petrol sounds like a diesel any ideas?

[tonsta1978]

hi my pug 406 exec turbo has started making a deisel type sounds when the engine is under pressure, ie low revs, it kinda sounds like a ballbearing being pinged around the engine! kinda like a rattle that sounds like a diesel.

any ideas? i have heard of pinking what is that? and could this be it?

it does not affect the engine or acceleration just annoying as sometimes its lound ish sometimes but sometimes really quiet, but makes the engine sound like a deisel lol before the turbo cuts in.

anyone know or think they know what could cause this and cost of fixing?

thanks

[steve_earwig]

Stop driving it now!
That does sound like pinking, which is pre-ignition. Ok in a diesel because they run cool but a potential disaster for a petrol, it'll also be trying to fire the pistons backwards - if that's really what it is then you're probably heading for burnt valves and holes in pistons

Not really sure why it's doing it, there should be a knock sensor or two that tell the engine management to wind back the ignition but I'm fairly sure it should detect a duff knock sensor, put the K light on and engage slug mode.

Hopefully someone with a better idea of petrol turbos will come along and put me right but that's what it sounds like to me.

[mjb]

hi my pug 406 exec turbo has started making a deisel type sounds when the engine is under pressure, ie low revs, it kinda sounds like a ballbearing being pinged around the engine! kinda like a rattle that sounds like a diesel.

Sounds familiar. Like a ball bearing in a tin can? Goes away when you hold the throttle open *just enough* to hold a steady speed on the flat, but comes back the instant you add more juice, even when there's no actual engine response for a while?

It's annoying, but normal. I did 100,000 miles in my tubby which exhibited those symptoms and the engine would have probably been good for another 100,000+ after I got rid of it (minor faults, but cheaper to get a new one) at almost 180,000 miles on the clock

I'd love to find out what was causing it though

[steve_earwig]

Once more my ignorance knows no bounds (Still sounds like pre-ignition tho )

[Welly]

Try Running it on Super Unleaded.

[Alfamonk]

Yeah i have same problem. Definitely pinking, which is distributor/rotor. But have done extensive interweb search for a new one and no dice - what gives? anyone know where to order a new distributor cap?

[ianst28]

alfa do you need a cap for your alfa or a pug ???

[mjb]

Yeah i have same problem. Definitely pinking, which is distributor/rotor. But have done extensive interweb search for a new one and no dice - what gives? anyone know where to order a new distributor cap?

You won't find a dizzy on a 406, just electonic ignition

[Alfamonk]

cough of course. does that mean if it's pinking i need a new ignition 'module', or is electronic adjustable?

[tonsta1978]

ok getting confused lol

ok what would i need to get to "cure" the pinking? and any ideas of prices?

someone said it could be the "botom ends" lol whatever they are!

should i stop driving her? as i have been for the last month like this and she seems ok other than the noise

please excuse my ignorance i am a turbo person not engine lol

[mjb]

ok what would i need to get to "cure" the pinking? and any ideas of prices?

It's a common problem to the 2.0 turbo, but I don't think anyone's ever worked out what it is although someone once told me it was valve clatter. Whatever it is, it's harmless and seems to happen with a correctly functioning ignition system

should i stop driving her?

No

does that mean if it's pinking i need a new ignition 'module', or is electronic adjustable?

The timing is automatically adjusted by the ECU. If you ever have the ECU reset you'll notice a stark difference over the first 10 or so miles as the ECU starts from a rough running default timing plan to one which is influenced by its various sensors

[Welly]

Try running it on Super Unleaded.

[Longintooth]

Hi
From what you say it is indeed pre-ignition and it occurs when the fuel mix ignites in front of the flame front then when the two meet the heat is intense and leads to severe burns in the top of the pistons,rings and valves. In modern vehicles this is controlled by the knock sensor , usually fitted in the cylinder head to detect the metallic knock you speak of. This sends a signal to the ECU to retard the ignition in nano seconds so you should never hear it - this was the job of lead in fuel before it was changed. If you purchase a scan tool or a digital analyser you will see instantly if the sensor is not working since there will be no change in the ignition advance when you disconnect it. If you do nothing then start saving for a new engine and you may not get it through the MOT - strange though you should have a check light on. Oh there is another thing that does cause this but it is extreme - if the engine is overheating badly but again you should see this on the temp gauge.

[mjb]

If you purchase a scan tool

That'd be a foolish investment on a tubby since they don't have the usual OBD facilities

If you do nothing then start saving for a new engine

The engines are worth more than the cars

and you may not get it through the MOT - strange though you should have a check light on. Oh there is another thing that does cause this but it is extreme - if the engine is overheating badly but again you should see this on the temp gauge.

It's a normal occurrence on the XU10J2TE. I've been in two that have exhibited this symptom (one of which I did over 100,000 miles in with perfect MOT emissions readings) and there have been many more reported doing it on this forum

[steve_earwig]

This was kind of resolved a while back but it's still puzzling me. I know that when dialing in the traditional dizzy it was considered optimum to be able to provoke the car to pink a little but it seems odd with modern engine management. Maybe there is a reason (built-in Italian tune-up?) or maybe the engine management just can't wind back the ignition far enough to suit the engine