: New HG Installed on a 99, Pings on Start Up?

01-18-08, 10:16 AM
Well, I was lucky enough for them to replace the HG on the 99 I just bought for 7k with 48k miles under the warrenty, they serted it too. Everything seems great, I smell a little coolent but I think it's just remenents burning out of the mufflers from when the HG was bad, I only drove it around 50 miles since the replacement. The car pings now on start up when it's cold, it goes away after a minute or so. I'm not sure if it did it before the HG replacement because I didn't have the car long and it wasn't that cold. I tried to WOT a couple of times and it made some noises (not bad sounds, I think it was and is making noise because she was never wot before, some old guy own the car before me and it's mint). The ping is still there but I can't tell if it's gotten better since WOT because of the outside temps have change some much here in NJ. Should I be concerned or content that I have a 99 that runs like a gem? Is there an additive I could try? Should I keep on WOTing for a while (I dont to break it or blow the HG)? Should I take it back to the shop or just enjoy. Thanks for all the support, love my car.

01-18-08, 11:59 AM
There is a difference between a "ping" (spark knock) and cold carbon rap. Cold carbon rap is more of a metallic sound. It Will go away in a minute or so. Spark know won't and would not likely be heard at idle, if at all due to the spark knock sensor. I'd take it out and whoop it some more.