There are two things to consider. One is a valve stem seal, the rubber
gasket that fits over the end of the valve guide and keeps oil from
settling into the combustion chamber, especially when parked. Symptoms of a
bad valve stem seal would be smoking on startup. the price quoted would be
ridiculous for something this simple that could be replaced with the head
on the car.

More likely it is the actual seal of the valve, more often referred to as
"low compression" or "burnt/warped valve" and which would require the
removal and possibly the replacement of the head. But does he know it is
the valve that is leaking, and not the rings, that is causing low
compression? there are ways to find out but not every mechanic knows them
or bothers to perform them.

If I were your friend, I would be looking for a discount of a lot more that
the cost of a head pull and refurb, which would be about $700 I think.
Suspicious anyway as vanagons sometimes drop valves, especially on some
aftermarket heads, but not burn them. At least not without a lot of other
stuff going on, and that's my point. Get a discount for a replacement
engine, and not a head, unless the price is already really right for a
non-running vehicle.

Jim

On Fri, Jan 30, 2015 at 8:53 AM, Jamie Fitterer <fittdog8848@hotmail.com>
wrote:

> A friend is looking at purchasing a van that is in really good condition
> but the mechanic reports the engine has a leaky valve seal and it would be
> around 500 - 800 dollars for the fix.  I don't have much more information
> on that and apologize for that, but it is what it is.
>
> My question is, does anyone know what valve seal this may be?  What are
> some repercussions of driving it to get it home?
>
> Appreciate your time,
>
>
>