Hi there:
Before to adventure on a replacement part, I sugges to check this information about "engine noses"...
ENGINE CLICKING NOISES
A clicking or tapping noise that gets louder when you rev the engine is probably "tappet" or upper valvetrain noise caused by one of several things: low oil pressure, excessive valve lash, or worn or damaged parts.
First, check the engine dipstick to see if the oil level is low. If low, add oil to bring it back up to the full mark. Is the engine still noisy? Check your oil pressure. A low gauge reading (or oil warning light) would indicate a serious internal engine problem that is preventing normal oil pressure from reaching the upper valvetrain components. The cause might be a worn or damaged oil pump, a clogged oil pump pickup screen or a plugged up oil filter. Using too thick a viscosity of motor oil during cold weather can also slow down the flow of oil to the upper valvetrain, causing noise and wear.
COLLAPSED LIFTER NOISE
Worn, leaky or dirty lifters can also cause valvetrain noise. If oil delivery is restricted to the lifters (plugged oil galley or low oil pressure), the lifters won't "pump up" to take up the normal slack in the valvetrain. A "collapsed" lifter will then allow excessive valve lash and noise.
VALVE LASH NOISE
If you can rule out lubrication-related problems as a cause, the next step would be to remove the valve cover(s) and check valve lash. On older import engines, mechanical lifters require periodic valve lash adjustments (typically every 30,000 miles). Too much space between the tips of the rocker arms and valve stems can make the valvetrain noisy -- and possibly cause accelerated wear of both parts.
To measure (and adjust) valve lash, you need a feeler gauge. The gauge is slid between the tip of the valve stem and rocker arm (or the cam follower or the cam itself on overhead cam engines) when the piston is at top dead center (valve fully closed). Refer to a manual for the specified lash and adjustment procedure. Also, note whether the lash spec is for a hot or cold engine (this makes a big difference!).
On engines with hydraulic lifters, oil pressure pumps up the lifters when the engine is running to maintain zero lash in the valvetrain. This results in quiet operation. So if the rocker arms are clattering, it tells you something is amiss (bad lifter or worn or damaged parts) or the rocker arms need adjusting.
DAMAGED ENGINE PARTS NOISE
Inspect the valvetrain components. Excessive wear on the ends of the rocker arms, cam followers (overhead cam engines) and/or valve stems can open up the valve lash and cause noise. So too can a bent pushrod or a broken valve spring.
RAPPING OR DEEP KNOCKING ENGINE SOUND
Usually bad news. A deep rapping noise from the engine is usually "rod knock," a condition brought on by extreme bearing wear or damage. If the rod bearings are worn or loose enough to make a dull, hammering noise, you're driving on borrowed time. Sooner or later one of the bearings will fail, and when it does one of two things will happen: the bearing will seize and lock up the engine, or it will attempt to seize and break a rod. Either way your engine will suffer major damage and have to be rebuilt or replaced.
Bearing noise is not unusual in high mileage engines as well as those that have been neglected and have not had the oil and filter changed regularly. It can also be caused by low oil pressure, using too light a viscosity oil, oil breakdown, dirty oil or dirt in the crankcase, excessive blowby from worn rings and/or cylinders (gasoline dilutes and thins the oil), incorrect engine assembly (bearings too loose), loose or broken connecting rod bolts, or abusive driving.
Bearing wear can be checked by dropping the oil pan and inspecting the rod and main bearings. If the bearings are badly worn, damaged or loose, replacing the bearings may buy you some time. But if the bearings are badly worn or damaged, the crankshaft will probably have to be resurfaced - which means a complete engine overhaul or replacing the engine is the vehicle is worth the expense.
ENGINE PINGS OR KNOCKS WHEN ACCELERATING
The cause here may be Spark Knock (Detonation) caused by an inoperative EGR valve, overadvanced ignition timing, engine overheating, carbon buildup in the combustion chambers, or low octane fuel.
Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.
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Thanks this is GREAT information. I live in MN and it is currently -40 outside. I notice my car making loud noises when I start it. This just started once it was below 0 outside. At first the oil light indicator came on once the car was warm it went off. I went out of town for 3 day once I returned I started the car and it was making really loud noise and several indicators lights were on and they all went off once the car was warm. Today the noise did not go away after running for an hour. I checked the oil and it is fine. The engine light is still on. Please help
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SOURCE: Tappets making a constant noise
i would suggest asking your mechanic which viscosity(thickness) oil he put back in and check it against the manufacturers recommendation as if it isto thin then it will make your tappets unusally noisey if he has put in the correct oil then i would say that they were quiet because of the old gungy oil and they either need adjusting or if they are hydraulic then the lifters need replacing
SOURCE: my 197 range rover wont start -replaced fuse box
hi i have a range rover p38 2.5 diesel it starts but wont drive when you put in drive
SOURCE: 1998 range rover p38 2.5 dse auto engine stalls
Sounds like something is overheating then and possibly a sensor. Not familiar with Rovers but might be a problem with the CAS and/or CPS which tells the ECU the motor is running and when to fire. Also maybe the IAC is bad and when you go from throttle to idle it can't control it and allows it to die.
SOURCE: rover 25 wont start with key, makes fast clicking
could be alternator not charging, put another good battery on and see what happens ,if it starts then check charge with a induction amp meter ,as these vehicles use intelegent charging system so disconnecting the battery with engine running to see if keeps running so you know alternator is ok doesnt work .if warning light goes out then renew the battery but if engine management light on then it could be a alternator fault or the ECU playing up ,and to check this out you wwill need a scope to read the fluctuations on teh sensor wire to the ECU and read the resistance to check for a fault as these vehicles use encrypted software to make it a dealer only job but it can be checked without it .
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hello i have a 2.5dt range rover i had the head done on it and a new turbo put n but now wen a drive it now rattels when warmed up can anyone help me piont out what it could be please thank you
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