Knock link question

Hope this is the right section im asking this in. Just driving on the motorway earlier, bearing in mind the car never gets over 6000 rpm. In fifth gear then the knock link lights up, and flashes on red, but when i ease up instantly shoots straight back to normal. Lads as people that know can anybody shed any light on the situation. Or is that normal? Considering theres no loud tapping or knocking. Appreciate the help guys.

Knock Detected!
Get off the throttle asap!

What model/version/year is your car?
Has it been mapped?

Could just be bad fuel!

@scoobymaniac, 98 sti wagon pal. Running it on maxol e 85, with miller octane boost mate. Took the boot straight off whe it came on.

Firstly I meant to say you almost never hear knock (better known as Detonation or pinking), unless you have a keen ear and the window down while listening out for it.

If your car is a 98 then she's a V4 so it is recommended by most to have it mapped as the factory ecu map is based on the higher octane fuel in Japan. Earlier Versions (up to V3) aren't as prone to knock without mapping because they ran on a lower octane fuel in Japan.

As I said before it could just be a bag batch of fuel or not enough booster.
Could also be a misfire leading to a build up of fuel in a cylinder then when it does ignite it can cause knock. (This can be caused by coilpacks, plug leads, plugs and other mechanical defects or variables)

How long have you owned the car?
When was she last serviced?

@scoobymaniac, i hear ye there mate, i got it in june n basicaly service it every if not before every 5000 k's. Lad that services it worked for tp waters. Problem is its a standard ecu n can dat be remapped? Wouldn't b as up to speed as lads from here but every bit of advice is appreciated pal.

Well if its serviced regularly then you can more or less rule that out. That's not to say everything is fine there but chances are its not that at fault.

The V4 factory ecu CAN'T be re-mapped as far as I remember, Only V5/V6 which can be ecutek mapped. So that would mean getting an aftermarket ecu to have it mapped. Lets put that aside for a second.

If you own the car since June and you've never had this problem before then you have to wonder what has changed in that time to cause this problem. Are we dealing with bad fuel or is this mechanical wear and tear/faulty parts somewhere along the line?

No real way of testing the fuel. You could take it easy on the rest of the tank and fill it in a different station next time and see what happens, If it happens again then its not bad fuel (or less likely, as the chances of getting bad fuel in 2 different stations is slim).

Next thing to do if the fuel change doesn't solve it is to get it onto the diagnostics and see if any faults are recorded or if any sensor shows up as out of range. (But not everything will show up on diagnostics so don't think all is OK if no fault is present)

Hope this helps Alan,

Let us know how ya get on

Phil

Are you using e85 fuel or e5?

E85!!!!! I hope you meant to say E5.

I guess he meant e5 - on e85 he would rather get CEL due to lean mixture first I think.

Lads bad fail on my behalf there, its e5 sorry half asleep typing it lst nite. I use d same station practicaly every fill but as scoobymaniac says cud b a bad batch. Again every bit of advice im grateful for.

Is there a knock led kit that you can hook up to the oem knock sensor?

[quote author=coopster link=topic=20116.msg244955#msg244955 date=1262123070]
Is there a knock led kit that you can hook up to the oem knock sensor?
[/quote]

Think he's unsing a knock link which comes with its own sensor

I was looking for one myself, I've just brought a brand new sensor as mine was banjacks. Was looking for one I can hook up to the oem sensor

the apexi SAFC2 that i have in my car uses the factory knock sensor

Thanks jp I'll look in to that so

Lads gave dave in sti tuning a bell gave me some advice, wana say cheers for the tips.