Once air and fuel are mixed together, the mixture is then transferred into the cylinders where the internal combustion takes place. Valves are responsible for managing the amount of this mixture that gets sent into the cylinders.
Each valve has a guide seal which prevents the toxic combustion gases from leaking through them. The top of each valve also has a seal which prevents valve cover oil from ending up in the engine.
Each seal is constructed out of a highly durable rubber material. However, this material does get worn out over time which results in the valve guide seals going bad.
Top 5 Bad Valve Guide Seals Symptoms
If you have bad valve guide seals, you will notice certain symptoms that are easily recognizable. You must understand what they are and then you can take proper action after you come across them. Here are five of the most common signs of faulty valve guide seals.
1) Too Much Smoke
Once the deterioration of the valve seals has gotten bad enough, the exhaust smoke that comes out of the car after you start the engine will remain there for a while. This blueish white smoke will not only show up while you’re idle, but it will show up more as you accelerate as well.
Eventually, the smoke will ease up and go away after you’ve had the engine running for a long time.
2) Excessive Oil Use
If you have damaged or worn out valve guide seals, then your vehicle will end up using more oil than it normally uses. If you check your oil level regularly with a dipstick then you will be able to detect this symptom early on.
As long as there are no oil leaks and that your engine compression is functioning properly, then you can be sure that your problem is with the guide seals.
3) Off-Throttle Braking
Anytime you perform off-throttle braking or even just go down a steep road without touching the gas pedal, you may have bad valve guide seals if burned oil begins coming out of your tailpipe during these actions. It won’t just be a little oil either. It will come out in abundant amounts.
In stop and go driving, you may notice that your car stays idle after you stop at stop lights or stop signs. If your car remains idle for extended periods of time, it means you have a bad valve guide seal.
You will likely also notice large clouds of smoke coming out of your tailpipe each time you stop.
5) Cold Engine
If you live in a northern climate where it’s usually cold and you’ve left your car out in the cold for a long time, then you’ll have a “cold engine” when you try and start the ignition. Furthermore, the oil which was previously used is thicker and this thick oil remains inside the valve cover.
The valve guide seal will also have a tiny gap in it after it’s been in the cold for a while. This means that when you start the engine, this thick oil will fall through the gap in the seal and end up in the combustion chamber. The result will be a large cloud of white smoke coming out of the tailpipe after you first start the car.
Valve Guide Seals Replacement Cost
The cost of replacing your valve guide seals will vary according to the make and model of your vehicle. The good news is the cost of the parts for valve guide seals is between $30 to $100 on average.
The bad news is that you are looking at about 2 to 4 hours of labor if you take your vehicle to a mechanic. Since the average mechanic will charge about $60 to $100 per hour, you are looking at about $120 to $400 just for the labor costs. Therefore, the total average price you can expect to pay is between $150 and $500.