Q: Water pump is leaking, do I need to replace the timing belt, too? The car also has a misfire on cylinder 3.

asked by on

I brought my car in to the shop for a valve cover gasket replacement (my dad was gonna replace my wires and found a bigger problem), and today they called saying it's leaking a little oil, but my car is "known for that"... And my water pump is leaking and when they replace that instead, they need to do the timing belt, too. This is going to cost $900. I'm really wondering if I should bother. The issue I was having was the engine misfiring every time I stepped on the gas and the code I got was misfire in cylinder number 3.

My car has 235000 miles.
My car has an automatic transmission.

Hi there. If the engine has too many miles on a timing belt, then a timing belt is suggested for replacement. The misfire for cylinder 3 could be caused by a spark plug failure, fuel injector failure, or a problem with the cylinder.

First, check for the fuel injector. Start the engine and disconnect the harness to the fuel injector for cylinder 3. If the engine sounds different, then the fuel injector was working. If the engine has no difference in sound, then the injector was not working and needs to be checked.

Next, check the spark plug for a solid blue / orange spark. If the spark is weak, the plugs and wires need to be replaced as a set.

To check the cylinder if it is getting hot enough to burn fuel, put a compression tester on cylinder 3 and crank the engine over. There should be more than 130 psi.

If you need further assistance confirming the misfire diagnosis, then a certified technician from YourMechanic, can come to your car’s location for a second opinion on the car.

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. Water pump is leaking, do I need to replace the timing belt, too? The car also has a misfire on cylinder 3.

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: Hard to turn steering wheel when on park.

Hey there. There is a check valve in the power steering pump that quite often sticks after a rebuild. Since these are "restoration" components, they tend to sit on shelves longer than present-day parts. Tap lightly on the power steering...

Q: Q: Head gasket leak

Hello. Leaks, especially from the head gasket, are problematic because they can lead to overheating and engine damage. This is something that you will want to take care of sooner or later. I would recommend having a technician locate the...

Q: Intermittent cylinder misfiring on a '98 Grand Marquis

What you should do, if you don't have the equipment and you don't understand it is to call a professional to take a look into your misfiring problem for you. Mechanics, like those from YourMechanic and myself, we've been doing...

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...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...