First let me vent about the amount of time it took to remove the torx head screws from the thermostat assembly. In doing so I decided to remove one of the hoses which broke when I pulled on it. This meant I had to remove the manifold to replace this cooling hose to the throttle body. This all started when I found I had no heat inside so decided to replace the thermostat.
-There is some oil sitting in the manifold and so I am wondering if that means value covers?
-Is there anything else I should consider doing while the manifold is off?

Much appreciated! Peter

 

And no heat inside the car means your heater matrix is highly likely to be silted up, and the problem is nothing to do with the thermostat ! There is also an auxiliary heater pump on the V8s that can fail too.

 

Thanks for your reply. Any help on the best way to flush the heater matrix would be appreciated.

 

Back flushing the core sometimes helps, changed the auxiliary pump, with new coolant on mine, & it helped a lot, but have not tried the back flushing yet.

Those eight internal gaskets on the intake manifold, come to mind, along with the valley hose.

 

Oil in the intake is normal, it comes from the PCV system. Just leave it alone. If you try to clean it out with solvent you might not get the cleaning solution back out.

The knock sensors and coolant hose in the valley are the only items known to fail. You could do the MAP sensor in the bottom of the intake for good measure, but I don't think anyone has commented on those failing.

 

+1 for sure on the knock sensors and the valley hose

My MAP sensor was very brittle so I ended up changing it just to be on the safe side. You can assess your situation though; its one of those that for me was better to replace while I had everything taken apart.

There was also a modification you could do to the small j-shaped plastic line that plugs in to the passenger side of the plenum (on one side, the other side of the j plastic line clips on to a vac hose from the brake booster I believe). The modification really secures and seals up where the tube connects to the plenum. A friend helped me with this a while back, I don't remember the name of the thread on here but I am sure you could find if you search or someone here will know what I am referring to and point you in a better direction. This is not a "must do" either but will prevent vac leaks and you having to dig into it again in the future.