Ok guys, I just finished my stock rebuild, put everything back together and now when I start it everything is ok until about 3k rpm's (give or take) I have a noise; not a grinding, not so much clinking, kinda a rattling but definitely not heat shield rattle. The noise does seem to go away around 5k or so and increases with rpm's. Oil pressure is good, 50psi at start then 25 when it warms up. Vacuum is good, 18-20 inHg and idle is ~850. I do have a cel, 12-61-11-32-55. If I remember correctly, I had 61 before the teardown from my SAFC, and 32 is because of the EGR blockoff. I've checked timing many times, pulled the valve cover and retorqued the head (I read through search that someone suggested that), reinstalled the cams and adjusters and rollers, and lubed it all back up. I do NOT have any shavings or metallic flakes in the oil. I also pulled the cam angle sensor, cleaned it and even tried to start the car with it unplugged (would not start), eliminating that as a problem. My question is, could something be wrong with the crank angle sensor and that could be causing the noise such as making the car detonate due to improper ignition timing from the ecu? Or am I completely off?
TIA
"Anyone who has never made a mistake has never tried anything new." -Albert Einstein
#100671, "RE: noise after rebuild" In response to Reply # 1
You may want to check the bolts that attach the clutch assembly to the flex plate to make sure they are tight. Also check the mounting bolts for the alternator.
#100676, "RE: noise after rebuild" In response to Reply # 3 Aug-27-06 11:14 AM by 96rs-t
I bet your downpipe is loose. Can cause an irritating rattle in certain rpms (as you described), and goes away at the high rpms. I killed myself a few years back on a rattle condition just like yours, looked everywhere, couldn't find anything, finally realized one of my bolts on the dp to my turbo was loose causing the rattle. Sometimes it's the simple stuff that make us go crazy. Best of luck.
SoCal DSM 1996 RS-T: Under Construction 1999 GS AE: New daily driver "USING NO WAY AS A WAY, HAVING NO LIMITATION AS A LIMITATION"--BRUCE LEE
#100856, "RE: noise after rebuild" In response to Reply # 4
Ok, it's none of the above things suggested, thanks anyway guys! I pulled the oild pan, no shavings-no flakes just clean oil. I pulled the rod caps; bearings look just like they did when I put them in. CEL 11 was due to a dirty section on the notched part of the crank, no biggie just cleaned it up with 2000 grit sandpaper.
Put everything back together(again) and drove the car, did some compression braking to settle the rings, and the noise was noticeable when above 2500-3000 rpms (somewhere in there) and appeared to go away around 4300 or so. What else could it be?
"Anyone who has never made a mistake has never tried anything new." -Albert Einstein
#100867, "RE: noise after rebuild" In response to Reply # 7
It sounds like it is coming from under the valve cover near the intake manifold, until I get up close, then it sounds like it is coming from the block. Then when I get under the car it doesn't sound like it is coming from the block, more like the head! I will be doing a compression test tonight to see if it is possibly a bent valve, but there are NO performance issues, idle is smooth and so is driving it (through the revs). When I checked the lifters, I couldn't push any of them down and all of the roller arms were good, no scratches on the roller surface and there weren't any cracks in the arms. Timing is dead on, checked it 4 times, marks lined up every time. I'm lost!
"Anyone who has never made a mistake has never tried anything new." -Albert Einstein
#100868, "RE: noise after rebuild" In response to Reply # 8
This is just a thought. Did you have your head rebuilt? If you did it is possible that the machine shop didn't get the valve stem to seat height correct. If they took to much off the valve stems then there is going to be some slop in the valve train and cause a rattling or ticking sound.
#100881, "RE: noise after rebuild" In response to Reply # 9
ok, here's my numbers from the compression test 205-200-210-197. I put about a quart of mystery oil in before the compression test and it seemed to help with the noise some, but when I drove it after the test, it sounded like it was back.
I did not have the head rebuilt, I had that done back last year. The whole reason I did I rebuild in the first place, which wasn't a 100% rebuild, re-used pistons and rods, just new bearings and rings was because I sucked in some water during a massive rain storm earlier in the year, I bent one rod (did not break it, and the car still ran but you could hear the rod hitting the block) but I replaced that one and the piston as well.
"Anyone who has never made a mistake has never tried anything new." -Albert Einstein
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