mechengrkj Posted November 10, 2013 Report Share Posted November 10, 2013 Just finished rebuilding the engine and have been breaking it in (only about 20 miles so far), and I noticed that at 2000 rpm there is a weird noise coming from the rear of the engine under the valve cover at 2K rpm. It sounds like one of the rocker arms is hitting the sheet metal portion of the rear part inside the valve cover. I took the valve cover off and retorqued all the bolts (head and rocker arms) and adjusted the valves but still makes the noise. I also inspected the inside of the valve cover and can't see any place it would be hitting. The video below is what it sounds like. Anyways, My question is this: what purpose does that sheet metal portion serve? Can I just remove it? If not, what suggestions do you have about how I can fix this noise? http://i1330.photobucket.com/albums/w561/mechengrkj/th_0C5F4DFE-4CDB-4EED-B307-B59C3553B385-630-0000006546E95E3F_zpsfbcfe328.jpg Link to comment Share on other sites More sharing options...
DieHARDmitsu. Posted November 10, 2013 Report Share Posted November 10, 2013 Not sure if I'm hearing right but the noise on that video sounds like a rod knock.Did you check the clearances on the crank before reassembly? Link to comment Share on other sites More sharing options...
Skullzaflare Posted November 10, 2013 Report Share Posted November 10, 2013 I have to agree with diehard sounds like a knock The issue you describe however is a rocker noise, which can be caused but stopped out cam tower bolts (Just chased down mine) but that's not a top end noise you got there Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted November 10, 2013 Report Share Posted November 10, 2013 I had a few sounds like that and they were the licence plate bracket and the fan shroud bracket. So check all you brackets first Link to comment Share on other sites More sharing options...
mechengrkj Posted November 10, 2013 Author Report Share Posted November 10, 2013 The machine shop that did the engine work supposedly had checked that. Can I check clearances with the engine still in or do I have to pull it again? Link to comment Share on other sites More sharing options...
Dad Posted November 10, 2013 Report Share Posted November 10, 2013 Normally the assembler checks the clearances. Link to comment Share on other sites More sharing options...
tsi_tom Posted November 10, 2013 Report Share Posted November 10, 2013 Why did yo rebuild the engine in the first place? To me it sounds like a rod knock. Link to comment Share on other sites More sharing options...
Skullzaflare Posted November 10, 2013 Report Share Posted November 10, 2013 i wouldnt run it any more until you find outhow is the oil pressure? seems like you might have a turned crank with standard bearings Link to comment Share on other sites More sharing options...
mechengrkj Posted November 10, 2013 Author Report Share Posted November 10, 2013 Looks like I need to provide a little more background info...I rebuilt the engine because I found metal flakes in the oil and discovered that the main and rod bearings were both hashed because the PO starved it of oil. My dad knows a guy who does a really good job with block work (who lives 400 miles away) who planed the deck, head and honed the cylinders. When inspecting the engine he found that the crank was pitted so we bought a new one and he machined it into spec. My dad then brought the engine up to me and we assembled it. We didn't check the tolerances because we have no way to check the tolerances and am working out of a garage that's really just a storage unit barely large enough to fit my car into. That being said, I need to specify a little better what the problem is. The knocking sounds ONLY happens at 2K rpm. The rest of the RPM range sounds fine. Could it still be rod knock? All the rest of the vitals seem fine. Oil pressure is at 90psi on my aftermarket gauge. AFR's are a little on the rich side but still fine. Now, with all this new info that I should have stated before, any suggestions? Link to comment Share on other sites More sharing options...
Skullzaflare Posted November 10, 2013 Report Share Posted November 10, 2013 new cranks dont get "machined to spec"to me, that says he turned it down 10/20/30 and you most likely installed std bearingsalso depending on this oil starvation, its possible the rods may have been heated at the journals egging them. what is your hot idle oil pressure? i had a rod knock on a past motor, fresh rebuild went out at 1200 miles. machine shop egged my crank Link to comment Share on other sites More sharing options...
Malykaii Posted November 10, 2013 Report Share Posted November 10, 2013 When I swapped pistons/did a bearing roll... I had the shop pressing the pistons check the roundness of the rods. They had to touch it up cause of flat spots. Link to comment Share on other sites More sharing options...
Malykaii Posted November 10, 2013 Report Share Posted November 10, 2013 What I think he means is he got a different crank, aka a used one. Then had that one turned. Correct? What bearings and size did you use for the rod and mains. Link to comment Share on other sites More sharing options...
Dad Posted November 10, 2013 Report Share Posted November 10, 2013 (edited) Plastigage needs no tools. Did you clean out the oil cooler and lines , that old metal trash from the failure will get washed thru your new bearings if you didn't, whats your oil pressure reading hot at idle? Still have balance shafts? Knock only after warming up? or all the time? louder when cold or hot? Dad Edited November 10, 2013 by Dad Link to comment Share on other sites More sharing options...
tsi_tom Posted November 10, 2013 Report Share Posted November 10, 2013 For example when I tried to flush my oil cooler I used compressed air and kerosene first. This is what I found: http://www.starquestclub.com/forum/index.php?showtopic=137174&hl=%2Bflushing+%2Bthe+%2Boil+%2Bcooler Link to comment Share on other sites More sharing options...
mechengrkj Posted November 10, 2013 Author Report Share Posted November 10, 2013 As far as I know it was a new crank. I cleaned the oil cooler out (had a ton of junk in it). The oil pressure at hot idle is about 60psi. No balance shafts. Knocks all the time but is louder when warm. Link to comment Share on other sites More sharing options...
mechengrkj Posted November 10, 2013 Author Report Share Posted November 10, 2013 Also, the shop said that they inspected the rods and they looked fine. Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted November 10, 2013 Report Share Posted November 10, 2013 As far as I know it was a new crank. I cleaned the oil cooler out (had a ton of junk in it). The oil pressure at hot idle is about 60psi. No balance shafts. Knocks all the time but is louder when warm.60psi? is that when the primary fan kicks on and at 850 +/- rpm Link to comment Share on other sites More sharing options...
mechengrkj Posted November 10, 2013 Author Report Share Posted November 10, 2013 Yeah I think so. I don't remember exactly what it was but I know it was higher than before the rebuild which was about 40psi hot. Link to comment Share on other sites More sharing options...
mechengrkj Posted November 10, 2013 Author Report Share Posted November 10, 2013 Cold pressure was 90-95 psi. Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted November 10, 2013 Report Share Posted November 10, 2013 (edited) hmm that just seems a little high, warm idle should be around 20psi with no balance shafts and your cold is normal I think Edited November 10, 2013 by 88-cnqst-tsi Link to comment Share on other sites More sharing options...
Skullzaflare Posted November 10, 2013 Report Share Posted November 10, 2013 Cold pressure was 90-95 psi.im running a 130k bottom end WITH balance shafts. cold start idle is 85, hot idle 20 hot idle is what is important(this is on 10w30) Link to comment Share on other sites More sharing options...
mechengrkj Posted November 11, 2013 Author Report Share Posted November 11, 2013 I failed to mention before that the PO had wiped the cam lobes by not seating the camshaft correctly and by starving it of oil, then taking sandpaper to the journals to "clean" them up. The machine shop rounded them out a little to clean them up but not a lot because you could still see the slight grooves from previous damage. Is it possible that the noise is coming from the cam having too much play in it causing this noise only at 2000 RPM? Link to comment Share on other sites More sharing options...
Skullzaflare Posted November 11, 2013 Report Share Posted November 11, 2013 I failed to mention before that the PO had wiped the cam lobes by not seating the camshaft correctly and by starving it of oil, then taking sandpaper to the journals to "clean" them up. The machine shop rounded them out a little to clean them up but not a lot because you could still see the slight grooves from previous damage. Is it possible that the noise is coming from the cam having too much play in it causing this noise only at 2000 RPM?sounds like you need a new headbut no, a cam will not cause a rod knock noise Link to comment Share on other sites More sharing options...
Starfighterpilot Posted November 11, 2013 Report Share Posted November 11, 2013 Did you get a "build sheet" denoting the engine clearances and "machined to" specs, from the guy that did the machine work? You said in reply #9 that the block was decked. How much did he deck it - the max is 0.008" ? That could be the cause of the noise if to much was decked off of the block. You also said that he "surfaced" the head. How much did he machine off of it? Did he exceed the head height limit of 3.535" ?I suggest that you read FSM Pages 9-42 and 9-67. For What It's Worth. KEN Link to comment Share on other sites More sharing options...
mechengrkj Posted November 11, 2013 Author Report Share Posted November 11, 2013 (edited) Did you get a "build sheet" denoting the engine clearances and "machined to" specs, from the guy that did the machine work? You said in reply #9 that the block was decked. How much did he deck it - the max is 0.008" ? That could be the cause of the noise if to much was decked off of the block. You also said that he "surfaced" the head. How much did he machine off of it? Did he exceed the head height limit of 3.535" ?I suggest that you read FSM Pages 9-42 and 9-67. For What It's Worth. KEN No he didn't give me anything like that. Unfortunately the block had work done on it previously with no info to be found so it's possible that he took more off the deck than he should have without even knowing. I'll talk to him though and find out. Thanks for the tip! Edited November 11, 2013 by kylejones Link to comment Share on other sites More sharing options...
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