Going to try to replace a valve, any tips?

Rottweiler28 · #1 09-17-2005, 06:24 PM

What special tools might I need for this, I know I will need a valve spring compressor so far, a tourque wrench and head and valve gaskets. Anything else I may need to know or tools I will need for this, anything special I should look for when I do get to the valves? I'mhoping that someone who has done this before will share a little experience with me.

GTP Dad · #2 09-18-2005, 09:46 AM

First of all why are you replacing the valve? If you have to remove the head, why don't you spend the extra money to have a valve job done on the head. I know it is a lot cheaper to replace the valve but if the valve is burnt then the possibility of seat damage exists and the only way to repair that is to replace the seat. You may also want replace the valve seals on the head you are removing especially if the engine has high miles. I would do this even if you don't have a full valve job done. It is much easier to do now than to have to remove the head again later. You didn't say what size engine you have but make sure that the bolts are not torque to yield if they are you will need to use new head bolts too.

Rottweiler28 · #3 09-18-2005, 03:18 PM

Thanks for the fast reply.

Quote:

First of all why are you replacing the valve?

Well the motor has what seemed like a small misfire or sputter as I called it and after replacing many parts I did a compression test and found one cylinder to be 50 PSI as all the rest were around 190. I then did a wet compression test and found it to be the same with no change at all in compression, this leads me to believe that it is a valve problem.

Quote:

If you have to remove the head, why don't you spend the extra money to have a valve job done on the head

I really don't have any extra money to work with here, thats why I was only planning on doing the one valve. Maybe i'll try to get some extra money together and do them all. Do you know any sites in Canada which have half decent prices for these parts? Best local price I could find was 18.50 for 1 exhaust valve and 14.75 for an intake. Thats expensive to me but what do I know.

Quote:

You may also want to replace the valve seals on the head you are removing especially if the engine has high miles.

My engine is a 3.0 from a 91 voyager with approx 185,000 on it.

Quote:

make sure that the bolts are not torque to yield if they are you will need to use new head bolts too.

I am not exactually sure what this means.lol. I know what tourque means and how to tourque and the settings but not to yield.

GTP Dad · #4 09-18-2005, 06:04 PM

Once you have the head off it will give you a better idea of what you are facing. If the valve is burnt then the seat may need to be replaced or reground but you may get lucky. The prices you indicate are about right. They unfortunately aren't cheap. As for the valve seals they are much easier to replace with the head off since you have to remove the valve springs to get to them. Since you have a high mileage car and are removing one head then I would change them. They are a few dollars but well worth it to prevent the engine from burning oil on start-up. Finally, torque to yield bolts mean that they stretch when you torque them and they cannot be reused since they will not hold proper torque. I am not certain if the bolts on your van are made this way but check the book or with a dealer to make sure. You don't want to have to redo this shortly after you have already torn it down once.

waltham41 · #5 09-18-2005, 06:50 PM

Years back when VW bugs and their motors were plentiful, I played with making one a off road dune buggy and running the crap out of it.

I would do poor mans overhauls on the motor since it was just going to be a toy. If I had to replace a valve I would then set the head with the combustion area up and fill it with gas and observe if it immediately started going down.

This would tell me that there was a problem with the valve seat or something like that. If the chamber stayed full for several minutes I would consider it good enough to go on the engine and would put it together.

Take into mind though that with the end of the car cut off I could have the motor off in 20 minutes so it wasnt a big deal if I had to pull the motor often.

Sometimes trying to save money can cost you a lot more in time and effort.

Rottweiler28 · #6 09-19-2005, 08:43 AM

I just want to make sure I have everything here to start this, doing only the front bank I will need 3 exhaust valves, 3 intake valves seals and rings? Should I go all out and get new springs to or will they come with the valves, will the seals or rings also come with the valves? Sorry but I haven't done this in many years and back then I just ordered the whole kit and all was there and extra. One front head gasket and one front valve pan gasket. 6 head bolts. This sound about right? Thanks for the fast replies, they are appreciated.

waltham41 · #7 09-19-2005, 04:49 PM

Quote:

Originally Posted by Rottweiler28

I just want to make sure I have everything here to start this, doing only the front bank I will need 3 exhaust valves, 3 intake valves seals and rings? Should I go all out and get new springs to or will they come with the valves, will the seals or rings also come with the valves? Sorry but I haven't done this in many years and back then I just ordered the whole kit and all was there and extra. One front head gasket and one front valve pan gasket. 6 head bolts. This sound about right? Thanks for the fast replies, they are appreciated.

Yes it will be 3 intake 3 exhaust valves, head gasket valve cover gasket intake gasket valve seals. if this engine uses the one use only head bolts replace them or you are asking for trouble.

you will not need piston rings this would include dropping the bottom oil pan and removing the pistons which I am not sure on this motor can be done without pulling the engine first.

as far as the valve springs there should be somewhere that you can find the measurement that the springs should be if they are that height and you see nothing wrong with them use them since you are doing this on the cheap

I would suggest one more time though that when you get the head off you take it to a automotive shop and at least get them to look at the head and give you their advice as to whether the valve seats look ok and look carefully for cracks.

good luck!

Rottweiler28 · #8 09-19-2005, 05:07 PM

Thank you all for your valuable input. I am doing this to fix the problem but also as a learning project. Many people look at these types of jobs and shiver, I on the other hand am looking forward to this. Thanks again folks, I'll let ya's know the end results after I tackle it.

waltham41 · #9 09-19-2005, 08:42 PM

Quote:

Originally Posted by Rottweiler28

Thank you all for your valuable input. I am doing this to fix the problem but also as a learning project. Many people look at these types of jobs and shiver, I on the other hand am looking forward to this. Thanks again folks, I'll let ya's know the end results after I tackle it.

I do as much as I can on our vehicles simply because we cannot afford the shop rates. That is the best motivator in the world to learn let me tell you

Good luck and keep us posted

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