1998 Chevy S-10 Engine making a tapping noise

RAYMOND8387

MEMBER
1998 CHEVROLET S-10
6 CYL
2WD
AUTOMATIC
107,500 MILES

I noticed about a couple of weeks ago, my truck started making almost a tapping like noise. I took it to a repairman and he basically told me I was getting ready to throw a rod. His diagnostic consisted of getting in my truck, starting it, letting it idle for about 3 seconds, and then reving it for about 5. He didn't open the hood. I went ahead and changed the oil, and put 10-40w in it instead of 5-30w. It seemed to help but not too much. If you listen really close to it, it almost sounds like it's coming from the center of the top part of the motor, other times it sounds like it could be under one of the valve covers. My truck isn't losing any power, and if I needed to "stomp" on it to get into traffic, it would easily go, even though right now I'm babying it. I can't figure this out to save my life. Any suggestions? This all did happen the day after I filled my tank up, and it was very slight tapping at first, almost un-noticable. Then I left work that day, and had to get out of someone's way that cut me off, so I had to accelerate kind of quickly and it got a little louder after that.

1 Reply

MJANOS07

MEMBER
3 POSTS

Im no mechanic but if the sound is coming from the top of the block it could be a lifter tick. I don't know how common that is with the s10's but some of the newer vehicles that are disposable like the neons develop a lifter tick very early. Its not surprising he said it'll throw a rod because that sound can only be blamed on a few things. My old half ton had 300k on it and it started ticking till it threw a rod out the pan. If its coming from the top its definitely not a exhaust donut tick. My guess is a lifter has gone, which makes sense because you wouldn't notice a decrease in power.

It would develop a knock from over revving it, running high revs for long periods of time or stomping on it when its cold.