This engine is in my '65 F100 Project. We picked it up from C/L as a 'runner'. It is a 390 FE out of a '64 T-Bird. Now the engine has plenty of power and torque, doesn't smoke or seem to burn any oil. It just has this slight rattle or knock that sometimes appears at idle or when decelerating, or right between shifts. Under load it goes away. Any ideas?
My 51 chevy did the same thing, I figured it was a wrist pin and started putting together another 283 for it. that wrist pin gave up the ghost and put a rod out the side of the block last Sat.. didn't sound like it was getting worse or anything. Just bang, crunch and smoke.....motor dead.
This is what I'm afraid of. My first instincts were to just drive it... but then again, I don't want it turn catastrophic.
Yeah man, mine ran awesome, never missed a beat, never smoked, and really ran like a sewing machine. I drove it that way for about a month, daily back and forth to work. then Boom..... as much as I hate to say it I would be looking for another motor, if just a temporary one to keep ya on the road and rebuild that 390. you could probably find a 352 real cheap and it would bolt right in.
Good advice. I've been looking for one. I'm new to the FE scene and I've noticed that they are a little pricier than the SBC's I'm used to. They don't pop up much around here.
oh yeah, an FE built to the hills will run ya dry. But stick with a mild build and stock parts its not to bad.
They do have floating wrist pins with a keeper holding the pin in the piston if one has come out that slight know may be the pin hitting the cylinder wall, or it could have a cracked piston, either way it's going to tear some stuff up when it fails, good luck to you.
I have had several FE's that had an annoying rattle like that. Most kept running forever. A cousin rebuilt his 428 twice and never got rid of it!
If it does it on first start up Id think main bearings. 390s & 428s are known for cracking/breaking piston skirts also
Im certainly no FE expert but my 31 coupe and the 65 Ranchero both have FE's and Ive owned FE's in various cars for decades. They are definitley different than a SBC. Im only guessing, but before I ***umed the worst, I'd pull a valve cover and look things over. The 64 T bird engine did not have solid lifters, unless modified, so the rocker arms should not be adjustable. You could have a lifter causing a rattle. Does the rattle sound "deep" in the engine or could it be valve train related. Changing lifters in an FE is a pretty big job, as the intake weighs close to 90 pounds if stock cast iron, rocker shafts have to come off both heads first as the pushrods run through the intake. You say you're looking for an FE, if you find one, be certain that the rebuilder is familiar with FE overhauls as they require special attention on simple things, like the cam plug in the back ofthe block goes cup side to camshaft, the rocker shafts MUST have oil holes facing down, distributor MUST be inserted through the intake manifold during installation before the intake bolts are tightened, or theres a very good chance you wont be able to insert it later. I would definitly become familiar with the engine if you plan on keeping the truck, they are different but bullet proof and reliable if ***embled properly. If the engines not smoking or knocking all the time, I'd drive that ****er. You've got a great looking truck there. As I said earlier, Im certainly no expert but if I can be of ***istance, contact me. I think if you start looking around, you can find FE parts at a reasonable price, now if you want to go fast, break out thhat wallet. Good :Luck... BOutlaw
Number 7 & 8 cyls fire consecutivly. If you look at a Ford F.E. spark plug wiring diagram the factory routs the wires on those cyls criss cross over each other otherwise the cyls will induction fire and knock a piston pin bushing out of #7 cyl. I have seen this many times when I was in the automotive machine business.
If it has an automatic check the torque converter bolts in the flex plate. and the flex plate it's self for cracks. I had a pretty good running truck given to me about 30 years ago because it knocked at an idle but the knock went away under load. Flexplate bolts were loose. That engine worked great in my 51 Merc for close to 100 k before I sold the engine.
what he said, had a Pontiac with a cracked flex plate that exhibited pretty much the same noise your getting
I checked the torque converter bolts...it has a c6. They were tight. And I tried to inspect the flexplate the best I could... I was hoping that would solve the problem, but no luck. The noise seems to be down low, not in the valve train. Thanks for all the advice guys!
It could be writs pin noise or it could be piston slap. Does it get less noisy when the engine is up to temp? If it does it is probably piston slap, they get old and loose, when they warm up everything swells and tightens up. The only way to properly check a flex plate is to remove it. But you can decide if you need to remove it to check it, first loosen up the torque converter so that the flex plate can actually flex, then get a big screw driver and pry it, you will need to turn the motor and pry it in several place unless you just get lucky. if it is cracked it will let you know.
True... it runs on the timing gear 'off-centric' thingy. At temperature it pretty much stays the same, if not a 'hair' louder... if that makes sense. I'll take your advice on checking the flexplate. Thanks 'porkn******'.
If you end up looking for a replacement engine, bear in mind they made these all the way up through 1976. The later (post-1971) ones can be had for rather cheap, mainly because they have lower (around 8:1) compression. This was done at the factory by installing 410 pistons to get the piston an additional .100" down in the hole. They still have bucketloads of torque, even with the lower compression, just only around 200 hp. All you'd need to do is buy a set of pistons for an earlier 390 ('68 Mustang should be just fine) and swap them out to get the compression back up. The 1972 and later heads also have hardened valve seats for unleaded gas.
Pulled an FE out of a truck and replaced it for a noise just like that. Put the motor in another for a temporary engine and the fuel pump quit. New one in, noise went away. Recommend checking your fuel pump.
It's got a new fuel pump. The old one stopped pumping about a month ago... replaced it. No difference as far as engine noise. Thanks for the input. JC
I love the HAMB and all the info but when it comes to FES as you've seen above some of the info is incorrect. SBC info doesn't apply to an FE, these hese people live and breath FEs: http://www.network54.com/Forum/74182
With engine idling and up to operating temperature pull a spark plug wire off and see if the knock stops. Work your way around the firing order and you should be able to determine which cylinder it is. This test should rule out water pump, fuel pump noises.........
Something in my previous post I should have added. I'm building one of these (390)now for my 63 Galaxie, I had the rods reconditioned and added ARP bolts, while checking out their work I noticed the small end of the rod was over a .001 out of tolerance so I had a 360 motor out of a 1/2 ton truck and checked those rods and there were over .002 out of tolerance. My machinist friend stopped by and we discussed and his opinion was that he thought either of these rod sets would make noise, I don't know if you can unload the cylinder by removing the plug wire to make the noise go away but I'd try it to see what happens. This I'm sure is common on motors that were made when gas was still 50 cents a gallon. Good luck.
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