Engine Knocking - Fixed

[SpidersWeb]

Had a topic before about how 96 killed my car, so Put 91 in it and it runs sweet. However NOW its decided it start knocking. Whenever I put any form of power down (past 25% throttle) or let the revs go above 3,000 (boost starting) it sounds like someone is smacking the head of my engine with a ratchet.

When this happens I also get a power loss.

So I figure this as knocking. Its horrible, and I don't like it.

For the sake of having something to drive, I'm going to put a little 96 in there to raise the octane.

Now if a full 96 mix causes the car to die, and 91 to knock, then I'm figuring its ignition based problem. The 91 burns under compression off little spark, 96 isn't interested.

So if 91 knocks, then I need to use 96, but 96 dies so something else must be the problem. I am thinking Ignition.

Compression: Check (if its knocking, its compressing)
Fuel: Check (huge backfires, didn't knock on 96)
Ignition: I dunno

Its got Iridiums that are 6-9 months old, but only done 500Km, same with the 8mm leads. So I'm thinking distributor or coil.

I don't think its fueling because I am gathering more unburnt fuel in my exhaust as described by the huge backfires on engine braking (three times normal volume, you could shoot someone and people would still look at my car).

So lets say ignition.

I'm going to pull it to bits tomorrow and have a gander. How do I test my ignition components, specifically the coil/ignitor?

Distributor I imagine I can just look at for imperfections.

Is there any Starion part that is known for causing problems like this commonly I really should look at?

Please help, car is driving me insane, no mods, no hard out thrash driving, and weird stuff happens daily. As this is my only car at the moment, I need it to work reliably.

[SpidersWeb]

Of course my Ignition timing could be out, but it has to of adjusted itself very quickly and all by itself since I haven't touched it. Knocking only appeared to day, as been running 91 for a week with no problems.

[ProZac]

I'd definatly check your static timing, and your vacum advance unit. 96 octane is harder to ignite, sure, and burns slower, yup yup, but no where near enough to mean that even a tiny spark wont ignite it when its compressed with air. I'd definatly suggest you run 96 and nothing else in your car, i dont think thats the problem at all. Plugs, Leads, Dissy, Coil and Ignitor unit are the places to look. I have a feeling your ignitor box will be a black plastic thing with 'Knock Box" written on it, mounted next to the coil. These are known for stuffing out all the time, and as such are near impossible to find in good condition second hand :(.

[SpidersWeb]

Well I don't have a plastic black box. But next to the coil is a silver box with Mitsubishi logos and codes on it. I imagine this is it anyway.

But everything is plugged in ok, vac lines to vac advance etc are ok with no leaks, my MAP sensor isn't reading again grrr, will have to just take it to a mechanic and see what they say.

Gonna go put some 96 in there to raise the octane today. Its knocking on idle now, so whatever it is, its getting a lot worse very quickly.

It sounds like its on all cylinders, by the beat, so I'm thinking ingitor,distributor,or coil - one of the three. Possibly also the power lines going to the coil as they look very old and factory.

Coil is not an original Mitsi part, so I imagine at some stage this has been replaced.

Vac advance can't be the issue because its now knocking at idle as well. Yesterday it was just at post-2000rpm or 25% throttle.

[scum]

really stupid ideas

- belt buggerd / not tight / skipped a tooth
- cordias knock really bad when out of oil
- dizzy bolts not tight
- blocked fuel filter
- your going insane, there is no knock, its in your head
- clutch is falling apart (happend in silvia, sounds kinda like knock)
- tape in tape deck has knock recorded on it, not music.

[SpidersWeb]

really stupid ideas

- belt buggerd / not tight / skipped a tooth
- cordias knock really bad when out of oil
- dizzy bolts not tight
- blocked fuel filter
- your going insane, there is no knock, its in your head
- clutch is falling apart (happend in silvia, sounds kinda like knock)
- tape in tape deck has knock recorded on it, not music.

1. possible -
2. gonna go check that! altho doesn't sound like the normal low oil noise
3. possible - altho it looks like its never been touched
4. replaced fuel filter recently - along with leads/plugs
5. likely
6. brand new clutch - came with my entire drivetrain replacement :) 12 month g/box warranty with rebuild too, yey
7. no headunit, I sold it to donate to the Starion repair fund, no speakers amps or subs for same reason too

[SpidersWeb]

Ok checked the oil

and

$**%&%&*$*$*$**%*%*%*

WHERE DID MY MOBIL ONE SYNTHETIC GO
WHERE ARE YOU OIL

Still doesn't explain the absolutely death experience on 96, but oh well see what happens when I put oil in her.

It doesn't leave spots on driveways, but there is lots of oil behaviour around my intake, so possibly a blow-by situation. I'll re-route my oil catch can output to a coke bottle, and see what happens. Possibly oil could of fouled the plugs, which might kind of explain the issue with 96??

135,000K on clock, seems a bit early to lose rings tho?? Well anyway stuff happens, and Ill see how it goes.

[SpidersWeb]

Filled up with 15W-40

Dipstick reads almost full.

Car has no noise at all now, minus exhaust and the huge KNOCKING NOISE

damn it

Today it decided to only knock over 2500rpm!!

Idle: One or maybe two cylinders knocked for a few beats, then became fine.
Above 2500rpm: Began knocking on all cylinders
Above 20% throttle: Began knocking on all cylinders

So maybe its a fuel thing.

beh it could be almost anything, Ill just take it to the mechanic when I find some cash.

[SpidersWeb]

PS. After I got the car I ran 91 in it the whole time with no knocking, when I had extra cash I put in 96 for a very small power gain once and a while. I've never HAD to chose one fuel over the other before.

[scum]

hate to be the one to make you worry, but if it ran out of oil mabey the bigends have died? new block time?

[SpidersWeb]

Surely then wouldn't the knocking be regular, and all the time?

Noise sounds like its coming from top of the engine, like put your ear towards it.

[scum]

sounds like mine when the bigends went. only knocked when you blip the throttle, or when you try to hold revs for more than about 3 seconds. then one day BANG! all over :(
anyway, i might be wrong, good luck.

[SpidersWeb]

Possible. But car only needed 500mL of oil to show a reading.

I'm just hoping you are not correct :)

[scum]

me too :D

[Cam]

drop the oil out of it and strain it through something fine and see if any pieces of metal come out in the oil, if you've done a bearing you will get some metal.