Somewhere in this forum I read that some F-150 owners had complained of a diesel (valve clatter) sound coming from their trucks when they accelerate from a stop. I have a 4.6 engine and have the same problem. However, mine did not begin until one night I had to make a panic stop, fully utilizing the antilock brake system. When I pulled away, immediately following the panic stop, a very loud rattling sound came from the front of the truck. I thought it was the valves rattling and have heard similar, but much less significant noises since that time, when the engine and brakes are hot. I have almost concluded that the noise is actually the antilock brake system and not the engine. Has anyone else experienced this problem?

 

There should be no relationship between the antilock braking system and the engine -- but taking your observation at face value, have you noticed anything continuing to be suspicious with your brakes? If so, what is/are the symptom/symptoms?

Are they repeatable?

Assuming that we can now rule out brakes, can you describe (or better yet post a recording) the engine noise?

Is it repeatable?

Is it temperature dependent?

Is it load dependent?

How long does it last?

In what gear or gears?

Manual or Automatic tranny?

Lastly - do you have the 4-wheel abs or merely the rear (what year truck - and does it have 4 disc brakes)?

------------------
Y2K™

Toreador Red, Keyless XLT SC SB 5.4L E4x4 4wDisc/ABS, 3.73LS, Skid, HD 7700# Towing, LT-245's on Chrome, Tube-Steps, Captain's, 6CD, Tonneau, named: "Nick"

 

My truck is a 99 F-150 Supercab, 4X2, with 4.6 (built in Romeo, Michigan), Automatic, 4 wheel disc brakes and ABS. The sound, which is not very loud, lasts only a split second and only occurs when accelerating in first gear, from a full or near stop. Brakes and engine are both hot. I have never heard the sound unless I had just applied and released the brakes. Again, it only began after I had made a panic stop using full ABS. When I first accelerated from the panic stop, it sounded like every valve in the engine rattled, but I think the noise I heard was actually the ABS and not the engine.

 

Hey guys,
My truck just started to do this same clatering valve sound thing about 2 months ago. It lasts for about 2 seconds only in first gear. It only happens when the engine is hot, and I have not had any panic stops in quite a while. I first noticed it when pulling away from a toll booth, where the wall was close to the fender of the truck. I just got back from Detroit last night (to Orlando) and it was a 2000 mile round trip with about 500 pounds in the bed running about 85mph the whole way and had no problems. The sound doesn't seem to be affecting the performance of the truck, but it does have me worried. I have a 97 4.6 with a 5 speed. It has rear wheel antilock brakes only. It also goes away with more revs and only seems to show up under load...meaning I can't make it happen by just reving, I have to be accellerating from a stop. Would like to hear what others have to say about this issue.
Thanks in advance,
Kapthowdy

 

Well BC, it looks like we're on our own here. I did just have a thought that maybe it might be some heat shielding on the exhaust thats rattling around after it heats up and expands...maybe? I have a 95 Ranger that had this problem when it had 20k on the odo. The mech at ford said he smacked the tar out of one of the cat converter heat shields whith a ball peen hammer and that took up all the play that allowed it to rattle. Only thing is I can't remember exactly how it sounded. As soon as I get a chance I'll get under there and check it out...stay tuned.
Kapthowdy

 

I'm no expert by any means, but this sounds to me like it is the brakes causing the noise. It is possible that you glazed the pads and/or rotors or one of the calipers is hanging up a little. The sound your hearing would be the pads/calipers chattering because they are slightly sticking to the rotors after you stop.
If your pads are fairly new, try removing the calipers and pads and breaking the glaze with some sandpaper. Sand the pads very lightly, just til the shine goes away with say a 150 grit. Then do the same to the rotors with a 100 grit, making sure to sand against the way the rotor spins, on both sides of the rotor.
Once back together, you have to break in the brakes. To do this, drive 20-30 miles like grandma would, being as light on the brakes as possible. Coast as much as possible, start applying the brakes to stop 2-3 times sooner than you normally would.
Doing this won't hurt anything. If your noise continues, you have just eliminated one thing that it could be. I'm betting this will stop the noise though.

------------------
Boss™

Just Ordered 2001 F-150 Lariat Wht/Slvr medium graphite leather, 4x4, SC, SB, SS, 99L 5.4L, 44E tran, 7700# payload, Class III Tow, 3.73LS, Skids, Capts chairs, 4W disc ABS, shift-on-fly, keyless, HD everything
Planned Mods:
Westin Chromed Stainless Nerf Bars, ARE LS II bed cover, Bedrug™, Gibson Swept Side Cat Back, K&N filter w/airbox mods, headers, Superchip, 3" body lift with at least 33's, alarm/pager/auto start system, stereo system



[This message has been edited by Boss96Hog (edited 07-20-2000).]

 

As I type this, my truck is sitting at the local Ford dealership with valve rattle. I have had it in the shop 3 times in the last month. I have a '99 Supercab Flareside Lariat equipped with a 4.6L. My valves rattle at 1300-1700 rpm. I have tried octane boost, changing gas octane ratings, changing brands of gas, fuel system clearner. You name it, I've tried it. The guys down at the Ford dealership are as clueless as I am. The valves only rattle when the engine is hot. I don't think there is any way my is related to the braking system as some guys have reported. The Ford dealership thought the computer had raised the desired octane rating itself. They lowered it last week with no results. Does any one have a clue about this problem? Performance doesn't seem to be happered by the noise. I'm starting to get concerned with the problem.

 

I just got through posting in allens Valve Rattle thread. I think it is heat related.

 

Mine does this everyonce in a while after a had brake. Sometimes I can hit the brakes hard then let off the brakes while I am still going forward and I hear it to. It is definately something to do with the brakes. Mine usually only does it afterthe antilock is activated