Skip the auto shop - Our mechanics make house calls

Q: Loses power after engine get up to temp, runs good cold

asked by on

Truck runs great cold when it gets up to temp the power decreases greatly. new fuel pump, new fuel filter, new air filter has been hooked up to two different computers and it's showing no codes at all. New muffler and dual pipes,the old ones were bad. im at a loss and so are my mechanics

My car has 84000 miles.
My car has an automatic transmission.

A: Heat causes electrical resistance in a circ...

Heat causes electrical resistance in a circuit or component to increase. If you have a bad component that may have a bad internal connection, the increase in temperature could cause a voltage drop in the component. Also, heat can cause a crank position sensor to act up if it is starting to fail.

Temperature sensor failure can sometimes cause similar symptoms. The dashboard temp gauge typically uses a different sensor than the ECU uses to determine if the vehicle is cold or warm, affecting the amount of fuel that is required for proper operation. Ignition coils and also other components are vulnerable to higher than normal resistance from heat.

It may be tricky to try and diagnose this yourself, but a fun challenge for a seasoned, certified technician to figure out. In depth electrical testing of individual components will be needed to determine the exact cause of your vehicle's loss of power.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: 1994 Chevrolet Camaro won't stay running

Hi. Since you have a bunch of aftermarket equipment, it's difficult for me to help you much without inspecting the vehicle firsthand. If the vehicle won't stay running, that means it either isn't getting spark or doesn't have the correct...

Q: Just did spark plugs on a 2013 ford car and now it is having problems shifting

You have a manual transmission and unless you created a problem in the hydraulic system the spark plugs will not have anything to do with the clutch or transmission problem. You will need to have the transmission and clutch checked...

Q: What Is an ECU and What Does It Do?

The electronic control unit (ECU) used in today’s cars and trucks is used to control the engine and other components’ functions. An ECU is a computer with internal pre-programmed and programmable computer chips that is not much different from a...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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.