Q: 2001 Pontiac grand Prix 3.1l engine tapping

asked by on

2001 Pontiac grand Prix engine starting tapping. About a month later I noticed coolant disappearing. A couple of weeks later I found coolant in the oil. Pulled the engine and tore it apart and found the intake manifold gasket failed on 4 ports. All the hydraulic lifters had collapsed, the crank and camshaft had damage (grooving) due to the leak. Completely pulled everything apart, had the block vatted and new camshaft bearings installed at NAPA. Rebuilt the engine replacing everything except the pistons, connecting rods, valves (did replace seals), valve springs and fuel injectors. Also replaced temp sensor, crankshaft position sensors, fuel pressure regulator, vacuum lines, coolant hoses, spark plugs and wires. Put everything back together filled with oil and coolant. Starts and runs but it still has the same tapping as before the leak. I checked the valves and springs when replacing the valve stem seals and they were good. Tapping is loud enough to hear inside the car. Help?

My car has 120000 miles.
My car has an automatic transmission.

Hi there. Typically an engine tapping noise is caused by either cylinder head lifters that are loose or worn out, rockers and valves not properly adjusted, a timing belt or timing chain that is loose or crankshaft / cam out of alignment or not balanced correctly. Oil restriction problems are also a leading reason for this type of problem. The problem with an overheating issue is that is can cause a lot of internal damage, especially when coolant mixes with the engine oil. An engine knock can also be produced by an ignition timing problem or misfire, which is also common after an overheating issue, especially if you didn’t replace the electrical wiring to sensors or fuel injectors as well.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. 2001 Pontiac grand Prix 3.1l engine tapping

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: adding oil to full synthetic

Hello. There is no problem with you adding a conventional oil to your vehicle if it already has synthetic in it. The only thing that you need to make sure of is that you are using the correct weight oil...

Q: Replaced master cylinder and brakes still going to the floor and not working. Bed both master cylinders and each wheel.

If your vehicle has ABS brakes, it is possible that there is an air bubble in the ABS system. Many vehicles require a special bleeding procedure for vehicles with ABS. This will require you to do the bleeding in a...

Q: When my car is at idle in park or neutral the Intake Air Control Valve fluctuates, causing the RPM's to do the same.

Hi there. It sounds as though the idle air control valve (IAC) may be sticking. It is not uncommon for carbon to build up in the valve, the computer will try to overcompensate to correct the slow reaction inside the...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...