G'Day guys, I as rewiring my trailer hitch on my 1980 240 GL today and all was good till the battery went flat, doh! I jump started it and finished my wiring and left the car idling for 30-40mins whilst i did so. Finished up and thought i should go for a spin to charge the battery. I made it about 150M and the motor started spluttering and wouldn't idle. A whole bunch of whinning high-pitched horrible noises but I gave it a few revs and all was good. Wanr for about another 30mins on the freeway and it was running great and when I was at the lights it idled great. However, on the way back as i came off the motor way the crazy noise started again. I made it home OK and the motor appeared to run fine but the noise was coming from the under car pump. I only had the in-tank pump replaced about 3 months ago when it was making this noise last time and it has been fine sinse. I could swear I also heard a noise from under the bonnet when this happened bu it is hard to tell when these noises travel. In-tank pump is working as i can hear it, what could this possibly be? Maybe the under car pump or something else? Any pinters would be greatly appreciated as it only came back from a service a week ago and they stung me nearly $700