89 Diagnostic HELP!!!

tbirdcrazy

Registered User
My motor on my 89 SC started knocking, it usually starts doing that before the DIS module goes out. So I ran a Diagnostic and it read code 74- Insufficient MAP/MAF/Baro change during goose test or dynamic response test, code 73-- Insufficient throttle position sensor change during dynamic response or goose test, code 25-- Knock sensor not detected during dynamic response KOER (which I just replaced the knock sensor). where does the wire from the knock sensor go?, Please point me in the right direction, would all these symptoms contribute to the knocking???
 
The goose test means you have to press the pedal all the way to the floor when running the KOER test. I'm not sure when you are supposed to do it (goose the pedal) with the paperclip method of checking codes the scanner I use tells me to. That's why you got those codes, has nothing to do with the knocking.

Please explain "started knocking" When you are trying to get some help on a BBS, over the phone or anywhere that the person or people are not physically there, you need to be as specific as you can.

Does the knocking change with engine speed? Does it only knock when the engine is not under load?

Jeff
 
You can hear the knocking on deceleration the most, you can also hear it a little when at idle, and only sometimes when under load. And it does change with engine speed, the motor runs a bit rough at 2500 rpm, and i can feel a slight loss of power, this is exactly what it does.
 
a mechanics stethoscope will help you pinpoint it. If you don't have one of those a long screwdriver placed where you want to check and your ear on the other end will work too.

Is it loud?
High or low frequency?
Where on the engine is it happening?
 
It is loud, and it is coming from left side of engine. If the knock sensor wasen't working properly or not at all would it possibly start knocking?
 
I don’t think you understand what a knock sensor is for. The knock sensor is there to pick up abnormal combustion events aka spark knock, detonation, pinging those terms are used interchangeably. The knock you describe is a mechanical failure and you need o figure out where it’s coming from EXACTLY. Buy a mechanics stethoscope there about $12 at most auto parts store.

Jeff
 
A broom handle also works pretty good as a stethoscope.

(I hope nobody wants me to explain that because its too ridiculous to describe)
 
trust me on this one...been there ..done that...tooo many times......are you sitting down?....you have a bearing on it's way out...bottom end ...terminal to the crank if u don't repair right away...
 
Figure out where it's coming from and get back to us. You still describe it as a "knock" and that could be many things. Details details details we need details.

Jeff
 
I was next to an LX T-Bird at a stop light then you can guess what happened, he was behind me and the "knock" was gone, I think my car was just having a bad week. It was pretty cold out those couple of days. But I think I will buy one of those mechanics stethoscopes for problems that might occur later. Thanx anyways guys
 
Back
Top