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HELP HELP HELP

  • Thread starter Thread starter javi_smtx1978
  • Start date Start date Jul 26, 2022
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javi_smtx1978

New Member
Jul 26, 2022
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san antonio
Jul 26, 2022
#1
  • Jul 26, 2022
  • #1
i have a 1991 fox body gt convertible. one day it started making a LOUD hissing noise! had a few people come out and take a look at it. EVERYONE said it was the headers. i replaced the header (almost 800 dollars later) and the noise continues. no one seems to be able to tell me what is really wrong with my car. the noise comes from the back right side of the motor and maybe even towards the back. is sounds exactly like a PIST sound but loud. can anyone please help me.
 
J

javi_smtx1978

New Member
Jul 26, 2022
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0
1
san antonio
Jul 26, 2022
#2
  • Jul 26, 2022
  • #2
hey buddy i dont know where or who to turn to. maybe you can help! i have white 1991 gt convertible. one day its started making a PIST PIST sound but very loud. had a few mechanics come look at it. each on told me it was the headers. i replaced the headers (almost 800dollars later) and the PIST sound is there. one guy told me it was a lose spark plug. ever had this issue or maybe know what it may be. id appreciate the help . kinda running out of money and this car is my baby.
 

96pushrod

I think they're a little easier to get off
5 Year Member
May 15, 2018
1,530
871
133
Savannah
Jul 26, 2022
#3
  • Jul 26, 2022
  • #3
what kind of mechanic thought it was the headers?

Take a video and post it
 

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
5,816
213
Jul 26, 2022
#4
  • Jul 26, 2022
  • #4
Is all the emissions stuff still on it ? Sounds like the thermactor plug or the pipe may be leaking. A picture of the passenger side would help.
 

nickyb

I gotta say i never painted my nuts, Never Ever
15 Year Member
Apr 3, 2009
2,963
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153
nevada
Jul 26, 2022
#5
  • Jul 26, 2022
  • #5
$800 headers? WTF. Wish I was closer to you, I'd come over to help you for free.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,824
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203
polk county florida
Jul 27, 2022
#6
  • Jul 27, 2022
  • #6
Is the emissions stuff still attached?
Check the pipe that connects to the back of the heads and the rubber hoses on the emissions pipes, there is another one under the car between the cats.
 
Reactions: manicmechanic007

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
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Kearney, NE
Jul 27, 2022
#7
  • Jul 27, 2022
  • #7
The car is pist off.
A hose with the other end near your ear should narrow the location down quickly.
 
Reactions: Reddevil91 and manicmechanic007

Potomus Pete

I'm still waiting for the fully nude shots
5 Year Member
Mar 7, 2019
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Sarasota Florida
Jul 27, 2022
#8
  • Jul 27, 2022
  • #8
What about a big vacuum leak... Thats a nice car you got there. Whats going on with the rear bumper
 

manicmechanic007

5 Year Member
Sep 26, 2017
2,524
709
143
Roy, Utah
Jul 27, 2022
#9
  • Jul 27, 2022
  • #9
That is my thought too
Check the pipe between the rear of the heads for the thermactor and the one way valve on top
Get a mechanics stethoscope
 

Potomus Pete

I'm still waiting for the fully nude shots
5 Year Member
Mar 7, 2019
3,308
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153
Sarasota Florida
Jul 27, 2022
#10
  • Jul 27, 2022
  • #10
Doesn't a blown head gasket make a big swooosh sound
 

96pushrod

I think they're a little easier to get off
5 Year Member
May 15, 2018
1,530
871
133
Savannah
Jul 27, 2022
#11
  • Jul 27, 2022
  • #11
Potomus Pete said:
Doesn't a blown head gasket make a big swooosh sound
Click to expand...
I had one go out and blew out a little coolant out, made a hissing noise. Got lucky and didn’t mix with oil or anything
 

mikestang63

SN Certified Technician
Aug 27, 2012
11,606
8,859
214
In the garage
Jul 29, 2022
#12
  • Jul 29, 2022
  • #12
with the engine OFF, you can make a cheap home made smoke machine with a $7 Harbor Freight syphon pump and a cheap thin $1 stogie. Take the hose off the vacuum pump that PUSHES the air and stick it in one of the exhaust pipes and tape it in the pipe. Tape over both exhaust pipe openings. Then light the stogie and stick the unlit end in the opening of the vacuum pump that sucks in the air and start pumping away. it will push the smoke from the stogie up through the exhaust and back up to the headers and engine block. If you have someone as a helper, have them look under the car and under the hood as you are pumping for smoke coming out where any leak is. You can also do the exact same thing by hooking up the hose from the pump to any vacuum hose going into the intake manifold- from the brake booster, PCV valve, purge cannister. As you pump in the smoke again look for any smoke coming from the engine, hoses,, etc. That would be a vacuum leak.

I have used this cheap pump for years and it works wonders finding these types of leaks.

Multi-Use Transfer Pump

Amazing deals on this Multi-Use Transfer Pump at Harbor Freight. Quality tools & low prices.
www.harborfreight.com
 
Reactions: manicmechanic007, General karthief, 90sickfox and 1 other person

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Jul 29, 2022
#13
  • Jul 29, 2022
  • #13
mikestang63 said:
with the engine OFF, you can make a cheap home made smoke machine with a $7 Harbor Freight syphon pump and a cheap thin $1 stogie. Take the hose off the vacuum pump that PUSHES the air and stick it in one of the exhaust pipes and tape it in the pipe. Tape over both exhaust pipe openings. Then light the stogie and stick the unlit end in the opening of the vacuum pump that sucks in the air and start pumping away. it will push the smoke from the stogie up through the exhaust and back up to the headers and engine block. If you have someone as a helper, have them look under the car and under the hood as you are pumping for smoke coming out where any leak is. You can also do the exact same thing by hooking up the hose from the pump to any vacuum hose going into the intake manifold- from the brake booster, PCV valve, purge cannister. As you pump in the smoke again look for any smoke coming from the engine, hoses,, etc. That would be a vacuum leak.

I have used this cheap pump for years and it works wonders finding these types of leaks.

Multi-Use Transfer Pump

Amazing deals on this Multi-Use Transfer Pump at Harbor Freight. Quality tools & low prices.
www.harborfreight.com
Click to expand...
Do you have another budget friendly method without tobacco? At least a pipe does not smell as bad.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,824
10,506
203
polk county florida
Jul 30, 2022
#14
  • Jul 30, 2022
  • #14
You could use some pot, problem is after a few minutes you won't care if it leaks or not if you even remember why you did it.
 
Reactions: FastDriver, Monkeybutt2000 and manicmechanic007

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Jul 30, 2022
#15
  • Jul 30, 2022
  • #15
General karthief said:
You could use some pot, problem is after a few minutes you won't care if it leaks or not if you even remember why you did it.
Click to expand...
Burning weeds still smell bad. But it at least reminds me of the haze at live concerts.
 

nickyb

I gotta say i never painted my nuts, Never Ever
15 Year Member
Apr 3, 2009
2,963
1,610
153
nevada
Jul 30, 2022
#16
  • Jul 30, 2022
  • #16
Hay general, I think the op. took you advise, he hasn't checked in since .
 
Reactions: General karthief

Patrick Sullivan

Member
Jul 1, 2022
17
5
13
Aurora CO
Jul 30, 2022
#17
  • Jul 30, 2022
  • #17
mikestang63 said:
with the engine OFF, you can make a cheap home made smoke machine with a $7 Harbor Freight syphon pump and a cheap thin $1 stogie. Take the hose off the vacuum pump that PUSHES the air and stick it in one of the exhaust pipes and tape it in the pipe. Tape over both exhaust pipe openings. Then light the stogie and stick the unlit end in the opening of the vacuum pump that sucks in the air and start pumping away. it will push the smoke from the stogie up through the exhaust and back up to the headers and engine block. If you have someone as a helper, have them look under the car and under the hood as you are pumping for smoke coming out where any leak is. You can also do the exact same thing by hooking up the hose from the pump to any vacuum hose going into the intake manifold- from the brake booster, PCV valve, purge cannister. As you pump in the smoke again look for any smoke coming from the engine, hoses,, etc. That would be a vacuum leak.

I have used this cheap pump for years and it works wonders finding these types of leaks.

Multi-Use Transfer Pump

Amazing deals on this Multi-Use Transfer Pump at Harbor Freight. Quality tools & low prices.
www.harborfreight.com
Click to expand...

nickyb said:
$800 headers? WTF. Wish I was closer to you, I'd come over to help you for free.
Click to expand...
Did he fix his psssst noise? buy a can of starting fluid! spray the hoses, it will either pick speed or stall out when ya spray near the leak
 

Patrick Sullivan

Member
Jul 1, 2022
17
5
13
Aurora CO
Jul 30, 2022
#18
  • Jul 30, 2022
  • #18
javi_smtx1978 said:
i have a 1991 fox body gt convertible. one day it started making a LOUD hissing noise! had a few people come out and take a look at it. EVERYONE said it was the headers. i replaced the header (almost 800 dollars later) and the noise continues. no one seems to be able to tell me what is really wrong with my car. the noise comes from the back right side of the motor and maybe even towards the back. is sounds exactly like a PIST sound but loud. can anyone please help me.
Click to expand...
Did ya fix the noise?
 

Patrick Sullivan

Member
Jul 1, 2022
17
5
13
Aurora CO
Jul 30, 2022
#19
  • Jul 30, 2022
  • #19
javi_smtx1978 said:
i have a 1991 fox body gt convertible. one day it started making a LOUD hissing noise! had a few people come out and take a look at it. EVERYONE said it was the headers. i replaced the header (almost 800 dollars later) and the noise continues. no one seems to be able to tell me what is really wrong with my car. the noise comes from the back right side of the motor and maybe even towards the back. is sounds exactly like a PIST sound but loud. can anyone please help me.
Click to expand...
spray starting fluid on the hoses (while running)
 
M

Monday

Member
Feb 8, 2022
40
19
18
British Columbia
Jul 30, 2022
#20
  • Jul 30, 2022
  • #20
As you work, clamp the crap out of everything. It's a compressor, there's why, now the how is a clamp missing or never re-installed. I had hissing, and never looked back after I started clamping everything.Notice everything - EVERY THING - on the pass side (top left) is clamped
 
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