Whistle noise from sunroof - 2004 Lexus GX 470

There are basically two types of whistle noises.

* Whistle when you get more gas (increase RPM, put gas pedal, sometimes just idling but louder when you put more gas)
This usually intake-side leak.
Intake manifold itself, intake manifold gasket (most likely), even airfilter housing, Airflow meter housing (connector), anything where air goes to engine.
usually engine get rough or unstable idle when intake leak occur.
Engine knocking or pinging may feel.

* Whistle when you decrease RPM (engine brake, reduce speed, sometimes just idling but louder when it dropping RPM)
This usually Vacuum-side leak.
There are many vacuum hoses in engine room. even inside of cabin (heater control, etc)
Try to spot where it coming from.
Vacuum also connected to Brake servo, heater control and spark timing.

Put metal or plastic pipe (small PVC pipe will work fine) to one of your ear then isolate source of noise and find where it come from.

They say replace because it is more money for them. Lots of work to replace them. Replacing the seal around the window is much easier. Even easier is shutting it and sealing the top with silicone. The seal will run between $150 and $200. I don't know why they are expensive, but this is about as cheap as I can get them.

Hi Gary,

Apparently there has been some 'alignment' issues with the sunroofs coming out of Cadillac. As noted in the attached thread, the dealer can perform an adjustment which eliminates (reduces) the windnoise.
08 CTS Sunroof Fix Wind noise when closed

Good luck

does it have a wind sheild that comes up when sunroof open has it done this all the time if not there should be a small wind shield that pops up when the roof opens if it has none you can buy a wind reflactor for a few pounds which atatches to sunroof

a leak in a hose or a bearing on a motor

Check your power steering fluid reservoir.

Check your air intake manifold hose if is crack this cause whistle noise replace the hose.

To determine what's making the whistle, try putting some tape over anything that might be causing it. I'd tape over any trim or moldings to try and find out where its coming from. You might try a wide roll of tape over the window edges, and trim points, if the whistle stops, take off a section at a time and recheck until it appears again, and you know what's causing it. Try to keep the tape flat, or you might create some new whistles! Let me know how you do. countrycurt0

It is the air bypass valve that makes this noise