Long story short, just got done with a fresh rebuild on the bottom end, but that's not the issue. Car is a 96 cobra with 160k on the chassis and 400 miles on the bottom end. Heads were straightened at a machine shop and compression checked, all good.
last night I got on the cobra a little bit, nothing too rough but took it up to about 5500 in 3rd gear on the freeway. I'm aware of the taboos of breaking in a new motor, etc., however I've been told by many people including my father who builds industrial diesel engines regularly that there really is no break in period necessary. Idle them for a half hour or so and they can be put to work. Still, I've been taking it easy and never over 4k rpm.
Either way, this ticking is not the bottom end anyway, so on to the real question...
Before the engine rebuild, there was a ticking coming from the top end, usually on cold startups and only at idle. When revved even the slightest it went away and usually went away after warm-up. This was still present after the rebuild, during the same conditions except it didn't seem to go away after warm-up.
After getting on the car a bit, which it feels like a huge power loss after 4k (possibly due to bad O2 sensors, I have a CEL showing currently but don't have the time or resources to address it immediately), the ticking is now there constantly. Hot or cold, idle or not, it ticks and it's driving me mad.
I'm assuming is a clogged lifter or something of the like, doesn't seem like there's much else that can make noise in the top end. The valves looked good as far as Dougan's was concerned, he straightened the heads which were warped .006" and did a very nice job of cleaning them up, and checked compression. If anyone can give any input on this as to what it may be, and what would be involved in fixing it (does the motor have to be pulled or can it be done in-car). I'm guessing just pull the cams and replace the lifters, but not sure whether everything is accessible with the motor in the car.
Thanks in advance for any input.
edit: checked the oil and it's about 1/4 the way between MIN and MAX, it was about half way after the motor was first run for a half hour or so. No visible leaks yet, but it is hard to see for sure with this damn motor. Currently running 5W-20 Motorcraft Synthetic Blend with just over 400 miles on the motor. Also, the oil consumption is probably due to the rings still seating
last night I got on the cobra a little bit, nothing too rough but took it up to about 5500 in 3rd gear on the freeway. I'm aware of the taboos of breaking in a new motor, etc., however I've been told by many people including my father who builds industrial diesel engines regularly that there really is no break in period necessary. Idle them for a half hour or so and they can be put to work. Still, I've been taking it easy and never over 4k rpm.
Either way, this ticking is not the bottom end anyway, so on to the real question...
Before the engine rebuild, there was a ticking coming from the top end, usually on cold startups and only at idle. When revved even the slightest it went away and usually went away after warm-up. This was still present after the rebuild, during the same conditions except it didn't seem to go away after warm-up.
After getting on the car a bit, which it feels like a huge power loss after 4k (possibly due to bad O2 sensors, I have a CEL showing currently but don't have the time or resources to address it immediately), the ticking is now there constantly. Hot or cold, idle or not, it ticks and it's driving me mad.
I'm assuming is a clogged lifter or something of the like, doesn't seem like there's much else that can make noise in the top end. The valves looked good as far as Dougan's was concerned, he straightened the heads which were warped .006" and did a very nice job of cleaning them up, and checked compression. If anyone can give any input on this as to what it may be, and what would be involved in fixing it (does the motor have to be pulled or can it be done in-car). I'm guessing just pull the cams and replace the lifters, but not sure whether everything is accessible with the motor in the car.
Thanks in advance for any input.
edit: checked the oil and it's about 1/4 the way between MIN and MAX, it was about half way after the motor was first run for a half hour or so. No visible leaks yet, but it is hard to see for sure with this damn motor. Currently running 5W-20 Motorcraft Synthetic Blend with just over 400 miles on the motor. Also, the oil consumption is probably due to the rings still seating