vacuum---needle bounce

[turbo]

The car idles and runs great! Sitting at a light I noticed the vacuum/boost gauge dipped a pound or two and immediately went back up. I didn't time it, but I'd guess it did it every 15 or 20 seconds. I later checked it in park and the same results.

Park shows about 17-18lbs and in drive, at around 800rpm, it was around 13 or so and would dip and come right back up.

Could it just be a vacuum leak? Most of the hoses were replaced about a year ago. I've had it since '87 (new) 140,000 miles and still runs like it has low miles. Is this a SYMPTOM of something about to go or wearing out?

Maybe it has been doing this for years and this is the first time I've noticed it...duh!

Ideas?

 

[GNX]

I think I remember someone posting that it could be a headgasket starting to leak.

 

[terryk]

My 86 TT does the same thing and it's not a head gasket. I suspect it's the CCP purging or something like that. It takes too long to cycle for me to nail it down.

Terry

 

[turbo]

Terry,
Maybe it's a fairly normal thing, that people just haven't noticed. I guess it's nothing to worry about since the car runs great, otherwise.

Maybe it's the CCP solenoid, like you mentioned, that's starting to go bad?

During the 4th we stopped at the In and Out in Auburn on our way to Lake Tahoe. If I ever find out what it is (vacuum) I'll post it.

Thanks!

 

[terryk]

Hey Turbo,

Some time I'm going to really look at it but as you said the cars runs great so I haven't really worked on it.

Auburn is a great place to be from .......