Q: I have p0128, p0304, and p0420 engine will not run.

asked by on July 11, 2017

I have codes p0128, p0304, and p0420,the engine will not run. when starting it seems to fire for a couple of rotations (maybe 1 second) then it just turns over. Either hot or cold. The car was on the road moving when it died. Lucky for us it died close to our house. The p0420 code has been around for a while.

My car has 172000 miles.
My car has an automatic transmission.

I believe it was the P0128 code that did it. This code indicates a faulty thermostat or a faulty coolant temperature sensor. If the P0420 code has been around for a while, this would not only not have caused the vehicle to die but would also prevent you from knowing if any other codes pop up since the check engine light would have already been on. In the event of a failed thermostat, the engine coolant is not able to circulate properly which can cause the engine to overheat. If the temperature sensor has failed as a result of this code, the gauge on the dash may not have indicated that the engine was overheating. Due to the large possibility of the engine being overheated, it is likely that one or more cylinders have low compression as a result. I would recommend having the compression tested to determine if the compression is low.

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

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

Engine coolant disappeared

The engine could have an internal coolant leak and the coolant is being consumed into the motor. This is is you do not see any leaks anywhere on the round or on the engine. I would recommend having a mechanic...

Antifreeze leak

The cooling system that is leaking and over 13 years old could be most any component in the system. The cooling system will need to be pressure tested to locate the leaks in the system. The radiators and expansion tanks...

Stalling when driving, idling is rough, and gas seems to be use up quickly. It also hesitates when accelerating. There's no Check Engine Light on.

This may be a sign of a failing throttle position sensor or mass air flow sensor. As you may know, the mass air flow sensor monitors the air flow into the intake as it is mixed with fuel prior to...

Related articles

Pontiac Certified Pre-Owned (CPO) Car Program
If If you’re in the market for a used Pontiac vehicle, you may want to check out cars under their certified pre-owned program. Many manufacturers have a certified pre-owned (CPO) program, and each one is set up differently. Read on...
How to Buy a Classic Pontiac
Whether you want to buy a classic Pontiac for yourself or as a gift, here are some tips on buying one for a great value.
Understanding the Pontiac Oil-Life Monitor and Service Indicator Lights
Car symbols, or dashboard lights, are a car service reminder. The Pontiac Oil Life Monitor (OLM) indicates when and what service your car needs.