Warm engine ticking

[kensz28]

Hi all. I bought a 98 M6 Z28 with 127,000 miles on it last month and it was in need of some cosmetic stuff interior and exterior. It drove good and made no strange noises so I bought it. Well. while I was out having fun one day it began ticking and increased with rpm's. I changed the oil to my usual synthetic 10w30 and it seemed o k. Then one day it did it again! I shut it off and waited a bit then restarted it, it was fine. Now Monday I drive it 600 miles to Georgia for a wedding and it ticked the whole way. It seems that once the engine warms up to operating temp it begins. My friend suggested the engine had crud and crap built up in it so I ran Sea Foam in it. As it idles the sound goes away! I take it out for a spin and beat the living crap out of it. I come back to my buddy's house and it is purring like a kitten. Next day we go to my friends shop and it starts ticking again! I pull the valve cover and start it up and he notices the inside of the valve cover is being cleaned off from the new oil squirting up through the push rods. So maybe the dirty engine theory is holding water. I change oil again this time with castrol 5w30 conventional since I had a whole pint of Sea Foam in it. We found no broken valve train and like I said when it's cold it's fine. My friend with the shop asked if nitrous had been installed before and I didn't know for sure. I did have a switch next to the cubby hole in the console and no horn buttons either. He looked in the trunk and we found some screw holes then checked the intake boot and found a hole where a wet-system was installed. That didn't bother me since the car ran good. Now this is the weird part, at times the radiator will gurgle after driving and it was suggested that using the NOS may have blown a head gasket causing the overheating. I have no loss of coolant and/or oil mixing with antifreeze. My temp gauge shows 170-180 driving and will hit 210 if parked idling. We thought the oil is overheating and thinning out and a lifter isn't staying pumped up. I drove it to his wedding and it was fine. The ride home it chattered badly. Next day I have to pop-start it. Weird at first then it fails to start three more times! I have determined the VATS crapped out. But why the ticking like that. The motor seems original save for the egr removal. I am going to pull top-end of motor this week and see WTF is going on. Please help guys. I am new to LS1s but not to engine builds. It is not piston slap or a knock. It also runs roughly and skips a bit when the ticking get bad. That makes me think it's valve train related.

[konigandy6]

You may have slightly bent a push rod. SES light on?

[kensz28]

EGR has been taken off so yes the ses is on.

[1MileCrash]

could be a collapsed lifter

[O'Learys_SS]

i almost have a similar problem mine ticks all the time tho it happend after i went to shift from 3rd to fourth on highway and it jumped into second and did a crazy over rev. i saved it a little by slamming the clutch in but no it ticks loud and constantly goin to get it checked out. i know its coming from cylinder #2 and its in the valve train it sux.

[kensz28]

Yea. I can't get it to start now either. I did the ole resistor trick for the VATS, nothing, didn't even turn over. I hate this piece of shit so bad right now! I have a 79 malibu and a 95 roadmaster with a built LT1. I wanted to sell the buick after I bought the camaro and I can't seem to sell the thing. Now I wish I kept walking when I saw this car. I love GM cars to death but I would trade this thing for a civic right now. [1998 Z28 6SPD]