Skip the auto shop - Our mechanics make house calls

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.

A: Hi there. If the engine has too many miles...

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?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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: Clutch chattering when shifting to first gear

Hello. A clutch chatter will be due to a couple of possible problems. Have the motor and transmission mounts checked to make sure none of them are broken. If all the mounts are good, then the only other problem is...

Q: Leak and low oil pressure

This suggests that you may have a leaking oil pan gasket. This can happen for a number of reasons, but is usually common due to excessive heat which causes the gasket to shrink creating a leak in the gasket. This...

Q: Engine power loss

Hello. Although the symptoms may feel like a misfire, it's worth checking out the transmission too, since the transmission on this vehicle has multiple technical repair bulletins pertaining to the transmission lower gears causing jerking, noise like whining can be...

Related articles

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 Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.