jbod

no big deal really. someone said they changed the motor mounts, and it still didn't fix it or get rid of the vibration. i'd just deal with it. the airbox won't fall out or anything.

Traildog

True, A lot of time and effort could be devoted to this problem but is it worth it?. I attribute it to a design flaw. Strange since the BB model (same car I guess) was driven in Japan before coming to US, some modification was not developed by Toyota

jadeT

My airbox assembly does the same but not the engine itself.

RiversideS13

Have you try to install ground wires set? It will make idle smoother, at least in my cases and past cars

RichBinAZ

My son's XB engine is vibrating quite a bit at 60K miles, we fixed a lot of the issue by simply replacing the spark plugs, which were eroding. I think the coils must put a lot of power thru the plugs.

Anyway, it idles fine, but put it in gear and off it goes. The revs drop and the vibes start. Today we tried an experiment with the idle stop screw, until we can figure out what is really going on.

The idle stop screw is under where the throttle cable runs in the front of the engine bay. It has an 8mm locknut and a tiny internal hex screw with a paint stripe on it. NOTE: If you are going to try this, beware of the fan, it can come on at any time and you will be very close to it.

With a long allen key in the screw I loosened the 8mm nut with a small ring spanner. Then I turned the allen key 1 full turn clockwise, held the screw in position with the allen key and tightened the lock nut. (we tried this 1/4 turn at a time and 1 turn seemed best)

This raised the neutral idle to almost 1000rpm instead of the 900 it was reading before and also raised the idle while it is gear so that the vibes are reduced. I think he said it drops to 750 or something like that.

The key thing about this is: It's easy & it's reversible, if you don't like the new setting for any reason and it does reduce the shaking.

We need to find a proper cure, which may be the idle air valve on the bottom of the throttle body - or something else...

amec2ldo

Hello all. Thanks for all the great info regarding engine vibes at idle. I have a 2004 xA purchased as a repo in 2008. It was my daughter’s until very recently, so I wasn’t aware of the problems. The first thing I found (thanks to this site) was the common problem of the hose not secured in the clamp on the firewall. A few posts indicated it was a fuel line, but it’s actually a vacuum hose running to the vacuum switching valve (VSV) that hangs on the side of the air box. The hose wouldn’t stay in place, so I secured it with two plastic strap ties in an ‘x’ pattern (each one routed behind the firewall clamp in different directions).

Now for the loose air box that plagues our cars. The problem is three worn rubber bushings where the bolts pass through the bottom of the air box. For easy access I completely removed the air box cover by:

1. Disconnecting vacuum hoses on both sides of the VSV.
2. Disconnecting electrical connectors to the VSV and to the MAF. You can also disconnect the wire harness clamp with a pair of needlenose pliers by the pinching plastic clips where the clamp is attached to the air box cover.
3) Disconnect the large vacuum hose attached to the rubber air intake duct. Loosen both clamps and remove the air duct.
4) Pull the intake duct from the bottom of the air box. This is the harder plastic duct running from behind the left headlight. No tools required and no need to remove the duct completely…just work it side to side while forcibly pulling one end from the bottom of the air box.

Unless I left out a step, you can now undo the air box cover clips (for access to the air filter) and remove the cover. I found it easier to remove the cover by leaving the filter in the air box. Now remove the air filter and voilà – three bolts! Now move the air box around and you’ll see how loose it is on the bushings. You can’t tighten the bolts because of the steel sleeves in the bushings. My first inclination was to just remove the sleeves. After reinstalling the bolts I saw a noticeable difference. What I didn’t like was the bolts weren’t that tight without the sleeves installed (no metal to metal contact). Tightening them too much would further destroy the bushings. I made a few attempts to reuse the same bushings and sleeves with washer stacks, etc., but I still wasn’t satisfied. I also learned the bushings aren’t sold separately…you have to buy the WHOLE air box at $260!

I stumbled across the final solution at AutoZone. I took a chance and paid $3.99 for Dorman wiper motor bushings (part number 49450). Unbelievably, they came as a set of three – exactly what you need for the air box. They fit like a glove! To see what I mean, leave one of the old bushings in place and install one of the new ones in a different hole. The old bushing is a very sloppy fit, the new one doesn’t move at all. So I installed all three new bushings. I also used the new steel “hat” sleeves that came with them by installing them from the bottom up. I realize two of the three original steel sleeves aren’t like the new ones, but trust me when I tell you the new ones work well.

Then I reinstalled the air box and tightened the bolts firmly. What a difference! I put everything back together (after cleaning the MAF) and took it for a ride. I will tell you it didn’t take care of all vibes associated with these small engines at idle, but it made a VERY NOTICEABLE DIFFERENCE! Let me know if this helps!

mseriously

I definitely think you're on the right track here...I will be messing with my box this next weekend and plan to try what you did...I pretty much tracked the problem down to the exact area you already seemed to have fixed...

I also wonder if the throttle cable becomes a bit stretched with age...would be curious to see what "new" 1st gen xb's idle at when in gear.

unlocknick

Have a 2004 XB one day noticed airbox rattling more then usual. Finally tried to fix after reading about wiper blade bushings from autozone. Bought some over the weekend installed and there is a 50 % reduction in vibration. It is now manageable. Dont replace anything else until you replace these $6 dollars bushings. All else is a waste. Still a little vibration but nothing like before. Had to take the time and post because the guys who gave me the tip saved me tine and money. Thanks XB Brothers!

kidkamel

So this is all happening with the stock air box, for the intake, right? If so what would cause it if you have an aftermarket intake such as a K&N Typhoon?

A little back story, owned my '04 xB since Oct of '03. I currently have 133010 miles. Continued regular check ups and continue to get the vibration. It doesn't only happens with the A/C on as it just happened while I'm typing this reply on my phone while sitting in my car, with the engine running waiting for my wife.

Not sure if the ground web kit will work as I've had it since 2004. As for the motor mounts I've had them replaced and still receive a jolt here and there.

I left today from Toyota as it's a "Classic" as the forums calls it. I want certified technicians working on it. Plus very little auto mechanics where I live. They are stumped as well and not sure what would cause it.

I've cleaned out the MAF and this weekend I plan on getting the throttle body cleaned.

Not sure what else to suggest and if it's just a thing it's just a thing.

casualride

On my 06 xA, I had a death rattle at idle while in gear and a/c on for a while. I thought it was the airbox so I bought a K&N typhoon CAI thinking that it would help. After installing the CAI it didn't improve the rattle at all. I found my cure while fixing up my squeaky serpentine belt. I tightened the belt and the squeaks and the death rattle was gone!

RichBinAZ

In another thread somewhere, I did take off the intake manifold and cleaned out the idle air circuit - which was pretty clean in the first place - That seems to have smoothed out the rattle a bit more, enough so that I could reduce the idle speed back down to something more reasonable.