Loose exhaust manifold bolts

Reply

  #1  
Old 04-23-08, 01:27 AM
Member
Thread Starter
Join Date: Feb 2003
Location: USA
Posts: 228
Loose exhaust manifold bolts

My 86 Corolla developed an exhaust leak about 3 months ago. Turned out that a couple of bolts at the head were loose. Had to remove the carburetor to get access. Anyway, tightened the bolts according to the service manual and everything was fine until last night. Then I heard that familiar exhaust sound from under the hood. The factory bolts did not have any lock washers. What is the accepted practice when attaching an exhaust manifold to an aluminum head? Should I have used some thread sealant? The head gets very hot.

If the bolts still don't hold very long, would using helicoils or keenserts be any better? Which is preferred? Thanks
 
Sponsored Links
  #2  
Old 04-23-08, 11:57 AM
ukrkoz's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Jan 2008
Posts: 222
any loktite type material that you'll apply to those bolts will cake from the heat and you'll have those bolts stuck there forever. as a matter of fact, i'd use antiseeze on them instead and torque wrench.
do you have bolts (post says so) or studs with nuts on them? switching to pinch nuts should help. nothing holds you from using locking washers though, if you have enough clearance for added thickness.
i think, your gasket is d-e-d, dead. if you were driving with lose bolts, exhaust probably burnt tiny channels through it.
but for the age - i'll be not surprised if the threads in the holes are worn out indeed.
i hate to suggest this, as it's major overhaul, but instead of trying to fix it with the head on, and risking cutting new threads or installing plugs at the angle, you might be better off pulling engine head off and having it done properly aligned. shouldn't be that hard on your car.
beware: if you decide to do so, and use the moment and overhaul your head, then you'll have to replace piston rings at the same time, or they might blow due to increased compression.
 
  #3  
Old 04-24-08, 08:54 AM
Member
Join Date: Apr 2008
Posts: 3
not sure if there are any avail for your application, but there are companies that make locking manifold bolts (i.e. Breslin). Check the size/thread pitch of the bolts that come on your corolla and you might luck out.


Originally Posted by davelew View Post
My 86 Corolla developed an exhaust leak about 3 months ago. Turned out that a couple of bolts at the head were loose. Had to remove the carburetor to get access. Anyway, tightened the bolts according to the service manual and everything was fine until last night. Then I heard that familiar exhaust sound from under the hood. The factory bolts did not have any lock washers. What is the accepted practice when attaching an exhaust manifold to an aluminum head? Should I have used some thread sealant? The head gets very hot.

If the bolts still don't hold very long, would using helicoils or keenserts be any better? Which is preferred? Thanks
 
Reply


Thread Tools
Search this Thread
Display Modes
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 02:50 PM.