• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

Leaking valve guide seals

  • Thread starter Thread starter Deleted member 38176
  • Start date Start date Jul 30, 2011
D

Deleted member 38176

Jul 30, 2011
#1
  • Jul 30, 2011
  • #1
My car smokes lightly when warmed up and has been doing so for some time now. I'm pretty sure that my valve guide seals are leaking. Is there any remedy for the situation other than replacing the seals? I heard that some high mileage oil might help. Any advice?
 

Rick 91GT

Mustang Master
Nov 29, 1999
9,692
95
99
PA
Jul 30, 2011
#2
  • Jul 30, 2011
  • #2
typically valve seals show up on start up, then go away. I would do a leakdown test on the motor.

If the seals are bad only remedy is replacement, id use a viton based seal...last longer, more durable.
 
D

Deleted member 38176

Jul 30, 2011
#3
  • Jul 30, 2011
  • #3
Well, I only notice it @ idle, usually stopped at a light. It isn't heavy, just a slight haze. The guy who helped me put my LT's on was the one who said it was leaking guide seals. What else could it be? I'll look into having a leakdown done.
 

1987stangman

Member
Jul 12, 2006
684
24
19
Jul 30, 2011
#4
  • Jul 30, 2011
  • #4
Nightfire said:
Well, I only notice it @ idle, usually stopped at a light. It isn't heavy, just a slight haze. The guy who helped me put my LT's on was the one who said it was leaking guide seals. What else could it be? I'll look into having a leakdown done.
Click to expand...

Your having the same issues I did on my old NPI motor. Pull the plugs and see what they look like. For me it was the #8 cyl. Plug was always oilly and I always had to check the oil level. I sold the motor to my step sons friend after I put new valve seals in it and it doesnt smoke anymore.
 
D

Deleted member 38176

Jul 31, 2011
#5
  • Jul 31, 2011
  • #5
1987stangman said:
Your having the same issues I did on my old NPI motor. Pull the plugs and see what they look like. For me it was the #8 cyl. Plug was always oilly and I always had to check the oil level. I sold the motor to my step sons friend after I put new valve seals in it and it doesnt smoke anymore.
Click to expand...

I just had a plug blow out of the head not too long ago so I had all the plugs checked and retorqued. They looked good.

Another scenario that I've thought of was that it is coolant leaking into the cylinder(s) since the smoke is white. Does a bad head gasket sound plausible?
 
You must log in or register to reply here.

Similar threads

J
Engine Coolant leak from oil filter
  • jr273
  • Mar 26, 2026
  • SN95 4.6L Mustang Tech
Replies
9
Views
287
SN95 4.6L Mustang Tech Mar 31, 2026
squeak93
C
C4 trans help needed
  • CPH89LX
  • Apr 26, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
6
Views
246
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 28, 2026
CPH89LX
C
O
8.8 Pinion Nut Leak
  • OX1
  • Jan 3, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
850
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 5, 2026
OX1
O
Engine Random Misfire at idle.
  • Gulftown980x
  • Jul 29, 2026
  • SN95 4.6L Mustang Tech
Replies
11
Views
317
SN95 4.6L Mustang Tech Jul 31, 2026
squeak93
D
Question about EGR valve, replacement, and a part on the valve.
  • DPP
  • May 9, 2026
  • SN95 V6 Mustang Tech
Replies
1
Views
162
SN95 V6 Mustang Tech May 23, 2026
DPP
D
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?