I have a question regarding engine termperature.

[Myco]

My car right now takes a long time to get up to temperature. It will eventually get up to temp but I can be 10+ miles away from home by this time ( on a warm day ).

Sometimes the temp of the car will dip back down a bit.

Never overheats, doesn't loose coolant. All new coolant.

Does this sound like a thermostat stuck open?

 

[chargerxr]

Yes.

 

[Right on the Mark]

Best way to check this is hook up OBD11 reader with live data. Watch coolant temp in numbers.

 

[sprocket]

If it does get up to temp and the swing isn't too bad I wouldn't make a big priority out of changing the thermostat. It's kind of a PITA. You need to have the correct thermostat (and the AP store WILL give you the wrong one), and you have to know the correct procedure to burp the cooling system. Search this forum for detailed instructions if you do decide to change it. Or just start a topic. Even If you brought it somewhere to have it changed, there is no guarantee they will do it right.

 

[Markviiiedrea]

Had the same problem on my truck. Make sure to change the t-stat with an OEM one because the aftermarket one restricts the flow of coolant from the radiator and also allows hot coolant to recirculate through the engine.

The one on the right is the stock one and the one on the left is aftermarket. It will cause additional problems if you don’t go Motorcraft.

Credit: racecougar

 

[Markviiiedrea]

Remove the battery and tray, which will give you room to work on the t-stat. It should take about 1-2 hours and have a good set of channel locks or one of THESE

Here is the exploded view, bolts are accessed through the bottom.

 

[Sapperfire]

1-2 hours? Remove battery ??

Do it from the bottom, 10 minutes

10mm?, 1' long 3/8 extension, ratchet

 

[racecougar]

My car right now takes a long time to get up to temperature. It will eventually get up to temp but I can be 10+ miles away from home by this time ( on a warm day ).

Sometimes the temp of the car will dip back down a bit.

Never overheats, doesn't loose coolant. All new coolant.

Does this sound like a thermostat stuck open?

10 miles doesn't tell us much. That's a completely reasonable amount of time if you're cruising at highway speeds, or excessively long if you're hitting stop signs every block. If the temp is dipping down right after initial warmup, that's a pretty good indicator of the thermostat opening.

The one on the right is the stock one and the one on the left is aftermarket. It will cause additional problems if you don’t go Motorcraft.

The one on the right is from Motorcraft, but it isn't the stock tstat. It's a 180 degree unit.

 

[Markviiiedrea]

1-2 hours? Remove battery ??

Do it from the bottom, 10 minutes

10mm?, 1' long 3/8 extension, ratchet

Did that way to clean everything up, and replace the clamps. I only work fast when I'm getting paid.

 

[dnsherrill]

toss spring clamps!!! my $.02....not a bad time to replace ofa gasket if not already done

 

[UltimateSVT]

It's better to be stuck open than stuck closed! I removed the thermostat all together off of my '93 & installed a '99 Mustang Cobra water pump. That sucker ran so much cooler & so much better. Temperature would never go over the "A" in NORMAL. I might just do the same thing to my Deep Blue.

 

[dnsherrill]

what's the coldest it gets in Miami? :shifty:

 

[sprocket]

1-2 hours? Remove battery ??

Do it from the bottom, 10 minutes

10mm?, 1' long 3/8 extension, ratchet

I also do it from the top because then I don't have to get under the car and get dripped on, except maybe to tighten the lower radiator hose clamp on the radiator end. I prefer to remove the entire thermostat housing and install the thermostat off the car. I can then be sure the o-ring is seated right and alternatively tighten the screws. I've got it down pretty good now and it takes me an hour tops and I make very little mess.

 

[UltimateSVT]

what's the coldest it gets in Miami? :shifty:

Yeah ummm... Once every 4-5 years we will get a couple days during our "winter" where it will dip down to 34, maybe 33 far inland. Towards where I live it's gotten close to 37 or so. Last time that happened here was back in 2009 & before that around 2002. It doesn't happen often at all.