Noises From Drivers Side Dash Area

[BUCK]

I've got this occasional between shift BRRRRRRRRRRRRTTTTT noise - sounds like my FPR regulator solenoid thingy on the engine bay firewall.

AND - this occasional between shift PFFFFTTTTTT noise that sounds like it's coming from My Turbo Gauge in the dash.

Normal? These things have more new mystery noises than anything I've ever seen...

 

[Lordpaxin]

is the "ppffffft" from the boost guage consistant at higher pressure level?

such as you have a small break in your hard line to the guage, or the fitting itself is leaking

 

[BUCK]

Yes - intermittenet at higher boost levels - higher shift points - I thought the factory gauge was electronic somehow? - I'm getting ready to install a better Boost Gauge - Thanx again LP.

 

[Lordpaxin]

you are right, electronic, thought you had aftermarket, hmmmm.....

i think your on the right track with your firewall mount solenoids.

 

[BUCK]

Never heard it till I replaced the Fuel Filter - maybe it's flowing better & the FPR actually lifts for a change? I need to check the darn Vacuum Booster for the brakes too - but it Idles great - no sign of a gross Vacuum leak.

 

[BUCK]

Well I found out what the PFFFFFFFttttt was from under the dash - Mechanic Error (me) - When I changed out the Vacuum Hose for the Brake Booster I neglected to look at the Manual & see there's a Check Valve slid inside the Factory Hose - luckily I throw very little away - Found the old hose, cut the valve out & carefully pushed it inside the New Hose with some Lithium Grease - Hopefully I haven't blown anything in the Brake Booster - It's never braked badly, just made that PFFTT noise when shifting at 3K rpm or more...

 

[GTM]

Originally posted by BUCK

...
When I changed out the Vacuum Hose for the Brake Booster I neglected to look at the Manual & see there's a Check Valve slid inside the Factory Hose - luckily I throw very little away
...
never braked badly, just made that PFFTT noise when shifting at 3K rpm or more...

Thanks for the heads up on the check valve.
...........
I would have thought you would have noticed the increased pedal pressure when braking??
............

This brings to mind a question that had crossed my mind but never answered. How does the booster get boost when the manifold is under pressure???

Cheers,
GTM

 

[Lordpaxin]

Hot shit.

i get a loud PSSSSSSSSHHHHHHH noise comming from my dash at 7 psi and it stops there.

did your valve fix the noise?
and did you have lack of boost before the fix?

 

[Lordpaxin]

Originally posted by GTM
Thanks for the heads up on the check valve.
...........
How does the booster get boost when the manifold is under pressure???

Cheers,
GTM

well, are you hitting the brakes under boost?

the pressure drop after you let off the petal is so fast, i dont thikn you would notice any defference in brakeing

 

[GTM]

Originally posted by Lordpaxin
well, are you hitting the brakes under boost?

the pressure drop after you let off the petal is so fast, i dont thikn you would notice any defference in brakeing

There are occasions when powering into a corner with heel and toe you will be looking at boost and brake and I don't think you can depend on waiting for the boost to build. You are riding the brakes so the vacuum reserve is gone and unless you back off the gas there is no way to replinish it. Now if they put the pressure on the other side of the booster it could compensate for this condition. ??

Cheers,
GTM

 

[GTM]

Originally posted by Lordpaxin
Hot shit.

i get a loud PSSSSSSSSHHHHHHH noise comming from my dash at 7 psi and it stops there.

did your valve fix the noise?
and did you have lack of boost before the fix?

LP / Buck, why don't you spend a little time and write what was happening, how it got there and the improvements that this made so other can learn? How long have you been living with this? How many other cars are out there that have this same sound caused by omitting the check valve??

Cheers,
GTM

 

[Lordpaxin]

well, for me, it all started with diagnosing a boost leak.

I decided I could Eliminate a leak by replaceing all my vacuum lines, and after i did that, i had a Drop in PSI, and the noise after I would hit 6 psi.

so i found my old hose, took the valve out, and microwaved the tube to be soft, slide it down inside, and reinstalled the line,

and the sound is gone and i can hit 8 psi. now.

I didnt know there was a valve in that hose, probably a LOT of popel dont know either.;

 

[Defiant]

Originally posted by BUCK
Found the old hose, cut the valve out & carefully pushed it inside the New Hose with some Lithium Grease

Er... you used wheel bearing grease on a rubber hose?

Get a new hose, and some silicone spray.

 

[BUCK]

I would have thought you would have noticed the increased pedal pressure when braking??

-There was no increased pedal pressure - as my post said GTM it braked fine - just went Pfftt in between shifts over 3K rpm.

i get a loud PSSSSSSSSHHHHHHH noise comming from my dash at 7 psi and it stops there.

These Check valves could go BAD - or easily become fouled & not seal readily - they are very teeny fragile little thin plastic deals - My noise wasn't continuous over 7 psi - but a pronounced & consistent PFFTTT BETWEEN SHIFTS at about that same boost (3K rpm).

did your valve fix the noise?

- YES! - the manual says change the hose - but I just cut the valve out of the old hose & slipped it into my new hose.

and did you have lack of boost before the fix?

Absolutely not - running 13 PSI on my stock POS gauge - the PFFFTTT under my dash may have been sent thru my stock BOV anyway (but back into the Intake) so this Check Valve SHOULD help performance a LITTLE - as I said the PFFFTT was ONLY BETWEEN SHIFTS!

How does the booster get boost when the manifold is under pressure???

-The VERY check valve we are talking about seals & maintains the vacuum in the Booster - that is it's job.

LP / Buck, why don't you spend a little time and write what was happening, how it got there and the improvements that this made so other can learn? How long have you been living with this? ?

-Just a couple weeks - as I said it braked great & ran great although I concur had I need brakes while boosting I would have been screwed - per my NO BOOSTER test run there are DAMN little brakes without that Booster - like most any other PB car.

How many other cars are out there that have this same sound caused by omitting the check valve?

-Ricers all over America & the entire PLANET are pulling this check valve as we speak so they can hear their "BOV" better inside the car! (it WAS pretty cool)

-I changed all my OTHER Vac hoses last year - but when I relocated my throttle cables a few weeks ago I noticed that the end of the PB Vac Hose looked bad & replaced it - hence the noise - but my FPR lifts between shifts sometimes & I thought my Booster was going bad & maybe the new hose was sealing so good it prompted the noise... Looked in the Manual to verify what a TOTAL PITA it was going to be to replace & saw an illustration of the hidden check valve on opposite page - GM's have these right at the Booster - I think Fords are built into the Booster...

Er... you used wheel bearing grease on a rubber hose?

It was a just a tee tiny squirt of the liquid aerosol light brown stuff - and it was actually some new 5/16 Power Steering Hose I had left over from my Power Steering return line mod - tuff stuff - sealed great...

- but Thanx for caring "D Man"....

 

[Lordpaxin]

Interesting.

My car after 7 psi would Make the Hissing noise constantly, aslong as I held that much boost, and it would not pass that boost level.

I put the check valve back into the hose and the noise is gone, and I can Hit 9 psi now.

Odd? Any idea?

 

[tt281gt]

When I got my car it didn't do it at all. The stock boost gauge worked fine. Now i guess I have a leak in that thing you guys are talking about it. Its constantly there except when I give it more than 45% throttle but as soon as I let off it comes right back...and boost gauge only reads boost up to 3/4 of the way.

I can live with it, I'll be getting an aftermarket gauge soon.

 

[BUCK]

I can live with it, I'll be getting an aftermarket gauge soon.

Uhh - TT281GT I realize you got in Saturday nite even later than I did but... None of this has anything to do with Boost Gauges - it's the Power Steering Booster Vacuum Line Check Valve that caused these noises from under the dash... SO>>>>>> off hand - from your faint description - It sounds like you have a "weak or fouled" Power Steering Booster Vacuum Line Check Valve - an aftermarket Boost Gauge isn't gonna cure that... Get a new factory hose that has the check valve in it or fit another one to your existing hose & cut out the old one.

& I think the Stock Boost Gauge is electronic BTW - meaning no "boost" is actually there like your future Aftermarket Gauge will probably have.

by Lordpaxin: My car after 7 psi would Make the Hissing noise constantly, aslong as I held that much boost, and it would not pass that boost level.

Only thing I can think of is that my Booster was leaking at Boost spikes with no check valve - & yours was leaking constantly without a check valve - but Hell if they brake well & run well with them back in I'm over it... I'l probably change the Booster when my Master Brake Cylinder dies some day anyway... they can't last forever.

It DOES make you wonder how much Boost that little Check Valve can take? Seems like someone HAS to have blown one of these all to hell - I would think you could backfit an old Steel Style PCV Check Valve in there if you wanted something more "robust"... that might be a fix for TT281GT.

 

[tt281gt]

Originally posted by BUCK
Uhh - TT281GT I realize you got in Saturday nite even later than I did but... None of this has anything to do with Boost Gauges - it's the Power Steering Booster Vacuum Line Check Valve that caused these noises from under the dash... SO>>>>>> off hand - from your faint description - It sounds like you have a "weak or fouled" Power Steering Booster Vacuum Line Check Valve - an aftermarket Boost Gauge isn't gonna cure that... Get a new factory hose that has the check valve in it or fit another one to your existing hose & cut out the old one.

& I think the Stock Boost Gauge is electronic BTW - meaning no "boost" is actually there like your future Aftermarket Gauge will probably have.



Only thing I can think of is that my Booster was leaking at Boost spikes with no check valve - & yours was leaking constantly without a check valve - but Hell if they brake well & run well with them back in I'm over it... I'l probably change the Booster when my Master Brake Cylinder dies some day anyway... they can't last forever.

It DOES make you wonder how much Boost that little Check Valve can take? Seems like someone HAS to have blown one of these all to hell - I would think you could backfit an old Steel Style PCV Check Valve in there if you wanted something more "robust"... that might be a fix for TT281GT.

Ahh crap. I just checked my mail and I read this post. I guess I'll need to get that part then. Can I get a factory hose replacement like you said from the local pep boys or autozone or must I go to a dealer?

 

[BUCK]

Yes - you could order the hose from Mitsu or grab one at a junkyard, you can feel the lump in the hose where the chaeck valve is - The check valve should be in the new hose - Or just make a cut in the hose & plug in any quick acting little aftermarket check valve that fits - I think the Hose is 5/16 ID - So any of the older style steel PCV Valves may work.