5 Signs Your Cylinder Heads May Be Bad (and What to Do About It) – Jalopnik

No one likes to spend money on car repairs. Changes? Of course, you can never throw enough money at mods. The same goes for detailing supplies. But actual repairs? That’s never a fun way to burn your hard-earned money. That said, some repairs are easier to swallow than others. Like replacing a faulty sensor or replacing tired brake pads, jobs like these are usually easy enough to do at home with basic tools, and are unlikely to cost a lot of money.

However, some jobs are best left to the professionals, and there are plenty of such tasks that can easily drain hundreds, if not thousands, from your bank account. An example of this is defective cylinder heads. For the uninitiated, a cylinder head is the top part of your engine. Inside you will find valves, spark plugs and various passages for coolant and oil. It fits perfectly on your block (the bottom of your engine) and rarely needs maintenance.

However, problems can arise. When they do, you usually see a whole host of warning signs. With regular use – such as commuting – your cylinder head is unlikely to fail dramatically; it is usually a process that takes place over time. This may lead you to think that you can ignore the signals for a while. However, that is never wise, because smaller problems grow into bigger problems, resulting in sky-high repair costs. So pay attention to the following symptoms and make sure you address them as soon as possible.

When someone talks about a ‘defective cylinder head’, they are most likely talking about a defect in the gasket or seal between the cylinder head and the engine block. If this happens, the coolant that normally flows through the various passages can leak out. As you might guess from the name, coolant is designed to keep your engine at a safe operating temperature.

When coolant leaks, especially if it is a significant leak, the temperature can no longer be kept under control. The first sign of a coolant leak is usually steam under the hood, as the escaped coolant hits hot engine parts on its way down. When enough escapes, your engine’s temperature will rise, and this will show up with an indication on the dashboard – either in the form of a warning light, or a high reading on the gauge.

If you see this happening, it is important to stop as quickly as possible and let the car cool down. Turning on the heater may allow some warm air to escape from the engine compartment, but you should still stop and allow the engine to cool. There is a possibility that it is a very slow leak and has gone unnoticed for a while. Realistically, you may need to have your head gasket replaced before driving again; continued use in this condition could result in serious and costly damage to the physical cylinder head itself.

Overheating doesn’t necessarily mean your head gasket is toast; Your radiator fan may have just been packed away. Contaminated oil and coolant are not definitive proof in themselves either, but they are common symptoms. The more of these symptoms occur, the more likely it is that your cylinder head is compromised in some way.

When the head gasket fails, it means that the routes for both the oil and coolant merge, while these two fluids are usually kept completely separate. When oil and coolant come into contact with each other, the resulting fluid is a thick white liquid – a bit like mayonnaise – with a brown tint. If you suspect there are problems with the cylinder head, remove the oil cap and take a look. If there is thick white sludge on your oil cap, that is a pretty strong indication that the head gasket needs to be replaced. It could also be related to condensation, especially if the car has been sitting for a while.

When your oil and coolant turn to sludge, both the lubricating and cooling capabilities of your engine will be severely weakened, so driving the car in this condition is a no-go. You run the risk of the temperature rising so high that the cylinder head itself warps, meaning it needs to be skimmed to be straight and usable again. So if you see sludge and aren’t sure it’s not just condensation, take it to the store right away; taxis and public transport probably cost a lot less than a new cylinder head.

Don’t sound alarm bells if your car loses power, as this could be anything from a clogged air filter to a faulty sensor. In other words, reduced power is no reason to suddenly panic about your cylinder head. However, when combined with other symptoms, this is a likely indicator that something is wrong.

When the head gasket fails or the cylinder head warps, your engine will operate at a lower compression ratio. This results in lower power, which will make your car feel a little sluggish compared to when it was in good health. You may also experience worse fuel economy at this point.

Again, the advice is simple: have your car inspected by a professional so they can determine what is causing your problem. If you’d rather try to diagnose the problem yourself, there are a few ways you can determine if your head gasket is blown at home. One of the easiest ways you can do this is by using a combustion leak tester kit. You simply attach it to the top of your radiator – with the tester cap removed and the test fluid poured in – and then run the vehicle. If the fluid in the tester turns yellow, the head gasket is likely defective and CO2 has been detected in the cooling system. This is not a guarantee that the head gasket is defective, but it is a strong indicator, especially when combined with other symptoms.

This symptom goes hand in hand with reduced performance and, like the other signs of cylinder head failure we’ve mentioned, can be related to a whole host of problems under the hood. In this case, however, a misfire or rough idling could be caused by your engine struggling to burn as efficiently as it wants to.

A warped cylinder head or a defective gasket means that the underlying combustion chamber is no longer completely sealed. This messes with the compression ratio and the air-fuel ratio and will eventually lead to a misfire. However, misfires are one of the most common problems you can have with a car. Before you assume the worst, it’s wise to rule out some simpler reasons why you’re experiencing a misfire.

Common causes include problems with the spark plugs, faulty sensors, or even bad or old fuel in the system – all less of a problem than a faulty cylinder head. If you’ve checked the more obvious and easily addressed causes and found nothing untoward, then it may be worth examining the cylinder head before things get any worse. If you ignore this, the problem can spread from one cylinder to another, and before you know it, the car can become undriveable.

This particular symptom is a little more specific, as white smoke from the exhaust means your engine is burning coolant. A little white smoke is normal, especially at start-up, but if there’s a plume of smoke hanging everywhere behind you, that’s a clear sign that something is wrong.

When your cylinder head fails, it is common for coolant to enter the combustion chamber. This causes the coolant to burn, causing white smoke to come out of the exhaust. Coolant also has a sweet smell, which is a pretty solid indication that your white smoke problem isn’t just condensation on a cold day.

As we discussed, burning out your coolant will quickly lead to overheating problems if you’re not careful, so don’t ignore that sweet smell and cloud of smoke. Burnt coolant running through your exhaust will likely damage your O2 sensors as well, meaning you’ll have to part with more money when you finally get it into the shop. Always act quickly to avoid further bills if you notice anything unusual about your engine.