Notices
Aerostar Ford Aerostar

92 3.0 Spark Knock

Thread Tools
 
Search this Thread
 
Old May 29, 2004 | 10:02 PM
  #1  
fcchief's Avatar
fcchief
Thread Starter
|
New User
Joined: May 2004
Posts: 19
Likes: 0
From: Port Orchard, WA
92 3.0 Spark Knock

Got a 92, 3.0 with spark knock. It starts after the engine gets warm and only when accelerating or under load (up a hill etc). It has no EGR valve since the intake was replaced 2 years ago. Thinking of cleaning MAF, already checked plugs. It does have exhaust leak at No 3 cylinder, bolt broken in block, I am not going to try and get this fixed due to age and mileage (JB Weld worked). A mechanic told me to also check the anti-knock sensor, where is this located on this vehicle? Any other info or tips would be appreciated. Engine has 160,000 miles on it and tranny leaks, but cannot tell from where, I know it is not the pan gasket. Thanks for any help.
 
Reply
Old May 29, 2004 | 10:34 PM
  #2  
lasher's Avatar
lasher
Senior User
Joined: Feb 2004
Posts: 195
Likes: 0
you might be leaking from front transmission seal. very common on aerostar.
good chance your engine is carboned up.
alot of guys use a spray bottle with water on the air intake
running at fast rpm to get rid of carbon or a safer way is
to try stuff from autoparts store. your on your own about which
one is best.
 
Reply
Old May 31, 2004 | 11:44 AM
  #3  
fcchief's Avatar
fcchief
Thread Starter
|
New User
Joined: May 2004
Posts: 19
Likes: 0
From: Port Orchard, WA
I got some additive that supposedly will help rid the carbon. However is there anything else I should be looking at? It only knocks when warm and under load (accelerating, hills). Will cleaning the MAF help? Since it has no EGR I am not sure what to look for.

Will check the tranny, but don't see where that would play into it other than I need to get the leak fixed.
 
Reply
Old May 31, 2004 | 11:51 AM
  #4  
jkorreck's Avatar
jkorreck
Senior User
Joined: Apr 2004
Posts: 239
Likes: 0
pull the line to to the vacuum modulator on the trans see if it's full of tranny fluid if it is, you might have found your leak and spark knock problem, just decarbon the engine after you replace the vacuum modulator if it is bad.
 
Reply
Old May 31, 2004 | 12:03 PM
  #5  
fcchief's Avatar
fcchief
Thread Starter
|
New User
Joined: May 2004
Posts: 19
Likes: 0
From: Port Orchard, WA
Thanks I will check that out. Open to other suggestions as well.
 
Reply
Old May 31, 2004 | 12:37 PM
  #6  
jkorreck's Avatar
jkorreck
Senior User
Joined: Apr 2004
Posts: 239
Likes: 0
forgot one thing with the vacuum modulator, if it is bad replace the rubber parts of the vacuum line that goes to it. I think it was the trans fluid that did it but mine were all kinds of rotted.
 
Reply
Old May 31, 2004 | 09:09 PM
  #7  
fcchief's Avatar
fcchief
Thread Starter
|
New User
Joined: May 2004
Posts: 19
Likes: 0
From: Port Orchard, WA
Yep, modulator was toast, not surprising after 160K on it. The hose seemed fine, still flexible. I took it for a drive and had a little spark knock still, but after about 10 miles it subsided and later in the day when I used the van, no knock at all. Thanks a bunch.
 
Reply
Old May 31, 2004 | 10:29 PM
  #8  
jkorreck's Avatar
jkorreck
Senior User
Joined: Apr 2004
Posts: 239
Likes: 0
Glad to hear it.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-1

Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-2

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-3

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-4

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-5

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-6

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-7

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-8

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-9

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
Old Jun 1, 2004 | 07:32 PM
  #9  
C Holmes's Avatar
C Holmes
Mountain Pass
Joined: Dec 2003
Posts: 154
Likes: 0
where is this modulater? what does it look like?
 
Reply
Old Jun 1, 2004 | 09:58 PM
  #10  
jkorreck's Avatar
jkorreck
Senior User
Joined: Apr 2004
Posts: 239
Likes: 0
Passenger side of the trans, kind of round looking, it's the only thing there that has a vacuum line on it so you could probably just trace that.
 
Reply
Old Jun 1, 2004 | 10:00 PM
  #11  
fcchief's Avatar
fcchief
Thread Starter
|
New User
Joined: May 2004
Posts: 19
Likes: 0
From: Port Orchard, WA
On my 92 3.0 it is located on the right side (passenger) about the middle of the tranny. The catalytic converter hides it some. It is a round device with a nipple on it, which has a vacuum hose going to the nipple. It is in an awkward place if working from the ground, but only one bolt on a hold down clamp, which keeps the modulator from backing out of the transmission. Modulator cost me $18.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Supercab
1983 - 2012 Ranger & B-Series
32
Jun 4, 2018 02:56 PM
gcpommom
Aerostar
11
Oct 15, 2011 08:53 PM
mfp4073
1983 - 2012 Ranger & B-Series
8
Dec 31, 2009 05:17 PM
madmax99
1983 - 2012 Ranger & B-Series
8
Feb 14, 2007 09:27 AM




All times are GMT -5. The time now is 05:11 AM.

story-0
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-02 21:45:57


VIEW MORE
story-1
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-05-30 18:33:59


VIEW MORE
story-2
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-3
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-4
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-5
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-6
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-7
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-8
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-9
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE