Tapping sound from engine

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Your valves r tapping could be low on oil. I had a slight tap in one of my cars the engine is still going strong thousands of miles later

Nope.

Hi, this really depends on its service history.

The following are the recommended service intervals on the Merc S500:

Note: operate A/C at least once per week, to maintain lubrication.

Underhood & Undervehicle

Every 3,000 miles - Replace engine oil & oil filter. Clean battery terminals. Adjust drive belt. Check power steering fluid. Check steering & CV BOOTS for wear and replace if necessary. Lubricate front end suspension.

Every 6,000 miles - Check transmission fluid condition and level. Check brake pads and caliper components - replace if necessary. Lubricate driveshaft U-joints. Rotate tires. Lubricate wiper arm linkage and pivots.

Every 12,000 miles - Adjust engine valve clearance. Replace distributor cap & rotor. Drain and replace engine Coolant. Replace Air Filter element. Replace Fuel Filter. Replace wiper blades.

Every 24,000 miles - Replace Drive Belt. Replace A/C Compressor Drive Belt. ** Change auto transmission fluid & trans filter (this is critical and must be adhered to) - preferrably do a trans flush at same time. Replace drive AXLE fluid.

Every 36,000 miles - Replace HT leads.

Every 2 years - Replace brake fluid (also clutch fluid if applicable). Replace power steering fluid.


** If you intend to keep this vehicle long term, then consider changing the trans fluid & filter every 20,000 miles. This is the secret to automatic transmission longevity.



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probably the throttle position sensor or the fuel filter... or fuel pump

Its usual for the Lambda sensors to cause this if faulty!!

For Automatic Transmission the fluid needs to be changed around 75,000 miles, but check fluid levels a few times a year to make sure of no leaks the transmission dip stick is located toward the back right of the engine if you can't find it have your mechanic show you where it is at.

It is probably a oil pressure problem. If there is some sort of small blockage in an oil journal it could stop oil from flowing to the lifters which would cause the the tapping noise. at this point the best thing to do would be to try and flush out the engine with some sort of desludging agent. One thing i usualy do is drain the oil and re-fill it with atf and run it for about half an hour or an hour and then re-drain and replace with normal engine oil. transmission fluid contains tonnes of detergents and should help clean out any blockages.

Sounds like the starter. You can try several things but the main idea is to start it to be able to bring it to a mechanic. Disconnect the battery and push on the brake pedal. This will drain the power from the vehicle. Reconnect the battery and try to start the car. The theory behind this is the starter solenoid could be stuck energized. You can also locate the starter slightly tap on the starter and then try to start the vehicle. Also if the vehicle has sacked for some time before you purchased it the battery may not have the cranking amps necessary to start the vehicle. The electrical gizmos will work but it will not be enough to crank the engine. Check the battery is fully charged and possibly try to hook up jumper cables to another vehicle or a jump start Appliance.

Yes. Sounds like a plugged Trans filter or burned fluid. A full service on the Trans usually runs about $90 and is money well spent.

Another problem-which bugged me for 3 months, and had your similar symptoms, was a worn out fan clutch. It sent a shudder throughout the vehicle which mimicked a transmission issue. I know it sounds silly, but a new fan clutch cured my shifting issues.

The fan should rotate smoothly with some resistance (Engine OFF, of course) If you feel binding of any kinf, it probably is bad. Also check to see if you can cause movement fore and aft. If you can get it to rock back and forth, it is bad and needs to be replaced.

A fan clutch for that vehicle usually runs about $55