2004 Lincoln LS Motor Noise

bagge72

So I had a new-used motor put in my 04 LS V8, this new motor had only 39,000 miles on it when it was put in. Ever since it was put in it has had this motor noise, where it either sounds like an exhaust leak or a small ticking in the motor when it is cold, or when I start it up even after it has been driven for some time. The only time it doesn't make the noise is after it's been running for about 10 - 15 minutes, and it is at operating temperature. If I shut the motor off, and start it back up it will make the noise again until I start driving it. The noise is most notable when their is a load on the motor.

cdnpinhead

I'm guessing an exhaust system leak. Crack somewhere or gasket leak, either one of which could seal up as the system heats up. Is it most noticeable between 2500 & 3K rpm under load, then reduces or goes away when you take your foot off the fuel feed?

bagge72

Yeah that sounds about right, I did have the exhaust checked out from the manifold back, but nobody could find a leak.

brucelinc

I would check the sealing between the exhaust manifold and the head, the manifold itself, and the gasket between the manifold and exhaust pipe. If you stick your head under the hood while someone revs up the engine a bit, you may be able to pinpoint where it is coming from.

akirby

I seem to remember this being an intake manifold problem, but I don't remember the details.

LincolnTech

hmmm...have you checked the diffrental pressure sensor that has 2 exhaust hoses running thru it and it tends to sound like a exaust leak....theses motors tend to heat up so much that it melts the plastic sensor....this sensor can be found on the passenger side of the firewall and looks like a black triangle with 2 hoses.

reddog66

Had the same problem with a 2000 F150 5.4L Was sure it was an exhaust problem. Sounded like lifters but as we know this is overhead cams and no lifters but turned out to be fuel injectors. The dealer knew right away. They cleaned them and no more clicking noise. Can't recall price of job as I had some other things done as well and it was about a year ago. Traded the truck in as well for a new one.