The Ford Barn

Brooks · 06-24-2014, 02:51 PM

My v8 flathead engine is making a pecking noise when it get hot. was rebuild about 200miles ago sit for 9 mos. while I restored my car. the motor is a stock 1940 v8. run good until it get hot driving it then running about 50 mph making the pecking noise. No noise at idle. Anyone had this problem or know what it could be. Also has good vacuum 21 at idle and all plugs are firing good. Have a Blessed Day!

Walt Dupont--Me. · 06-24-2014, 03:15 PM

How is the oil pressure, on the road and hot idle? Walt

Brooks · 06-24-2014, 04:00 PM

Walt, The oil pressure is good 50lbs cold ilder about 25 to 30 hot, ilder at 20 hot. Thanks.

Ken/Alabama · 06-24-2014, 05:32 PM

If you havent already, try going up to speed and when the noise starts push it up in neutral and see if the noise continues while coasting with engine at idle.That would rule out a driveline noise. I had a simular problen once and found thet when the engine got hot the dome of the pistons on the right bank was just barely bumping the head. But that engine did had a pair of Offenhouser aluminum heads on it. The noise it made was a little heavier than a pecking noise.

flatjack9 · 06-24-2014, 05:52 PM

Exhaust leak?

35 coupe · 06-24-2014, 07:47 PM

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I had a similar thing in my 50 f1, would make a ticking noise at certain speeds, could not find it and then one day out it started and my speedo cable broke and the noise went away, put a new cable in, lubed the speedo, and no more noise. the noise was pretty loud, like a lifter ticking in the cab

Brooks · 06-24-2014, 08:15 PM

Ken, the noise is in the engine on the right side I believe in #3 cyl. I had a pertronic dist on it and found that #3 cyl was not firing above 500 RPM. I took the plug out it had lot of carbon on it. Could it be carbon on top of piston? If it is what is best way to clean it out? Thanks

TomO · 06-25-2014, 09:44 AM

Seafoam will clean the carbon out of the cylinders.

charles in east texas · 06-25-2014, 11:46 AM

At fast idle slowly pour a 16 oz. bottle of MMO into the carburator, right before
The bottle is empty quickly pour the rest of the MMO in, probably will kill the engine.
Next turn off the key and wait 24 hours. That's what I did and got rid of my noise
That sounded like an insert. Also good for mosquito control. Charles

Ken/Alabama · 06-25-2014, 12:40 PM

Quote:

Originally Posted by Brooks

Ken, the noise is in the engine on the right side I believe in #3 cyl. I had a pertronic dist on it and found that #3 cyl was not firing above 500 RPM. I took the plug out it had lot of carbon on it. Could it be carbon on top of piston? If it is what is best way to clean it out? Thanks

Once you get it firing on all 8 do as TomO suggested then take it out and run it hard for a mile or two.

AnthonyG · 06-25-2014, 01:45 PM

MMO is the ticket for loosening / cleaning off the carbon. Have a '67 442 and years ago when I first got it (1983 ) it was high mileage and I knew it was loaded up with carbon. Did exactly what Charles said except went with two 16 ounce bottles and purposely stalled it with excessive dump at the end of the second ( definitely killed a lot of mosquitos ) Mine sat for a couple of days and ran a lot better. I was amazed at how clean piston tops and valves were when I finally rebuilt it several yrs later.
Go MMO

06-24-2014, 02:51 PM	#1
Brooks Senior Member Join Date: Aug 2013 Location: AL Posts: 115	'40 flathead engine noise My v8 flathead engine is making a pecking noise when it get hot. was rebuild about 200miles ago sit for 9 mos. while I restored my car. the motor is a stock 1940 v8. run good until it get hot driving it then running about 50 mph making the pecking noise. No noise at idle. Anyone had this problem or know what it could be. Also has good vacuum 21 at idle and all plugs are firing good. Have a Blessed Day!

06-24-2014, 03:15 PM	#2
Walt Dupont--Me. Senior Member Join Date: May 2010 Location: Gardiner Me. Posts: 4,200	Re: '40 flathead engine noise How is the oil pressure, on the road and hot idle? Walt

06-24-2014, 05:32 PM	#4
Ken/Alabama Senior Member Join Date: May 2010 Location: Alabama Posts: 3,395	Re: '40 flathead engine noise If you havent already, try going up to speed and when the noise starts push it up in neutral and see if the noise continues while coasting with engine at idle.That would rule out a driveline noise. I had a simular problen once and found thet when the engine got hot the dome of the pistons on the right bank was just barely bumping the head. But that engine did had a pair of Offenhouser aluminum heads on it. The noise it made was a little heavier than a pecking noise.

06-24-2014, 05:52 PM	#5
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,600	Re: '40 flathead engine noise Exhaust leak?

06-24-2014, 07:47 PM	#6
35 coupe Senior Member Join Date: May 2010 Posts: 373	Re: '40 flathead engine noise Sponsored Links (Register now to hide all advertisements) I had a similar thing in my 50 f1, would make a ticking noise at certain speeds, could not find it and then one day out it started and my speedo cable broke and the noise went away, put a new cable in, lubed the speedo, and no more noise. the noise was pretty loud, like a lifter ticking in the cab

06-24-2014, 04:00 PM	#3
Brooks Senior Member Join Date: Aug 2013 Location: AL Posts: 115	Re: '40 flathead engine noise Walt, The oil pressure is good 50lbs cold ilder about 25 to 30 hot, ilder at 20 hot. Thanks.

06-24-2014, 08:15 PM	#7
Brooks Senior Member Join Date: Aug 2013 Location: AL Posts: 115	Re: '40 flathead engine noise Ken, the noise is in the engine on the right side I believe in #3 cyl. I had a pertronic dist on it and found that #3 cyl was not firing above 500 RPM. I took the plug out it had lot of carbon on it. Could it be carbon on top of piston? If it is what is best way to clean it out? Thanks

06-25-2014, 09:44 AM	#8
TomO Senior Member Join Date: May 2010 Posts: 362	Re: '40 flathead engine noise Seafoam will clean the carbon out of the cylinders. __________________ TomO

06-25-2014, 11:46 AM	#9
charles in east texas Senior Member Join Date: May 2010 Location: Winnsboro, Texas Posts: 463	Re: '40 flathead engine noise At fast idle slowly pour a 16 oz. bottle of MMO into the carburator, right before The bottle is empty quickly pour the rest of the MMO in, probably will kill the engine. Next turn off the key and wait 24 hours. That's what I did and got rid of my noise That sounded like an insert. Also good for mosquito control. Charles

06-25-2014, 01:45 PM	#11
AnthonyG Senior Member Join Date: May 2013 Location: Pa. Posts: 2,217	Re: '40 flathead engine noise MMO is the ticket for loosening / cleaning off the carbon. Have a '67 442 and years ago when I first got it (1983 ) it was high mileage and I knew it was loaded up with carbon. Did exactly what Charles said except went with two 16 ounce bottles and purposely stalled it with excessive dump at the end of the second ( definitely killed a lot of mosquitos ) Mine sat for a couple of days and ran a lot better. I was amazed at how clean piston tops and valves were when I finally rebuilt it several yrs later. Go MMO __________________ Nomad