97 Blazer LT clicking at low acceleration

I have a noise at low acceleration that sounds sort of like what I remember in the old days as valves clicking. Granted, I have nearly 150K on this thing, but is there any common/short of overhaul/new motor fixes for it? Seems to be leaking a little oil from the rear main also, but I always make sure it is full of oil, doesn't use much between oil changes.

As an unrelated issue, I got raaaaapt by an electrical guy apparently. The lumbar support switch under the seat created a short which led to frying my wiring harness front to back, and starting a small electrical fire in the fuse box with one particular related circuit breaker being RED HOT. Wasn't much fun, cost me around 1,000 dollars to have it fixed, and he told me that the lumbar support wouldn't be rewired....not a problem. Apparently he also bypassed replacing the ODBII plugin underneath the dash. I don't know the first thing about electrical, but he insists they informed me of that. (I have a temper, which didn't fix the situation). What are my options, there are very few guys around here that can fix those things, and I am burned on it now. Is there a book or some advice on that?

Thanks!

It could be lifter noise, but you would usually hear it worst at idel.
I would sugest doing an engine flush the next time that you do an oil change. It comes in a can which you can get from Walmart or any parts store.
Also consider adding a quart of ATF fluid with the oil change. Then change it again in about 1/2 the time that you usually would
ATF fluid is a good cleanser, and has more lubercating powers than engine oil.

I don't know anything about the ODBII system, however Chevy has used it fior years and there are lots of books out there on it.

Good Luck

Like OBP said, it could be a lifter problem, or it could also be a exhaust leak at the exhaust maniflod causing the tapping noise of the valves to be heard. As for the wiring problem, you mention OBD under the dash, do you mean the ALDL connection, or the plug-in for diagnostic reader? If it still works, like a scanner can still communicate with the system on the truck, then you have no problem, if you have no engine light on, and the truck runs alright, then you should be o.k.

Sorry, think they took you on a few things.
The wiring problem I've had and all parts are replacable - see the post on it under the FAQ section.
Lifters - is your coolant level dropping slowly (look at plastic tank) and if so lifter noise is often a first clue that the lower intake is slowly leaking internally into the valley right on the lifters - do a search here and many similar posts. 5w-30 high mileage oil helps with a good filter regularly changed and this also slows the rear main leak. Have to pull the trans to replace it.