Engine clatter & miss after running @ top speed

[Travler]

After running at top speed the engine starting clattering. Is there something in the valve train that could come loose and cause this noise? I trailered it home; it still starts but has a bit of a miss with the clattering noise... could I have dropped a valve? Thx in advance (2007 M45)

[EdBwoy]

Might you be able to pinpoint what part of the engine it is? left/right bank, front/back of the engine or is it coming from the headers? Might be material from the precats

[TXT]

Check your oil level. It's probably low. This happened to me twice. I didn't do a top speed run but I accelerated very hard.

Put some oil in there to proper level. The sound might not go away right after but this is what your car needs.

This happens to the M45's. The 8 cylinder burns lot's of oil.

[EniGmA1987]

M35's too when oil is too low.

[Travler]

I've got it at the shop now; maybe a dropped valve; I will keep everyone apprised; thanks for the help (also it has 110k miles on it)

[FlawleZ]

I hope you trust the shop 100%. It may be an easy fix that many shops would take he chance to charge you an engine rebuild/replacement.

[TXT]

I hope you trust the shop 100%. It may be an easy fix that many shops would take he chance to charge you an engine rebuild/replacement.

This is very true. Maybe you can do something and perhaps stop by and check the oil level yourself. Ask them if they added oil and ask them if it was low. Like i said, once you add the oil the sound may or may not go away right away. When i added the oil to mine after doing similar to what you did to cause the noise, after 2 days of the sound being very audible (but getting better), I decided to mash the pedal one time and once I did that, the sound went away.

In other words, the very thing that caused this noise to occur is the also the same thing that made it go away (after adding oil).

The sound in more detail is a ticking sound that is very loud. The faster you drive the faster the clicking/ticking becomes. It sounds terrible and will worry anybody but it could simply be low oil and now a lifter is stuck and all it needs is a little push to get it unstuck AFTER you put in some oil. I'm no mechanic and I am a novice to internal parts of an engine, but after extensive research on google, this is the main reason for the sound occurring (it comes up often on many websites).

Don't let them replace something on your car that will hurt you financially, you may have money but wasting money will get me very upset. I wouldn't really blame the shop if they do end up telling you that many things need replacing. After all myself and others have already been through this and know how to fix it.

These engines are strong, but it just burns oil and if the engine is lacking it's blood, then this happens.

[mazz]

i have a hard time believing you plan a high speed run without checking oil and tires and etc on a 7 year old car please be safe
Mazz

[Double E]

True Mazz... because I do top speed runs occasionally I check it often... even the old Y34 units burn oil.

[Travler]

Well; we found out the clatter was deeper than the valve train; maybe a wrist pin? we have plenty of metal in the oil, (which was full)...
Anyone know a good place to get a new or used 4.8 engine?
The Avatar pic shows the 4.8's pretty alloys with their molecules rearranged to an undesirable shape...

[Travler]

My mistake; 4.5L engine

[RemtechM35x]

This happened to me once. Oil was a bit low. After doing some personal investigation to the engine I found the #1 cylinder spark plug was a bit loose. DARN DEALERSHIPS... Anyways. Not sure if thats in your case but doesn't hurt to check.