I've got an '01 Camaro that gets a rattle going when it's been hot out and I've been driving it around for a while. When it gets to rattling, it does it upon acceleration right between 10 to 20 miles. I brought in to some place and they say it's valve clatter but I'm not really sure what might have caused it or if it could be something else. I'm planning to check the spark plugs tomorrow, but was just curious if anyone had any ideas or advice? I don't have any mods done to the car, only thing I changed were the spark plugs about 2 1/2 years ago. It's only got 91,000 miles so I'm just wondering what I might have done wrong.

 

Are you sure its not detonation (spark knock)? What grade fuel to you use? Which engine - V6 or V8?

 

I've got an 8 cylinder car. We're going to try and check the spark plugs today. I know when they changed them about 2 and 1/2 years ago they had a real hard time getting them in. They've got the NGK spark plugs right now. I'm hoping it might just be a spark plug because lias far as the valve stuff, the tech told me I risk blowing a valve and blowing out a piston if I don't replace the valves and I start racing around and what not. The car is my daily driver and I don't go around racing all the time, but I mean I didn't buy it to not be able to if I so chose. Thanks for the suggestion, I'll give it a try. Sorry if I replied with too long a message.

 

Oh and as far as the fuel, the car's always had 91 grade from various places. I bought some BG 44K fuel treatment stuff but I need to gas up again first lol

 

If its spark knock, you run the risk of burning a hole in a piston, shattering a piston, broken ring land, etc. Make sure its not detonation. You should never be able to hear it - the knock sensor should pick up the noise before you can hear it and start pulling timing to eliminate the knock.

As far as the valves, has anyone tried adjusting them? If the rocker arms loosen up, you'll get a lot of clatter.

You also want to look at your oil pressure. If the engine is running hot, and the oil pressure is dropping, you may have the wrong weight oil, or you may be seeing the signs of bearing wear. What is the oil pressure at 2,000 RPM?

Since you have the LS1 engine, I'll move this thread to the "LS1 Based Engine Tech" forum.

 

Ok so my husband changed out all the spark plugs except #8 (what a bitch that one is!) and we figured we'd try and just drive around to see if it helped at all....it didn't the rattle sounds like it's actually coming up under the driver side so changing the spark plugs didn't help. I really was hoping it wouldn't come to having to decide about putting the car in the shop, but it seems like it's going to be heading that way. How much can I expect to have to spend for the valve job? A place nearby me said 1500 to 2000 to take off the heads and replace the valves would be the starting price but I think that's kinda high. Also, I really can't go without the car for long...is this something where the car is going to be in the shop for a week? Ugh this sucks

 

Could just be a rocker going bad. I've heard of several cases of the needle bearings blowing out.

You definitely need to take it in and get it checked out before coming to any conclusions. I wouldn't even tell the shop what you think is wrong, just that you hear a noise from the engine. I'd take it in soon though, sometimes noises like that can be a warning of more damage to come.

 

Yea, I'll definitely be bringing it in to get another opinion and not even mention that I've brought it in before. I'm just puzzled by the fact that we first heard the noise a long time ago but we thought it was exhaust or something so we never took it in. We even got on it I don't know how many times, and it's never affected anything. Up until recently has it actually gotten noticeable. I think I'm just going to have to suck it up, max out my credit card, and take it in to get fixed. I love this car too much to let it go. haha.

 

Put in higher octane. Try 93, unless their is an airport around where you can buy 104 octane, otherwise you can always buy an octane booster. Also, try putting in a half to a whole quart of marvel mystery oil. It's high detergent stuff and it's very thin so don't romp on the throttle right away while it's in there, but if you have sticky lifters (which it sounds like you do) then this should fix it. It's worked for me for this problem everytime I've used it.

 

Thanks for the help everyone. I haven't gotten a chance to get the car to anyone who can look at it yet but I did start getting 93 octane gas and we put some fuel treatment in it a week or two ago. I'll try buying that detergent stuff later and see how it goes. Car's got about a half tank now, is that sufficient for any additional treatment stuff or does it need to be full?

So far car's still doing alright other than the rattling when it gets hot, but I've been trying to be careful not to really push it. Just need to finish this last week coming up of school so I can focus more on getting the car fixed.

 

You could have the valve cover out to check the rockers and back on again in less than one hour instead of throwing money away on additives. Hook a scanner up to check for codes, if the knock sensor was faulty it will throw a code, if it's not then move on because it's not a fuel issue.

 

Hmm I hadn't thought of that sensor stuff....the car doesn't throw a code at all. All it does it just rattle when I accelerate in between 10 and 20 mph and then that's it. I can tell its getting worse though because it doesn't take it real long for it to start rattling.

 

By throwing a code do you mean check engine light coming on or actually hooking a scanner up? Not all codes throw a check engine light so if you haven't already head to an auto parts store and have them hook one up. Depending on the scanner you can check all of the parameters and maybe you'll be able to see if something is not right. Anyway you can get a video or sound clip uploaded?

 

It really sounds like you are describing detonation/spark knock/pinging. Can you give any more detail? Does it make the noise under hard acceleration? Any other speeds?

With what little you've given us I wouldn't be at all surprised if cleaning the MAF sensor and performing an induction system cleaning solved the noise!

Where in Texas are you? There are TONS of LS1 oriented performance shops in that state. Any of them would have a much better chance at properly diagnosing and fixing your car, rather than some general repair shop.

 

Sorry, didn't get a chance to come online this past week due to finals. To answer your questions, I live in Odessa, TX. As far as the rattling goes, I can't say that I've heard it at higher speeds, only when accelerating in between 10 to 20 mph. It is under a more moderate acceleration though and as the day gets hotter and I'm driving around in traffic and what not, the more pronounced it gets. If you don't accelerate just right you won't really hear it.