5 Symptoms of a Bad Valve Guide Seals and Replacement Cost

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.

4) Idling

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

Looking for Replacement Parts?
We recommend PartsGeek.com or BuyAutoParts.com for the best prices and selection.

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.

8 thoughts on “5 Symptoms of a Bad Valve Guide Seals and Replacement Cost”

  1. Hi I have the issues listed above will I have to replace valve guides and valve stem seals?and can It be done with the head left on the car thanks

      • Unless you too end the cam and use an air hose that screws into the spark plug for that cylinder and pressurize the cylinder to hold valve from dropping while you compress remove and replace the valve stem seals. No I’ve not done this. It saw it done on a Honda single overhead cam

    • I think there is a way to do it without removing the head. You take out all the spark plugs. Now start with the first piston, turn the engine until it is at the bottom on the compression stroke. then take nylon cord and feed it into the spark plug hole. Then slowly turn the engine in direction of rotation until you feel resistance. Then stop turning, Now the camshaft has to be removed, Now you need a special tool to press the valve spring down to allow the removal of the cotters. Then the valve spring can be removed, and then the seal can be pride off with a screw driver. Then after lubricating new seal tap it into position. Re fit spring and cotters. Now turn engine in opposite direction and remove the nylon cord. Do the other cylinders and reinstall camshaft etc. I have never done this myself. Perhaps there is a u tube on this.

      • Yes but you don’t have to remove camshaft. I like the idea of feed hose into cylinder the. Turning to press it up to hold valve in place for dropping and you can screw in an air line that fits that plug size and pressurize it as well. Either way sure helps save that cash. It’s $400 plus $65-$120 gasket set and $50-$100 for the seals. Doing it without removing heads will save you the gasket set cost and about $200-$250 of labor as it’s about 2 hrs work and at $75-$100 an hour you save $200 so you save $300 plus

  2. You can replace seals with head on motor but if when you have old seals off grab valve stem rock back and forth any play means guide is bad and head has to be removed. I got a price of 150 to do all guides given I pulled heads off, but not all guides might be bad so might be cheaper look it up on YouTube you’ll find everything you need to know. ✌️

  3. Ive repaired cylinder heads for 46 years and yes, you can replace the seals without taking the head off but..If you’re having that much going on I’d suggest just biting the bullet..you need to take the head off and have it reconditioned.

  4. Remove all spark plugs then turn engine by hand on front crank pulley and bring the pistón to tdc on the cylinder that you are replacing the New seals.install adapter on spark plug and put 100psi air pressure to hold valves so they wont Drop when u remove valve keepers.


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