Valve Guides & Stem Seals: Questions & Answers

Hi DIY enthusiasts,

I'm currently in the process of replacing the valve stem seals on our Audi TDI 1Z with 270,000 km (the cylinder head is removed). During the process, one valve guide was slightly damaged (it's not perfectly round due to the pressure from the pliers) . However, the valve fits in without any problems. Is it a serious issue if the valve guide is slightly out of round in the upper area? Shouldn't it have little influence on the valve movement? Also, the valve stem seal is located above it.

Unfortunately, I don't have a foolproof method for removing those pesky valve stem seals on the TDI. How do you do it? Do you use those Hazet pliers or the Matra tool? With the good old TD, at least you could remove the seal along with the valve spring retainer and then knock it out externally .

Perhaps it's time to put a new head on the LL ? Well, never change... Besides, we all want to know how long something like that lasts .

Thank you very much in advance }.

Hi,

So, the engine is running smoothly -> it seems like there's no problem .

For expanding the valve stem seals, I recommend the Hazetzange 791-8 . It worked very easily with it .

I don't think you can squeeze the valve guide with pliers. If you somehow managed to do that, the valve definitely wouldn't fit properly anymore, because a valve guide is designed to provide a precise fit.

I always use a Facom pliers (they're not cheap, but they work quite well). However, they only help you grip the object; you still have to do the pulling yourself.

More importantly, you need the right tool and the right technique to avoid damaging anything. If you damage the sealing lip or the piston ring (which isn't always immediately visible), the whole process will be useless.

Varianti wrote:

So, I don't think you can squeeze the valve guide with pliers.

If you somehow managed to do it, the valve definitely shouldn't fit anymore, because that's a precision fit.

Hi Varianti,

I first tried using a regular pair of pliers, but the excessive pressure slightly damaged the valve guide. However, the valve went in without any problems -> so it shouldn't be a problem

Varianti wrote:

.

I always use a Facom pliers (it's not cheap, but it works quite well). However, it only helps you to grip the object. You still have to do the pulling yourself.

Sure... but the Hazetzange is very good

Varianti wrote:

.

However, what's more important is that you have the right tool or the right feel for striking. If you damage the sealing lip or the piston ring (and this isn't always immediately visible), the whole process was for nothing.

To protect the sealing lip, there is a protective sleeve that is fitted onto the valve. To push the seal in, I use the insertion tool from Matra (8mm valve stem). However, the seal does not need to be hammered in . A little pressure is enough, and you can feel how the seal settles in the lower area }.