Hey ya'll! New to the site and have one persistent problem with my otherwise great truck. I have a 2000 F-150 4x4 with the 5.4 motor with about 105,000 miles. When I start it it's fine but as soon as I apply just a little throttle it makes a tick-tick or knocking type of sound. It goes away as soon as the RPM's get above 1900 or so. What's the most economical way to figure this out ?

 

Take it to a dealer and pay them the $89.95 to tell you what is wrong.

 

Check your exhaust manifold bolts. Particularly the rear cylinder ones on either side. Bet you'll find a broken one or two......

I've got a broken one on each side.... Mine only ticks for a minute or so when it's cold. Once it's heated up, it's quiet.

Not looking forward to fixing them either.....

 

Mine does the same thing when you start it up but doesn't make any noise after it's warmed up. I never would have thought to check for an exhaust leak because normally an exhaust leak is noisy through all rpm's. But I'll guess I'll check the manifold bolts anyway.

 

the timing chain guides wear out at around ur milage and will chatter around cause a noise like a tick tick. id check that. but cost to fix them is alot so just drive it till it breaks

 

I would check the exhaust manifold bolts. They probably are very rusted and one may have broke off in the head. Another possibilty (and I would check this one real quick) is that you have a spark plug getting ready to achieve low earth orbit and blow out of the head.

 

Sure, drive it till the chain guides break. Never mind the fact that it is an interference engine and you'll need a new engine after all the intake valves smack the pistons. Great advice!!!!!!! That sure would be cheaper than having the guides fixed before hand.

 

My money is on exhaust leak as well, those will always be most pronounced at idle and low RPMs. You can REALLY hear it on trucks with headers.

 

When I have time I'll check the timing chain guides. I doubt it's the spark plug blow out I've already blown one of them and I know what to listen for. Besides it's been doing it for a while. I'm going to check my manifolds today. Thanks!

 

cost of a new engine and engine replacement is cheaper then the time and labor to replace the timing chains.

 

HI!... Not really, you must deal with some real SLOW mechanics. Timing chains can be changed in like 4 hours.

I believe what you are hearing is the famous 5.4 piston slap. Because the 5.4 has such a long stroke the piston skirts are VERY short. When the engine is fired up cold it takes a bit till the piston actually heats up and expands slightly in the bore making it more stable. The cold start knock is just basically the pistong wobbling in the bore ever so slightly. Don't worry though I have never heard of a engine failure do to this. My 5.4 did this from day one and it had 200,000 KMS on it when I installed my new built 5.4. Bores were still in great shape and the pistons too.

 

That sounds exactly like what I'm hearing. Not just Ford has that problem Chevy's 5.3's come with a wrist pin knock.lol I just heard my friends truck make the same exact noise as mine and she has a 5.4 too. So I'm ignoring it from now on. Thanks
https://www.f150online.com/galleries....cfm?gnum=7219

 

my father doesnt remember exactly but time to replace timing chains on a 5.4 is 6-6.5 hours according to the book. now it may only take 3-4 hours to do it. if u are fast and have done it several times. but thats is how many hours it costs the customer. and avg dealership it 65-80+ an hour. for labor. then to add parts and misc. your looking at close to 700 dollars to replace them

 

i can check fmcdealer for u.. but id need ur vin

 

Lets see...$700 to replace timing chains...$2500-$3000 to put in a new engine. Yeah your right, might as well just put in a new engine since you arent saving that much money