kick in even if your foot is on the accelerator - then there’s a pretty decent chance that it’s to do with your head gasket.
Can you drive with a blown head gasket?
You might find it’s possible, depending on how serious the issue is. But you really, really shouldn’t. It’s very risky and can even be dangerous. What’s more, even if it doesn’t put you in the way of actual harm, it can aggravate any developing problems and may even end up putting your car out of commission. Permanently.
If you’ve got the skill, tools and knowledge yourself though, you might find that you’re able to fix the issue yourself to a decent standard. That’s where we can help here at RAW2K. Our online car auctions are home to a huge range of salvage cars, which can be used for spare parts, or simply as second hand replacement vehicles. We’ve got makes and models from a wide array of manufacturers, like Ford, Renault and Mercedes. Why not take a look through our stock, and see what you can find?