[rich1]

Originally Posted by tr32valve

A couple of things. I just purchased an 04 mach1 TR with only 3,500 miles on it. Whoo Hoo! OK Now that that this is over with let me voice in. I have been building engines for a very long time. I have also had some very ferocioulsy fast cars as well. This is what I know. I have an 04' with a build date of 10/07 second shift. My cylinder heads have no blue paint on them and also have 8 thread spark plug holes. That kind of adds a twist to some of the earlier posts claiming that I should have a blue painted cylinder head and that the 8 thread design didn't start until until 11/15. Ok no big deal here because weird things happen during manufacturing all the time. As for the noise...........This is also what I know. Most of your posts are all right. Mis-detonation and heat will cause pistons to do some very strange things like scoring, marring, cracking, breaking etc. As for us having soft blocks.......that shouldn't matter much as our cylinders are sleeved due to the aluminum blocks. There should be no issues there. A piston slap usually only occurs when the engine is cold and this is fact. I do admit that I do not understand the water circuit diagrams of our engines and how the water flows, as I just haven't had the darn thing long enough to understand it. Heat will also do some strange things to valve guides. The ticking noise many of us hear usually calms down for the most part as our engines cool down (idling for about 2 or so minutes) so the heat theory seams to hold some water. As for how detrimental it is to our engines........that is another story. The tick most of us hear isn't much more loud than the normal noise from our injectors. This isn't too alarming as our engines are made entirely of aluminum and that stuff really conducts sound, much more so than iron. The tick could be caused by a number of more issues. For any of us old timers (not that old really, under 40) I remember a TSB Ford had out in the day for the #5 cylinder lifters in the 5.0's (1991 or so) would tick if operated with synthetic motor oil. That certainly didn't stop anyone from using sythetic oil and certainly didn't stop any of us from beating the tar out of those cars. Oil does strange things when it's heated too. It gets very thin. Thin enough to where lifters will not pump up as much as they should due to blead off. Since the tick I hear isn't present when the motor is cold and calms down quite a bit if I let the engine idle for a few minutes before shut down, I believe it to be a oil thinning issue. I may be wrong, and have been wrong before but this would also agree with the heat issue just not related to the engine coolant but rather the engine oil. Two of my friends also have Mach 1's and to be honest they also have a very slight tick when hot and more noticable right before shut down but again if alllowed to idle for a bit this too seems to settle the noise down. I also own an 08' GT/CS and this engine also experiences a more noisy vlave train when the engine is hot and even more noticable if pulled into the garage after a hard running and not permitted to cool down further before shut down. It would be great if we could get our hands on the oil circuit diagrams as well as coolant circuit diagrams. I am sure they exist somewhere. That is my .02 worth and I am sticking to it. BTW - this board has some very passionate members and I hope I will be able to strengthen the community. I am glad to be here and more importantly I am glad to be a proud owner of these fine cars.

I too agree with most all of the info given here. I know that working for a large manufacturing company for many years that parts is parts . They are not going have a firm date when the heads are installed just whenever they recieve them at the plant.
I also agree with the above post about oil .I was using Motorcraft 5/20 Full Syn.for quite a while. Earlier this year I changed the oil after the winter and could only find Castrol 5/20 Blend . I changed the oil using that and posted how much less noise was present .This is still true and noted alot less when the motor is hot and idling .I think the Full Syn .oils thin out too much too. When I first used Full Syn Oil in my old 5.0..it used it alot more because the Forged pistons had more cylinder wall clearance .I went back to just Reg Castrol and this issue lessened back then .I know not a 4.6 just noted.
I think that is it also worth saying that a Coolant addative like Water Wetter will also be helpful try to even out the cooling heat transfer in the motor too.