Author Topic: Noisy diesel sound after head gasket  (Read 3010 times)

jmsra

  • Newbie
  • *
  • Thank You
  • -Receive: 0
  • Posts: 30
    • View Profile
Noisy diesel sound after head gasket
« on: May 26, 2010, 04:50:00 PM »
After changing out the head gasket on my '91 Convertible i am getting that diesel sound coming from the valvetrain.
I'm hoping its not lack of oil pressure as everything was fine before except for the cracked head which led to the repair in the first place.
The new head was machined and a valve job was done by a reputable machine shop.
I have no oil lights coming on while running, but i know the light works.
I've looked inside the oil pan and everything looks good. no loose bolts or slipped pan gasket and the oil pickup was tight as well.
As far as i could tell there was no blockages to the oil pump and everything looked pretty clean.
It looked like the PO had changed the cam gears, chain, and guides. The tensioner seems fine as the chain had no slack in it.
I keep seeing references to this "diesel sound" but no actual fixes besides the timing chain.
What could i have installed incorrectly or not done when i put everything back together?
Sorry for the essay, but any help is much appreciated.
BTW: This is my first post, but i hope to have more input in the future!
« Last Edit: May 26, 2010, 04:52:50 PM by jmsra »

nickmpower

  • Hero Member
  • *****
  • Thank You
  • -Receive: 0
  • Posts: 890
    • View Profile
Noisy diesel sound after head gasket
« Reply #1 on: May 26, 2010, 05:14:58 PM »
The cam timing is probably off. Or maybe an exhaust gasket?

nicknikolovski

  • Sr. Member
  • ****
  • Thank You
  • -Receive: 0
  • Posts: 389
    • View Profile
Noisy diesel sound after head gasket
« Reply #2 on: May 28, 2010, 06:15:31 AM »
Recheck your timing!

jmsra

  • Newbie
  • *
  • Thank You
  • -Receive: 0
  • Posts: 30
    • View Profile
Noisy diesel sound after head gasket
« Reply #3 on: May 28, 2010, 07:46:33 AM »
I'll double check the timing tonight.
thanks for the feedback.

Janne

  • Newbie
  • *
  • Thank You
  • -Receive: 0
  • Posts: 42
    • View Profile
Noisy diesel sound after head gasket
« Reply #4 on: May 28, 2010, 08:58:57 AM »
Are all spark plugs tight?

jmsra

  • Newbie
  • *
  • Thank You
  • -Receive: 0
  • Posts: 30
    • View Profile
Noisy diesel sound after head gasket
« Reply #5 on: May 29, 2010, 03:56:49 PM »
So i checked the timing and the spark plugs last night.
Spark plugs were fine.
The timing was off by one tooth on both sprockets, but there was still 14 chain pins in between the cam arrows.
When i originally put it back together, the slots in the cam gears were all the way to one side. i should have have known then.
anyways, it runs great now and NO DIESEL NOISE!
The only sound i hear are the injectors and the whine from the timing chain guides.
Thanks again for the input and i hope this helps someone else.