The bearing on the tensioner pulley have protective membrane(seal).Wd-40 couldn't get into it without dismantling. If you want....you can remove tensioner arm,it is bolted with 2 bolts to the engine and then remove the pulley which is held with big torx bolt....but first release the tension and remo...

Release the serp belt.

Spin the pulley by hand, if it spins freely and does not slow down quickly, it could benefit from maintenance (see misha suggestions) or replacement. Most are freewheeling by now and need service.

Most likely a Thermostat that opens too fast or is stuck open. It could be the Temperature sensor. Use a IR thermometer to measure the engine temperature and check it against the temperature gauge. 1/2 on the gauge is about 180℉ .

It could be the pump. Were the brakes operating ok before the fuses were pulled from the ABS? If the peddle is a little low or soft, there could be an air lock in the pump. It takes a pressure bleeder to really bleed the pump.

Neil.

I have a 93 850 and the ABS has made a noise for a long time - mine sounds more like metal scrapping. But it only does it once soon after I start driving. Not causing any problems for me. You may need to replace the donut at the manifold/exhaust interface (assuming that year has one). I did that onc...

The error code P0477 usually means a broken/stuck EVAP purge valve.
Replacing is straight forward and done in 5 minutes (on most vehicles).
A new one costs around 50-80 bucks. But first check if not just the connector is corroded or dirty.

If the in my previous post mentions specs are correct, this is the diagram for your engine. The part number 9125243 is correct. This valve was used til '99, after that it changed, see parts under number 19 in the parts list. There seems to be a replacement for your valve with the part number 8631285...

Speedometer also should not work if you removed abs relays.

Yes, over pressure of the coolant system can blow off hoses. The cap on the coolant overflow tank is the over pressure relief. They can fail. You may also have a head gasket problem allowing exhaust gas pressure in to the coolant system. You could modify an old coolant cap to add a gauge for the coo...