Is it possible... good leakdown/good compression but leaks
05-03-2010, 09:52 PM
#1
Is it possible... good leakdown/good compression but leaks A while back I posted about a noise I get from like 2500 RPM up when dropping the hammer. I really thought it was the gaskets on that side. Well nothing there!
We got rougly 210/220 PSI all cylinders.
Pumped up the cylinders and didn't get any notable leakdown.
I'm wondering if it could be poofing through the layers of the Cometic on the left side in the R's. I'm taking it to Fran's shortly to see if maybe an injector or something is causing knock.
Given good numbers could it still be a head gasket? Runs good other than in the R's on the throttle.
We got rougly 210/220 PSI all cylinders.
Pumped up the cylinders and didn't get any notable leakdown.
I'm wondering if it could be poofing through the layers of the Cometic on the left side in the R's. I'm taking it to Fran's shortly to see if maybe an injector or something is causing knock.
Given good numbers could it still be a head gasket? Runs good other than in the R's on the throttle.
05-07-2010, 07:37 PM
#7
Motor problems... lifters, Cometics and unknown
Just read this too, and I'm
One thing - I did read that there were no bubbles in the coolant when you pressure checked it, but have you checked the coolant for combustion gasses? As indicated elsewhere, cylinder pressure will be much higher than pressure in the cooling system.
If you can't isolate anthing else at this stage, it may be time to pull the heads and check the lifters, reseal it, etc.
Good luck!
Just read this too, and I'm
One thing - I did read that there were no bubbles in the coolant when you pressure checked it, but have you checked the coolant for combustion gasses? As indicated elsewhere, cylinder pressure will be much higher than pressure in the cooling system.
If you can't isolate anthing else at this stage, it may be time to pull the heads and check the lifters, reseal it, etc.
Good luck!
Trending Topics
05-09-2010, 04:00 PM
#9
I changed the header gasket on that side and also the collector gasket. Could be a warped flange or something. We are swapping the cam this weekend so going to pull that header again and put a straight edge to it. Inspect it real good visually while it is out.
Usually you get a spike in the water temp gauge if you have hot gas going into the water jacket. None here.
Usually you get a spike in the water temp gauge if you have hot gas going into the water jacket. None here.
05-10-2010, 06:49 PM
#12
My buddies WS6 had a slight valvetrain noise that got progressively worse over time, but were talkin months here. He was going to work and the noise became awful. We brought it back to his house and yanked the heads and it ended up being that the roller broke off the lifter and just the lifter was riding on the cam with no roller. It ended up ruining everything with the chewed up metal being everywhere. I think the roller stopped turning and was just sliding on the cam like a flat-tappet lifter then after time it finally broke off.
and your reply
If that really is the case, either something mechanically let go when it was tuned, or the new tune may be causing detonation, as had been pointed out in the other thread.
Since your gaskets are weeping, you may be best off pulling the heads and looking for signs of detonation. You're going to have to fix that sooner or later, and if you do have an issue with detonation, you need to have the tuner address it before damage is done. While you are there, you can inspect the lifters to see what kind of shape they are in. Whether you pull the cam or not is up to you, as the lifters will tell you what you need to know.
I know you were going to swap the cam, but that really doesn't tell you much unless you find damage to one of the lobes. If that happens, your heads need to come off anyway...
05-11-2010, 07:59 AM
#14
At what point did you fix this? I read the other post from back to front and didn't see that you retorqued the head bolts anywhere.
I had a post about what a failed/failing lifter has for symptoms but got little info. This stemmed from a noise I have picked up on going WOT of a knock/rattle you can mainly hear on the driver's side. One suggestion was to check the car underneath for the exhaust hitting, etc... It hadn't been changed at all from when I did heads/cam/intake but we put it on the lift regardless. Nothing found. Everything looked good and no shiny places like a new hit or anything.
What we did find:
- Driver's side head had ever so slight drip of coolant near the bottom/rear head bolt. I mean very slight. I know this isn't to out of the norm for Cometics sometimes. Should I be worried?
- Nothing abnormal looking in the flywheel area
- No oil in the water. No water in the oil
What we did find:
- Driver's side head had ever so slight drip of coolant near the bottom/rear head bolt. I mean very slight. I know this isn't to out of the norm for Cometics sometimes. Should I be worried?
- Nothing abnormal looking in the flywheel area
- No oil in the water. No water in the oil
05-14-2010, 11:15 AM
#15
Okay so it is acting like my Buick did long ago with a head gasket problem. Today the temp spiked and it pushed out coolant. It's getting combustion into the radiator at certain higher RPM/Loads. So going to strip the heads off, notch the pistons and try again. Hope the block or heads didn't get flame cut.
