Thermostat replacement necessary?

[97tbird]

I'm getting the infamous crack-prone plastic intake on my 4.6L T-bird replaced with the updated one with an Aluminum cross-over. (My intake has a little crack, and coolant is seeping out, not much, but still...been wanting to do this for a long time, I've been freaking out about the VERY slow coolant drop in the resrvoir tank, and the "wetness"/little puddle on top of the valley of the engine...)

The dealership-tech also said my valve covers could be tightened further; hopefully it'll take care of the little oil-weeping, too, and I can have my "zero-consumption" and again.

I'm able to get the updated intake-kit almost $200 cheaper thru a contact, which I'm so happy about.

NOW, while I'm getting this done, I thought of something else:
I have my original thermostat still, with 105k miles. Car operates fine, I think. But what's the life-span of a thermostat? How do I know it's operating like it should? should I replace it when I get my intake update done, just as a preventive maintenence?
And how about the Coolant Temp. sensor(the one for the PCM)? should I replace that, too?

What else would you guys get done at this point?
Thanks for any advice.

 

[jthorner]

Your thermostat is already on overtime. Most seem to fail by a 50-80k miles. Cheap to do, do it at the same time.

Most thermostats fail stuck open, so unless your car has a temperature gauge you will never know it. If you do have a temp gauge, stuck open can be seen as abnormally low water temps, especially in light load, high cooling conditions like long downhill stretches.

John

 

[ZR2RANDO]

I agree, change it, they do have a life and yours has seen its best days already. Do it now while you've got the top open is a good idea. I just changed mine on a 1989 Niss truck- my part-time driver..It's been a little more than 2 years, (about 15k miles) so I just drained the radiator and changed it and 1 gallon of coolant. It was opening at the correct temp but then staying open. It's been doing that for about a year so I just decided to do it on a pretty day...
Yep, they don't last forever. It may be some kind of metal fatigue that makes them fail, but they do die sometime...

 

[jthorner]

quote:

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Is that typical of Fords, or are you talking in general

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I was speaking in general. The last two I changed were a German made one on a Volvo and a US made one in an Oldsmobile.

John

 

[Mud]

Check out the 2 crown vic forums on the web - one is www.crownvic.us/forum I think. There is a ton of info on replacing the plastic intake cost-effectively.

Not slamming you, but why on earth would you not want to replace a $5 thermostat if you are going to the trouble of ensuring that the cooling system is in good shape!

Just me, I would replace the valve cover gaskets, coolant temp sensor, flush and fill with new coolant, and replace any hoses that look marginal. More parts $$, but easy to do labor wise while it's apart. I have a 95 CV and it's my daily 120 mile driver - I would much rather know I've not cut a corner that may bite me later.

Also, this is a good opportunity to clean out the EGR passages at the rear of the engine - much easier to get to while the intake, etc is off. Info also covered throughly on the CV forums.

 

[rpn453]

quote:

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Originally posted by jthorner:
Your thermostat is already on overtime. Most seem to fail by a 50-80k miles.

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Ouch. Is that typical of Fords, or are you talking in general? Strange that I've never personally experienced it or heard of it happening to anyone I know if they fail in such a short interval.
A buddy of mine did have the thermostat gasket fail while on the highway at about 200,000 miles. It eventually lost enough coolant that he had to shut it down.
If it's cheap for your car, it's definitely not a bad idea to replace it when doing work on the coolant system.

 

[97tbird]

quote:

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Originally posted by Mud:

Not slamming you, but why on earth would you not want to replace a $5 thermostat if you are going to the trouble of ensuring that the cooling system is in good shape!

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Thanks. I never said I don't WANT to do it. Just wanted to know IF it SHOULD be done.
Thanks for the link for the cv forums. will definitely check it out.

So, I think I'll repalce the t-stat, the hose that runs on the valley, and perhaps the CTS(?). The coolant gets flushed anyway, when the intake is replaced, I think.

 

[ZR2RANDO]

Ok here's an update...no more store brand (Duralast) thermostats for me!
I changed my thermostat a couple weeks ago. I tested the old thermostat right along side the new one (both 192) before I installed the new one...
They both opened at the right temp..right about 190-195F...then the new one closed after the water cooled..the old one stayed open down to about 180. Ok, so it has served its time. I installed the new one. Temp gauge now reads normal again and truck is driving MUCH better..everything is peachy. Now move up a few days...temp gauge is back to where it was when old t-stat was failing again...and I have only driven the truck a couple times!
Now I go up to Advance this time and get a STANT SUPERSTAT (195-heavy duty).. I was amazed at the difference in the construction! Work is complete, test drive is done, temp is back up to where it should be...truck is driving much better again....I feel better now
Happy hour is upon us!

Rando
Yes, I got my money back for the recently defective one...

 

[JHZR2]

funny, in my MB, Ive had 3 citric-acid coolant flushes (MB standard procedure) of my system, and the dealer has never replaced the thermostat.

Its designed to fail open, and so Ill know if its going bad.

I dont think my father's toyota previa has had it replaced in its 186k of dealer service (except for oil changes!).

If it fails open, use it until temperature operation gets screwey. If it fails closed, replace it every time you do coolant (hopefully 2 years).

the thermostat lasting 105k is a testament to the longevity a good one actually has.

Stant seems to be good. I know of MB owners who have bought OEM/behr thermostats, and upon test, all open erratically, and at non-correct temperatures. many have gotten autozone or stant thermostats as they work much better!

If youre in touch with your car, chances are youll know early on that there is a problem.

JMH