Why does engine temperature drop to almost cold when I go down hill?

Asked by Dec 10, 2015 at 12:49 PM about the 2006 Mitsubishi Lancer ES

Question type: Maintenance & Repair

My car was overheating, and thank God I caught that and made it to the mechanic. He switched the thermostat, but the radiator still wasn't heating up. He tried putting a hole in the t-stat, didn't help.(Could it have?) it turns out the water pump was totally dead (the "teeth" fell out!), and he switched it out. Now the engine takes a good while to warm up, and if I go down hill... the engine actually cools down.. to 1/8 the gauge, instead of staying right in the middle. Did the mechanic ruin the t-stat? Is it stuck in open? The only way to prove this to him is to have him drive up a big hill with me... the temp gauge stays in the middle when its idling by the time I get to the mechanic's. Any advice? Thanks!

4 Answers

70,175

It will be the hole he drilled in thermostat,put you a new one in it.

1 of 1 people found this helpful.

Is it really bad for the engine to run cold like that sometimes? How long can I drive with it like this? I've heard of people expanding the hole on t-stats a bit... why do this?

Because they hear things they don't understand, and drill holes in parts that are engineered a certain way for a reason. Yes, a cold running engine is very bad. It is designed to run at a relatively high temperature and cooled by the circulation of coolant by water pump. It is NOT wise to mess around modifying a thermostat. The manufacturers know what they are doing, and 'why' ? Because they think they know more than the designers and engineers

1 of 1 people found this helpful.
85,995

The engine will not run as efficiently as it should if it is cold all the time and you won't have heat inside the car.

1 of 1 people found this helpful.

Your Answer

Lancer

Looking for a Used Lancer in your area?

CarGurus has 5,241 nationwide Lancer listings starting at $2,450.

ZIP:

Mitsubishi Lancer Experts

  • #1
    Daniel Foster
    Reputation
    190
  • #2
    T_S_T
    Reputation
    170
  • #3
    COMETGUY61
    Reputation
    160
View All

Related Models For Sale

Used Mitsubishi Lancer Evolution
11 Great Deals out of 581 listings starting at $12,999
Used Honda Civic
822 Great Deals out of 60,826 listings starting at $950
Used Subaru Impreza WRX
43 Great Deals out of 1,180 listings starting at $1,500
Used Ford Mustang
611 Great Deals out of 39,252 listings starting at $1,895
Used Subaru Impreza
218 Great Deals out of 22,518 listings starting at $1,505
Used Toyota Corolla
964 Great Deals out of 65,101 listings starting at $1,850
Used Honda Accord
1,114 Great Deals out of 73,321 listings starting at $1,100
Used Dodge Charger
464 Great Deals out of 33,534 listings starting at $1,999
Used Mitsubishi Eclipse
14 Great Deals out of 1,134 listings starting at $1,799
Used Mazda MAZDA3
361 Great Deals out of 27,650 listings starting at $899
Used BMW 3 Series
1,170 Great Deals out of 32,725 listings starting at $1,200
Used Subaru Impreza WRX STI
28 Great Deals out of 626 listings starting at $9,490
Used Nissan 350Z
43 Great Deals out of 1,174 listings starting at $2,900
Used Toyota Camry
1,142 Great Deals out of 86,705 listings starting at $800

Used Cars For Sale

2017 Mitsubishi Lancer ES For Sale
1,482 listings starting at $9,990
2016 Mitsubishi Lancer ES For Sale
14 Great Deals out of 459 listings starting at $7,990
2015 Mitsubishi Lancer ES For Sale
9 Great Deals out of 234 listings starting at $6,990
2014 Mitsubishi Lancer ES For Sale
121 listings starting at $5,900
2013 Mitsubishi Lancer ES For Sale
82 listings starting at $5,500

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.