Reply
 
Thread Tools Display Modes
 
Old 04-21-2016, 07:09 PM   #1
Veteran Member
 
City: Channel Islands
Country: United States
Join Date: Nov 2015
Posts: 54
Ford Lehman 120 Bad cylinder

I have a Grand Banks 32 with rebuilt ford lehman. It has about 1800 hours on it. My mechanic said today that one of the cylinders/pistons is bad.

Does any one have any experience with this? Im wondering if the engine will need to be removed or whether it can be lifted in the boat and redone there.

thx
__________________
Advertisement

mplangley is offline   Reply With Quote
Old 04-21-2016, 07:27 PM   #2
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Which cylinder is it?
__________________

__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 04-21-2016, 07:47 PM   #3
Guru
 
Capt.Bill11's Avatar
 
City: Sarasota/Ft. Lauderdale
Country: USA
Join Date: Apr 2014
Posts: 5,422
Depends. And it's pretty rare for a Lehman to need a rebuild with so little hours on it.

I bet he says it's the number 6 cylinder?
Capt.Bill11 is offline   Reply With Quote
Old 04-21-2016, 08:11 PM   #4
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 3,889
What symptoms is it showing?
Ski in NC is offline   Reply With Quote
Old 04-21-2016, 09:50 PM   #5
Veteran Member
 
City: Channel Islands
Country: United States
Join Date: Nov 2015
Posts: 54
It is the first or last cylinder - the cylinder nearest the stern.

The symptoms were excessive blow-by. Also the mechanic did a check whereby be listened for engine idle change as he loosened the injectors. When he loosened the cylinder nearest the stern no changes were noted however as we tested the others the idle speed changed.

So I am trying to figure out what my options are and what to expect and am wondering if the engine can be lifted and repaired right in the boat.

thanks for any insight into matter.
mplangley is offline   Reply With Quote
Old 04-21-2016, 10:26 PM   #6
Guru
 
City: kemah
Country: USA
Join Date: May 2015
Posts: 997
You can bore it in the boat but you need to find a mechanic that has the portable boring jig.
what_barnacles is offline   Reply With Quote
Old 04-22-2016, 12:13 AM   #7
Veteran Member
 
Busterbrown's Avatar
 
City: Corona
Country: USA
Vessel Name: SCRAMBLER
Vessel Model: 1974 Grand Banks 32 #536
Join Date: Jul 2013
Posts: 55
Engine Savers in Chino, California ask for Dan
Busterbrown is offline   Reply With Quote
Old 04-22-2016, 12:44 AM   #8
Senior Member
 
City: Gig Harbor
Country: USA
Vessel Name: Selah
Vessel Model: Ocean Alexander 40
Join Date: Dec 2011
Posts: 191
You could have your mechanic swap the #6 and the #5 injectors and repeat the test to rule out a bad injector. You could also get a diesel compression tester and confirm the #6 cylinder is low, $850 from Snap-on or $169 from Harbor Freight.
av8r is offline   Reply With Quote
Old 04-22-2016, 01:09 AM   #9
Guru
 
City: Sydney
Country: Australia
Join Date: Jul 2015
Posts: 1,354
Id also be testing the manifold temperature on the 6 cylinders and comparing the results and insert a little camera down the injector hole and have a look at the cylinder wall and compare it to another cylinder
gaston is online now   Reply With Quote
Old 04-22-2016, 01:21 AM   #10
Veteran Member
 
City: Langley BC
Country: Canada
Vessel Name: Shalady
Vessel Model: 1981 Cheerman 38 Europa
Join Date: Oct 2013
Posts: 67
Excessive blowby and one dead cylinder may be caused by
1- A hole in the piston, likely caused by a stuck injector
2- Broken rings
stanfromhell is online now   Reply With Quote
Old 04-22-2016, 01:50 AM   #11
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
I`m interested in why, and why no.6(as expected)? Fortunately we have some experts on the thread. My understanding, as a Lehman owner who bought mechanic time flushing one of mine, is overheating at no.6 due to poor cooling, due in turn to sludge blocking the cooling passages.
Interested to hear more, hoping the OP`s engine can be efficiently repaired. Was the past rebuild before the OP bought, or are details of the need for rebuild known?
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 04-22-2016, 07:52 AM   #12
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,531
"The symptoms were excessive blow-by."

Excessive blowby and no compression are different animals .

My guess would be stuck rings . A couple of long hard runs with very fresh oil might help.

The outboard folks have super cylinder cleaning products that actually work and might free the rings if that is the problem.

If the problem is mostly at idle and there is no billowing white smoke , ot rapid lube oil consumption, live with it.

It might cost an extra cup of fuel an hour or a quart of oil between changes , so what?

Heaven might be "perfect",,, but for a cruising diesel reliable IS perfection.
FF is offline   Reply With Quote
Old 04-22-2016, 09:33 AM   #13
Guru
 
Mule's Avatar
 
City: Fort Pierce
Country: USA
Vessel Name: Florita Ann
Vessel Model: 1982 Present
Join Date: May 2014
Posts: 1,789
Any thoughts about injecting a few tablespoons of Marvel Mystery Oil into the offending cylinder to try to free things up. Doubt if the voodoo will work but maybe if you chant and face Haiti. Injector out anyway so why not?

On such issues I defer to FF. On this one I am adding to and building on his diagnosis.
Mule is offline   Reply With Quote
Old 04-22-2016, 09:45 AM   #14
Guru
 
Xsbank's Avatar
 
City: Pender Harbour, BC
Country: Canada
Vessel Name: Gwaii Haanas
Vessel Model: Vancouver Shipyards Custom Aluminum 52
Join Date: Sep 2013
Posts: 2,447
The number 6 cylinder fails on some Lehmans. It's always number 6 and it's a cooling issue. I have not heard it satisfactorily explained why it fails but there is conjecture the angle of the engine mount and the distance from the water pump, failure to regularly "burp" the coolant jacket, the distance from the Simms pump perhaps causing slight lean conditions, not regularly changing the coolant...
Anyways, that cylinder overheats, the oil breaks down, the cylinder walls are badly scored and the piston leaves large amounts of aluminum on the cylinder walls. You will see the damage with a boroscope.
In a 32, the engine comes out through the back door. You can do it in place but you'll get a better result in a shop. You can also buy rebuilt from places like Industrial Engines near Vancouver, BC if you don't want to wait for the rebuild.
Sorry. I have heard of three that failed like yours.
Xsbank is offline   Reply With Quote
Old 04-22-2016, 11:11 AM   #15
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 2,740
Quote:
Originally Posted by Xsbank View Post
The number 6 cylinder fails on some Lehmans. It's always number 6 and it's a cooling issue. I have not heard it satisfactorily explained why it fails but there is conjecture the angle of the engine mount and the distance from the water pump, failure to regularly "burp" the coolant jacket, the distance from the Simms pump perhaps causing slight lean conditions, not regularly changing the coolant...
Anyways, that cylinder overheats, the oil breaks down, the cylinder walls are badly scored and the piston leaves large amounts of aluminum on the cylinder walls. You will see the damage with a boroscope.
In a 32, the engine comes out through the back door. You can do it in place but you'll get a better result in a shop. You can also buy rebuilt from places like Industrial Engines near Vancouver, BC if you don't want to wait for the rebuild.
Sorry. I have heard of three that failed like yours.
And I was warned of this possibility from overheating by more than one "experienced timer" when I told them I had a Lehman 120.
The temp sender is on the front of the engine, so the back of the engine may be hotter and you won't know.
This is one of the reasons I am a little over anal about maintaining the raw water system, changing impellers too often, etc.,
__________________
Jay Leonard
Attitude Adjustment
40 Albin
Mystic,Ct. /New Port Richey,Fl
jleonard is offline   Reply With Quote
Old 04-22-2016, 12:00 PM   #16
Veteran Member
 
City: Channel Islands
Country: United States
Join Date: Nov 2015
Posts: 54
Quote:
Originally Posted by FF View Post
"The symptoms were excessive blow-by."

Excessive blowby and no compression are different animals .

My guess would be stuck rings . A couple of long hard runs with very fresh oil might help.

The outboard folks have super cylinder cleaning products that actually work and might free the rings if that is the problem.

If the problem is mostly at idle and there is no billowing white smoke , ot rapid lube oil consumption, live with it.

It might cost an extra cup of fuel an hour or a quart of oil between changes , so what?

Heaven might be "perfect",,, but for a cruising diesel reliable IS perfection.

Is there any risk of further damage by a couple of long hard runs? I was wondering the same thing, namely whether a cylinder cleaning product may work.

I don't know that there is "no compression" but I do know there is excessive blow by and there seems to be insufficient compression for combustion. I will see about following up with a compression check but my mechanic seemed to think it was not necessary as he was pretty convinced that it was a bad cylinder issue.
mplangley is offline   Reply With Quote
Old 04-22-2016, 12:01 PM   #17
Veteran Member
 
City: Channel Islands
Country: United States
Join Date: Nov 2015
Posts: 54
Quote:
Originally Posted by FF View Post
"The symptoms were excessive blow-by."

Excessive blowby and no compression are different animals .

My guess would be stuck rings . A couple of long hard runs with very fresh oil might help.

The outboard folks have super cylinder cleaning products that actually work and might free the rings if that is the problem.

If the problem is mostly at idle and there is no billowing white smoke , ot rapid lube oil consumption, live with it.

It might cost an extra cup of fuel an hour or a quart of oil between changes , so what?

Heaven might be "perfect",,, but for a cruising diesel reliable IS perfection.

Is there any risk of further damage by a couple of long hard runs? Also I was wondering the same thing, namely whether a cylinder cleaning product may work or is this just wishful thinking?

I don't know that there is "no compression" but I do know there is excessive blow by and there seems to be insufficient compression for combustion. I will see about following up with a compression check but my mechanic seemed to think it was not necessary as he was pretty convinced that it was a bad cylinder issue.
mplangley is offline   Reply With Quote
Old 04-22-2016, 12:18 PM   #18
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 3,889
Does blowby "puff" each time that cylinder should fire? If blowby puffs in sync with one cylinder firing and that cylinder misfires, pretty much nails a piston problem.

Can also take injector out and with valves closed shoot compressed air into inj hole. If pressure does not build and air is going into crankcase, just pull head.

Sometimes pistons screw up and cyl wall is not damaged, or not damaged much. A bit of honing and a new piston/rings and good to go.

I would not run the engine hard in that condition, you could cause more damage.

Makes me wonder if during your last rebuild the piston/bore clearance was a bit too tight. If that cyl 6 tends to run hot, you want the clearance on the loose side of spec. And honing will get you just that.

Solvent like two stroke outboard "ring-free" may be worth a try. I have unstuck rings with that before on a diesel. But don't run engine hard unless the compression comes back and blowby goes to normal.
Ski in NC is offline   Reply With Quote
Old 04-22-2016, 01:12 PM   #19
Veteran Member
 
City: Channel Islands
Country: United States
Join Date: Nov 2015
Posts: 54
Quote:
Originally Posted by Ski in NC View Post
Does blowby "puff" each time that cylinder should fire? If blowby puffs in sync with one cylinder firing and that cylinder misfires, pretty much nails a piston problem.
I would say yes. Nice billowy white puffs.

Do you think there is any harm in trying marvel mystery oil or "engine restorer" just to see what effect it has or is this a waste of time. I'm just thinking that if engine restorer brings compression up enough that the piston fires then that may help determine whether honing the cylinder would be sufficient.
mplangley is offline   Reply With Quote
Old 04-22-2016, 01:22 PM   #20
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,531
Mystery Marvel oil is #1 diesel, some coloring and oil of wintergreen to change the aroma.

Removing the injector to swap it with a different cylinder will allow both to be hooked to a compressed air source to see a difference.
__________________

FF is offline   Reply With Quote
Reply

Thread Tools
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 Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 01:29 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012