I'm new to this forum so bear with me. I have a '97 HB and it has had this ticking/knocking sound while under a load for quite some time (like 30k miles). I think the sound is getting worse (meaning a lesser load makes it happen). Its not "knocking" b/c I've done all the obvious things with no effect: timing is sitting about 8-10 degrees BTDC, plugs look ok, switched to higher octance fuel, etc. Its really bothering me now b/c I can't seem to pinpoint where it is coming from and I am fixing to sell it (to my boss nonetheless!) and I'd like to at least know what it is, even if I can't easily fix it.
Right now I am leaning towards the timing belt tensioner, mainly b/c I am out of ideas. Could a lack of oil flow through the tensioner cause it to knock/tick under load? The sound is nonexistent at idle or when revving it with no load, but I do hear a similar noise at cold start up (like when the oil hasn't fully circulated through things). But the thing continues to run great.
Has anyone else had a similar problem? What was the cause and/or fix? Any help is appreciated.
Check the oil level, if it is low it might cause that ticking noise you hear from teh engine. My brothers car made an awful ticking noise, and when I drained the oil to do an oil change, there was probably one quart of oil(it takes 5).
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Minor Modifications To My Car: Razo Shift Knob, Eibach Sportline Springs, KYB AGX Shocks, SS AutoChrome Header, Custom Cat-back, Injen CAI, B&M Short Shifter -- More to come soon!
It's a '97 KA24E w/ & 5 speed. The engine oil is full. The sounds is really hard to describe, its almost like a rattle and won't do it until the engine hits about 2500 rpm -- then it hits a resonance and will make the sound when under load. It doesn't do it when idling or revving it freely, so I ruled out broken rocker, piston slap, things like that.
Hey, I have been looking at different stuff about knock -- my knock sensor is bad according to my ecu . What I found was a website that had a question posted that was very similar to yours. Hopefully it can answer your question. Good luck to you.
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Minor Modifications To My Car: Razo Shift Knob, Eibach Sportline Springs, KYB AGX Shocks, SS AutoChrome Header, Custom Cat-back, Injen CAI, B&M Short Shifter -- More to come soon!
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Minor Modifications To My Car: Razo Shift Knob, Eibach Sportline Springs, KYB AGX Shocks, SS AutoChrome Header, Custom Cat-back, Injen CAI, B&M Short Shifter -- More to come soon!
This may sound crazy, but mine does a similar thing and it's the cowling between the hood and windsheld rattling at certian RPMs only when the truck is moving. A mechanic friend stuffed insolation between the cowling and the body and the sound went away. I removed the cowling and replaced all the broken brackets, screws, double stick tape, etc and reinstalled it as per the FSM. The sound came back.
This may sound crazy, but mine does a similar thing and it's the cowling between the hood and windsheld rattling at certian RPMs only when the truck is moving. A mechanic friend stuffed insolation between the cowling and the body and the sound went away. I removed the cowling and replaced all the broken brackets, screws, double stick tape, etc and reinstalled it as per the FSM. The sound came back.
Something else to check......
Good suggestion, I will check that. That kind of sounds like a possibility.
And yes, there is such a thing as a KA24E...its what is stamped on the block.
The timing checks out between 8-10 degrees BTDC at idle, which is what the manual calls for. I assumed timing related at first, but I checked the timing, pulled the plugs, and even ran 100 octane unleaded through it, and it still did it. Therefore, I eliminated the cause. I don't think this version of the KA24 has a knock sensor either...at least I haven't found on on the block and no one seems to sell a replacement for it.
Thanks for all the replies and comments, keep em coming if you have em!
Update: I taped the cowls down between the hood and windshield with some of my 200 mph duct tape, and that didn't seem to have any effect.
I also pulled the valve cover to replace a leaking gasket and the timing chain appears nice and snug and the guides seem to be OK. I think I am going to switch to a thicker oil temporarily to see if that has any effect on the noise. I'll keep y'all posted if you're interested.
P.S. I think I might try to remove the heat shield and see if I don't have an exhaust leak under it. I'm hoping the manifold isn't cracked. Has anyone else experienced a cracked manifold on these things?
Your use of the word cowls make me think that you may have only taped down the plastic grills. I was referring to the entire metal cowling. You have to find and isolate what ever part of it that is vibrating against the body. Still may not be your problem.
I had to replace my manifold. You can get aftermarket ones pretty cheap now. They were only available for the V6 when I replaced mine so I got one from a junkyard. Be sure and get a replacement for the tube that goes from the manifold to the EGR valve. A new one will save you a lot of grief.
[quote=Oldnissanguy]Your use of the word cowls make me think that you may have only taped down the plastic grills. I was referring to the entire metal cowling. You have to find and isolate what ever part of it that is vibrating against the body. Still may not be your problem.
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Correct, I only taped down the plastic grills, I didn't know you meant the entire metal piece between the hood and windshield. I will check that this evening as well.