Smoke test and EGR modulator

LIVINGSSKY

MEMBER
2001 TOYOTA CAMRY
2.2L
4 CYL
2WD
AUTOMATIC
145,000 MILES

Performed a smoke test for vacuum leak, only spot leaking is from under the cap of EGR vacuum modulator (the hole to the modulator filter). Is it normal? Thanks.

10 Replies

ASEMASTER6371

CERTIFIED MECHANIC

Good afternoon.

Is this what you are talking about?

This is called a VSV valve.

Roy

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Thursday, September 27th, 2018 AT 3:51 PM

LIVINGSSKY

MEMBER

Hi Roy or any other pros,
Please excuse me for bringing this topic back. With manuals etc, I did thorough tests on my EGR modulator both on-vehicle and off (with vacuum gauge). All indicate this part is still good.

And per some readings, the EGR modulator (at least for Toyota) is designed to be open to air at engine off. So I am very confused, as leaking smoke appears to be normal during a smoke test for vacuum leak. Any advice appreciated.
-Simon

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Monday, October 1st, 2018 AT 2:19 PM

KEN L

MASTER CERTIFIED MECHANIC

It could be vented to the atmosphere when the engine is off. Does the new part do the same thing?

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Thursday, October 4th, 2018 AT 12:13 PM

LIVINGSSKY

MEMBER

Thanks Ken. I did not replace it. I did a couple of tests particular on the modulator: (1) Sealed the vent hole with a piece of tap and (cold) start the car, idle still behaved the same. (2) Spray carburetor cleaner to the modulator after cold start, no change to idle. So this part must be good.

You are right that the modulator is open to air when engine off. Just so surprised that this was never noted anywhere as to vacuum leak test.

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Thursday, October 4th, 2018 AT 8:37 PM

KEN L