blow by - Ford Truck Enthusiasts Forums



Pre-Power Stroke Diesel (7.3L IDI & 6.9L) Diesel Topics Only

blow by

Reply
 
 
 
Thread Tools Search this Thread
  #1  
Old 04-02-2009, 01:42 AM
Red Cobra's Avatar
Red Cobra Red Cobra is offline
Senior User
Thread Starter
 
Join Date: Oct 2008
Posts: 251
Red Cobra is starting off with a positive reputation.
blow by

i happend to see that blow by was something to look at when buying a truck in another thred ..... my truck has some BLOW BY! like a good steady steam coming from the hose on top of the valve cover that leads to my intake .... i just took it off today and pointed it toward the back of the moter ... ha ha what does this meen?
Reply With Quote
  #2  
Old 04-02-2009, 02:12 AM
starmilt starmilt is offline
Post Fiend
 
Join Date: Oct 2007
Location: Faibanks Ak.
Posts: 10,501
starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.
It means you have got some miles on that rig.
All diesels have some but you are getting some compression in your crankcase usually going by the rings.
Reply With Quote
  #3  
Old 04-02-2009, 02:22 AM
Red Cobra's Avatar
Red Cobra Red Cobra is offline
Senior User
Thread Starter
 
Join Date: Oct 2008
Posts: 251
Red Cobra is starting off with a positive reputation.
230klm is whats on it .... and it does blow blue when i start it up but goes away when warmed up i hope my frickin moter is not shot ...
Reply With Quote
  #4  
Old 04-02-2009, 02:51 AM
starmilt starmilt is offline
Post Fiend
 
Join Date: Oct 2007
Location: Faibanks Ak.
Posts: 10,501
starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.
The blue at startup is valvestem seals I have seen rigs run forever and not use much oil like that.
Reply With Quote
  #5  
Old 04-02-2009, 08:15 AM
Dean88's Avatar
Dean88 Dean88 is offline
Postmaster
 
Join Date: Jun 2007
Location: Sweetwater Texas
Posts: 2,621
Dean88 has a good reputation on FTE.Dean88 has a good reputation on FTE.
Mines gotta good bit of blow by, but hardly uses any oil.

That 22.5 to 1 compression is what gets ya, it doesn't take hardly any gap at all with that kind of pressure to get a little compression in your crankcase.
Reply With Quote
  #6  
Old 04-02-2009, 08:17 AM
Dean88's Avatar
Dean88 Dean88 is offline
Postmaster
 
Join Date: Jun 2007
Location: Sweetwater Texas
Posts: 2,621
Dean88 has a good reputation on FTE.Dean88 has a good reputation on FTE.
ooh I just remembered, have you serviced your CDR? Its whole job in life is to relieve the pressure out of the crankcase, so it may be real dirty, thus not letting the pressure out, thus causing some of your blowby.
Reply With Quote
  #7  
Old 04-02-2009, 10:29 AM
David85's Avatar
David85 David85 is offline
Post Fiend
 
Join Date: Nov 2003
Location: Campbell River, B.C.
Posts: 6,900
David85 has a good reputation on FTE.David85 has a good reputation on FTE.
Before you start worrying about blow by, look at this:

YouTube - 1985 Ford 6.9 IDI Blow By Take Two

That video shows normal blowby at the filler cap and thats nothing to worry about. If you can feel actual pressure under there while the breather system is hooked up, then you might have a problem. One of the old school ways to check for how much is too much is to leave the filler cap in place but not turned to the lock. If the blowby pushes it up, then its too much.
Reply With Quote
  #8  
Old 04-02-2009, 02:46 PM
Red Cobra's Avatar
Red Cobra Red Cobra is offline
Senior User
Thread Starter
 
Join Date: Oct 2008
Posts: 251
Red Cobra is starting off with a positive reputation.
Quote:
Originally Posted by Dean88 View Post
ooh I just remembered, have you serviced your CDR? Its whole job in life is to relieve the pressure out of the crankcase, so it may be real dirty, thus not letting the pressure out, thus causing some of your blowby.
CDR??? haha what is that? and does anyone have pics of where it is located an idea on price and or if it can just be cleaned thanx



Quote:
Originally Posted by David85 View Post
Before you start worrying about blow by, look at this:

YouTube - 1985 Ford 6.9 IDI Blow By Take Two

That video shows normal blowby at the filler cap and thats nothing to worry about. If you can feel actual pressure under there while the breather system is hooked up, then you might have a problem. One of the old school ways to check for how much is too much is to leave the filler cap in place but not turned to the lock. If the blowby pushes it up, then its too much.
i have that much if not more blow by out of the filler i have not done the cap check yet tho but i got crazy amounts coming out of the end of the hose coming from my valve cover and now when i open my filler car it sounds like the inside of my moter is screaming at me kind of a high pitch i dont know if i remember it doing that before
Reply With Quote
  #9  
Old 04-02-2009, 02:59 PM
starmilt starmilt is offline
Post Fiend
 
Join Date: Oct 2007
Location: Faibanks Ak.
Posts: 10,501
starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.
The cdr is what your hose your talking about is hooked to. You can clean it soak it in gas and swish it around do not use compressed air as it will ruin it.
You will have some noise out of your oil filler cap as the gaers are noisy that is the only reasons most gassers had a timing chain instead.
Reply With Quote
  #10  
Old 04-02-2009, 03:03 PM
Red Cobra's Avatar
Red Cobra Red Cobra is offline
Senior User
Thread Starter
 
Join Date: Oct 2008
Posts: 251
Red Cobra is starting off with a positive reputation.
Quote:
Originally Posted by starmilt View Post
The cdr is what your hose your talking about is hooked to. You can clean it soak it in gas and swish it around do not use compressed air as it will ruin it.
You will have some noise out of your oil filler cap as the gaers are noisy that is the only reasons most gassers had a timing chain instead.
thanx is there a way to tell if its not working and in need of a new one after i clean it?
Reply With Quote
  #11  
Old 04-02-2009, 03:29 PM
starmilt starmilt is offline
Post Fiend
 
Join Date: Oct 2007
Location: Faibanks Ak.
Posts: 10,501
starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.starmilt has a very good reputation on FTE.
There probably is bit I don't know it . I do know if you get pieces of rubber out of it you need a new one. It is basically the same as a pcv valve on a gasser.
Reply With Quote
  #12  
Old 04-02-2009, 04:41 PM
David85's Avatar
David85 David85 is offline
Post Fiend
 
Join Date: Nov 2003
Location: Campbell River, B.C.
Posts: 6,900
David85 has a good reputation on FTE.David85 has a good reputation on FTE.
All you can do with the CDR to make sure its working (after the mentioned cleaning) is inspect it and make sure the rubber diaphragm isn't falling apart.....or just replace it with a new one.

The vapors will come out of the valve cover with more speed because the opening is smaller. Again, thats probably not much to worry about. If you look closer at that video I posted, you will see that the vapors get pulled back in if the engine is revved up a little. If yours does that, then its normal.

There will be high pitched noise comming out of the filler cap from the timing gears, not really loud but enough to notice. I suspect what you are hearing there is also normal.
Reply With Quote
  #13  
Old 04-02-2009, 05:30 PM
Red Cobra's Avatar
Red Cobra Red Cobra is offline
Senior User
Thread Starter
 
Join Date: Oct 2008
Posts: 251
Red Cobra is starting off with a positive reputation.
Well I cleaned it and no change. I could not see any rubber maybe its stuck open or closed...? And now I think I may have a rear main seal or pan leake this truck is really getting on my nerves
Reply With Quote
  #14  
Old 04-02-2009, 09:51 PM
Red Cobra's Avatar
Red Cobra Red Cobra is offline
Senior User
Thread Starter
 
Join Date: Oct 2008
Posts: 251
Red Cobra is starting off with a positive reputation.
if there is no oil on the fly wheel and clutch is there a chance that it could be my main seal? or maybe just pan i have not had the chance to get underneath it with a wrench yet to see if maybe the pan is loose at the rear or maybe its just the gasket i cant remember can you pull this pan without pulling the moter ?
Reply With Quote
  #15  
Old 04-02-2009, 10:05 PM
David85's Avatar
David85 David85 is offline
Post Fiend
 
Join Date: Nov 2003
Location: Campbell River, B.C.
Posts: 6,900
David85 has a good reputation on FTE.David85 has a good reputation on FTE.
Any leak on the top or rear of the motor can and likely will drain down the back of the engine to the access cover of the transmission. If your CDR grommit in the valley pan of the engine isn't sealing perfectly, that can already send oil down the back of the engine during idle conditions.
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
82 bronco 4.9l oil spray timwoodbury 1978 - 1996 Big Bronco 1 02-19-2017 06:38 AM
Shock choices for the ex Ex man Excursion - King of SUVs 38 02-23-2016 09:11 PM
Behind the seat storage option and pic Winmagbar 1994.5 - 1997 7.3L Power Stroke Diesel 1 02-14-2016 09:17 AM
Help! 6.9L Spewwing Oil FLDuckHunter Pre-Power Stroke Diesel (7.3L IDI & 6.9L) 15 01-10-2010 11:18 AM
Behind seat storage, regular cab, besides DU-HA Wagion 1999 to 2016 Super Duty 5 08-25-2009 07:33 PM


Go Back   Ford Truck Enthusiasts Forums >

Tags
69, 73, blow, blowby, by, crankcase, diesel, f150, filler, ford, hose, idi, normal, presure, turbo

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -5. The time now is 12:52 PM.