a few vacuum gauge questions

msm15 · Post by **msm15** » 20 Nov 2008, 18:35

will a clogged pcv affect the turbo max psi

Post by **MadeInJapan** » 20 Nov 2008, 19:15

Just went out to grab some dinner for the family and noticed that there was no slow moving on the boost gauge even with cold start (it's in the 30's now) so you've got something going on...some type of leak and it's not necessarily in the line to your gauge...any leak in any of those hoses from the vacuum tree is going to have an effect on your gauge (all interconnected). I would say that the slow moving of the gauge when cold shows the leak is even more pronounced when the car is cold...but what stumps me is the 24 or so vacuum you get when you let off the gas...that's strange. Maybe someone else has a better understanding and description of what's going on.

msm15 · Post by **msm15** » 20 Nov 2008, 19:28

ok thanks for the info MIJ, I am thinking about changing all the hoses with silicone hoses, but I have to figure out at what point it doesnt pay to keep working on the car, the bad oil leak caused some pretty bad results, and now I have at least three oils leaks, clogged pcv, and 17 mpg combined.

but what makes me feel good, is that my 98 volvo s70 glt with 224k miles and all the problems that come with it, is still better then my friends 2005 ford taurus with only 45k - he's only getting 15.5 and his car is pretty new !!

Post by **holler1** » 20 Nov 2008, 19:53

My LPT only goes to 7 at max acceleration, usually goes 3-5 psi at 2500 to 3000 rpm with 2/3 throttle. I did notice a delay today in going to -20 at idle when cold. It was sitting at -18 when I first started it up. I was only moving the car so didn't let it warm up.

Post by **holler1** » 20 Nov 2008, 19:56

I also get -23-24 vacuum reading when letting off the gas after revving.

Post by **holler1** » 21 Nov 2008, 19:16

I checked vacuum today after warming up, and I get -20 at idle in neutral, but -18 at idle in drive, so it depends on the load on the engine. I really have to drive hard to get above 5 on the boost side.

msm15 · Post by **msm15** » 22 Nov 2008, 16:11

yup those are my exact results glad to see I am not out of the loop here, I only go down to 22-24 after letting of the gas after a boost. In the future I plan to redo my vacuum hoses and clean out some other areas associated with the air intake to see if I can get it up to 7 psi, I will probably add a manual boost control if I ever get around to it, or if the car lasts that long

bmxandy89 · Post by **bmxandy89** » 08 Jun 2011, 17:09

i hooked up a vacuum gauge on my NA just to see if i had a vacuum leak i have it hooked up at the tree at cold idle it sits at 20 and on acceleration it drops down to around 5 . it drops fast the second i put my foot on the gas were should i look for a vacuum leak and were can i get like red vacuum lines

a few vacuum gauge questions

Re: a few vacuum gauge questions