Odd Noise

Bluecorsica

Bluecorsica

New Member
Hello,

My car started to make a funny metalic noise, like if there were rocks shaking inside the engine. It only happens when it's hot and mainly when I am driving uphill. I believe it is pinking (?). It came from the garage for a setting up last month, and I believe I had 97 octane petrol in the tank on the occasion.Now I've switched to Tesco 99 and I am using Castrol valvemaster (the one with booster). Could it be that once the car was set up to run on 97, it will complain when I use 99+booster (100?)

Andre
 
Yer sounds like pinking. Advance the timing a very little. Quite a few owners here have found they have to throw the form book out because of modern fuels and keep tweeking the timing a little until it stops or is reduced to a minimum. I did'nt find the octain booster to help and in my car and it caused it to run on. (engine still turns over of a bit when the ignition is turned off). So I use normal fuel and an addtive with no octain booster. I set the timing to 4 degrees if I remeber correctley and just advanced the ignition a little bit until it was gone. Only took a few very tiny tweeks to get it right, she still pinks when very hot but with my fan upgrade that never happens now.
 
Advancing the timing will just make any pinking worse, it needs to be retarded. Go too far and eventually it could cause it to run on. Improving the octane rating of the fuel should make things better, not worse. It may be that the timing has been set too far advanced when it was at the garage, or it's possible that the higher engine temperatures when under load are causing a coolant leak from the head gasket, and that coolant is causing the noise you are hearing.
 
Yours is probably pinking but it's worth mentioning that I just cured my V8 of a similar noise. It sounded like the fan was clipping something, only when accelerating but not all the time. I spent a while playing with mixtures and timing and looking for signs of contact but to no avail. I then replaced the front driveshaft universal joint and the noise disappeared! It seems it had been dry for a while and was making creaky cracky noises when under load.
 
Thanks to you all for the great insights.

A few stupid questions,

1) to retard the the dizzy, shall I turn the small wheel on the top of it clockwise or anti-clockwise?
2) if the coolant is leaking from the head gasket, will I necessarily notice any reduction on the coolant level inside the radiator? In that case, will I have to replace the head gasket?
3) Richard, I am curious about the fan upgrade in your car. Can you tell a bit more about that?

Best,

Andre
 
The vernier adjustment is marked on the dizzy body with a double ended arrow with an "A" at one end and an "R" at the other. Turn it towards the "R". Checking the timing with a strobe before you start would be a good idea.

If it is loosing coolant through the head gasket then yes you will notice that the coolant level in the rad drops, but don't assume that a falling coolant level is automatically the head gasket, it could be leaking from anywhere.
 
Thanks Harvey,

Actually I did not notice any drop on the coolant level, so I think I can it is not leaking. As for the timing, if it is set as 6 degrees BTDC (as the garage people told me they did), should I still tweak with the vernier?
 
If you think that it is pinking, and you are satisfied that the timing is correctly set at 6 degrees, then you could try retarding the timing a bit using the vernier to see if it cures the problem, but make sure that you mark your starting position so you can return to it if necessary, and remember that it's not only incorrect timing that can cause pinking.
 
I will try to retard it to see if it improves.
I don't know if this could have any relation with my problem, but I just found that my distributor is not the correct one for the car. Apparently it's got the SC one fitted (LU 41119) and also the vaccum unit is not the right one, even for the SC (544 3989). I've phoned Martin at the Distributor Doctor and he will send me a different vaccum unit (model 476) to see if that cures the problem.
Any thoughts on that?

Andre
 
Unless your dizzy has been rebuilt to the correct spec, then it certainly wont help your situation as it will have a very different advance curve and therefore throw your timing out whilst driving (possibly causing pinking). I'd either get the correct dizzy, or have that dizzy rebuilt to the correct spec.

If you don't have any spindle wear, then you could probably just replace the springs and weights under the dizzy baseplate, but personally I'd go for the rebuid option.

Bri.
 
Thanks Brian,

I wonder if my dizzy hasn't been rebuilt already. After I took the car from the garage for timing adjustment, I've driven around 2000 miles, and only now it started to pink. Could it be that there might be carbon deposits in the cilinders?
I have tried a bottle of NOS octane booster this week, but no joy. I still haven't tried to retard the ignition though.
I am starting to ask myself if the noise I am hearing is really pinking...
 
Hello again,

Tried to retard the ignition, still no joy.
One thing I noticed is that the problem started after I've fitted a set of Magnecor leads. Could this have any relation with pinking?
What else causes pinking? Carbon Deposits?
 
You must log in or register to reply here.
Back
Top