TonyG

Has anybody had this problem, and if so, what did you do to fix it (and what do you think the cause is/was)?

My previous head had 2 of the valve guide seals come loose.

My Milledge head has 6 of them loose.

Yes I can easily put them back on since the head is off the motor, but I'm wondering why they keep coming off!

This has happened with 2 heads now.

Thoughts????

keith

do you have the crappy smooth guides, or the ones with the rings milled into them to grip the seal?

nine-44

I just had the head off of my turbo motor and all the exhaust seals were popped loose. My guides were smooth, I guess stock? I don't know the problem, I've heard of it on domestic cars, mainly from sitting. When you do finally start them, the seals are stuck to the stem and pull off. I thought this was the case on mine, replaced them and waiting to finish the car for install. I guess it's the heat from the exhaust that make them stick. Don't know on the intake.

TonyG

It's a pretty serious problem obviously and you (and me!) need to figure out exactly why this is happening, and how to prevent it.

I've had it happen on 2 heads now. 1 stock, and one $4000 JME head. I'm pissed.

ftanguay

Do you have the Viton seal on the intake side and the Teflon on the Exhaust side?

Just a supposition.

Danno

I've had this happen a couple of times. I think having at least one groove on the guide would really help. Here's the trick I've found that actually worked:

1. get a new set of seals
2. clean off the end of the valve-guide really well
3. wipe down with acetone to remove oil film
4. apply thin layer of 3M Fastak #08031 (#08014/08011 would be OK too) to outside end of valve-guide
5. apply thin layer to inside of seal (thin meaning as thin as you can smear it)
6. let both dry for about 1-2 minutes
7. apply thin layer to valve-guide again and immediately install seal
8. using seal-installation tool, tap seal all the way down onto valve-guide

That's it really. When installing valves, oil the ends and twist the valve through the seals to prevent hurting it. Also be very, very careful with install the springs & keepers.

Olli Snellman

This has happened to my 951 also!

Check out you have a new type of guides (with rings machined to guide).There are also a new type of valve seals available.Some seal kits still have old type valve guide seals.Usually they are brown by color.New type seals are black.

keith

Old style suck and require gluing. The new ones seem to hold pretty well. (as I said.)

If the head is coming off, change them out. If not, glue them like the factory did.