How to Replace Valve Seals Without Removing the Head

Now, if it seems to you like an often lot of effort to remove the cylinder head to replace a few of your valve seals in your vehicle, well, we tend to agree with you, and the good news is with the right tools, you don’t have to. We will show you how to replace valve seals without removing the head cylinder.

Time and money are sometimes constraints in vehicle maintenance, so learning some DIY skills makes you worry less about these constraints. You should know that the function of the valve seal is essential. So Immediately, you notice your seal is damaged. There is a need to replace it on-time, as driving with a damaged valve seal can eventually lead to your engine knocking down completely.

How to Replace Valve Seals Without Removing the Head: A Step-By-Step Guide

So removing valve stem seals is a pretty simple procedure, but getting to them is a bit tough because the valve seals are tucked right away inside the valve spring. So if you want to do this job with your cylinder head-on, you’ve got two main problems. One, how do you compress the valve spring to remove it. Then two, once you’ve removed the valve spring, how do you stop the valve from falling into the cylinder.

To know if your valve seal or seals are faulty or damaged, the main symptom is cloudy blue smoke from your exhaust when you start the vehicle after being parked for a while. This is basically because the faulty seals or seal overtime, let oil down the valve guide into your combustion chamber, and when you start the car, it burns off the excess oil. That’s why you get the cloud of blue smoke.

For the first problem, you need to get a valve spring compressor tool; this tool is designed for use with overhead cam engines, and for the second problem, you need to get an air hose with end fittings. You are going to use this to pressurize the cylinder to hold the valves in position.

So let’s Start our Process:

valve stem seals quick fix

Step One:

Now you need to get your car bonnet raised cause that’s where you can access your seals. Then take the rock cover off to expose the valvetrain. Ten mounting bolts usually hold on the rocker cover; however, it sometimes varies. So use the right socket size to remove the bolts and take the cover off. These are common engine parts, so you shouldn’t have a problem dealing with them. Just in case you are wondering, your engine does not need to be taken out from the car to do this, OK.

If you look towards the exhaust ports on your engine, inspect any of the ports for oily fluid. If you know how to check valve stem seals that are faulty, you can spot this out quickly

When you find the oily port, look towards the valve stem seals on your exhaust valve of the affected port, you will see that it is completely removed from the top of the valve guide and is just riding up and down on the valve stem.

Step Two:

Now the solution we’ve found is to glue the seal in place. But first, you need to take-off your spray bar (if your engine has any). About three bolts hold on this. The next important thing that you need to do is make sure that the affected cylinder is on its compression stroke. And the easy way to do this is to rotate your engine by hand until both cam lobes are pointing upward.

Step Three:

When you are done with that, remove the follower of the valve you are working on, you should use a spanner to quickly remove the follower. You will also have to remove the spring retainer. You need to have in mind that as you take off the follower, make sure it is coupled back the same way the component was initially fixed. Please note this.

Step Four:

Now you remove the spark plug with your socket wrench and then screw one end of the air hose. Hook the other end to a compressor. Now you want to pressurize the cylinder to around 80psi, and you have to keep topping that up because you will gradually lose pressure past the piston rings over time. The other thing is, the pressure will want to push the piston down. You need to put your car in gear and put your hand brake on to prevent the piston from moving. It’s as simple as that.

Step Five:

Please turn on your air compressor to begin applying pressure. Then use a good quality valve spring compressor tool to compress the valve spring so that you can remove the cotters. After this, you can easily get the spring and of the way.

Step Six:

Now with the valve spring out of the way, you can get clear access to your valve seals. To remove it, lift it to the top of your valve stem. If you have a valve stem seal removal tool, like the 8milelake valve kit, it will help a lot. With the old seal out of the way, you can now fix your new valve seals. This is the reverse of how you removed it.

Step Seven:

Push the new seal down from the top of the valve stem to the top of the valve guide. You can use a socket to help do this properly.

So that’s it, your new valve seal is in place. Reassemble everything. Just use the reverse process. Do not forget to keep checking your compressor to ensure you are not going low.

Once you have gotten your valve spring well seated, stop the airflow from the compressor. You can also adopt this thorough guide in replacing valve stem seals on chevy 350 without removing head cylinder or the whole engine system.

Of course, if you are replacing the full set, you will have to repeat this process for every valve in the engine. It’s a fairly time-consuming process, but it is a lot easier than when you remove the cylinder head. So there you have it, the whole process. If you are still uncertain about this, you can try watching this video to get a visual explanation of the whole thing.

If you are also looking for how to replace valve springs without removing head cylinder, you can use this process as a reference to get you through it.

FAQs

What happens if you don’t replace valve stem seals?

If your valve stem seals are either missing, broken, worn or installed incorrectly, it will cause your engine to use up a lot of oil than usual. Your engine still can compress, but it will use up a lot of oil. This will overwork your engine, causing a rise in its average temperature, and this can cause it to wear out sooner than expected.

If left for a long time, a damaged valve seal will eventually lead to loads of problems aside from a level high of oil consumption. The effects range from blue smoke coming out of your vehicle for a long time whenever you drive your vehicle to other engine problems.

How long does it take to change valve seals?

Valve seal replacement is not difficult, but it is a fairly time-consuming process. The process can take about three hours if you need to replace the sixteen valve seals. It also depends on the method used in the replacement process. If you know how to replace valve seals without removing the head cylinder, it should take less time, especially when you’ve already gotten access to an air compressor, air hose, and the required tools for the job.

How do you know if your valve seals are leaking?

A good way to tell if your valve seals are leaking is to carry-out a cold engine test on your vehicle. Another way is to observe your vehicle’s behavior during idling. If your valve seals or seal is leaking, you will notice bluish smoke from your vehicle’s exhaust due to oil burning. Your engine will begin to overwork, consuming a lot of oil.

Acceleration and brake problems are other indicators that point out this fault. If your valve seals are leaking severely, it can cause white smoke from the engine.

How much does a valve seal job cost?

Since valve stem seals are manufactured with rubber, it is very affordable to purchase. These seals do not break easily, so you should not bother about changing them frequently. Valve stem seal replacement cost within the price range of $35 to $140.

The saddening news is that replacing valve stem seals consumes a lot of time. It requires around three hours at most, making the labor costs of your mechanic quite expensive. Professional mechanics might charge you $120 or more. The final cost might be up to $350 for replacing your valve stem seals.

What does a bad valve sound like?

When your valve is faulty, you will most likely hear a clicking sound while driving your vehicle. But the noise reduces when you increase the rpm of your engine. When you hear your vehicle making this type of noise, you should know that something might be wrong with your valve.

Final Words

You are now aware of the whole process of how to replace valve seals without removing head cylinder. It’s a straightforward process. We actually don’t think it gets simpler than this. This is the easy process to follow for valve stem seals quick fix in your vehicle.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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