Engine Knocking from where?

[ArcaineGST]

It started about 3 weeks ago and happened while I was driving home from work. I was just driving normally and it was only city driving. I first heard the noise when I would let the car float down from over 3k rpm only. By the time I made it home it was making the noise only over 2500. The next morning I had my uncle who has been doing mechanics for 20+ years listen to it, and it now did it at idle.

I jacked the car up and started the process. I found no shavings in the oil pan or on the sump. The rod bearings looked fine and the crank still looked perfect, no scratches or anything. Three of the main bearings however had wear that looked like lack of oil (overlay wiped out), according to our buddy Haynes. Two days ago I finished putting the bottom end back together with new ACL Race Main Bearings. I torqued all the bolts to spec and started the car and it didn't fix it. It still knocks the same and now I'm lost again.

I've read numerous threads and I still don't know what it could be. If you guys have any input I would appreciate it a lot. Thanks in advance.

 

[crimsondragon]

Can you pinpoint the noise? If it's at the head, it could be lifter tick. Check all four cylinder walls from beneath to make sure bent rods are slapping the cylinder walls.

 

[pj91gsx]

I would say check the balance shaft bearings. did you replace them or did you eliminate the balanceshafts?

 

[ArcaineGST]

It's tough to pinpoint. When you stand over the engine it sounds up top, and when you roll underneath it sounds bottom. Before we started we listened with a mechanics stethoscope, and that's why we took the bottom apart first. When I had the bottom open during the main replacement I checked out all four cylinders from underneath and didn't notice any wear on any of the rods. I'm pretty sure I and/or my uncle would have noticed if a rod was bent too, but we could have missed it. I'll double check since I'm most likely going to have to open it back up.

I haven't done anything with the balance shafts. You think that might be the problem? If I'm gonna have to take the bottom end apart again how long/hard is it to do the balance shaft eliminator kit? And I can do it with the engine still in the car correct?

Late tonight or tomorrow I'm probably going to check the valves. I've taken the VC off and there is no noticable damage, but the springs need to come off to check for a broken/bent valve rod.

Jim

 

[pj91gsx]

make sure its nothing like the power steering pump low on fluid. Mine was low and rattled like a spun bearing sound.

 

[dsmmaniac12787]

Check your harmonic balancer/dampner/crank pulley...whatever you wanna call it

 

[crimsondragon]

Harmonic balancers squeal when they're going out the door.

The balance shaft elimination will probably take a good whole day with a case of beer. Depending on your skill and experience it might take less time and yes you can do it with the engine still in the car but it's much easier to do it out of the car.

 

[dsmmaniac12787]

Well I speak from experience. Dont know if it was just really messed up or what but mine was going out and It sounded just like a knock. Put a new one on and it quit...

 

[ArcaineGST]

Well, here's a picture of that guy. Everything appears to be just fine. Tomorrow I'll take a video and post a link to it.

Thanks for the suggestions so far guys.

 

[crimsondragon]

Can you manually turn the crank and make that noise?

 

[Colt4G63 also]

Well, here's a picture of that guy. Everything appears to be just fine. Tomorrow I'll take a video and post a link to it.

Thanks for the suggestions so far guys.

ARE YOU SURE THAT'S FINE? THE RUBBER LOOKS TORN TO ME!

 

[91tizzy]

Harmonic balancers squeal when they're going out the door.

no not the case typically....had a friend who had his motor rebuild because it sounded like it was knocking...not a very intelligent friend when it comes to vehicles....then the sound came back one day really bad and it threw the crank pulley...without ever sqealing...turned out that was the original problem

 

[Shadow21]

I had a similar problem with my galant. So i pulled the motor out cause it sounded like it was the oil pump. Turned out to be my timing belt tensioner. I would check that as well.

 

[ArcaineGST]

By fine for the crank pulley I mean that it doesn't look like the center has pushed anything out of place, but yes the rubber is worn.

As far as the video goes, I took two, and the audio picked up all the engine noise and you can't tell the difference between the sounds when watching. However, this time I was able to pinpoint the location of the noise. It is in the bottom of cylinder 4, and it speeds up as the RPMs increase too.

When turning the engine by hand it doesn't make the noise/knock from cylinder 4, but it get tight and difficult to turn at one point and a there is a creeking noise that is coming from the valvetrain over cylinder 1 by the cam gears. It gets tough to turn whenever cylinders 1 and 4 are at TDC and BDC I noticed.

 

[ArcaineGST]

Figured out what the noise was. Flywheel bolts came a fraction of tight loose. You can see it move, but you can just barely feel it. Ohh yeah, and my Fidanza 3.2 Kevlar disc wore out after 6500 miles. By worn out I mean that one side of the disc has the pads worn to the bolts. The 3.2 kit is the 4 puck kelvar disc. Needless to say, everything is going to be cleaned again, and I get to install another new clutch kit. Probably won't be another 3.2 Fidanza.

Thanks for all the help trying to guess what it was guys.

 

[ArcaineGST]

Here's those images of the damage not resulting from the loose bolts.

 

[Colt4G63 also]

I would be sure to take a closer look at that harmonic balancer too. If you look at the rubber ribs on the inside surface that extend inward from the bottom of the letters:"34231T". I believe those ribs are supposed to be continuous with the rubber part of the balancer. I also believe that if you look more closely you can see a seperation there at the bottoms of those ribs. That usually indicates that the outer ring of the balancer has spun. Check it out; you may find it worthwhile. Harmonic vibration can ruin your crankshaft, and your day.

 

[Tim Melton]

I'll bet it's the tming belt tensioner or the water pump.

 

[ontario AWD]

just wondering if you were running the fidanza flywheel as well?

 

[Colt4G63 also]

I'll bet it's the tming belt tensioner or the water pump.

He already said it was the flywheel coming loose. I just wonder if sonic vibration could have loosened it. After all, Dr. Who performs monumental tasks with his sonic screwdriver.WTF

 

[ArcaineGST]

ACT flywheel. I didn't want to deal with a possible warping or falling apart flywheel. Funny thing was with mine, is that the bolts were all still in pretty tight. I didn't really have to break any though so I know that the locktite i used was either old, or didn't set up by the time I went out for the first run. Ohh yeah, and I put the ARP flywheel bolts in with it too. Not sure if that was the problem, but I didn't want this to happen, that's why I used them. However, I guess I can blame something if I ever get angry about the situation.

I'll check out the front of the engine again. Colt, thanks for the heads up on what to exactly look for. I just compared it to pictures from a tech article before. If it needs to be replaced, would you guys suggest getting a new one(HB), or just swapping it with an aluminum underdrive pulley from MachV or something similar?

I was trying to decide between the ACT 2100 or SPEC 2, and just decided to go with the ACT and mate up ACT flywheel with ACT clutch. That way I know that they've measured the stepping and made everything bolt up. Plus, I've had my experience with a short lived Kevlar disc and feel like having a clutch for a few years this time instead of a few months, .

 

[ontario AWD]

Good choice on the ACT setup.There is a lot of conflicting interest on the solid underdrive crank pulley,especially if you are not running balance shaft's.I did the whole ## pulley set on a stock TSI of mine and noticed a good diference in power.

 

[ArcaineGST]

My balance shafts are still in as I didn't want more work when I replaced the mains. So maybe it's for me? Would the underdrive cause the BS to wear quicker, or?