Low grade fuel pinging. need help

[hcloud13]

So I've had my XLR since September with no issues at all. I let my boyfriend borrow the car and he filled it up with low grade gas, and sure enough I started getting the pinging noise when under load.
Put some octane booster to balance it out until the next fill. It fixed it and the pinging went away, but sometimes it comes back in short bursts. Will this ever go away? think my knock sensors are going bad? Will my XLR EXPLODE!!!???? lol just kidding.In all seriousness, why would I still hear it from time to time?

 

[onalaska]

Have you refilled your tank with premium since this happened? The base XLR engine will run on a good grade of regular.

 

[hcloud13]

Have you refilled your tank with premium since this happened? The base XLR engine will run on a good grade of regular.

Should have mentioned that. Yes, I filled it up a week ago with the high grade.

 

[onalaska]

If it is doing it with premium you may have some carbon build up in the cylinders causing the compression to be higher than normal. Brief pinging under load is not normal, but if it is continuous for any length of time it can damage the rings and pistons. There is a procedure to remove the carbon that the dealers use if that is the problem. You might try adding some Techron to your tank during a couple of fill ups for a couple of times to see if that helps. If it is pinging bad I would recommend taking it to a mechanic.

 

[hcloud13]

If it is doing it with premium you may have some carbon build up in the cylinders causing the compression to be higher than normal. Brief pinging under load is not normal, but if it is continuous for any length of time it can damage the rings and pistons. There is a procedure to remove the carbon that the dealers use if that is the problem. You might try adding some Techron to your tank during a couple of fill ups for a couple of times to see if that helps. If it is pinging bad I would recommend taking it to a mechanic.

no, not pinging bad at all. You can barley hear it. I have to turn off the A/C and radio to hear it. and it only dose it around 2/3rd gear if I hit the gas hard. only last a second or 2.

 

[XLRATING]

So I've had my XLR since September with no issues at all. I let my boyfriend borrow the car and he filled it up with low grade gas, and sure enough I started getting the pinging noise when under load.
Put some octane booster to balance it out until the next fill. It fixed it and the pinging went away, but sometimes it comes back in short bursts. Will this ever go away? think my knock sensors are going bad? Will my XLR EXPLODE!!!???? lol just kidding.In all seriousness, why would I still hear it from time to time?

You need to quarantine the boyfriend from the car!

 

[xlrlist01]

If it is doing it with premium you may have some carbon build up in the cylinders causing the compression to be higher than normal. Brief pinging under load is not normal, but if it is continuous for any length of time it can damage the rings and pistons. There is a procedure to remove the carbon that the dealers use if that is the problem. You might try adding some Techron to your tank during a couple of fill ups for a couple of times to see if that helps. If it is pinging bad I would recommend taking it to a mechanic.

Just for info, the carbon build up has an almost trivial affect on compression BUT, it glows red/white hot and pre-ignites the fuel. Ideally you need to get it removed as explained here.

And for my benefit, does anyone know why it doesn't just burn off? It is a creamy/white hard deposit, not black like ordinary carbon. I'm guessing it is partly carbon and partly some other impurity that stops it burning off in the usual way.

 

[hcloud13]

So I looked into what dealers do to get rid of the carbon build up and it's a spray! it's sprayed into the Air Intake while the car is running. Found some Sea Foam spray with a real long nozzle. The directions say to loosen the air intake hose and stick the long nozzle into the small opening while having someone in the drivers seat just barely rev the engine while I spray it into the air intake. Think I should try it?

 

[pure zen]

Fill with fuel again and pour one can of Sea Foam liquid and one bottle of Techron both into the gas tank and see what happens.

The computer normally controls the engine timing to correct from pinging...... Must of been a real low grade of regular unleaded to cause this or possibly that gas station had some water in their underground tanks? With all of the rain and flooding in Florida after the recent hurricane,,,,nothing would surprise me. Good luck, and I agree, kick the b/f's butt out of the driver's seat