How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Scott W. Your Own Question
Scott W.
Scott W., Ford Technician
Category: Ford
Satisfied Customers: 3311
Experience:  28 yrs. experience as Ford ASE Master Technician. Accolades include being a 2005 Ford PTS Regional Finalist and 2006 ASE Ford National Technician.
26022388
Type Your Ford Question Here...
Scott W. is online now
A new question is answered every 9 seconds

2001 explorer sport: overheating, temp..idle..traffic light

Customer Question

ford 2001 explorer sport trac. Was overheating, temp would reach near max at idle and then cycle down and back up (at traffic light). Figured it was thermostat. Replaced 2 wks ago and seemed to then be ok. Starting doing same thing again today and even on highway.

I know could be t-stat again but thinking its the fan clutch 1st choice, water pump 2nd.
Submitted: 5 years ago.
Category: Ford
Expert:  Scott W. replied 5 years ago.

Steve W :

Hello my name isXXXXX is the cooling system full? Is it blowing coolant out the overflow?

Customer:

Good question which I forgot. WHen I replaced the thermostat a few weeks ago reservoir was dry.

Customer:

Flushed the system and replaced coolant at same time

Customer:

as the thermostat replacement

Customer:

It did initially pull down the reservoir the first few days and kep it between cold and warm levels

Steve W :

No leaks you can see?

Customer:

haven't added any since and at normal level. Could here and smell the coolant in the air.

Customer:

No leaks at all

Steve W :

Okay, does the heater blow hot air at idle, or does it blow cold air when hot?

Customer:

heater blows warm / hot air when cabin temp set to for warm air and cold when adjusted for colder temps.

Customer:

manual adjustment for cabin temp

Steve W :

Ok, I would drive vehicle for 5 miles get warmed up, then leave running, open hood and look into coolant bottle for bubbles. If there are bubbles you could have a head gasket problem or cracked head.

Customer:

ok ...

Customer:

will try that now

Customer:

do I just leave this open and get back to you or ?

Steve W :

Is your engine a SOHC?

Customer:

Yes

Customer:

pretty sure it is ... let me check real quick ... BRB

Steve W :

Ok, I have never seen a bad head or gasket on these engines, I was thinking of the 4.0 OHV.

Customer:

Yes it is the 4L SOHC

Steve W :

Ok, was the t-stat a Ford part?

Customer:

No was I guess you'd say OEM from auto parts store

Customer:

It's acting now, exactly like it was with the Ford thermostat I replaced.

Customer:

I figured it was a stuck thermostat initially ... and when I replaced it the trouble appeared to be resolved ... until this morning

Steve W :

Okay, I have seen many of these engine overheat and was always the t-stat, if you drive this and you don't see any bubbles, I would try a ford t-stat first, I would also remove a heater hose and have a assistant start the engine and check for good flow out of the heater hose, if it does, this means water pump is working, if this is okay, then this would leave the fan clutch, if it doesn't overheat running down the road, but does while sitting in traffic, I would replace the fan clutch.

Customer:

ok ... before I replaced the t-stat it would not overheat on interstate. Today was different story. Today at 70mph the temp at times would creep up to max (redline) and then drop. Act like the t-stat just opened up. 5 minutes later temp would get say get to 3/4 or so of the gauge range and cycle back down to mid-range on gauge (where it normally just sits). 30 minutes into my drive to client it stayed mid-range for the rest of the trip. Coming home on interstate stayed pretty normal. On surface streets got back to the cycling up close to max (never had check engine light today) and then back down.

Steve W :

Also check the front of the radiator sometimes they can get built up with bugs dirt debris etc.

Customer:

I'll go ahead and drive for 5 minutes and will check from of radiator again for obstruction. Was ok a couple of weeks ago.

Steve W :

Sure sounds like T- Stat to me. Let me know what you find.

Customer:

will check for bubbles and also check front of radiator for obstruction

Customer:

How is best way to let you know?

Customer:

1st time for me using your service

Steve W :

Just reply to this question, the system will let me know, if I am online I will answer soon, or will reply as soon as I can if offline.

Customer:

OK ... is there a reliable indicator of a bad fan clutch? Read an article about cold versus warm the other day when I replaced the t-stat

Steve W :

If the engine is overheating and the upper hose is flowing coolant and is real hot, the clutch fan should come on and roar when the engine is revved. It will be noticable.

Customer:

OK

Steve W :

Here is fan clutch test from service manual.

Steve W :

Click here

Related Ford Questions