Stuck open thermostat?

[Fordlover96]

Hey guys, now that it's getting colder, I think I might have a sticking open thermostat. On the almost 3 mile drive to school in the morning, the car isn't fully warmed up when I get there. This only worrys me because all the other cars I've driven to school (1999 grand Cherokee v8 and '05 dodge magnum rt) are warmed up before I even get there? How long does it take for your guys' SHOto warm up? Granted, the car sits inside a garage and I almost never use the heat while driving. Thanks!

 

[Storm-Chaser]

From the time I start the car and drive little more than one block, I can detect "heat" from the vents.

I've twice had a thermostat fail partially opened.

In the summer coolant temperature on the gauge was tied to speed (ie. the faster I drove, the higher it climbed.

In the winter, I only had heat on low blower settings. If I turned the heat up at all, it pulled what little heat there was in the engine and would start blowing "cold" again in 15-30 seconds.

 

[rubydist]

iirc, it always took a couple miles to start to warm up.

 

[kevinspann]

I wouldn't think three miles is long enough to get it warmed up, especially if there is little idle time before, and during the drive.

Also at your mileage, it may never have been changed - it's a pretty simple procedure, and worth doing.

 

[SHOdded]

Used to take my ATX about 5-6 miles to get up to normal operating temp in trafficless driving when temps were nice outside. 40s & lower ambient temps meant it could take 10+ miles to reach the same operating temp.

Worth it to change the thermostat, check coolant levels, and make sure you burp the system properly in the process.

 

[Storm-Chaser]

One thing I did not mention - if your coolant level is low, you will generally get a condition at some point where the heat will only work while driving. At idle it will blow cold air, but as soon as the RPMs increase from driving, heat will return.

Check your overflow bottle, its generally the first indicator that you've been slowly loosing coolant.

 

[DJSHO91]

My 91 takes about that long to start moving the temp needle. Early mornings, it won't go much above the A. I've had it checked and it is fine. I've hads two t'stats stick open and, when it does, the temp won't get up to the L on the gage.

 

[Dirk37]

Mine gets up to temp in about 2.5 miles, I like to hang around in 1st and 2nd though so that may have something to do with that

Like the others have said, replace the thermostat and check your coolant level and see if that helps. I always check my coolant level in the radiator as well as the overflow bottle, just make sure the car is cold.

 

[msteiny]

Why do they stick open?

 

[SHOdded]

S.A.S. syndrome?

 

[RonPorter]

If you drive all day and it never gets to the "L", it's stuck open. Been this way with all of mine when they stick. No BFD, 15-minute job to replace one. Good idea to replace it, and the rad cap, as a cheap way to eliminate a couple of possible problems. The suggestion of air in the system is also a good thing to check.

 

[rubydist]

Why do they stick open?

they are metal mechanical devices that live in a world of water and ethylene glycol, which is not an environment that leads to infinite life. Eventually, they get enough crud built up on them that they start to stick. btw, it is much better to have them stick open than closed...

 

[msteiny]

they are metal mechanical devices that live in a world of water and ethylene glycol, which is not an environment that leads to infinite life. Eventually, they get enough crud built up on them that they start to stick. btw, it is much better to have them stick open than closed...

I understand the environment they are in. I ve just never seen an engine with this reacurring problem. Its just weird to me, Ive had the same stat in other engines for years. I've changed the one in my 3.2 twice now within a year because of it sticking open and running too cold. I know its not hard to replace, but still. I expected them to go a little longer. Oh well.

Thank you all for answering my stupid question.

 

[sperold]

I usually buy 2 thermostats at a time to make sure I get one that works properly.
I always do the "stove top water-boil" with the thermostat immmersed to make sure it works properly in the first place.

 

[Fordlover96]

Much thanks to all you guys who explained everything. Ill just go ahead and change out the thermostat when i do the 60k, which i plan to do soon.

 

[Fordlover96]

Well, I haven't done the 60K yet, but I decided to change the thermostat out because its been pretty cold here lately. The car still takes more than a couple of miles to warm up. Are these cars just inherently slow to warm up?

 

[TimboSHO]

Yes. The SHO is always a slower car to warm up than other cars I've driven. I drive 6 miles to work and it takes at least 3 just to get the needle to budge. If the t-stat sticks, it almost never warms up (especially with temps in the teens that we've been having here!).

Both t-stats that have failed open for me on the SHO have physically been broken in pieces. Is it just me, or is that the norm for failure?

 

[rubydist]

yes, but keep in mind that a thermostat stuck open is a much less serious problem than a thermostat stuck closed.

 

[Off Road SHO]

Most new thermostat will fail in the open position as an engine saver function. The V-6 Yamaha SHO's are cold blooded, slow to warm up and slow to cool down. That is a good thing because it usually means that the engine has more mass to it and that means less twisting and warping.

Tom

 

[raff18]

i live in the northern ontario Canada and we hit -22f on a normal winter night
and up here we run our cars at a 70-30 mix of coolant
i have found that if theres too much water in the system say 50-50 mix my sho took for ever to warm up
so i say this to u
take 2.0L of mixed out and put 2.0L of pure in and your sho will warm up much much faster