Hardened valve stem seals - What is this?

[Gokhan]

Originally Posted By: Spetz
I know it'll be a fairly tedious job for me seeing as I have 24 of them to change and the rear bank will be hard to get to.

Though seeing as I don't need the car I can take my time and can do a cylinder a day or even less.

I replaced my rocker cover gaskets some 10,000 miles ago, will they be ok to reuse?

The cost for OEM seals is only about $4, so no reason to go aftermarket (unless they are better)

Tedious? No kidding! That's why you should allow two days in case.

Don't forget to get a magnetic pickup. It's much easier to deal with the valve keepers with a magnetic pickup and it will reduce the chances of dropping them into the engine.

I always replace the valve-cover gasket when I open the valve cover. The only exception is if something goes wrong and I need to do it twice in a row. However, it's probably OK if it's only been 10,000 miles. Aftermarket valve-cover gaskets are usually of very high quality and Fel-Pro brand here is only $15 for the whole set including washers and semicircle plug.

 

[Spetz]

I think though doing 24 valves in a V6 will be much more tedious than 8 in a 4 cylinder. The only positive is that I will be in no rush with time.

Are Fel-Pro valve seals better than OEM would you say?

The tools I plan on buying specific to this job are:
1. Valve seal removing tool
2. Valve spring compressor
3. Magnetic pick up tool
4. Is there a tool to aid in installing the valve seals?

I plan to buy a few more valve seals than required just in case I damage one or two on installation

 

[Gokhan]

Originally Posted By: Spetz
I think though doing 24 valves in a V6 will be much more tedious than 8 in a 4 cylinder. The only positive is that I will be in no rush with time.

Are Fel-Pro valve seals better than OEM would you say?

The tools I plan on buying specific to this job are:
1. Valve seal removing tool
2. Valve spring compressor
3. Magnetic pick up tool
4. Is there a tool to aid in installing the valve seals?

I plan to buy a few more valve seals than required just in case I damage one or two on installation

Good list.

Toyota OEM synthetic-rubber gaskets are very good. Fel-Pro is good too but I don't know which one is better. Probably Toyota OEM is better though. I've used both.

You should get a torque wrench if you don't have one to torque the cam bolts.

You need the 3/8-in nylon rope of course.

I needed deep sockets but that may not be needed for your engine.

Plastic hammer can come handy to gently tap the valves (not the seals!) after they are reassembled with the springs and valve keepers but it's probably not a crucial step to tap them.

You need some plastic tape -- good quality -- to wrap around the stems so that you don't damage the seals. Sometimes kits provide plastic tubing or perhaps you can buy some thin plastic tubing instead.

Of course, you need a feeler gauge if your valve clearances are adjustable. Make sure that you fully tighten the screw and then loosen it slightly with the gauge in between to slide out the gauge with moderate friction. This way you don't accidentally set them too loose.

 

[Spetz]

My car is a Mitsubishi BTW not Toyota.

I have a torque wrench, and my lifters are hydraulic so no adjusting needed.

The only think I may need is the plastic tape to prevent damage to the seals. Are they really that fragile that gently putting them on would damage them without the tape?

 

[Gokhan]

Originally Posted By: Spetz
The only think I may need is the plastic tape to prevent damage to the seals. Are they really that fragile that gently putting them on would damage them without the tape?

Yes, you definitely need the transparent tape (or tube). The problem isn't sliding the seals down over the stem body. Of course, the stem-body surface is mirror-smooth. The problem is that the tip edge of the stem and groove edges where the valve keepers are seated are razor-sharp, and they will cut or scratch the seal if you don't wrap some transparent tape around or put a thin plastic tube over the tip and groove.

 

[Gokhan]

That's why some seal kits come with tubes.

Transparent tape works, too. You need to clean the oil to have it stuck but then you want some oil over the tape after you wrap it. However, one caution: I had the tape stuck under one of the seals and had to pull it hard to get it out. What happened was that when I pushed the seal it also dragged the tape and then tape got stuck under the seal. Fortunately, the seal wasn't seated and it still came out when I pulled hard on the tape. You can't remove the seal without damaging once it's seated. So, just be careful and take your time and have a couple of extra seals in case something goes wrong.

 

[Spetz]

Thanks Gokham. Can I buy these tubes separately?

Also, is there a problem in turning the engine the wrong way?

And, when putting back the rocker arm assembly does the engine have to be in the same rotational position as when taken off?

 

[fpracha]

Originally Posted By: Gokhan
Originally Posted By: Spetz
Gokhan, did you notice your car running any different after you installed the new valve seals?

Before I replaced them, it was consuming 2.5 US quarts in 1000 miles with fully synthetic 5W-30. Oil consumption virtually completely stopped after I replaced them. I also no longer get spark-plug deposits. There would be tailpipe smoke when taking off from a traffic-light stop after idling for a minute with a hot engine but that's obviously gone too. Engine runs very well...

So in hindsight, do you believe that you changed the vale stem seals a little too late or just in time ?

 

[andyd]

Not replacing them mostly leads to oil consumption that could result in engine seizure when ignored. On a V6, I would do the front bank first.Do the easy side, to get your moves down before moving to the back bank.

 

[Gokhan]

Originally Posted By: Spetz
Thanks Gokham. Can I buy these tubes separately?

Also, is there a problem in turning the engine the wrong way?

And, when putting back the rocker arm assembly does the engine have to be in the same rotational position as when taken off?

Sure. Tubes only come with seal kits but you can use transparent tape instead.

Do not turn the crankshaft the wrong way.

It needs to be at the same rotational angle.

 

[Gokhan]

Originally Posted By: fpracha
Originally Posted By: Gokhan
Originally Posted By: Spetz
Gokhan, did you notice your car running any different after you installed the new valve seals?

Before I replaced them, it was consuming 2.5 US quarts in 1000 miles with fully synthetic 5W-30. Oil consumption virtually completely stopped after I replaced them. I also no longer get spark-plug deposits. There would be tailpipe smoke when taking off from a traffic-light stop after idling for a minute with a hot engine but that's obviously gone too. Engine runs very well...

So in hindsight, do you believe that you changed the vale stem seals a little too late or just in time ?

If I could do it earlier, I would do so. I think they were completely worn when I replaced them -- like using no seals at all -- and the oil consumption through the valve guides had already maxed out. It was still manageable with 15W-40 (1 qt per 1000 miles) but 15W-40 created too much drag on the engine. No damage was done on the engine by excessive oil consumption. Perhaps the catalytic converter got some hit but the car still passes the strict California emissions test fairly easily.

 

[Spetz]

Gokhan, why can't I rotate the engine the wrong way?
What if I need to do so to loosen the rope?

 

[Gokhan]

Originally Posted By: Spetz
Gokhan, why can't I rotate the engine the wrong way?
What if I need to do so to loosen the rope?

Timing belt could jump a tooth or drive belt could come off. It could damage the tensioner too. There is also a chance that the bolt could come loose. There may be some other unwanted consequences that are not obvious.

I doubt the rope will get stuck. It could get stuck if you turn the crankshaft too hard after you put the rope in. If it gets stuck, usually pushing the end of the rope in a little frees it and then you can pull it out. So, don't tighten the piston against the rope too hard after you put the rope in. The rope method should work fairly well.