QuestionHello,
I have a Chevrolet 305 (5 Liter) powered 1992 Cadillac Brougham (1980-92 Sedan De Ville/Fleetwood Brougham/Brougham general body style). I bought it 7 months ago with 170K+ moles and have added an additional 8K since. About 4K miles ago, not knowing any better I added a "stop leak" additive due to a perceived coolant leak (while the leak stopped, I later found out the source was the cracked reserve overflow tank, later replaced by a junkyard donor for a $10 fix). This week I changed the oil (second time since owning it, this time used synthetic Castrol syntec 10-30) and drained and refilled (with tap water from the hose, then distilled water) the coolant 5 times in one session until it was relatively clear and finally got it close to a 50/50 fresh mix of distilled water and green coolant. Also by chance had to replace the alternator (which was despite my initial trepidation a very simple task.
After these three jobs were completed, I took a test 10 mile test drive and she seemed to run great but when I parked her in the driveway and (with the engine on) I went to retrieve a few items from the trunk I heard a very slight "ticking" sound emanating from the exhaust pipe. It was obviously at idle and the "tick/click" repeated at pretty much the same frequency as the stopwatch sound at the intro to the TV news program "60 Minutes" as heard here: youtube.com/watch?v=Lb6UgPSdp0o . Then I noticed the sound again later that day echoing off the wall while idling at a drive thru. I am not sure if I am only noticing a difference in engine sound because I am listening for it after dong the afore mentioned three maintenance tasks or it is a result of one or more tasks performed improperly.
-Thanks, Vincent
P.S. It has been very hot and humid here the past few weeks, and I wondered if I should use a more viscous oil, although the Cadillac factory service manual (best $30 I ever spent on a car) specifically says not to use 10W40.
AnswerHello,
10w40 is not compatible with the Chevy small block. Don't use it!
To be perfectly honest, you take care of your car much better than I bother to. Possibly that noise was in the exhaust since the car was new. I don't feel it is a concern that it is coming from the exhaust. Strange noises are commonly heard through the exhaust and there are many things beyond the engine that can cause it coming from the exhaust system itself.
concern should be if you hear ticking noises from the engine that are not related to the fuel injection system.
If you listen close enough, you will hear a constant hum which is your electric fuel pump as well.
I apologize for not looking at your video, but at this moment I simply do not have the time, but as I said, I would not worry about any noises coming out of the exhaust because there is simply no way you are going to be able to determine what is making that noise. If the oild pressure is good and the engine is running on all eight, that is what you are concerned about.
http://www.autotheftexpert.com
