Thread: Was it something I did

For those of you following my 1998 D1 V8 dilemmas here is a brief synopsis.

Bought car , Oct 2014 . It had the idle issue where it would step from 750rpm down to a rough idle at 450 and back up again in 5 second cycles. Never stalled. I think it only did it on gas and was fine on petrol.

It also made a cracking noise when cooling down. I thought it was just the ext manifold.

It started to do the idle thing on gas and petrol.

I took out the stepper / IACV valve and it was spotless. I squirted some WD40 in the stepper.

After that it only did the idle thing after about 40 minutes of driving when warm.

I had an auto elect fit a new coil and ignition module. It stopped the idle thing
for that night and the next morning.

On the next night , the Friday in the heat ,it just stopped on gas. Started on petrol fine. I had an inkling it might be running hot.

Had an engine temperature watch dog fitted to the t;stat housing the next Monday. On a 25 degree day in traffic it would peak at 102 degrees and drop to 96 whilst moving. Didn't seem to be losing any coolant.

Wouldn't run on gas when over 95 degrees or so it seemed.

Thought it might still be an ignition problem so on FRiday had $1300 worth of performance ignition fitted with new dizzy , coil , module , leads and plugs. Turned out the gas mixer also had a kink or some damage to the diaphragm so they fixed that too.

Great I think. I head 10kms down the road after. I think I smell oil and see some smoke/fumes ( not thick white clouds ) coming out the back. Think it was just coolant on the exhaust manifold. Look at temp and it's 102. Pull up at next set of lights and temp starts climbing through 112 degrees.

Pull over and find exp tank cap has blown off and coolant all over RHS of motor near the tank.

Surely playing with the ignition bits and gas mixer didn't cause a cooling system problem?

Maybe it was just coincidence.

Currently at the repair place getting a diagnosis. The heads were done about 2 years ago.

clean throttle body out for idle problems plus clean out flame trap plus all those little hose and t -piece making sure nothing blocked also check vacume diaphram to see it stiil works all the little things add up to poor idle