• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Oil burning on my recently buil 302

  • Thread starter Thread starter The blk67
  • Start date Start date May 15, 2026
T

The blk67

New Member
Jun 7, 2025
2
0
1
Lansdowne, Ontario, Canada
May 15, 2026
#1
  • May 15, 2026
  • #1
Hi guys, I am having an oil burning issue with a recent rebuild in my car.
302, gt40 3 bar heads, 5 angle valve job, x303 cam, 1.6 roller rockers,
Gt40 tubular intake, with 1inch spacer and rebuilt stockbottom end.
As engine idles, there's no signs of blue smoke, the moment I start to drive it will smoke as I up shif, once cruising it stops the blue smoke, as I deceleration or gear down blue smoke, I need some help with this issue
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,894
4,019
183
Claremore, OK
May 15, 2026
#2
  • May 15, 2026
  • #2
Did the machine show home the cylinders correctly? I had this happen once and had to tear the motor back down and the cylinders were not finished honed. Could also be a poor ring selection or installation. Best way to tell this is to do a leak down test.
 
Reactions: Mcmahst and Noobz347

Blackhawkxx

Advanced Member
Mar 3, 2023
483
477
73
May 15, 2026
#3
  • May 15, 2026
  • #3
Valve seals will also act like this. If they were replaced there is still a slight chance that one or more was damaged with the install.
 
Reactions: Noobz347

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,107
21,285
234
Box behind Walmart
May 15, 2026
#4
  • May 15, 2026
  • #4
How many miles are on these heads?
Were they also rebuilt?

It sounds to me like no matter what it is, you're going to have to pull the intake and heads and explore until you find the issue.

I saw that somebody already suggested a leak-down test. That's a good place to start.
 
Reactions: General karthief and Mcmahst
You must log in or register to reply here.

Similar threads

SOLD Sold.
  • TTSaleen
  • Jul 1, 2026
  • Engine and Power Adder
Replies
6
Views
290
Engine and Power Adder Jul 2, 2026
Noobz347
Engine Gas in my oil
  • limp
  • Jun 15, 2025
  • Fox 5.0 Mustang Tech
  • 2
Replies
35
Views
1K
Fox 5.0 Mustang Tech May 16, 2026
Mindseye007
6
Hey all,I’m putting together a 302 for my 1968 Mustang and wanted to post the combo + some questions to make sure I’m not missing crucial
  • 68_Disgustang
  • Feb 22, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
4
Views
900
1965 - 1973 Classic Mustangs -General/Talk- Jun 20, 2026
gray owl
G
F
289 to 302 Engine
  • Fri Guy
  • Feb 13, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
4
Views
674
1965 - 1973 Classic Mustangs -General/Talk- Feb 13, 2025
Fri Guy
F
S
Requesting Guidance for 306 motor swap - Fuel? - SD? MAF?
  • So_Flo
  • Jul 26, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
32
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 4, 2026
Mcmahst
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 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?