Here are the mods I have as far as power is concerned:

Strup Header
TRD Cold-Air Intake

I first noticed a weird rattling sound coming from my engine area when I was in a drive-thru lane with the windows down. Upon inspection, I noticed that I have an intermittent sound that is coming from the top of my engine area. Sometimes it happens when I'm in D or R, and it's just a constant metal-to-metal kind of sound.

I checked all my connections to make sure nothing is lose. I thought maybe it was my dipstick initially and had my brother rev the car to see if I could catch it rattling.

I also removed the engine cover so that I could get an idea of where it was coming from, and it definitely sounds like it's coming from the top of the engine.

I'm at 51,000 miles and have done no other performance mods to my xB. I also have no error codes.

Has anyone heard anything like this before? It's really freaking me out.


EDIT: 1/30/2011
Problem solved! The CEL Eliminator was rattling as well as the connection between the flange and the header itself. See page 2 for details.

Does it only do it when your idling? I know with the tc's the cai piping would rattle against the hole the piping went through when at an idle in D or R. Don't know how they mount in an xB but I suppose it's worth a look.

this sounds like it is definatly your cold air intake. you just have to adjust it so in is not sitting that close to anything. i had the same problem

Does it only do it when your idling? I know with the tc's the cai piping would rattle against the hole the piping went through when at an idle in D or R. Don't know how they mount in an xB but I suppose it's worth a look.
Basically I only really hear the sound occasionally when idling in Park, but I hear it mostly when idling in Drive or Reverse. The mounting process is similar in an xB to a tC I suspect.

this sounds like it is definatly your cold air intake. you just have to adjust it so in is not sitting that close to anything. i had the same problem
What part of the CAI do you think it would be rattling against?

The reason why I don't think it's the CAI I installed is because the sound is literally coming from the top part of the engine. That's where it sounds like it is coming from. And I don't think I had that rattle before I installed the TRD CAI. I rocked my Strup Header for a while, then installed the TRD.

What should I do to fix it? The only thing I suspect might be "loose" with the CAI is the box with the filter. There's only one bolt that holds it, but it doesn't explain why the sound would be coming from the top part of the engine.

I think I know where your rattle is coming from. Everything that you stated applies to me. I also have the TRD intake, and thought that it was the problem.

Check your fuse box in your engine compartment. I was sitting at an idle in drive, with my foot on the brake, and sure enough the rattle started. Open you hood while this rattle is going on, have someone put their hand on the fuse box, and you will notice that the rattle will go away when they do that.

The rubber connector for our intakes barely comes in contact with the fuse box at a low idle, thus causing the rattling.

Hope this helps,

Slugo

I remember a friend who had a TRD CAI on their xB2 and it was installed in a way that the negative battery terminal was very close to the intake and caused rattles upon acceleration. So, check that?

It could also be the latch for the hood. Under the hood you will see rubber stoppers that twist in and out to adjust their height. They may not be extended enough to keep the hood from moving so check those as well.

It could also be the latch for the hood. Under the hood you will see rubber stoppers that twist in and out to adjust their height. They may not be extended enough to keep the hood from moving so check those as well.

This is what it probably is, it sounds like you have the same problem as me. When Im in drive it rattles from the engine bay, when im in neutral it doesnt do it. I adjusted these runner stoppers and fixed the problem. You may want to try and do this...

Hey guys, sorry, I haven't had a chance to investigate the car because I've been super busy.

Basically to give you an update, I'll have the hood open and the rattling is coming from the top of the engine. I took off the engine cover to investigate, and it sounds like it's coming from the top left area of the engine. I looked at all the connectors quickly and everything is seated properly (i.e., nothing appears to be loose).

So I don't even know where to begin. My xB's not throwing any error codes still.

The only mods I have under the hood are as follows:
- TRD Cold-Air Intake
- Strup Stainless Steel 4-1 Header
- TRD Remote Start

Next week I'll look at it for sure, but I'm tempted to reverse those mods and see if the rattling continues. If it does not, then I can trace it back to one of those.

EDIT:
Tomorrow if I have time in the morning, I'm going to investigate those rubber stoppers. The sound happens even when the hood is open, but maybe I'll get lucky or something.

If you get the rattle sound when the hood is open, then it's NOT the hood bump stops.

could be a exhaust leak. tighten everything that was involved with the CAI.

Its the where the header meets the down pipe. I have the same problem.

Ahhh welcome to aftermarket :rofl:

Its the where the header meets the down pipe. I have the same problem.

Ahhh welcome to aftermarket :rofl:
Do you know of a solution to this problem then? The sound really sounds like it's coming from the top of my engine, so are you sure it's happening at the down pipe?

What steps would I take to approach this problem?

P.S. - I'm not going to be able to look at my car until at least next week (maybe this week if I'm lucky). I'm slammed with projects for school.

Double nut all of your flanges.

i have this problem every other day. different aftermarket parts scrambled amongst the engine bay with eventually rattle. and the amount of crap crammed under my hood leaves lots of room for ping and pangs. you just have to find out exactly where its comming from. do you have HID's?? cause the box can cause rattling. CAI pipes against the frame. what pasquale said about the header. and many other little things. you could have left a tool or a bolt under there. the possibilities are endless, and i hate when that happens! but just keep looking yourself. you'll find it. and when you find it, either wrap it in heat wrap, or reposition it to kill the noise!

This is one of those problems that needs hands-on trouble-shooting. Bring your car to me and I'll have a look, otherwise I won't even hazard a guess. Too many possibilities.

Recently my mom thought her Highlander needed a new transmission because it makes a "shrieking sound" when placed in drive or reverse when cold. It turned out to be nothing more than a noisy A/C compressor clutch. Check everything.

Here are the mods I have as far as power is concerned:

Strup Header


Check to see if the s-pipe is hitting the frame. The Strup header is longer than the oem and places the s-pipe closer to the frame cross member.

I wasn't able to tackle the box today (Thursday) because I was waaaay too exhausted from school projects and spent most of the day eating and watching movies. Plus we hit a cold weather snap in Jacksonville and I didn't want to work outside.

So, I'm going to be looking at my box next week. I have a few days off work so I'm thinking of just reversing the mods I installed to see if I can locate the issue.

I'm starting to think it's my Strup Header. But I'm going to remove it and see if that rattling still continues that I hear at the top of the engine.

The blistering cold still hasn't afforded me any time to look at the rattling sound, but now I have a new problem that sprung up today:

I'm showing the Check Engine Light, VSC, and Traction (or whatever the other light is) on my dash. Naturally, this was present when I didn't have a CEL eliminator installed on my header.

But now it's sprung up and I have no idea what the problem could be now.

Because of the seriousness of the issue, I'm definitely going to look at it on Wednesday, regardless of the weather. I need to get this done before any other ramifications ensue.

...I'm showing the Check Engine Light, VSC, and Traction (or whatever the other light is) on my dash...

Check your gas cap and make sure it is screwed on all the way. My dad put some gas in my xB a few months ago, forgot to tighten the cap all the way until it clicked, and the same thing happened to me. After I tightened my gas cap, the warning lights on the dash went away after a few miles of driving. I hope this turns out to be the issue and an easy fix for you.

Good luck,

Slugo

The blistering cold still hasn't afforded me any time to look at the rattling sound, but now I have a new problem that sprung up today:

I'm showing the Check Engine Light, VSC, and Traction (or whatever the other light is) on my dash. Naturally, this was present when I didn't have a CEL eliminator installed on my header.

But now it's sprung up and I have no idea what the problem could be now.

Because of the seriousness of the issue, I'm definitely going to look at it on Wednesday, regardless of the weather. I need to get this done before any other ramifications ensue.

Have the DTC read at Autozone or wherever. It could easily be a P0240 for catalyst efficiency or a P0101 for MAF range. These pop up often with CAI and no primary cat. Even with a CEL eliminator, it's common to get a P0240 occasionally. As already mentioned, a loose gas cap is always a possible cause too.

I had this happen 3 months ago and it turned out to be my engine wiring harness which there is a TSB for. I was 3000 outside of warranty but luckily Toyota said they would cover it. Otherwise it would have been $$$. This happened right as my mpg started tanking and I thought it was cause of that. But since I had the harness replaced, the mpg has stayed the same. Maybe we have something related because you had the lights and you noted in another post that you mpg was about like mine. I'm wondering if the bad harness affects one of the sensors. I cleaned my MAF but no dice.

@Slugo: I'm aware of that trick, but that wasn't the issue.

It was the weirdest thing. All those indicators came on, and then the next day, they were off. And I filled up the xB days ago previously.

Weird. Hopefully on Wednesday I can address this issue if time permits. I think what I'm going to do is remove the Strup Header and put the OEM one back on and see if there's any change in that rattling sound. That should give me enough time to drive it around a bit and see if anything changes.

If there's still a rattle, then I'll remove the TRD Cold-Air Intake and put the OEM air box back on.

Failing that, then it's off to the stealership!


EDIT:
@ScionFred: So I would still get these error codes from time to time even with the eliminator installed? Hrm. I wonder if it just popped up on its own. The error code disappeared as quickly as it came.

@rjjone2: That could be another issue. I always suspected my fuel economy (although not as low as yours) has decreased due to the application of my header. I assumed that with the addition of a performance Header, my mpg would decrease. But then I figured if I added a Cold-Air Intake (which is rumored to add more mpg) it would balance out a little better insofar as reducing the amount already lost. If that makes sense.

If this issue is not resolved when I remove the parts and revert back to stock, then it might be best if I visit the stealership and have them inspect my engine wiring harness. I haven't had any other unusual issues arise, though, so I'm not sure if this is the case. But there's only one way to find out!

i had that but was coming from underneath from the heatshield

That's a lot of work to replace the header and CAI just to find a rattle. You should be able to find it without all that by just listening carefully and looking closely. Feel around the s-pipe and see how much clearance there is between it and the oil pan and cross member, etc. Same thing for the CAI. If either one is less than 1/2" from anything, it could be the cause. Of course it could also be a lot of other things.

Certain DTCs (CEL) are easy to set with the primary cat removed and a CAI. All DTCs cause the check engine, VSC and TC dash lights to come on. Whenever a CEL is active, the ECU disables VSC and TC. If the CEL clears on it's own and doesn't reappear, it's nothing to worry about. The most important thing is to know which DTC caused the CEL. IMO anyone planning to make IHE mods or to fix their own car should invest ~$100 or more in a OBD2 scan tool. Otherwise you can still have the codes pulled and reset for free at many auto parts stores.

A "CEL eliminator" is usually just an extension pipe designed to distance the 2nd O2 sensor from the main exhaust stream. This causes it to sample less exhaust gas and often prevents or reduces the frequency for the sensor to read the increased level of ceratin gases still present because the primary Cat has been removed. It is not uncommon at all to get a P0240 from time to time even with a "CEL Eliminator". Another very common DTC is P0101 for MAF range. This can be caused by a dirty MAS, CAI, turbo, etc.

As for the wiring harness, no need to go to the stealer. Just find the TSB and it states which VIN cars are affected. IIRC the only XBs affected were built in 2007 with AT, like mine. Just find the TSB and check it against your VIN. If you can't find the TSB, just ask. I've seen it and could find it for you, so could many others here.

@ScionFred: So what does it mean when the rattle is coming from the top left corner of the engine, underneath the engine cover? No mods I installed interacted with that area.

All I have are TRD Intake and Strup 4-1 Header.

My CEL fires intermittently, sometimes it disappears, and other times it reappears. I wasn't able to look at my car this week because of my school work load, but maybe next week I can squeeze in some car time. It's been way too cold, and I don't have a garage anymore.

Top left corner could be valvetrain noise but you'd hear that all the time. The only thing I can think of off-hand that might cause a rattle in that area when in D & R would be the motor mount or a loose bracket. Maybe something fell under the engine cover? Tough to say without actually hearing it in person.

I could guess all day about the CEL but you really need to find out what the DTC is before anyone can figure out how to fix it.

could very well be the intake.

So today is my week of PTO from work and I had a chance to work on the car.

The rattling was coming from the top of the engine, so I talked to my brother and asked him about it. He informed me that sometimes sounds in a car do not come from their origin and that it could potentially be bouncing around in the engine bay.

Upon jacking it up and shifting gears with the parking brake engaged, I was able to track the sound.

The sound was coming from the header attached to the flange, and then I inspected it to find that the two nuts I put on there disappeared! Apparently they are not needed for the header though, as the tension springs have stoppers that prevent them from sliding off once they are torqued properly.

Then after feeling more dumbfounded, I accidentally smacked the s-pipe and heard a rattle. So I shook it some more and then located it: the CEL eliminator.

Turns out it came loose somehow and was rattling. That explained why I was tripping error codes periodically.

Further, now that everything is tightened down, the header sounds like it did when I first installed it, and I can feel an immense gain in speed and acceleration. I figure that exhaust was leaking through the flange and potentially at the point of the CEL eliminator.


In essence... problem solved. I feel dumb. :)

Nothing to feel dumb about. You found the problem and fixed it yourself. Good job.

I am really curious about those 2 nuts you mentioned. On my car the spring bolts thread into the flange and there are no nuts. The spring bolts install through the s-pipe flange and thread into the downpipe (header) flange. Did you tighten the spring bolts until the shoulder seated tightly against the flange? This is necessary to provide the correct amount of spring pre-load and prevent the bolts from coming loose. I don't know the correct torque spec but 40-50 ft/lbs should do the trick.

Nothing to feel dumb about. You found the problem and fixed it yourself. Good job.

I am really curious about those 2 nuts you mentioned. On my car the spring bolts thread into the flange and there are no nuts. The spring bolts install through the s-pipe flange and thread into the downpipe (header) flange. Did you tighten the spring bolts until the shoulder seated tightly against the flange? This is necessary to provide the correct amount of spring pre-load and prevent the bolts from coming loose. I don't know the correct torque spec but 40-50 ft/lbs should do the trick.
The 2 nuts I placed because on the OEM header I had two nuts there. So I naturally assumed they just went with the Strup header, too, when I installed it.

I do not thing I tightened the spring bolts enough because they must have come loose. At first I was confused because the spring closest to driver side was shorter than the one closest to passenger side. So I figured that I did not have them balanced, but through deductive reasoning, I realized that the pipe is angled, so the pre-load springs are of different lengths in order to compensate for the appropriate fitment.

Thanks for all your help ScionFred. I really, really appreciate it.

Hmmm... I didn't have any nuts on my spring bolts but mine was an early build (2007). I also never noticed any difference in length between the 2 springs but considering what an imprecise connection this is, I don't doubt it. Despite the pipe angle, the flanges are intended to be parallel to one another and the springs are interchangeable.

Don't worry about over-tightening the spring bolts, the shoulders prevent that. Just tighten them up to 40-50ft/lbs and the springs will keep the connection tight yet flexible.

You're most welcome, as always.