Back on my 91 351W,
The knocking gets bad if the car is warm. On a side note,I notice the temp gauge sure fluctuates a lot. If I sit at a light, the temp climbs to almost a 5/8 to the max, and then when accelerating, gets back to a normal level.

If I park it for like 5 minutes, when I get back to start it, the gauge is like almost 7/8, but immidiately goes down...whats the deal? Too much water not enough Coolant"? or Vice versa? I am also running Red line water wetter....

THis might be part of my dieseling problem??

Is the fan clutch OK? That would explain why it would run hotter at the traffic light - no air flow.

When you shut it off, you are experiencing "heat soak." The coolant is picking u heat from the engine, but it isn't going anywhere. The gauge reflects that extra heat, which goes away as soon as you start it and get some flow from the water pump. Perfectly normal.

It sounds like your car may be running a little on the warm side, which means the heat soak would be more pronounced on the gauge. Extra heat will also promote knocking.

Start by checking the clutch, anyway.

wes, i think it may be the thermostat. mine does the same except when i park, it sits at a nice cool level. but one thing with mine is that in the morings it will climb up to 200 (sometimes more) before it drops to a good level. i check the coolant evereyday and theres no leaks, and the fan is good.

this doesnt happen as bad as it was back when mine was dieseling. it used to climb to 195-200 at stops even in 50 degree weather!. what may be happemning is that its running lean. i believe when it runs lean, you get that diesel sound and it runs hotter than normal.

Thanks guys.

Hey Stave, how does one czech the Fan Clutch??

When it is way hot, there should be significantly more resistance when you try to turn the fan by hand.

The fan should also roar when you start it wind up the motor.

Are the clutches the same between both cars? It would be fairly easy to swap them and see if the situation changes.

here's a handy quick fan-clutch check: with the engine warm, shut the car off and watch the fan (difficult but possible if you're alone). if the freewheels for a second instead of stopping almost immediately, then you have a bad clutch.

and yes, a hot engine is definitely more prone to "dieseling"...but Epi's "problem" of reaching 200º temps, really isn't a problem, unless he has a 180º 'stat in there or something. the stock 195º thermostat is plenty for a STOCK 302.

Try the clutch first....and don't spare the cash. If you go to a discount parts store, get the more expensive one of the two. the one with the spring in the front is the one to get

Pat

well this is one reson i dont like a fan clutch lol ill take a 2hp cut to make sure my engine stays cool

gah! i kept askin ya guys if 200 was beyond normal!

if 200 is safe then no need to worry.