Vortec ping

Z16 · July 28, 2001

My 98 Vortec 5.7 has a pinging problem. When put a slight load on the motor, like going up a bit of a hill, it starts to ping quite a bit as soon as the converter locks up both in 3rd and OD. It is worse when the temp is hot outside. If the RPMs are increased somewhat it goes away. It doesn't do it at higher RPM like highway speed. We scanned it and it looks like the timing isn't retarding as much as it could, but this test was really inconclusive. I ran premium through it, for a few tanks, and while we were on holidays pulling the fifth wheel, it had to work pretty hard. No ping. After we got back, I started back to regular, and now the ping seems to be slowly coming back. GM dealer said all those trucks ping a bit, but this is more then I am willing to live with. A couple of other mechanics have looked at it and are unsure. Anyone out there have any thoughts? It's a great truck and good motor, but this is driving me crazy

July 29, 2001

I'd check the base timing, make sure it is perfect. If premium makes the pinging stop, I'd run it. I hear a lot of people say that the dealers are telling them that the pinging is okay. In all my years of wrenching, pinging is bad. It puts more load and stress on the main and rod bearings and can burn a hole in a piston.

How is it that now, it's harmless? I think it's a problem that GM wants to ignore.

sweet94 · July 29, 2001

Sounds like you must of had a tank of sh-tty gas. Once you've been stung with a tank, you need to change your plugs.

Change your plugs and start fresh with quality 89 octain and use that as a baseline. Let us know after that point how it goes.

Chris

Z16 · July 29, 2001

The base timing on Vortecs is preset from the factory(Great idea that is?). I'll try the plugs, but they look OK. Never heard of that before.

76BBSub · July 30, 2001

I have always run premium unleaded in my Vortec trucks, 350 or 5.3 liter. If you drive hard at all it will ping on cheap gas. Also, what brand are you using? Cheap gas is cheap because it is less refined, and will sometimes cause symptoms of low octane even if the rating is there on the pump.

Also, depending on the age of the engine, you could have some deposits built up that have increased the effective compression ratio of your combustion chamber, causing detonation where it used to not be. Additionally, deposits hold more heat in the combustion chamber which will also cause detonation. When I did the valve job on my '76 454 there was a fair amount of deposits on the valves, pistons, and combustion chambers. After cleaning them all off I am now able to run 87 Octane with plenty of advance and no pinging.

Jeff

P.S. See my post in the Classic Truck Forum for details on the '98 Vortec 350 Suburban I raced over the weekend...hehe

BIG BLUE · August 1, 2001

Z16,

How many miles on the truck? When, if ever have the plugs been changed. First thing I'd try is a couple of bottles of FI cleaner. I like the Chevron Techron in my trucks or B-12 Chemtool. My 97 Sub was begining to "ping" on hard take-offs and pulling heavy loads on a steep grade. The injection cleaner helped.

I don't believe in this 100k mile tune up crap. If the ignition parts are all original and are pushing 50k then I'd consider doing a tune up. Like others have mentioned a bad tank of gas can cause this but your engine is designed to run on 87 octane, so there is no need to run premium in my opinion (unless all other fixes fail then I'd run mid or high grade in that order until the pinging stops). Those are the things I'd try first, from there you can at least rule out those attempts.

Good Luck,

BIG BLUE

Z16 · August 1, 2001

Hey Blue, My truck has 90 000 kilometers on it( 58 000 miles) so I will try a set of plugs. Did you replace yours with GM ones? I have run a few bottles of injector cleaner thru it over it's life, and had the injectors flushed by GM.

LT · August 6, 2001

Z16, I'm in complete agreement with Big Blue. I'd look at spark plugs first. I also agree that if the manufacture recommends 87 octane, you ought to run 87 octane. Running 92+ is really a waste of money and may really ignore a more basic problem such as routine maintainance. With saying that I confess to using "hi test" a couple of times in the winter because of additives. My .02

lbrough · August 6, 2001

Re the Vortec pingiing.....my '01 4.3 liter V6 does the same thing and has from the day I picked it up from the dealer. I've had it to two dealers w/o any success in getting it corrected. Calling the Chevy Customer Service is a waste of time because the yahoos they employ there don't know diddley about cars (really). Premium fuel didn't help either, in my case. Best to document the problem in writing to Chevy Customer Service so when the engine craps out it'll be their problem.

DigUout · August 6, 2001

At 58K you shouldn't hear any pinging and any dealer that tells you it will ping a little is just being lazy. More money for them selling trucks than fixing them. I've always run 85 octane at high alittude so it doesn't run too rich, pulling loads and have never heard pinging in my '98 350. I would say if running FI cleaner, new plugs and higher octane aren't taking care of the problem, find another GM dealer in your area and yes, definately document your problem with customer service.

Z16 · August 6, 2001

Thanks for all the info guys. I am buying plugs tomorrow. Hopefully that will cure it.

1badk2 · August 18, 2001

I'd make sure the egr is working properly, secondly, run some top engine cleaner through the engine, helps to get rid of any carbon buildup on exhaust valves,, due to the fact there are no rotators. I work for chevy(tech) and no,, they shouldnt ping. Thats what I do,, gets rid of the ping, everytime. good luck!

98K2 4"trailmaster 33X12.50's

Z16 · August 18, 2001

OK, put new plugs in it and what a difference. Truck idles smoother, hasn't pinged yet, and seems to be getting better mileage. Now I don't believe that the plugs in new vehicles will last as long as the manufacturer says. These ones didn't last much longer then any other plug I've ever used. Hopefully this was the cure, thanks to everyone who gave an opinion.

fullyloaded · October 11, 2001

what kind of plugs did you put in your truck??

Pantera · October 16, 2001

Hey DigUout

Just picked up my newly ordered 2500HS 4X4 5-Speed 6.0 Liter and I have a tranny problen and an engine hessitation problem as well. Truck has 395 miles on her.

Do you ever get a hessitation problem when going into 3rd gear, say around 1300 RPM or so? I am getting it all the time and not just in third. Sometimes 2nd and fourth as well in the 1200-1600 RPM range. Bothers the hell outta me.

#2 Do you ever get a vibrating noise when in 5th gear. I am getting it while in fifth gear and it even happens when I shift into nuetral and coasting for a while in the 35-45 MPH range.

Let me know what you and others think about this.

Thanks,

Pantera