Motor problems... lifters, Cometics and unknown
01-15-2010, 02:23 PM
#41
It's common practice on here, but if the block is prepped properly you don't need any copper spray. I've talked to cometic about it and they specifically advised not to spray anything on them. I followed their advice and haven't had any sealing issues FWIW.
A leakdown test will tell you if your losing compression in a cylinder. You may be able to hear where the air is escaping to narrow it down. It won't tell you anything about detonation. What's your compression look like? Also, what thickness is the gasket? What size heads? Just trying to get an idea of your quench...
A leakdown test will tell you if your losing compression in a cylinder. You may be able to hear where the air is escaping to narrow it down. It won't tell you anything about detonation. What's your compression look like? Also, what thickness is the gasket? What size heads? Just trying to get an idea of your quench...
01-16-2010, 12:15 PM
#44
Well still no answers! Here is the list of what we did today:
- All plugs pulled and they all looked excellent
- 200 PSI all cylinders compression test
- Did a leak test and got no bubbles in the water with the cylinders pumped up
- Checked the flywheel and no cracks
- Checked the converter bolts and they are tight
- Checked the torque on the rockers all were tight and clicked at 22 ft lbs
- Checked the header bolts and all were tight
- No water in the oil/ no oil in the water
Car runs excellent but under a load if you mash on it 4k up it has the noise. Not down on power or carrying on in any manner. Great oil pressure, etc... I checked I have 1000 miles on this combo and 15 11 second passes.
- All plugs pulled and they all looked excellent
- 200 PSI all cylinders compression test
- Did a leak test and got no bubbles in the water with the cylinders pumped up
- Checked the flywheel and no cracks
- Checked the converter bolts and they are tight
- Checked the torque on the rockers all were tight and clicked at 22 ft lbs
- Checked the header bolts and all were tight
- No water in the oil/ no oil in the water
Car runs excellent but under a load if you mash on it 4k up it has the noise. Not down on power or carrying on in any manner. Great oil pressure, etc... I checked I have 1000 miles on this combo and 15 11 second passes.
01-16-2010, 07:45 PM
#48
Nope. Mine runs, sounds and acts totally normal. Maybe I can get a small clip but all I have is a cell phone and camera. Only time the ugly noise appears is say you are cruising along at 2k RPM then you mash it hard. About 4k RPM it makes like a rattle and will be there until you let off.
01-18-2010, 09:16 PM
#49
Been doing searches here using " Ticking on acceleration" and seems header gaskets come up often. We never pulled the gasket to see. Could it be fine at idle and as pressure increase in the header it is an escape thing I am hearing? Since the head gasket compression and leakdown tests look okay I was thinking about buying a set and pulling the driver's side. I guess the MLS do go every so often looking in the archives. This would be nice!
GM dealer or a vendor has the best prices?
Still logging it Wed but does anyone think my Accel noise could be this?
GM dealer or a vendor has the best prices?
Still logging it Wed but does anyone think my Accel noise could be this?
01-18-2010, 10:44 PM
#50
If it were mine i would pull the injectors and have them flow checked!!!!, one dirty or clogged injector can cause exactly what you are experiencing. If it is an injector running lean the next noises you will hear will be pieces of piston ring lands entering the exhaust headers.
If the noise is detonation you can't fix it quick enough. If you have hand held pyrometer you could check each exhaust header to see if you have a lean cylinder also.
If the noise is detonation you can't fix it quick enough. If you have hand held pyrometer you could check each exhaust header to see if you have a lean cylinder also.
01-19-2010, 05:25 AM
#51
True. They were brand new 1000 miles ago though and the car doesn't have 40k miles yet. I'm really thinking it is the header gasket now. Sounds like a couple of cylinders and I remember this weekend wiping some black residue off the header on that side
01-19-2010, 06:51 PM
#52
I had some black stains on #1 and put a new gasket in but that wasn't the smoking gun. I am pretty sure though it is the exhaust and particular drivers collector. I am going to order another band clamp and cut some soft copper for gaskets there.
