This could be any number of things... a slipping belt, burnt valves, old bearings. Try plugging some of the car symptoms into this search engine... it's handy: http://findzer.com/searchengines/000017.html
It depends on what is making the noise.
There could be numerous reasons why a Suburban is making engine noise at start up. It could be anything from a blown gasket to a spark plug. A mechanic will be able to find out the cause of the noise.
no,if it is normal functional sound.if it is grinding or making some other kind of noise then there is definitely an issue.
If the 1999 Suburban noise is a sort of loud banging noise, the problem could be that the engine have jumped time. Jumping time would cause the noise and jerking in the engine.
a lifter
Maybe you have a miss in your engine?
over 55 mph
Its the variator on the intake camshaft that is making the noise put engine flush into to the engine run it for ten minutes and then change the oil and the noise will be gone.
If it was overheating at the time, you cracked the block.
When you can not figure out why your car makes a strange noise, you take it to a mechanic.
If a Lincoln LS V8 is making a engine noise when it is shifted into drive or reverse, it could indicate a seized gear in the transmission. It could also indicate a low transmission fluid warning.
Usually it's the lifters in the engine making that noise until they become fully pressurized with oil, then they stop ticking, like on the 3 liter caravans.