I am considering replacing my valve steem seals with the head attached to the motor. My question is this... if you have had your valve steem seals replaced, did you experience any problems with the head within 50,000 miles after that, like burnt valve or bad head gasket?

 

Ive put on 37k since I did mine... no problems as of yet...

I pulled the head for mine.. New bolts and correct torque is key

Now on rob's 70 we did it with the head on, used the rope in the cyl trick.
Put in his N/A cams, seals, and polished cam cover all in one day..
He beats the **** out of his car on a daily basis...Pushing it to 20 psi every chance he gets.... No Problems

If you need to borrow the tool to do them with the head on let me know me, alan, rob, and jamie chipped in for a community tool and we do rent it out..

 

I cant see how replacing the stem seals would result in a burnt valve or head gasket issue. I dont see the relation.

I have replaced them on two heads and both heads had 185k+ on them. The stem seals rubber was hard. So if your approaching that mileage you should do it. What I have not done is replace them with the head on the engine. I suppose with the piston all the way up using Matts rope trick you could pull it off but you are going to really struggle with the keepers on the exhaust valves.
Did you purchase your stem seals from FCP? I had a set come from them that did not work. They were green and would not seat tight on the guide. I could hand pull them off.

 

Well, I am trying to figure out if this occasional smoking is the valve steem seals or turbo related. If it's the valve steems, I was thinking that it would be easier to pull the head, send it to a shop and let them clean it up, check it out, and install the seals. Might cost me another $175 but might be worth the extra to have a head that I wouldn't have to worry about for 200,000 miles.

My thoughts is that is the steem seals are leaking, and they are about to make a valve burn (I'm almost convinced that leaking valve steem seals are the #1 cause of burnt valves), why not get the head check out and properly cleaned. If I just replace the seals and a valve is about to burn, I would be wasting time.

My car has 220,000 on it. From what I've read, most people have to deal with this at about this age and mileage. Not sure if anyone has been able to put much more miles on the car without replacing those seals.

 

hey I hit 413,000 before I had to do mine...LOL

 

Hi
I'm kinda with boxpin on this one!

If valves burn out its due to a soft head seat, a worn stem or a badly adjusted valve clearance. as you know a compression test should pick this up.

As well you know worn valve seals normally let oil pass to the stem, a worn seal will drip oil down the stem to the bore and it usually will result in a puff of blue/grey on start up. unless they are harder than a Russian hob carrier,then it will **** oil and smoke like a crack *****.

I would clean/flush all the inter-cooler ancillaries, pipes/cooler anything that is on that path, i use cellulose thinners for this, you can reuse it, and keep flushing/shaking till it drips clean thinners from it.
Turbo's love clean air and clean oil, Who wouldn't?

If it doesn't make a difference or is worse by your cleaning, then it might point to the seals in the turbo leaking.

Have you ever changed the turbo? has it ever been changed/do you have the full history?
Turbos love an oil change, more regularly than a N/A car.
When i fit a new turbo i will do a full service/oil/plugs filers. Tune?
or the work isn't guaranteed.

Your motor has reasonable miles on it, but it shouldn't be excessive if the oil/filter change has been earlier than regular.


One question? do you see this puff in day or night.

Reason i ask its easy to see smoke in other peoples headlights in the dark.

There is a steam seal tool that i used to use on old 80-90 Fords that you didn't have to take the head off, but i can't remember what it was called or who it was made by.

 

I didn't think the stem seal change would cause the valves to burn but rather the leaking seals would have caused them to get to the point where they would burn due to the oil blow by from the leaking seals. Hope that makes sense.

As for the head gasket, I had to change the HG on our S70 so I was thinking that the HG may fail when approaching 200 - 300k. I read these head gasket threads and it just makes me wonder.

These cars don't have adjustable valves so that's not the issue with all the burnt valves I have read about. Soft head seats? Not sure how that would happen to these motors.

As for the motor history, I purchased the car with 188,000 on it. The PO was an older man that had the car for about 9 years. He was a fire chief and the car was equiped with radio equipment so I'm sure it seen boost regularly. However, evidance shows that repairs were done when needed and oil was changed regularly, probably every 3,000 miles. When I checked compression at 205,000 the numbers were between 173 - 179 across the board and the motor wasn't hot. I doubt the turbo was ever changed, it has some rust on it. It has new plugs, newish PCV, newish wires, cap, rotor, new timing belt, etc. All of the hoses were washed out real good when the PCV was replaced.

I use full synthetic, I believe the PO used regular oil.

@ Matt, glad to hear that you got 430k out of your's before you had to do the seals. I like to believe that these motors are 500k motors without major work and I am starting to wonder.

As for the smoke I see, it's really random. I have only noticed it at night once, I don't drive much at night. It has been so random that I can go days without seeing any and then I see smoke while going through a drive through or at a light or something like that. I was able to video it once when I was stuck in traffic on a freeway. Here is the link.