Knock Sensor????

[tjm73]

Do '98 GT's have a knock sensor?

My '98 GT is making what sounds like spark knock (detonation, whatever you want to call it). Here's the thing though. It started doing this about 1.5-2 months ago when I was running 87 octane fuel. So I switched to 89 octane and it stopped. This morning on my way to work I downshifter to 4th at 75 mph to quickly pass a guy on level ground on an expressway and it detonated like crazy. The car is totally stock with a MagnaFlow cat-back and just under 61,000 miles. It should not need anything more than 87 and it should definitly not be having spark knock. I have no MIL's and it runs fine other wise.

Anyone have any input they can share?

 

[COBRA90GT]

Simple question, have you pulled the sparkplugs & inspected them yet to see what they look like? If not, when was the last time you changed them?

 

[4.6_02_Black_GT]

I may be mistaken but GTs dont have a knock sensor, but 4v Cobras do. Not sure what year the Cobra's started adding the knock sensor.

 

[tjm73]

Simple question, have you pulled the sparkplugs & inspected them yet to see what they look like? If not, when was the last time you changed them?

No way it should be due for new plugs yet (only 61,000 miles), but I'll check them. Never been changed. Service spec is 100,000 miles........I think, now I gotta check that too.

 

[BVille99GT]

Do 99 GT have knock sensors, if not can someone tell me where to buy such a device. Thanks

 

[4.6_02_Black_GT]

maybe I was unclear..... GT's SOHC 4.6 engines have NO knock sensor


Cobra motors...4.6 DOHC engines do have knock sensor, it is located under the intake manifold.

..I'm not really sure how you add one to a GT motor...but with a good dyno tune you really shouldnt have to worry about detonation.

If you are serious about the sensor you might consider some aftermarket engine management computers. Some of the kits are capable of excepting knock sensor inputs...but you still need a way or place to mount the sensor. for the money .... you could probably buy a used Corba motor.

 

[BVille99GT]

Okay, cool I was just wondering. Like they say "their is no stupid question".

 

[COBRA90GT]

No way it should be due for new plugs yet (only 61,000 miles), but I'll check them. Never been changed. Service spec is 100,000 miles........I think, now I gotta check that too.

You'd be surprised (especially when you are having spark knock issues with your car). If you pull the factory plugs you will probably see what I mean. Remember, just because a service book or manufacturer claims the plugs CAN last for 100,000 miles doesn't mean that the part(s) in question WILL last for that amount of time.