Thread: Slipping Serpentine Belt or something else?

1997 V8 D1.

A few weeks ago while driving up Mt Ousley on the F1 near Wollongong I noticed my temperature gauge started to climb quite quickly when I was about halfway up. (For those who don't know Mt Ousley the climb is about 4.5km at a average grade of about 7%). I eased off the accelerator a little and got to the top with the temperature gauge at the top end of the scale but not in the red.

At the time I thought that my radiator must have been a bit clogged with mud as I was on my way home from the Yalwal trip and I've cruised up Mount Ousley in the past without trouble or anything like this.

But, even after I've given the car a good clean and checked the radiator to make sure it isn't clogged up with mud I had the same issue at Mt Ousley both times I driven up it since.

I wondered if the issue was with air flow to the radiator so drove up a long steep hill in low range first to see if the fan could blow enough air through the radiator to keep it cool enough and that all seemed to be okay. The viscous coupling was replaced only a couple of years ago so I didn't think that was the problem.

Coolant levels all seem fine and my EngineSaver isn't making any noises other than the initial test beep.

So then I thought maybe the water pump is on its way out and not able to push water though the radiator quick enough?

I also noticed that the voltage at the alternator was sometimes only about 12.5v until I gave the engine some revs. After giving the accelerator a bit of a push the voltage raised to a respectable 13.8v as expected but sometimes dropped back down again for a few moments but my tacho needle doesn't seem to waver.

So, what might be going on and where is the best place to start?

The radiator was cleaned and rodded 4 years ago, the viscous coupling replaced 2 years ago.
The temperature is okay at low speeds driving up steep hills in low range 1st but at under load at speed going uphill it rises quickly.
The voltage at the alternator is sometimes a bit low when idling but returns to normal and stays there after giving a few revs and returning to idle.

Might these issues be separate or are they all symptoms of a slipping serpentine belt? But, I don't get any belt squeal and my power steering and air con all seem okay. How do you check the correct tension etc if it might the problem?

Thanks in advance!
Sam

I'll go for a bit of a spin and get the radiator nice and warmed up to have a look.

When it was cleaned last they didn't mention anything specific though.

Originally Posted by dullbird

Sam when they cleaned and rodded your radiator did they discus the actual condition of the radiator with you?

it could be that the internals of the radiator are perhaps starting to perish.

have you ever put your hand over the radiator when hot? I remember once when we had issues with the 90 radiator and blockages you could actually feel the difference in temperature between the top and the bottom of the radiator, it was quite remarkable.