Engine Rattle

[fsu99gsx]

I have a loud rattle coming from what I believe is the timing side of the engine or the front is actually where it seems loudest. It is very annoying but the car does not seem to be affected in any way other than the rattle is very annoying. The noise started sometime while I was driving my basically new motor around to break it in and tune it. The rattle will happen at idle while the engine is around 3,200 rpm. It will not happen when the car is first started hot or cold. It takes about 2 to 3 minutes then it starts to rattle a little until it gets loud within 30 seconds. It will constantly rattle if held there and will also rattle around that rpm when you rev the engine up. It also does it while driving the car at that rpm.

The whole motor has 1,000 miles since complete rebuild.

Ok let me start off by telling you the huge list of things i have already done.
- ALL timing accesories including belt, pulleys, tensioner have been replace with new oem
- New oem main pulley/harmonic balancer
- New oem oil filter housing

- Taken the Bushur built head off and a very good local machine shop took it apart and checked everything and reassembled it saying everything was fine. They suggested changing the lifters but I don't think that could be the problem since I have 3g big bore lifters. Trying not to waste any more money on things that are not the noise.

- Checked and rechecked every bolt I could think of under the hood.

- I have aem so I ran the car with the turbo out of the car, alternator out of the car, power steering disconnected, water pump belt off, pulleys off.

The reason why I don't think it is something outside the motor is because it only happens at this certain rpm and after the car runs for 2 or 3 minutes.

If I left out any info that would be helpful in helping me find the source of this rattle let me know and I will let you know but I think I pretty much said it all.

Again like I said the car runs fine boosts great. Everything works and is good besides this horrible noise. Please help me this has been going on for months and I have taken many steps to try and fix this noise but all have failed.

Im thinking maybe it the oil pump but why would it only have this rattle at a certain rpm and not higher rpm too. Same thing with anything being wrong in the bottom end. Why is it only at this rpm and not at higher rpm an also why does it take 2 to 3 minutes for the noise to start and does not do it immediately?

Oh and I also want to add that this noise sounds like a thin bracket or some pingy metal sound. Does not sounds at all like it would be described as a tick or a knock but since I have not been successful in finding the source of the noise yet I will not rule anything out for sure.

Sorry for the looong post but I just want anyone trying to help me to see that I have tried alot already and also help eliminate some possibilities.

 

[TwoLiterLaser]

If it only happens at a certain RPM then you can safely deduce it is not any physical piece of the engine making the noise as any bad bearing would make the noise constantly and at all RPM's.

Do you have a logger? You said you are running AEM EMS, so maybe, jusy maybe something with your tune is out at that RPM and it only happens once you get some cylinder heat. I am not familiar with AEM EMS; I am only speculating.

When you had the head off, did you check the valve cover baffles? I don't know why one of those would make noise at only 3200 but you never know...

 

[fsu99gsx]

Yeah I hear you on the bearing thing. From all the threads Ive read it seams to me that if it were a problem with the bearings or rods it would be even louder at higher rpm not go away. But Im not ruling out something in the bottom end yet because Ive messed with EVERYTHING outside the motor I can think of including all brackets and the head just got checked over.

To answer the baffles in the valve cover question Yes I did check the valve cover. All of the rivets seemed to be still holding tight. I could hear a kinda a real low clicking noise when I shook it fast but I have another valve cover that I was going to put on instead to see if it was causing the noise but it made the same noise and all its rivets were tight so I figured that wasn't it.

To answer the question about aem and logging. I don't know how to tune with the AEM I guess I never really thought it could be something with the tuning. I didn't want to bring the car back to the guy who tunes my car to get more tuning until I figured out what this noise was first cause I thought it was something major and didn't want to destroy the engine. When he was tuning the car to get it to run and be drivable. He did say the logging was showing some knock and it might be picking up that noise. That was months ago and we both thought it was some stupid bracket that I would find and tighten.

My friend who's worked on alot more of these cars than me thinks the oil pump might be bad but it doesnt sound whining like people explain in threads.

 

[PieEyedPiper]

I've heard of the timing tensioner doing odd things like that, even when brand new (broken, but new). Just something to check.

 

[TwoLiterLaser]

If you had a logger we could look at it real quick and see if it is in fact knock.

Chasing after the oil pump or engine bearings can get expensive and take a good deal of time to replace.

Do you know anyone that has a logger or something you could borrow?

 

[fsu99gsx]

I am going out of town and won't be back until after the weekend. I will see about getting a log and posting it online. Im pretty sure the aem can log. Also I am going to make a video of my car and the noise and get a friend to put it online for me so you can actually hear this noise.

It really sounds like it is a noise that is coming from something outside the motor but then why is it only at this certain rpm and why is it still there when I practically remove everything. Also why does it not do it immediately upon start up. It seems to be heat or oil pressure dependent.

 

[TwoLiterLaser]

It seems to be heat or oil pressure dependent.

That's what I was thinking, but if it were oil pressure dependent then it would most likely occur immediately ofter start up when the oil is still cool and thick.

 

[fsu99gsx]

I found the source of my noise. When reasembling my car I noticed some cracks in welds. I have a DNP exhaust manifold and it has 2 braces in a v shape under it that brace the turbo. The welds on both sides had completely cracked though on the motor side welds. I can't believe it but the noise is gone now that I had those welds repaired. I don't know why it only made the noise at a certain rpm. Crazy but atleast it's gone now and it didn't turn out to be anything serious or hard to fix, just really hard to find.

 

[BlackMetal]

I got a 90 GSX 213k miles
rebuilt head, trans (some gears are grinded from noob driving)
Dejon intake
2gMas
14b ported wastegate
findanza clutch (feels like a 2600)
3in exhaust
dump O2 pipe
560 injectors
everything else is completely stock

I have somewhat the same problem. Except I got stuck in the snow and the same rattling sound is so loud that it pulls on the motor speed to about 500 rpms then stalls the motor.

There's a junk yard in the back of my parents garage and it was never shoveled out from the winter snow. Tuesday, I decided to back the car in for the night in the garage and that's how I got stuck. I litterally tried everything to get the car out, which would include pretty much beating on the motor . When I mean beating on the motor, I mean but I was boosting 10psi at 7k RPMs to get out of the snow (I know it was a dumb idea, but it worked half of the time). Well, in the end, I found some boards in the garage and set them near the tires and got out of the snow. After that, there was this burning smell of tires, and not only that, but some other smell I just couldn't name.

After I got the car out of the snow, I just let the car idle for a lot while hoping the damage wasn't too bad. Then, when I came back to check on it and start it up after letting it cool down, the rattling noise began that same day (Tuesday). Today it's been doing what was posted earlier, it doesn't start up until a certain rpm, then the motor sounds like it's being pulled down by that rattling sound and then stalls out the motor.

My next question is how bad do you guys think it is and how much damage have I done? I know I sound stupid and probably don't even deserve this car, but I'm really trying my best to maintain this car. I would complain if I had the tools and equipment to work on this car, but I wasn't even expecting to get stuck in the snow and I bought all season tires and still can't figure out how my car got stuck in the snow. I just want this car to run right...I guess I made a fool of DSMers.

Please help.

 

[97GSTAUTO]

Video Clip?

 

[BlackMetal]

Video Clip?

Unfortunately, not this time, I lost my camera about a month a ago. Basically the car starts fine, but a little while after, the motor begins to make a rattling sound and it comes from the timing side. Then the sound progresses and gets louder and the motor slows when it gets louder, then the motor completely stops running.

 

[Dsm2Nv]

This happen to me also after a 6 bolt engine swap and it ended up that the rear tranny motor mount had loosened up check all the motor mounts.

 

[BlackMetal]

Are you sure, because I didn't do a simple 6 bolt swap, I was stuck in the snow and literally (childishly and sadly) raped the motor to get out of the snow.

 

[Defiant]

http://www.dsmtuners.com/forums/pro...-just-time-pics-video.html?highlight=harmonic