Tapping Sound from Engine

I have a 96 Blazer, 4.3L and two days ago I noticed at tapping from the engine. the car ran flawlessly for a long time. Oil changes were made on the regular basis. I noticed the past few weeks there was a tapping noise after I started the car, but it went away after a few minutes. As of 2 days ago, when I start my blazer, the tapping noise starts and does not stop. I flushed the engine twice with b12-chemtool and the first time I drained it, the oil came out black, the second time it was semi-black, and the third time the oil came out clean, oil filter also.

I refilled oil crankcase and changed filter and started my car, the tapping is still there. I dont know what else to do. should I take off the valve covers and clean the lifters that way? Someone please help. I dont want to drive it with that noise and end up hurting my engine.

What filter are you using?

Wouldn't hurt to pull the valve cover on the side that is tapping, could be a rocker arm or push rod problem. The lifter itself is down in the engine, have to pull the intake manifold off to get to it. Getting into a major repair.

I've always used Bosch oil filters, recently I went to Fram on the last oil change. It was recommended by someone at Autozone. He also recommended I go with a heavier weight oil (10/40 Valvoline) to give my engine more cushion on the older parts, so I thought I'd try that. It has 149,000 miles on it right now. I haven't tried using the sludge cleaner or motor flush stuff I found in a store yet. I thought the b-12 would have taken care of the grime problem. I didnt run it for 30 mins, but I did hop on the highway and took a route around town to give it a chance to work the engine a little, then drained it when I got home while the oil was still hot. At that time, it seemed to have cleaned the engine. I plan on checking under the valve cover today. If anyone has any other suggestions, I am open to them.

I've always used Bosch oil filters, recently I went to Fram on the last oil change. It was recommended by someone at Autozone. He also recommended I go with a heavier weight oil (10/40 Valvoline) to give my engine more cushion on the older parts, so I thought I'd try that. It has 149,000 miles on it right now. I haven't tried using the sludge cleaner or motor flush stuff I found in a store yet. I thought the b-12 would have taken care of the grime problem. I didnt run it for 30 mins, but I did hop on the highway and took a route around town to give it a chance to work the engine a little, then drained it when I got home while the oil was still hot. At that time, it seemed to have cleaned the engine. I plan on checking under the valve cover today. If anyone has any other suggestions, I am open to them.

Oh god, first of all do the following:

1.) Smash your head on the nearest wall for listening to an AutoZone monkey. They are just everyday people, NOT automotive experts. You can see this when they recommend a Fram piece of junk oil filter. Use a good quality oil filter and ANYTHING other than Fram.

2.) Was the B12 chemtool a fuel system cleaner or the oil cleaner?

3.) Did you follow the directions on the bottle? It says idle for 2-3 minutes but you know better and you took your engine out for drive? Do you know what damage you are doing? Do you have a clue at all? Why would you disregard instructions like that?

4.) No, you don't use a heavier oil, you use what is required for that engine and don't believe the cushion crap he was telling you. Use 5w30 like I do and I have no problems.

5.) Go get a bottle of gunk engine flush AND FOLLOW THE DIRECTIONS AND DON'T GO DRIVING AROUND WITH IT IN YOUR ENGINE. IDLE ONLY!!!!!

Honestly, don't start listening to people that don't know, do some research yourself before you take an parts store moron's advice. Most of them are just parts pushers with no automotive experience at all.

I never used a different oil other than 5w30. I was told to recently try a heavier weight. I have a manual on my car and know enough about my ride to not put a different oil in there. After I got home, I thought about the heavier oil thing and it didnt make sense to me, so I didnt do it.

The b-12 chemtool I used is for the oil crankcase, I ran my car no more then 20 mins then drained it for the second time. I always follow the instructions on the bottle, but I did drive it home from the parts store with the chemtool in the engine. It's about a 20 min ride. That's when my crankcase first came out clean. This was recommended by a reliable mechanic to do this. He told me it would not hurt anything to drive it home with the chemtool in there as long as I drained it when I got there, which is what I did. After I filled it back up, I noticed that the ticking was not as loud as it was before so it's gotten much better. You can only hear it when you are really close to the car and not at a distance like before.

The Fram oil filter is coming off today, and I'm going back with my Bosch filter. I have 2 new ones in my garage. I'll also do the Gunk Flush at home and see what happens. If this does not work, its going to the shop and getting some new lifters. The guy at the shop I talk to alot works only on GM cars and said he can get me a good deal on some quality parts w/o paying out my ass for them. He's the only honest guy in town that's helped me out in the past when I didnt have the tools to do it myself. But it will be at least two weeks before he can get to it. Hopefully this will last flush with the "GUNK" you recommended will either fix the problem or buy me some time. I've heard of it before, but I always used b-12 chemtool.

Ok people. the following has been done to my car and it is still tapping inside the engine. Before it goes to the shop, what other bright ideas does anyone have.

Day 1;

I woke up and got ready to leave, started car and heard tapping sound. Normally it went away after a few mins, but this time it didnt. added B-12 chemical to oil and ran for a few mins, then drained and refilled. Oil came out black the first time around. Assumed engine was clean, added new oil (5w30 valvoline max life) and new filter (bosch). started car, engine still had tapping sound.

Day 2

Talked to someone in parts store and they suggested going with heavier weight oil (10w40) to help protect worn parts, if any, and change filter to Fram. Changed the filter, but didnt change oil weight (that would be stupid) and took vehicle to my old mechanic. Mechanic said to add b-12 chemtool to crankcase and drive it home, then drain oil immediatly and change filter. It should clean up the rest of the engine. Since I had success with b-12 in the past, I went back to store and bought product, poured it in crankcase, and drove home (about 20 with traffic), then drained oil and refilled with 5w30 and new filter. Started car again and tapping sound was still there, but you could barely hear it. Only when you are close to car and not at a distance.

Day 3

Recieved recommendation to use Gunk Motor Flush to get rid of tapping sound. Went to parts store and bought a bottle. Also purchased some more oil for later. Flushed engine as directed on bottle and refilled crankcase and changed filter (bosch). Oil drained from pan was clean and looked like new. started car and tapping sound is still there.

Again, the noise is not as loud as it was before. Its actually alot quieter and you can barely hear it unless you are standing next to the car or got the hood up. After flushing and filling engine 3 times, the tapping noise decreased, but didnt stop. The last time I changed the oil, it came out clean. Mechanic says lifter my be bad and thats what it sounds like to him.

Ok, I would recommend you use some AutoRX

http://www.automotiveforums.com/vbulletin/showthread.php?t=385384&highlight=autorx

Site is here to purchase it.

You will be amazed as to how much stuff it will get out of your engine.

Also, how much oil are you adding when you fill up your truck after a drain?

It better only total 5 quarts and thats with the filter.