Car runs great until it warms up, then it shuts off?

Tiny
CHRISTINE 77
  • MEMBER
  • 1994 BUICK LESABRE
  • 3.8L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 140,000 MILES
While driving about two miles car stalls and don't start again until engine cools? Fuel pump replaced fuse's checked MAF changed injectors cleaned.
Friday, May 2nd, 2025 AT 6:58 PM

4 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,114 POSTS
It sounds like you have a faulty crankshaft position sensor. When they begin to fail, they are adversely affected by heat. Heat causes expansion. The wire winding within the sensor expands and causes a disconnect, shutting off the engine. Once it cools, the connection is once again complete, and the vehicle runs.

Take a look through this link and let us know if the link's description mirrors what you are experiencing.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

If it does, this is what I would replace. Here is a link that explains in general how it is done:

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

On this vehicle, the harmonic balancer will need to be removed. If you look below, I have attached the directions specific to this vehicle. I can't guarantee it without further testing, but I am very confident this is the problem.

Let us know if this helps or if you have other questions.

Take care,

joe

See pics below.
Was this
answer
helpful?
Yes
No
+1
Friday, May 2nd, 2025 AT 9:03 PM
Tiny
CHRISTINE 77
  • MEMBER
  • 24 POSTS
I'll check that out but thinking it may be temperature sensor or EGR or even MAP sensor but do you happen to know where I can get a copy of where the sensors are located on the top of the engine block light throttle position sensor the half sensor area the EGR MAP sensor locations also where it's supposed to be ground to the block.
Was this
answer
helpful?
Yes
No
Saturday, May 3rd, 2025 AT 12:54 AM
Tiny
CHRISTINE 77
  • MEMBER
  • 24 POSTS
Also fan works when ran direct but not when it's plugged into harness fuses and relays are good.
Was this
answer
helpful?
Yes
No
Saturday, May 3rd, 2025 AT 12:56 AM
Tiny
STEVE W.
  • MECHANIC
  • 14,538 POSTS
I will second the crank sensor as being the issue on this. That is a very typical failure mode. The internal electronics fail and generate heat and shuts off. Then you need to wait for it to cool down before it works again, and being bolted to the engine means it has to cool as well. A quick way to test if it's the sensor, go to a store like Walmart or best buy and get a can of "canned air" or "computer duster". That stuff is a different version of the AC refrigerant in your car. Now for the test. First locate the sensor so you are sure where it is. Now put on gloves and some eye protection. Take the car for a drive until it stalls out. Now take the can of "air" and flip it upside down and spray the sensor with the liquid that comes out. Be careful that you spray only the sensor and not yourself. Spray it for about 5 seconds or so and let it evaporate off. Wait 10 seconds and spray it again. Now try to start the car. If it starts up without the long wait you have the answer that it is the crank sensor.
Was this
answer
helpful?
Yes
No
+1
Saturday, May 3rd, 2025 AT 1:16 PM

Please login or register to post a reply.