Just to start at the beginning, bought my '98 blazer LS in 2004 with 75K. I have had some issues but nothing major.

Couple of months ago noticed coolant was disappearing at an alarming rate and heater stopped blowing hot air. Did some research (found this site) and determined it was the intake gasket. Spent all day on a Saturday two weeks ago tearing it apart, cleaned it up, and installed the new gasket. Drove it the next morning after letting the RTV cure overnight. No problems what so ever up until this week.

Now onto wednesday of this week. Started it in the morning noticed a loud chug/tick (kinda like one cylander not running) Immediately shut it off. turned it back on and it was still there. Let it run for about 5 min and it went away. Ran 5 mi to work with no issues. Lunch time and it ticked/Chugged again until it got up to temp. Now every time it sits more than an hour or so it does this.

Today i changed the oil and added some seafoam. It chugged and ticked pretty hard. let it warm up in the drive for about 10 minutes hoping that it would straighten out. Never did. Took it for a ride and by the time i got the end of my subdivision (2-3 blocks) it stopped all together. drove it about 5 miles pulled it into the drive and then parked it at idle. no ticking.

I think it could be a lifter, any ideas?

 

Yea, it's probably a lifter that's dirty. As they warm up, what ever is on them will soften and the lifter will expand just a little. So the difference in seating and whatever may be on it softening up is probably why the noise goes away.

 

you think it will ever settle out? not had much top end engine trouble so i am not really sure what to expect. I would think that this should eventually settle once the junk in the lifter passes, if that is what the problem truly is. One other note the oil pressure is variable during the period of time the noise is being produced.

 

You could try an engine flush to see if you could clean that lifter up... I have never had any luck quieting a lifter in the few instances I have dealt with one. The only thing that has worked in my experience has been replacing the lifters.

 

How many miles are on your engine? Engine flushes are not generally recommended for engines if they're high mileage and have never had one before. Reason being, your engine can get to where sludge is litterally holding it together. So when you do the flush, any sludge that may be gunked up in places like your seals would be washed away.
Also, you gotta figure that sludge has to go somewhere. On it's way to the oil pan, it's gotta go through a bunch of small ports and it may even wind up going through your oil pump. That can mean bad news for your engine.
I did an engine flush on my volvo with high mileage and it ended up blowing the front and rear main seals. That was along with screwing up the turbo. Eventually, I blew my engine after the rear main went out as I was going down the highway.

 

Generally the best way to get rid of the knock is to take apart the top end and have it cleaned/rebuilt. It's up to you weather it's worth the cost or not.

 

I have heard bad things about flushes in the past, and had bad luck (in my teenage years) with some cures in a bottle. I will try and ride the thing out and see if it at least shows to be consistent. I will definitely be pricing out some new lifters and rods in the meantime.

Just really sucks, i could have done that when i had it apart two weeks ago. Hopefully the gaskets will stay in tact.

and BTW, thank you both for you help, sometimes a sanity check is priceless

 

I should have clarified by saying with seafoam or Marvel Mystery Oil. Not the harsh chemical flushes.

 

I've heard lotsa good stuff about those two but haven't had the chance to try them out myself. Maybe I'll have to try it on a work truck first lol

 

Was thinking the same thing.