'86 XJ6 just died
 

This morning, I started my '86 XJ6 Series III. It was making a rattling noise with a slight hum, like maybe the power steering pump was dying. As I got a little ways down the road, it was getting louder. No change in power, RPM's or engine temp. About 2 miles away & it started sounding like there was a chunk of sheet metal in the fan. I pulled over, killed it & opened the bonnet for a look-see. Nothing. No indication that anything was wrong. Going to start it back up & find where the noise is exactly... but all it does is click once. Oddly enough, the speedometer is on 150 mph. I don't know when it got there. Also, I have a new Optima battery. I'm sure there's juice in it. What to do??

Clue:


The speedo isa stuck at 150!! AKA pegged at max read1 As it is electric, that suggests an electric issue. No crank and a bunch of noise suggests mechanical woes.


A connection? Guess. At the transducer on the transmission?


1. Even though the Optima is new check it's voltage and it's connections.


2. Sudden thought. The starter tried to crank a running engine. Been there.


3. Jump 12v to the small post on the starter solenoid. Will that cause the starter to crank the engine? If so, relay failure? Failed in two modes? closed then open?


4. Get a big wrench on the crank snout. will the engine turn or is it stuck. The latter obviously, not good.


5. Oil level?


Objectives:


1. Resolve any electrical issues.


2. Resolve any mechanical issues.


WAG: Diode issue. Juice in the wrong place at the wrong time. Been there!!!


Carl

Alternator seizing up/failing internally....and no longer charging. Lots of noise, battery becomes drained?

Just a guess at this point

I agree with Carl---make sure battery has oomph and go from there

Cheers
DD

Hi KC

Just throwing another option, which Jags are good at doing.

Do you have an air pump, also known as a smog pump fitted?

It is located above the a/c compressor, which in turn sits on top of the alternator.

Shot bearings in that do make an awful racket, I can attest to that as that is what happened to me.

Honestly, I thought the cam chain had let go is was that noisy.

Cheers,

Nigel