I'm going to do a timing belt replacement with the kit that includes the tensioners and water pump etc, but i was wondering if i should do the cam seals and valve cover gaskets at the same time?

 

Only if they're leaking.

 

so it would be pointless to do so if they arent leaking?

 

Might as well spend the extra money and do it now. No use putting the timing belt and tensioners in and then 100 miles later having the camshaft seals start leaking all over your new belt.

 

If it isn't broken...

 

The cam seals are cheap and easy to change. I change them with every timing belt and they are always very hard and brittle due to the incredible heat of the cylinder head during operation. When the rubber seal gets hard (think ceramic) they will start cutting a grove into the cam. I have been maintaining my Mother-in-Law's '89 3.0 from day one and have changed the cam seals every 5 years. There is no grove at all on the cams and the seals have never leaked. Yours may not be leaking now but it will start eventually and it will probably have cut a groove in in the cam, making the new seal leak after a short time. Change the crank seal while your in there. It's really cheap and easy and cheap insurance against future leaks.

The valve covers are guaranteed to be leaking after five years. Most of the slime on an engine comes from leaking valve covers and the oil will get all over the engine. Changing the valve cover gaskets with each timing belt will prevent the engine from getting all covered in slime, making maintenance a lot easier and identification of other leaks easier. The plenum needs to come off anyway to replace the upper idler pulley and PCV valve. Other common leak areas are:

distributor o-ring
front and rear cam bearing caps (FIPG)
rear cam seals
rear crank seal
oil cooler cover o-ring

I have also had the intake manifold gasket fail at the number 6 cylinder position (the hottest), leaking antifreeze onto the rear of the left cylinder head, and down the block where the transmission joins. There is a water passage in the intake manifold into the head at the left rear that uses a pre-moulded o-ring seal that will eventually start leaking.

After 25 years and hundreds of seal changes, I've reached the point where I always change a seal if it's exposed as part of another job. It's cheap insurance, kind of like changing the water pump during the timing belt change.

Bugs

 

I'm a noob, but chasing an oil leak and would agree with Mr Bugs about doing things while you are there. Since you've removed the plenum and the timing belt, you're already in there so why not change anything you can get to? That is, anything cheap like seals and VC gaskets and such.

Thanks, Bugs for replying to that post, I just learned some things reading your list of leaky spots!