Spatting sound in right front on idle

[Oongawah]

Judging from previous replies in the archives this is a sore subject to some of us. I searched though and did not find the answer the same as what I found on my truck. I installed an EGT Gauge last week, and while drilling the hole in the exhaust, I left the truck idling as mentioned in a previous post. I heard the loud spat sound that I indicated to my dealer last year(and just figured why fix it if it ain't broke). I looked in the direction of the sound(with the wheel well cover off), and low and behold I see exhaust residue around a round plate the size of a 50cent piece in the middle of a diaphram connected to the smog pump. I put my hand over the cap area, and the spat was gone. Lift it away, and the spat was there. I don't ever remember an EGR system leaking like this on purpose. Does anyone know if this is by design, or has the diaphram seal failed. It's been this way since 3 miles on the truck. I know, if it ain't broke don't fix it, and it ain't a smog pump, but an air pump(LOL). Be good, Chuck. P.S. I saw a D/A this morning that wasn't spatting. Sounded nice, and mean GRRRRRRRRRR.

[Kennedy]

The vacuum pump (used in EGR equipped trucks) will make different noises. The "exhaust residue" you are seeing (if on the center of the vac pump dome) is just dirt that accumulates as the pump breathes.

[mackin]

So if I understand it.....In 01 all 50 states got no emission restrictions....

In 02 the Liberal State of Kalifornia received the door prize of Cats and Egr's.......I thought they only got cats....Who knew.....

In 03 we all get at least cats???

In 04 will we all be similar equipped?????

Or is the standard not going to effect the rest of us owners????

Omitting the West coast of course ......

MAC

[ 11-02-2002: Message edited by: mackin ]</p>

[FirstDiesel]

Maybe CA got cats but my 02 has no cat.

[mackin]

Larry


I edited my post ...I think your right it's in 03 we all get cats not 02.......

Or it could be a GVW issue and 3500 are exempt....My case is here in CT we have had biyearly emission testing....Now on hold due to fraud....That's right unbelievable....

I don't have to test due to my over 10,000 GVW statues....Would be nice to have a sense of who got what and who's getting it next....

MAC

[Steve Cornell]

My 03 has no cats.

[FirstDiesel]

I like the inspection thing. smile.gif

We here in S.C. don't even have safety inspections anymore. The reason??? The cost was 3 bucks and the state took $2.50! That left the station doing the inspection a whole 50 cents. The problem?? They either just gave you the sticker and did nothing or found 100's of dollars of needed work!

The solution by our government. Cancel the inspections instead of allowing them to make a reasonable profit.

The result, you can't believe the cars on the road here now. Bald tires, no stoplights, no headlights etc etc.

What do the police ticket you for?? SPEEDING! :(

[ 11-02-2002: Message edited by: FirstDiesel ]</p>

[OC_DMAX]

Chuck,

My California 2002 DMAX also has the same noise that you mentioned in your post. I have had the truck for a little over a year and the noise has been present since day one. The truck has about 10K miles on it and has been to the dealer only once for warranty work; a squeaky driver door and the noise you mention. The dealer fixed the noise but I could not convince him that the vacuum pump noise was abnormal. I had always suspected the vacuum pump was making the noise and now I will have to investigate further.

Someday I will come across another 2002 DMAX owner/truck and will be able to compare the trucks side-by-side. So at this point, there are at least 2 California trucks with a similar noise.

Regards,
Alan

[Oongawah]

JK,
You know, I should have been more clear on the residue. You are right. What I see is what a gasser exhaust residue would look like. Kinda reddish. More like an oxide. I need a book so I can learn what each component is. My experience is all gasser, but picking up quick on the diesel.
Alan,
I'm beginning to think that if this sound is not normal, it's not hurting anything. My biggest concern would be if the diaphram in there was leaking, then dirt would get in the engine.

[GMC-2002-Dmax]

Mac,

I got three house cats........No CAT in my '02 :D

Just a little purr....... under the hood.

;)

GMC :cool:

[dieselburb]

OC_, come see me in Newport or we'll arrange something where I come see you. I've got to pick up my engine hoist from a friend's house up there and my 02' does not have any spatting sound at all, 14,500 miles. If your interested, look me up in Newport under "Newport Landing Fuel Dock". My name is Cory

[Kent Tuttle]

I always have thought the noise from that side was the vacuum pump as JK said. The truck runs so well I would hate to mess with anything. I would have to look a little closer for any leaks or residue. Also, if anyone ever wants to compare trucks for noises or what ever I would be happy to try and accommodate.

[stutzismydog]

Hay you Calif. guys.....do we have to smog our DMAX trucks in this State or not ??? This is my first diesel and I heard that diesels are exempt....is this true or false ??

[Kent Tuttle]

So far no smog requirements. I'm sure it is coming :mad: