I have a 2 month old 2004. When I pull up long hills at low RPM I can hear some engine clatter. Kind of sounds like lifters. My Dad said his Silverado did the same thing when he ran mobile one. I get so paranoid ever time I hear something out of the ordinary. Is this a normal sound?

 

Similar to a question I was going to ask, when the engine is low low in RPM I also hear this noise when giving it some gas.
Is your auto or standard?
TTT

 

It could be Valvetrain noise which LS1 engines are famous for. It could be a little engine knock due to low RPM and high load. In other words are sure you'er not lugging the engine? Also, what octane fuel are you using? Anyway, hopefully some of the other guys will chime in and may be able to clairify whats happening.

 

Check out this thread:

http://forums.corvetteforum.com/showthread.php?t=873082

 

I did not get much out of the thermostat tread to link me to my engine clatter. I have an automatic and although my dealer said I could run 87 octane I have been running 93 with hope of iliminating the clatter. This is my first vette. Man if you let it this thing likes to run in a tall gear and low RPM. I guess that is how you get 25 MPG out of a 300HP motor. I only hear it like I said when I am pulling up a hill at just over a thousand RPM. So do you think it is normal LS1 valve train clatter or is there something seriously wrong with new jewel?

 

In this hot weather, you could be running hotter - like 210degF or more - and getting some knock. The road/rpm combo you describe is prime for knock. The computer will sense and correct for it which would make it go away, along with some power as it does its magic.

The thermostat thread helps understand how to lower your temps into the 180-190degF range, where knock doesn't happen as often.

I read something the other day about using the NGK TR55IX plugs to help reduce/eliminate knock. I haven't tried them yet, so no personal experience.

As far as the gas goes, Supreme is the only grade you should buy. The only time you might be able to run 87 octane is at high altitude, and even then, I don't know what the computer would do to compensate for the high altitude. With such a fabulous ride under you, give it the best at all times - gas, oil and lubes!

Have fun...Bill

 

Note that while your computer is designed to HELP reduce knock by retarding timing and richening up air-fuel ratio, via knock sensors that "listen" for the knocking/clatter/ping/detonation you describe, it simply can NOT always eliminate the condition completely.

If you're really lugging the motor up that hill, at a low RPM like 1000 -1500 RPM, I'm not surprised you're getting pinging. Drop a gear and see if the condition goes away. If it does, and you're not revving real high, I'd say you're golden. However, if you experience ping under ANY other conditions, pay attention to your coolant temps. Does it seem that the ping increases with temps?

In fact, if you can, try pulling that hill when the car is colder. Does the ping go away, or lessen? That will tell you something. All in all, it seems that the stock tune seems to encourage pinging. Higher temps, not optimal timing and air/fuel mixture all contribute to ping. And, remember, while GM makes a powerful car in a vette, it also has to meet more stringent emmissions standards than the typical consumer level smog check we experience, so they did what they had to do to even make the car saleable.

Search the forum for ping or detonation and you'll find that you are NOT alone. If you read the thread I referred you to thoroughly, you'll see what I discovered, and what I had to do to eliminate mine.

 

If I drop it down a gear and bring the RPMs up a little the clatter goes away. There was a lot of replys to sift through on the thermostat tread I must have missed the part you are talking about. What did you do to iliminate clatter in your ride?

 

First, you should educate yourself, via this forum, on a contributor to the common cause of detonation, which is the poor design of the PCV system in the standard C5, which literally allows oil to get into the intake system. Do a search for a thread that includes DRCOFFEE and myself, and contains the word PCV and/or FILTER. There is a good improvement mod you can make to alleviate the condition, complete with design instructions and photos by DRCOFFEE. I installed this mod, and see amazing results, which prevent the oil from getting into the intake.

Next, take search for some threads that contain DECARB. These will educate you on how you can potentially rid your pistons for the EXCESSIVE carbonization caused by the oil getting into your combustion chambers.

Third, look at the threads regarding thermostats to help you understand that heat is another major contributing factor to the pinging you're experiencing.

You might also want to consider getting your car dyno-tuned, because:

a) You'll need to reprogram your fans, via the computer, in conjunction with changing your thermostat to really lower your coolant temps.

b) Since you need a programming device, or software and laptop and knowledge to do do, you might want to consider just paying a knowledgeable, experienced, licensed technician tune the computer for optimal performance at the same time.

Note that it sucks that you need to re-program the computer to adjust fans. Although you can buy and install fan controllers, by the time you start factoring in all the time and nickel and diming, you might as well contribute to the computer-tune fund, you know what I mean?

Now, you're lucky that your car has low mileage. I would think if you licked the PCV problem and decarb now, you may in fact improve your condition with just those steps alone. But, be prepared to take steps to cool your coolant operating temps as the next step.

BTW, where are you located? And, what temps are you seeing on for coolant? Have you noticed that the ping is significantly less or not present at all when the engine is cooler? I did.

Since we're coming up on the end of summer soon, as your coolant temps drop, you may experience some improvement, which might give you some more time with the car, so you can evaluate your needs. In other words, do the PCV mod, if your car's PCV system is the same as my '01's. I've heard that the Z06 engine's system is better, but I also know that many experienced people will still install a "catch-can" (PCV system mod I referred to above), which tells me that although the Z06's system is better, it may still allow for oil to get into the intake. It's an easy, $20 mod, which requires no permanent modification, so you can always remove it later, if you desire.

FWIW, I did the PCV mod, installed a 160 thermostat because I live in California where it doesn't get too cold, and I had my car dyno-tuned. I am now going to perform the easy DECARB procedure (there are two methods advocated on this forum), and then I'm going back to the tuner for a final check.

Hope this helps at least get you pointed in the right direction. Remember, your situation might be slightly different than mine, so take what I said with a grain of salt. And, I feel for you. Getting a brand-new car and having to make it run right just doesn't seem right, does it? But, in the case of the Corvette, it's par for the course, and all of us on this forum are in the same boat. But, then again, there are those others who are NOT on this forum who aren't as picky as we are, either. And, if you think about it, you wouldn't be on this forum if you didn't feel the same way people like me do.

Granted, if GM's quality control were that of the foreign cars, we couldn't need to be here!

 

Thanks for the advice Mr. Leadfoot I will do a search and see what I can come up with. Unfortuantly I live Arkansas and I am unaware of any reputable dyno-tuners. My coolant generally runs 192 to 196.

 

If you're running those temps right now, then I wouldn't be too concerned with the temps. However, I noticed that temps at 200 or above DEFNITELY caused my stock car to ping ALOT and LOUD, well, kind of like "clatter".

If it were me, I would do the PCV mod first, then decarb. If you still have the ping, then lower the temp a bit. If that doesn't eliminate it, then tune. However, I failed to elaborate, so for clarification, a lower stat will help keep temps down when moving, but doesn't help while sitting in traffic. That's when the fans come in. BTW, some people on this forum referenced an article that said coolant temps in the 180 range yield the best performance. So, if your car doesn't get too hot, then getting a Hypertech 180 degree thermostat will probably put you right about there. My car, on the other hand seems to be running WELL with a 160 stat. I'm seeing a constant 178-185 in ambient temps of between 83 and 96 degrees. Some people also say that a 160 runs too cold in the winter, but we get mild winters, so I'm thinking I'll be ok. If it does run too cold, I'll put in a 180 stat in the winter. Then I'll see what happens with that stat next summer, and if it gets too hot, I'll just switch 'em as needed. Another forum member suggested that, as he does the very same thing, but I think his winters are colder than mine.

Good luck!

 

Blyoth....you are getting some very well thought out advice backed by hands on experimentation from MrLF

MrLeadFoot.....where exactly is EDH. I'm in Ventura County. Just curious if we experience same abient temps or not.

 

Thanks for the compliment. I hope I'm not coming off as too much of a know-it-all, because I am far from an expert. But, this thread really caught my eye, because my detonation really was more like "clatter" than ping, like Blyoth said about his car, which is a much more accurate description for the condition I was experiencing. And, like you, that ping was driving me nuts. So much so, that I actually lost sleep over it, because my car would "clatter" so much I actually thought I was going to ruin something, and I truly believe that. It felt like if I drove it any longer in that condition, I was going to bend a valve, or worse.

While I'm no expert, I must admit I'm really more in tune with things around me than the next person. Take my vehicles, for instance. I have the C5, a 1000cc crotch rocket, a 300hp two-stroke bass boat that goes 90mph on the water on a windless day, and a Suburban; all of which I am quite meticulous about, so when something's amiss, I can almost feel it, you know what I mean?

And, I started noticing that when my coolant temps were hitting 228+; my oil was running at 230 - 235; and the ping turned into clatter, my car ran so bad that I could barely get moving from a stop when going uphill (presumably from the complete lack of power from the tip-in detonation, and the computer retarding itself so badly), I was smelling something like a burnt smell for a couple of days when in the garage. It didn't smell like a cat, brakes, clutch or coolant, but it was definitely a burnt smell.

For some reason, I decided to change the oil, which was about a week ago, and boy, was I shocked! The oil was black and my DIC was only at like 82%! You know what I think? I think the car was getting so hot it was breaking down the oil prematurely. I don't care what anyone says about oil withstanding temps like 230 plus, from what I saw with my oil, that's a bunch of garbage. I don't need an expert to tell me when oil's bad. It was so obvious it wasn't funny. I've never seen oil that bad before. I really think I'm lucky that I am so in tune with my car, because from what I saw in that oil, I'm sure if I let the heat problem, ping and that oil go much longer, something was bound to go bad!

I'm in El Dorado Hiils, which on the south east shore of Folsom Lake, just outside of Sacramento. I am one hour and 15 minutes from Lake Tahoe. Temps in the peak of summer hit the 100s usually for about two or three weeks, and it's not unusual for us to pull triple digits every once in awhile. Nights usually cool down considerably in the summer, sometimes into the 60s and high 50's. It's like a mild desert climate in the summer, but nothing like Vegas or Phoenix.

Winter sees a few 30s days, but not many, and not often. Nothing like the winters of the true Northern states or the East Coast. It does not snow here; we're below the snow line. I'd say dead winter days are mostly in the 50s and high 40's sprinkled throughout, although nights can get quite chilly. But, I'm originally from Hawaii, so temps below 72 are freezing to me, and anything above 88 has me breathing hard, or should I say "detonating"? Too bad I can't re-program my body's fans!

We do get some rainy periods here in EDH, and I mean RAINY PERIODS. Heavy storms and hard rains means no Vararam for me. In fact, I've been trying to come up with a way to modify my fog lamp shrouds to be flexible enough to run open in the Spring, Summer and Fall, but closed in the rainy season. I've almost got a design worked out in my head, but that's another one of my long-winded threads.

A couple of years ago, I stayed at a friend's place for a week in Ventura. It just so happened that the back deck of his house was literally a tide wall. It was so cool to be able to just jump off the wall right into the water to surf high tide. His house pretty much owned that point break.

Oops, an ADD tangent; sorry 'bout that. Anyway, are our ambient temps close? BTW, we hit 96 today; yesterday the high was 83.

 

I appreciate the advice. That is why I posted the thread. Speaking of oil. I have nearly 4000 miles on my car (yeah I didn't buy it to sit in the garage) and it says I still have like 70% oil life left. Do you think I should change the break in oil sooner?

 

Others may not agree, but I'd change it right now!

My rule of thumb is 1000 miles (if not less) on the first change of a new car. This gives you time to break it in, get used to it, and also time to find a driving "rhythm". But, 4,000 is too long on the first engine oil, IMHO.

The second change I do is 3,000 miles after the first. The time between the two changes is long enough to see how the oil fares with your style of driving and the environment in which it's driven, after the break-in period, and the break-in oil is removed. Also make note of the percentage left on the DIC. That percentage and the condition of the oil after 3,000 miles will help you better guess how long is right for you. For example, if your driving rhythm and style is fast-beat and hard, and you're in a dusty area, your oil will show the need for a change sooner than others. Similarly, if your oil looks like new, then next time change it at 5,000 miles and so on, until you find the right interval.

Whatever you do, remember to never let it go more than 10,000 miles or one year between changes, although the manual I believe says 15,000 miles is the limit.

 

Yeah that is what I thought. I stopped by dealer and ask when I turned over 3000 and they said don't even worry about it until 7500. I think I will take your advice and change it tomorrow. I still got to try and find that PVC tread. I not to good with these computers. I may have to get my 16 year old to look it up for me

 

Try this link:

http://forums.corvetteforum.com/show...fee+mrleadfoot

 

You are probably warmer than me where you live because I get ocean cooling. However I daily comute to Santa Barbara, Semi Valley and Valencia. So I see some pretty high ambient temps on average.

My car runs at 192-196 coolant/ 210-223 oil during normal spirited street and freeway driving the last couple of months. It obviously gets higher temps when stoped in the heat because I don't have the cooler stat and fan resets.

"CLATTER" that is precisley the term to describe my engine noise that I would experience although mine was worse at WOT but very noticable under load as well...even my wife asked what that noise was on a rare occasion I let her sit shotgun. I still have not had a single ping since running 1/2 can TORCO per tankful!!!

On oil changes. I would never trust a computer (DCI) to tell me when to change my oil. I rather be on the cautious side. Change mine around 3500 miles. I did a canyon run a couple of weeks ago. We had engine temps up to 160...2 1/2 hours of ***** out driving!!! The car was smoking hot and smelled. I changed the oil the next day!!

 

What is TORCO? Some kind of octane booster or something? Mine may clatter at WOT but my ear to ear grin kind of stops up my hearing at WOT. Mine sounds like a stock car blasting down the back stretch when you get on it. I can't wait until the Corvette ralley in Eureka Springs the first weekend in October. I want to hear what some aftermarket exhaust really sound like. I have listened to some of the sound bites on the internet but do not feel they do them any justice.

 

Yes Torco is an additive and can be purchaced from Joel here on the forum. Do a search...I started a thread a while ago. If you can't find it let me know.