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Fresh rebuild has high squeeky noise


softopz

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I just rebuilt my l28et I got it running last week with ms2 for first time. It idles nice and I still got lots of tuning to do. Soon as I rev anything over idle a large squeeky noise comes out of front timing cover. Sounds like a belt but its actually in the motor. Iam pretty sure its the timing chain tensioner I think its too close. I used all new parts however when Iwas rebuilding I fealt something was not right. Is the tensioner controlled by oil pressure? I remember a spring a little ball and that block. Anyone want to shed some light this way would be great. Looks like Ill be having to cancel tuning for now to go this corrected.

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The timing chain tensioner can fall out REALLY easy when you're putting the chain back on. Maybe it didn't seat back right and you didn't notice before putting the car back together?? I actually fashoioned a wedge shaped block of wood and jammed it in between the two sides of the chain to hold the tensioner in whilst working on the cam last time. Worked a treat. Put a little string on it so i could pull it out when i was finished without taking the front cover off too, saved a lot of hassle.

 

I would think something like that would squeek all the time though, so I'm not too sure.

 

The tensoiner is a block mounted to a rod that sits in the front of the engine and has a spring pushing it out. Kinda like how a pen spring works, where the spring forces the top of the pen back out. The tensioner can come out of its hole and the spring flicks off, or even just jams the tensioner. I had this problem about 3 times the first time i tried to put my motor back together.

 

I know you said its coming from the timing cover but is it maybe the fan belt? Just throwing up options here...

 

I'd check it out. If the tensioner fell off, or the distributor gear snapped (i've done this one :P) it can make a real mess of your engine as it ruins the timing and you get MASSIVE pinging. Like the spark plug sparking still well into the upstroke.

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The tensoiner is a block mounted to a rod that sits in the front of the engine and has a spring pushing it out.

 

yes I know what the tensioner is I just put together the motor. I was reading the manual and it says the tensioner is adjusted and operated by oil pressure, however I dont remember seeing that much complexity.

 

Dizzy gear that sounds interest could be. Well theres only one way to tell tomorrow Im removing it and going to sping the crank pulley manually and see what comes out.

 

Question. Since Iam running EDIS does it matter which postition my oil pump shaft/dizzy shaft is inserted. I will still do it per manual Just in case it pumps/sprays oil at a certain time.

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I shot a video of the noise Turning by hand and a little of the datsun garage Non running

Here is the link. http://www.youtube.com/watch?v=SmqTZ8o-7rU

 

Here is the link the sound comes High squeel. This one is running.

http://www.youtube.com/watch?v=PewmUqUoFEI

 

What you guys think?! serious?

 

So last night I pull out oil pump, dizzy gear and then turn by hand. Still squeeks ok.

Removed cover , tensioner and chain guides still Squeeks. Looks like its coming from the crank possibly a main bearing? This really sucks I just rebuilt it I used all new parts (rod/main bearings, pistons, piston rings/pin, ARP hardware) Today I put everything back on what a Joy that was.

 

Im so pissed hopefully it goes away during a good run or two; when I get ms tuned properly. When it was on the engine stand during the rebuild, and after dropping the motor in running with the original l28et eccs I didnt hear that noise. Could it be I messed up bearings from too many attempts at starting with ms2 gas flooding?:S

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I have a similar sound, my 300zx does something like that (and i noticed onefast87 mentioned in your video comments that his does too).

 

I'm not sure what it is at this point, but I narrowed it down to something near the front of my engine making a whistly sound, and if i hit the front cover a couple of times it will go away or it will go away on its own too sometimes... so really I'm not sure, but I hope it's nothing too major.

 

Do you think it could be a cam journal or something not getting enough oil? How hard is it to pull the cam and inspect for wear?

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How hard would it be for you to replace the water pump? sometimes the bearings in aftermarket water pumps are terrible out of the box. but the sound you get from hand turning and what seems to be the high pitched running sound seem like 2 different things to me. alternator belt too tight?

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I have heard a similar noise before about ten years ago. On a fresh rebuild of one of my L28's, the first cam tower was not getting any oil. I tore the top end apart and found a small metal shaving in the oiling hole of the tower. after cleaning all of the oil passages again, the noise was gone. Luckily the tower and cam were OK. That motor is still driving around today, although not with me. Maybe check for proper oiling on the top end.

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Its not anything external I shot the video with out alternator waterpump and fan pulley.

My oil pressure is good, I remember getting plastigauges for the machine shop because they bored/honed the block. They said it was good he gave it back to me with the crank in. Then I put the rest of it together.

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Im pretty sure a good run or two wont fix the problem. I would think if it was a bearing, you oil press would be high or not there at all. I would pull the chain and rocker arms, yank the cam and inspect, and rotate the bottom end without the cam installed. If the noise is coming from the rotating assy, looks like your pulling the engine again to find it. Or...you CAN run it till it stops turning then figure it out.

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