libtec
10-29-2004, 19:22
Well thanks for the advice everyone! I have a 90 6.2 with around 110k on it. I am the 3rd, 4th owner, no one knows for sure. Anyhow, I got the suburban for a song ($600) and it is very straight and very clean and runs pretty darn good. This was one of those things where the previous owner didn't know or care to know how to maintain a vehicle aside from checking the oil and filling the tank. Anyhow it developed a starting problem, he let it sit for two years and cut the price low just to get it out of the yard. Two fresh batteries, a new starter (low cranking rpm)and a new glow controller, new alternator and were on the road. My only hangup is that at some point in it's life the motor was not cared for properly and is showing signs of being tired. It does make a very obvious hallow knocking sound when it is first started, like a hard rubber hammer being hit against the block. The colder it is the worse the sound untill the temp comes up then the noise is not so evident but always in the back ground if you know what to listen for. Oil pressure is excellent (45ish when warm) and the motor seems to run well. I'm not one to waste a machine, I got it for cheap, it has a ton of potential and I intend to make it last as long as I can with some TLC (talk about a gold mine). I just don't want to throw a rod or cause some expensive damage to the motor by ignoring something that sounds like a problem from inside. I have been told that a bad injector can cause a sound similar to a bad rod bearing. Is this true? and if so would it change intensity with the motor temp? Any easy methods of isolating a bad injector? Lots of people have told me that some diesels are noisy and loose when they first start, but this knocking is a little more I think. Any input would be appreciated. Thanks!