Just bought 2003 discovery II. It checked out fine - drove home 150 mi. Going down a hill heard a metal sounds. Louder when reved engine. It drove fine and no warning lites are on. Went to start it this morning and it sounds like someone threw a knife in a garbage disposial. Sounds like it is coming from the back of the engine. ANY Ideas on what it could be. It is so loud on starting I am afraid to even drive it. SO sad hope I didn;t get taken- I so love this vehicale. ANy ideas??

 

when i had my heads off i did clean the surfaces with a scotts brillo pad just to clean the old gasket off and i was very careful not to stay in one spot to long it did not have much junk on the heads just a couple spots and that came off pretty easy then i skimmed the whole head. im having it towed to my father in law garage today i guess im going to start taking it apart again. i really do not want to tear my heads off again but if that is what you guys think that it is then i will have to.

 

tntbecca did you have any loss of power when that is going on, or is it rough running like vibrating a lot

 

You can also use a yard stick or such to hold to your ear and touch various spots on the engine (valve covers, etc.) to track down the sound. That said, low oil, low oil pressure; these are things that can make mechanical parts fail. If racket is from under valve covers on one side, time to examine the rocker arms and related parts of the valve train. It is not dead yet, but should not be driven. Only crank for quick testing.

 

no - seems to drive fine. Just loud noise like spoke in fan. Drove it to neighborhood mechanic. Noise seemed to stop as I accelorate. Then start up as I let off.? He has not had a chance to look yet. Only had it 1 day so sad!!

 

hey guys i am starting to tear it down again to get heads checked and planed if needed i should order new gaskets for the heads am i able to reuse the head bolts they are only in for a few days and it has only ran for about 15 minutes.

 

The bolts are "torque to yield" or "stretch" bolts. You might find a spec and measure them, it is the length and not the hours of operation that drive that decision. Not wanting to do this again, I'd suggest new bolts. Here is the spec sheet on the heads.

 

If you have a slipped sleeve/cracked coolant duct/both, new head gaskets won't fix the root problem. You'll be continually replacing head gaskets. I won't go into the best fixes for this as there are already a lot of threads on that...just depends on your means.

 

Ok here is the update, just had them checked and they were 4 thousands out so they shaved them and also pressure checked them at 40 psi and no further issues, now my concern is that it seemed like my oil level got higher due to antifreeze while it was not running I am going to take the intake manifold in to get checked also, have you ever seen a intake manifold cracked

 

Not cracked, but a number of posts about the rear bolts being found finger tight.