Why is my truck Overheating?

10

Asked by maloneym Apr 25, 2020 at 01:55 PM about the 1986 Nissan Pickup

Question type: Maintenance & Repair

My 86 nissan 4x4 v6 will idle
all day and not get
dangerously hot, until I start
driving, then the temp
climbs fast. Driving 55 on
the highway after it got hot I
turned on the heater on
high. I brought down the
temp to about 3/4 on the
guage. I left the blower on
high and switched the
selector over to cool, and it
dropped down below
halfway on the guage. Why?
I don't understand what
needs replaced. I chaneed
our the thermostat
yesterday, no change at all.
Is it my clutch fan?

3 Answers

154,885

This is going to be a coolant circulation problem. Bad water pump, clogged radiator, clogged water passages in the engine, or possibly a collapsing lower radiator hose. Hope that helps!

1 people found this helpful.
10

How do I go about cleaning the clogged water passages inside the motor? Radiator? With a radiator flush kit? I took the fan and clutch off, there is no fluid seeping from the weep hole in the pump, and no wiggle to the shaft. However, there seems to be ALOT of resistance in the fan clutch causing it to not want to spin at all by hand. Shouldn't I be able to spin it by hand a little bit, if the motor is off and cool?

1 people found this helpful.
154,885

You'll want to get a chemical cleaner for the cooling system. Then follow the instructions on the bottle. Yes, the clutch fan should be somewhat "loose" with the engine off and cool. But if it's locked up it will actually pull more air through the radiator. Hope that helps! Jim

Your Answer:

Pickup

Looking for a Used Pickup in your area?

CarGurus has thousands of nationwide listings and the tools to find you a great deal.

Postal Code:

CarGurus Experts

  • #1
    beater
    Reputation
    510
  • #2
    tibags55
    Reputation
    390
  • #3
    Larry Larsen
    Reputation
    360
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Ford Ranger
19 Great Deals out of 533 listings starting at $6,500
Used Mazda B-Series
8 listings
Used Chevrolet S-10
3 listings
Used Jeep Wrangler
136 Great Deals out of 5,920 listings starting at $8,995
Used Nissan Pathfinder
31 Great Deals out of 1,726 listings starting at $285
Used Nissan Sentra
56 Great Deals out of 1,895 listings starting at $2,288

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. Content will be removed if CarGurus becomes aware that it violates our policies.