ticking sound from mr vortec engine

Hi,
New to forum,hope someone can help.
I drive a 1998 astro passenger van with a 4.3 vortec engine. Bought it at 120k almost 2 years ago. At 150k on a cold day I started to hear a ticking sound from the engine but it would go away after the engine warmed up in about 10 minutes. After a few months the ticking sound would last longer and longer. Someone told me to switch to synthetic oil so I tried that, and for about 3 months I didn't hear the noise.Now the ticking sound is back and it doesn't go away.One mechanic said that an exhaust valve was sticking and for $1200.=$1500. he could fix it. Another mechanic said that a leaking gasket was allowing antifreeze into the oil and that it was a serious problem. He didn't look at my oil he just said he could tell by the noise. Another mechanic said it was noisy lifters and not to worry about it. Can anyone help or advise me on how or where I can find out what the problem is. I'm not that mechanical so I don't know which mechanic to listen to. Thanks!!

Without listening to it myself, and doing a little diagnostic work, it's impossible to tell. However, a few possibilities could be: #1 Possible exhaust leak at the gasket between the cylinder head and exhaust manifold, (if it even uses a gasket there). To repair, obviously replace the gasket. #2 Possible piston slap caused by the skirt on a piston contacting the cylinder wall as it goes up on the compression or exhaust stroke. Piston slap is caused by insufficient oiling of the lower cylinder wall and would require a modification to the piston rod to correct, (if possible). To repair, new piston. #3 Possible clogged oil passage in a valve lifter. To repair, replace the faulty lifter/s. Each of these possibilities could be apparent only when the engine is cold and not noticeable after it warms up, even slightly.

If an exhaust valve was sticking, you'd have an engine miss.
A leaky gasket allowing antifreeze into the oil you would never hear.
Your 3rd mechanic with the noisy lifter theory may be onto something.

I just had the exact same situation with my '97 Astro (105k miles). Occasional lifter or valve tapping at start up that turned into a nearly constant intermittent tap after a few weeks. I was thinking major expense to fix... nope!

Yea, this sounds too easy but it worked for me...

Change your oil and oil filter, using a high quality oil filter (try a Purolator PureOne) with "high multipass efficiency". Prime the filter, meaning fill it with oil before installing it. You might have to keep filling the filter up slowly to let the air escape. The filter I was using when my noises started was a cheaper brand...

Since you just started using synthetic and you have 150k miles you might not want to get too aggressive with engine cleaning products, unless your engine is really clean inside, which is questinable since you bought it with a lot of miles and don't really know the vehicle's history. Some people run a bottle of Rislone or ATF for a few hundred miles. Works for some to clean out oil passages but it can stir up more gunk to clog oil passages too... you take your chances.

I ran a small bottle of Rislone and a half bottle of Seafoam for a few hundred miles on my Astro before the oil change but I don't think it did much - the noises just kept getting louder until my oil change, then no noises whatsoever.

I'd try the oil/filter change first. You can always change just the filter by itself before changing the oil again if you think it's getting clogged up or the if noise starts up again. You might go through a few filters getting clogged if a lot of junk is being stirred up in your oil. If you are using pure synthetic like Mobil1 you shouldn't have to change the oil as often so just change the filter if you want and save money on oil expenses if your next scheduled oil change is far off.

Right before I did this my engine was making hellish noises. No noises since the oil/filter change, smooth as silk!

Let us know how it works out...

My old '81 van with a 305 v8: it started ticking, I suspected a lifter, so I used Rislone. On a highway trip shortly after, the ticking stopped, but was now running on 7 clyinders. I feared the worst, pulled off a valve cover, to find that 1 rocker had come so loose on the the stud that it flipped off the valve stem. I got a new nut and reassembled it. -no further problems.
So I would also try the oil changes, maybe Rislone added. And I wouldn't worry too much about a little tick, it seems they're just as expensive to fix as a big tick, which is easier to find.

Thanks for the help guys. The mileage is in kilometers since I'm in Canada so I think the conversion is 2.2 kilometers=1 mile so my van started "ticking" at 68,000 miles. I didn't think I would have any type of engine problems until at least 300,000. kilometers or136,000. miles. Anyway I'm going to change the oil filter. I bought a cheaper one from Canadian Tire but I did buy Mobil 100 percent synthetic oil so I hope that was a good oil. I didn't think there was any difference in oil filters. I change the oil every 6 or 7000 kilometers or3,200 miles.I did put a can of rislone in it last year but I only did it once and didn't notice any difference. Don't know how many times I need to do it.
I think the next time I purchase a used vehicle if I don't see the service records then I won't buy it. This vehicle came from a used car dealer but who knows how well the previous owner maintained it.Actually I'm beginning to think luck has a lot to do with it because I had a 1986 Astro van years ago and when the body started to rust away I didn't maintain the vehicle, thought it was going to die soon anyway but it just wouldn't. I didn't change the oil for a couple of years and when I sent it to the wreckers in 1999 it was still running and it never had that "ticking sound".

Thanks for the help guys. The mileage is in kilometers since I'm in Canada so I think the conversion is 2.2 kilometers=1 mile so my van started "ticking" at 68,000 miles. I didn't think I would have any type of engine problems until at least 300,000. kilometers or136,000. miles. Anyway I'm going to change the oil filter. I bought a cheaper one from Canadian Tire but I did buy Mobil 100 percent synthetic oil so I hope that was a good oil. I didn't think there was any difference in oil filters. I change the oil every 6 or 7000 kilometers or3,200 miles.I did put a can of rislone in it last year but I only did it once and didn't notice any difference. Don't know how many times I need to do it.
I think the next time I purchase a used vehicle if I don't see the service records then I won't buy it. This vehicle came from a used car dealer but who knows how well the previous owner maintained it.Actually I'm beginning to think luck has a lot to do with it because I had a 1986 Astro van years ago and when the body started to rust away I didn't maintain the vehicle, thought it was going to die soon anyway but it just wouldn't. I didn't change the oil for a couple of years and when I sent it to the wreckers in 1999 it was still running and it never had that "ticking sound".


Check this thread: http://www.automotiveforums.com/vbulletin/showthread.php?t=502914

I hope you've forgotten the Imperial measure rather than fudged the metric conversion. We've been metric for 30 years now, I don't why Imperial keeps popping up.....
I've read that info on filters previously. I found it disturbing. I thought Fram was a good filter. Unfortunately, Fram and knock-offs are a big seller around my area. Fram Extra-Guard looks to be a compromise, at twice the price of the other Frams. I guess you getwhat you pay for.
Change your oil at say, 2500 Km for a few changes and add the Rislone each time. If it's a dirty engine, that would cure it I think. If it's something more, at least it shouldn't get worse for a while.

My erroe: the Fram "Tough-Guard" is a better one, not the "Extra-Guard

My error: the Fram "Tough-Guard" is a better one, not the "Extra-Guard"

If you're willing to spend $5.00 on an oil filter, might as well spend it on a good one, Pure One by Purolator or Wix, (NAPA Gold). It's the best (and least expensive) insurance policy you can buy for your engine.

Thanks.
Here is a NAPA resonably close to me.