Valve stem seal replacement

Renno123

Has anyone replaced their valve stem seals themselves? How big a job was it and would you have any tips
Thanks

biko

It's a big job, are you good at car DIY?

https://www.youtube.com/watch?v=Et5aJnTE5w4

Renno123

biko wrote: »

It's a big job, are you good at car DIY?

https://www.youtube.com/watch?v=Et5aJnTE5w4

Thanks biko. Servicing and a few small jobs is the level of my ability at the moment. I have looked into it and not going to attempt it.

PukkaStukka

Some engines are a lot easier than others. Old car I had could swap the seals in situ without removing cylinder head using a special tool

biko

Maybe one day when OP reveals what car this is about (it's in the forum rules) then a discussion about his particular car can be had.

TheBoyConor

Valve seals is a fairly complex job, often requiring specialist tools.
When doing the seals you'd normally be doing it as part of a wider re-conditioning of the engine, such as reseating the valves etc.

Unless you have oodles of time and the car is not essential, then stay away from it.
If the car is older and the leakage is only small, then there might not be much benefit in the expense of renewal - burning a small drop of oil is no great harm in an old car.
And if a car is burning oil through wore out valve seals, then it is probable that the rest of the engine is pretty worn too. If the valves are that bad, just replacing the entire engine might be a more sensible approach and straightforward approach rather than messing around with valve stem seals.

It would not be common for someone to change these seals. It is a labour intensive and painstaking job requiring complete disassembly of the cylinder head. In a more modern car, if it was not done under warranty, generally it is more cost effective to just do an engine swap as the labour involved is less. you might also have better confidence in the swap engine as it hasn't been pulled completely apart and interfered with, with the risk of incorrect reassembly or internal damage caused during the work.

Outside of a warranty repair, the only scenario I can think of where it would make sense to change valve seals would be on a highly valuable, or rare engine, or as part of a classic restoration project where you could justify the time and expense over replacing the engine. Perhaps if an engine was not available.
Even then, you'd never really change valve seals just on their own then either - you'd usually be doing a substantial refurbishment of the entire engine.

Esel

Yeah, an engine needing valve stem seals should be scrapped... :rolleyes:

blackbox

I replaced them once on an old engine. It was a big (head off) job and in the end it was a waste of time, as the bores were also in terrible shape.

Symptoms were blue smoke on overrun and at max power.

Definitely confirm compression is ok and use camera to check bores before commencing. Don't make my mistake!

CJhaughey

I have seen air pressure used to hold the valves up while the stem seals were replaced.
Not a job for a novice but if you know what you are doing its definitely doable.
Viton ones should see the rest of the engines life out if the guides aren't totally worn out.