spark knock sound under any acceleration

[slartyblarfast]

If you don't have a real bad compression leak it won't degrade performance that much. ANd to be honest I'm kinda thinking worst case scenario. I had an old Nissan pick up that did the same thing. It ran ok but when you did any kind of acceleration it would knock and clatter like an SOB!
Hav you had any engine work done? I worked on a Hyundai that had a real bad knock on accel. Come to find out it had just had a timing belt installed and the crankshaft sensor was installed backwards which ended up severly advancing the timing. Just a thought...

[Steve Clark]

sbf,

No...no recent work done on it. I tried the diagnostic test of on-off-of-off-on several dozen times this weekend and it never ran through the test, which is odd because I'm very familiar with the procedure from doing it on my Shadow. NEver ONCE did it even register. So now I'm wondering if there's something wrong with part of my engine control module. It might explain why it's knocking if the knock sensor's signal isn't registering with the ECM.

It's weird because the engine could be cold from sitting out in the snow and it'll still knock after starting and giving it about half-throttle. I've always thought that spark knock (detonation) was caused by a cylinder getting too hot and for it to knock when cold seems unusual. Not impossible, but unusual.

Another thought is that I've got some valve clatter, but I'm hoping it's not that.

Any more thoughts?

[THier]

Now for the worst case, are you sure its spark knock, and not a rod or pin knock, if you try some of the oil treatments, and it goes away,you would know, but I think a bad knock sensor is FAR MORE likely.
If the oil treatment does help, get it repaired and just don't rely on the treatment band-aid.
Tom

[MX-5]

Steve,
What was the cure?

[2207 of 7500]

Check your EGR valve...... and personally, I wouldnt use the premium gas...... it may be igniting too quickly..... believe it or not, I had the same problem in my DOHC 16v MR2 and had the Toyota service guys scratching their heads for months, till one day I couldn't find 92 octane and HAD to go with the 87 octane and wa-lah..... the trouble stopped!!!!! I thought I was being good to my engine by feeding it the good stuff...... but it was making it do crazy things like bogg down on the freeway and check engine lights comming on and stuff..... once the 87 octane went back in....problem was GONE!!!!!

[THier]

quote:Originally posted by MX-5

Steve,
What was the cure?

This was my thought exactly[:I]
Tom

[brngrhd]

a knock will not happen from to high of octane. octane is the resistance to knock. the higher the octane the more stable it is when comrpessed. the biggest preblem i have seen with high octane is people who run it in cars that don't have the compression to light it, it burns slower and colder. there is a TSB that was released in 1996 i think that discussed the poor running with high octane fuel. as for the knock i think it is not related to fuel more like there is some other noise the engine is making that sounds like knock.

[quicksilverdon]

Dying to find out what it was - Steve??? (My hunch is ignition-advance is off).

[THier]

Update? what was the problem?[:I]
Tom