Anyone else hearing a slight knock or tap on cold start up. It kinda has me annoyed now...^_^
Yes, I have had this occur once on my Borrego. It was a light tapping sound like a tappet or cam follower losing its prime. It went away in about 60 seconds and it has never done it since. I attributed to the fact that the Borrego had set for almost 2 weeks without being started and the oil had run down. If it occurs again, I will contact my dealer.Anyone else hearing a slight knock or tap on cold start up. It kinda has me annoyed now...^_^
Do DOHC motors have lifters??My V6 does the same thing. What is happening is the hydraulic lifters bleed down and loses pressure. Once the engine starts oil pressure builds back up and feeds the lifters. This is not a "normal" condition. I had the factory rep inspect my Boreggo and was told it was normal. I don't buy the explanation but not much I can do until they acknowledge the problem and come out with a repair.
I always use a longlife teflon additive in my cars from the first oil change after the engine has done a few miles and loosened up a bit. I use a nulon product that is made here in Australia, but any of the well known brands will work ok. You do actually notice a change in engine noise and the revs used at certain speeds actually drops slightly. I don't think using an additive would cause any warranty problems.I had a Euro V8 SUV before the Borrego and it did the exact same thing, only worse. This is a very common noise for a new technology 4+ valve/cylinder V8.
I've heard of some aftermarket engine lub additives that help with cold start friction noises, but afraid to try on a new engine.
This could be a balky hydraulic timing chain tensioner. Hyundai had similar problems on the early Lambda V6 engines (3.3 & 3.8 liter). Sounds like a tappet rattle until the oil pressure comes up during a cold start. I would take it to the dealer since it should be covered under warrenty.Anyone else hearing a slight knock or tap on cold start up. It kinda has me annoyed now...