Engine low-rpm pinging?
Engine low-rpm pinging?
Anyone ever have their Vibe sometimes make a rattle/spark knock type sound at low rpm (between 1500-1800) under light load?If I kick it out of OD, or bring the RPMs up and it's gone.Doesn't do it every time, but when it happens it almost seems it's going into overdrive too soon forcing it to lug the engine.Seems to do it hot or cold - but again, not every time.I don't think it's the belt tensioner only because it truly sounds like the engine is knocking. Car is an '04 base auto with about 50k miles.
Re: Engine low-rpm pinging? (jhugh)
Just wondering why you would suspect the belt tensioner? When these parts are going or the belt itself, both can cause strange noises or rattles.If not, then it is fact some engine pinging can be cause by carbon build up on the pistons. Not all pinging is caused by his but some can be so try this...Buy a bottle of Chevron Techron Fuel system cleaner on concentrated form. Add it to your tank. This product cleans valaves and piston tops.If that does not work got to any GM dealer and buy the GM Top Engine cleaner. Follow the directions and or pay someone to do the job.
Re: Engine low-rpm pinging? (ToolGuy)
Toolguy - thanks for the info.I mentioned the belt tensioner only because I know this has been a source of some noises coming from the engine compartment. To me this sounds like pinging. I guess one quick test would be to just run a tank of premium and see if it goes away.I'm familiar with Techron, I'll have to run a bottle through and see if it makes any difference.I know one of our vehicles had a similar problem and it turned out to be a plugged EGR passage - does this engine have an EGR system?
Re: Engine low-rpm pinging? (jhugh)
I do not see EGR listed or anything similar in name so I will say no but I am not 100% certain. Engine drive belts that are old and stretched out can cause strange noises, how old is you belt?
Re: Engine low-rpm pinging? (ToolGuy)
The belt(s) are original.
Re: Engine low-rpm pinging? (jhugh)
Quote, originally posted by jhugh »The belt(s) are original.Even if it is not the belt causing the issue you have, I would change it out at this point any way. esp. if it has those little cracks across the ribs.
