Temperature Gauge spikes for 10 secs, then returns to Normal range

[KevinM2003]

About 10 minutes into the first drive of the day, my '03 NBX(XLT) temperature gauge will spike instantaneously from normal to all the way hot . This activates the check engine light, but then about 10 seconds later, it instantaneously falls back down into the normal temperature range and the check engine light goes off. It does not behave like this the rest of the day, but will do it again on the first drive the following morning. It appears to be working fine as it slowly climbs from cold all the way to the normal temperature range, but then it has this sudden spike all the way hot and then a sudden fall to normal temperature range (all within a 10 second time frame). In other words, it does not slowly climb from normal range to all the way hot. Rather, the jump is instantaneous and then 10 seconds later it instantaneously falls back to normal temperature and stays that way the rest of the drive. My long-time trusted mechanic replaced the coolant temperature sensor, but he now believes the gauge in the dash may need to be re-programmed or replaced. Anyone have any suggestions or any experience with this problem?

 

[abarkl]

Mine did the exact same thing for a few weeks until I replaced the thermostat.

 

[EasyRhino]

Mine did the exact same thing for a few weeks until I replaced the thermostat.

How did you center up on the T-stat being the problem. Was it sticking in the shut position at warmup? Weird.

 

[mikbor1]

x2 on the thermostat--Same exact thing happened w/me--When I changed it, the old thermostat came out in 2 pieces--The spring was broke--

 

[nasty_north]

same problem with spike. im going to try a new thermostat tomorrow.

i know we have seperate tranny cooler, but you think this might be adding to my tranny overheating problems. it dumps out trans fluid someitmes

 

[brkandjfk]

One month ago, while driving, my 2005 Explorer XLT Sport 4.0 v-6 overheated. Coolant steam from under hood, through the vents inside, etc. I pulled to the first stop I could about 1 mile later.

I opened the hood a few minutes later and found my Thermostat Housing looked like it had exploded from within. The bolts were broken, the plastic was in pieces, and the fluid had spewed all over...

I had it towed to the nearest Ford dealer where over two days they replaced:

Thermostat Asy
Housing - Ther
O ring
Anti-freeze
Gasket
Sender Asy

at a total cost of around $550. My initial conversation with the dealer was centered around the housing, but I inquired whether the issue was the housing or whether it was the result of another issue. Guy told me the sender assembly was the cause, the housing was the effect.

Fast forward... Every COLD start begins the same way as the OP described above... Gauge spikes, then returns to normal. It's important to note that the operation of the vehicle doesn't change, just the gauge.

I left for business travel for a couple weeks, and returned last week to deal with the issue. Appointment day arrived and I dropped the vehicle back off at the dealer.

Next day, guy calls to tell me that they have narrowed the problem to the radiator, which needs replaced because it is plugged. Cost = $800.

Fast forward... yesterday was my first time driving that vehicle post-new radiator. Same problem. Now I'm a bit peeved (and out of $).

Here's what they said they did this time:

Pressure test - No leaks
Check for head gasket leak - no hydrocarbons in coolant
EEC test - pass no codes
Test Drive & check radiator - top of rad cool, bottom hot. possible plugged. replace radiator and flush cooling system. test drive and temp gauge stays in middle.

Of course, their test drive post radiator would not have been a 'cold' start.

The Explorer goes back in tonight and they're springing for a rental... but frankly I don't have the ability to fund further repairs... the radiator screwed my finances for a couple months...

Any clues?

 

[brkandjfk]

Ok... so today they call me and say two things...

1. We really really did need to replace the radiator... honest.
2. There has to be a crack in the cylinder head. $3500 is cheapest option to replace engine.

Holy cow... sorry for my ignorance, but this entire deal sounds difficult to believe... Can anyone tell me if these symptoms are explained in this way?

 

[brentfaulk]

About 10 minutes into the first drive of the day, my '03 NBX(XLT) temperature gauge will spike instantaneously from normal to all the way hot . This activates the check engine light, but then about 10 seconds later, it instantaneously falls back down into the normal temperature range and the check engine light goes off. It does not behave like this the rest of the day, but will do it again on the first drive the following morning. It appears to be working fine as it slowly climbs from cold all the way to the normal temperature range, but then it has this sudden spike all the way hot and then a sudden fall to normal temperature range (all within a 10 second time frame). In other words, it does not slowly climb from normal range to all the way hot. Rather, the jump is instantaneous and then 10 seconds later it instantaneously falls back to normal temperature and stays that way the rest of the drive. My long-time trusted mechanic replaced the coolant temperature sensor, but he now believes the gauge in the dash may need to be re-programmed or replaced. Anyone have any suggestions or any experience with this problem?

Kevin did you get this fixed? I have the same problem in my Ranger, but have already replaced the thermostat ... :/

 

[esclamada]

About 10 minutes into the first drive of the day, my '03 NBX(XLT) temperature gauge will spike instantaneously from normal to all the way hot . This activates the check engine light, but then about 10 seconds later, it instantaneously falls back down into the normal temperature range and the check engine light goes off. It does not behave like this the rest of the day, but will do it again on the first drive the following morning. It appears to be working fine as it slowly climbs from cold all the way to the normal temperature range, but then it has this sudden spike all the way hot and then a sudden fall to normal temperature range (all within a 10 second time frame). In other words, it does not slowly climb from normal range to all the way hot. Rather, the jump is instantaneous and then 10 seconds later it instantaneously falls back to normal temperature and stays that way the rest of the drive. My long-time trusted mechanic replaced the coolant temperature sensor, but he now believes the gauge in the dash may need to be re-programmed or replaced. Anyone have any suggestions or any experience with this problem?

You probably have air in the cooling system or a faulty thermostat. Was there a drain/flush being done before this happened? Try bleeding it first before changing the thermostat.



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