I have a 2001 S-10 Blazer with about 60k miles. It recently started knocking while going uphill or while accelerating. It almost sounds to me like a diesel engine. Otherwise it runs fine. Its seems to do it a little worse just after the first start of the day. It may be coming from under the hood but it almost sounds like its some exhaust thing. I tried using a tank of 93 octane gas instead of 87 and that didn?t seem to help (only maybe a tiny bit).
Anyway, I?d prefer not to spend a bunch of money if its something I can do. Does anyone have any suggestions where I can start looking.
Thanks. PS