hi all, owned my alfa 147 now for nearly 6 months, its done 95,000 and been a great car, recently I discovered that the engine is 'pinging'. I always use BP or Caltex 95, and only seems to happen when the car is warmed up and under load - any ideas why this may be happening? Coolant and oil levels are perfect, timing belt due to be changed in 6 months...Is it a common problem on this engine? Any help would be appreciated, thanks!
Its not common. Are you sure its pinging? Try 98RON
It could be a bad batch of fuel or worn plugs. Failing that an electronic problem.
Everything that Steve points out. Make sure the petrol your using isn't an ethanol mix! There are stations that claim 95 Ron yet have are mixed with ethanol. Check the bowser and the pump handle when feuling. Engine lnock or pinging will occur during load and warm hot engine. Does the engine shut down straight off or want keep running? If does thats different to knocking. Wouldn't hurt to get a diagnostic hooked up. Run through what Steve pointed out; fuel, check plugs. A diagnostic would hopefully indicate any electrical issues such as a failed cam or knock sensor but I would expect more symptoms with these. Is your odometer flashing? That would indicate a fault code has been logged as reoccurring.
Even if you have a bad batch of fuel, the knock sensor should pick up the vibrations and retard the timing to avoid knocking, try some high octane BP or Caltex, stay away from the cheap petrol, the no name stuff, you don't know whats in it, try running some good petrol in it for a week and see if it still pings, if yes, have a look at the 8 spark plugs, Colin.
thanks everyone for the replies, as the 100,000km service is close im thinking its a wise move to have the sparkplugs changed and see if it rectifies the problem, while im at it going to replace the thermostat, oil and oil filter, air filter and sump plug. will report back once all done, thanks again!
Actually plugs should be changed at 100k...
Sump plug? Is there something about Alfa sump plugs that I'm not aware of... ???
Just changing as its a little rough someone must have used wrong tool in the past
Don't change the thermostat, unless its faulty, the sump plugs are available off the UK ebay site from Alfa Dealers, and get a new rubber washer seal for the sump plug, sometimes called Dowty washers, use a good allen key in the new sump plug, as the plugs are soft and round off easy, Colin.
hi Col, thanks for the tip, mine is definitely in need of replacement, takes forever to reach 90 degrees so assuming its stuck open ordered all the parts today so will advise once all arrived and installed
I would love to know what makes 147-156 thermostats so short lived, looking at them, the thermostats seem very small buried in the housing, had a thermostat in the 33 for about 20 years, still working when i took it out, [was a bit rusted up], i have tried different brands of thermostat in the 156, and they all seem to open too early after a few years, one thermostat i had, developed a leak before it started to open too early, Colin.
Ok so changed the plugs and air filter yesterday plugs can out a whitey colour which suggests its running too lean I believe? Would this explain the pinging??
Yes pinging is caused by a too lean mixture or incorrect engine timing, both cannot be fixed by a home mechanic, take it to an Alfa Service provider before you cause any serious engine damage, Colin.
Thanks col going in for a cam belt change next week will also ask for timing and fuel mixture to be adjusted correctly
The ignition timing and mixture is all controlled by the engine computer, the pinging may be caused by a faulty knock sensor, that retards the ignition when the fuel is low quality and the engine is hot, Colin.
Might be worth mentioning this pinging issue to your mechanic, so they can set up the new timing belt by using the cam-locks to check the accuracy of the cam timing in relation to the crankshaft.
thank you! all good advice, will do....
hi all thought i'd update you on the progress of my 'pinging issue' so today i had all the cam belts, water pump and thermostat replaced, the mechanic confirmed the timing was correct and also noted that pinging was 'common' on these motors once they had done a few kms and wasn't excessive...no errors came up on the diagnostics so have been asked to 'monitor' the issue and if it get worse take it back for further analysis. i'll keep trying alternate places for fuel as well thanks for everyone's assistance.
I have not heard of pinging issues for the twin spark, but i don't know everything, use the best and highest octane fuel you can get, ie 98 octane with no ethenol, you may have a lot of carbon buildup on your pistons and cylinder heads, causing an unwanted increase in the compression ratio, and your injectors may be blocked, causing a lean mixture, Colin.
Ours used to ping a little depending on fuel.
I didn't think it made sense (knock sensor) but that's what it sounded like.
Try adding in a dash of good octane booster into a tank of good premium 98 and see if it solves the problem, really pinging is not good.
Pinging breaks piston rings and puts holes in pistons, it is really uncontrolled combustion, something that can ruin an engine, make sure your knock sensor is ok, i have heard that a knock sensor is not so much a knock sensor, but like a piezo that hears the predetonation noises and tells the engine computer to retard the ignition, Colin.