Bad Thermostat? Radiator heats up along with engine

[xj2202009]

I think I have similar problems. Tempeture in Tampa fl was 36 degrees, I let it warmed up three minutes, took off overall it took fifteen minutes for the gauge to reach the normal operating tempeture and the heat was bearly warm and took over twenty minutes to get hot. On warm days sixty and above is fine. just ordered the Motorad that Jon suggested. Is this made by Motorola,,Just kidding..people relax I was just kidding..I'm pretty sure is a Samsung..again just kidding..rotfl

Do I have to take the ALternator out?

 

[WarGawd]

Thats great info guys. Jon that demo you did is great. I am going to boil my new tstat one more time fully assembled. I could only get it to pop fully when removed from the housing. Jon what brand is that? Motorad?

Wargawd. Thats was a cool demo as well. Thanks for clarifying. Did you notice the upper radiator hose having any warm coolant escaping towards the radiator during that test? I dont have a thermocouple so cant replicate your findings exactly. So just to clarify you tested the temp of the coolant at the top and bottom of radiator?

As it turns out the wire on the TC is only about 3 feet not 4 as I first thought, so the TC is actually in the water very near the upper hose inlet to the rad. So the pictures really are very accurately showing the point in time when the water first started flowing out of the block and into the rad when the t-stat just started to open. Hope that answers what you were after - if you were asking if I was able to feel that small temp diff by hand, I didnt try but even if I had I wouldn't have been able to detect it. Those pictures are both taken within seconds of noticng temp movement, and the hose would not have had any time at all to get even slightly warmer (and an IR thermometer probably wouldn't have been able to see a difference until a little while later as well).

I wish I had been a bit more thorough testing my new t-stat before installation. I was more focused on the temp aspect of when it opened vs the rating, and not how far it opened, so given your new one seems not to open too far, I'll have to keep an eye on mine for a while this summer.

 

[WarGawd]

I think I have similar problems. ....

Do I have to take the ALternator out?

I believe it has been done without removing the alternator, but the consensus seemed to be that it was easier overall if you do. And because that seemed such a PITA, especially when you have to do it in the cold, I just felt it was easier to pay someone to do it - and at that point I'd found a competent guy who didn't charge me an arm and a leg, so it wasn't too hard to swallow the 2 hrs labor ($150) he charged me. I already had the parts and had PB blasted all the bolts beforehand to minimize the chances of breaking a bolt off in the block so that probably made his job easier too.

 

[meerschm]

I think I have similar problems. Tempeture in Tampa fl was 36 degrees, I let it warmed up three minutes, took off overall it took fifteen minutes for the gauge to reach the normal operating tempeture and the heat was bearly warm and took over twenty minutes to get hot. On warm days sixty and above is fine. just ordered the Motorad that Jon suggested. Is this made by Motorola,,Just kidding..people relax I was just kidding..I'm pretty sure is a Samsung..again just kidding..rotfl

Do I have to take the ALternator out?

Only if you want a straightforward R&R of the thermostat. search for a few other strings and videos. the lower bolt that mounts the alternator will back against a freon line pretty close, so you cannot just use a ratchet and socket to remove it.

some folks have jiggered a set of extensions/swivels from the wheelwell, but I suspect this requires some blind (by touch) work. I like to see what I am doing.

 

[CaptainXL]

some folks have jiggered a set of extensions/swivels from the wheelwell, but I suspect this requires some blind (by touch) work. I like to see what I am doing.

Agreed. I don't like to work with wobbly universal joint adapters if I can help it. More torque is usually needed which may be a contributing factor with bolt heads being snapped. A direct heads on fit seems best for bolts imho. Also a couple light raps on the bolt head doesnt hurt either to break the torque.

 

[CaptainXL]

However, I'm pointing out another problem with your new thermostat. This is what a properly functioning open thermostat looks like:

Compared with your new one:

If your new thermostat does not look like that at 212 degrees, it is no good. Regardless if it is brand new or not. I flow rate of the coolant.

So I got my new Motorad thermostat and here it is fully opened. No where near as open as yours. What do you think is going on here?

I have noticed the bulb and valve are possibly scraping against the spring retainer and sidewall once again. Same as the AC Delco. Ive just had about enough of this. Please comment.

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[Jon A]

Oops, I made a boo-boo, sorry. First I think that thermostat looks good. It’s open dramatically wider than the AC Delco so I think it’s working fine.

The reason it’s not open quite as far as mine is I had forgotten to mention the difference in temps. Mine’s a 180. Now that’s a whole different discussion/can of worms I don’t have time for at the moment but that’s the difference.

By 20 degrees above opening temp, a thermostat should be open 80-90% which it looks like yours is (.25”+ or so). If you heated it another 10 degrees in anti-freeze (not sure I’d do that indoors) it would probably open that last little bit. In general, they should open pretty quickly and linearly for the first 20 degrees and more slowly after that, opening the last 10-20% over another 10 degrees or so.

My stock thermostat that went bad would close properly (so I didn’t have the running cold problems you had) and crack open right at 195 as it was supposed to so there were no obvious signs anything was wrong with it. But after cracking open it would stop and not move at all over the next 15 degrees. That’s bad. That’s not how they’re supposed to work. When I saw the pic of your AC Delco I suspected that’s what it was doing as well.

It looks like the Motorad is opening farther and farther as you heat it up just like it’s supposed to; you just didn’t heat it up quite far enough to see it as wide open as mine. So I’d use that one without worry—it’ll work dramatically better than the AC Delco, that’s for sure.

 

[CaptainXL]

Ok the different temp makes sense. Was a bit worried there. I guess there really isn't a whole lot difference in valve height when comparing the AC Delco to the Motorad. At least none that I can see. So what I think I am going to do is go one step further and order a Stant thermostat. They are supposed to be the best.

A couple things about the Motorad that worried me aside from the pciture differences was that the inside appears to be narrowly obstructed. The entire housing is aluminum cast and they didn't do well with that. Second, there is no ball check for bleeding the air out like there was with the AC Delco. Third, there is no gasket on the valve itself like the AC Delco. If I had to grade this thermostat in relation to the AC Delco I would have to give higher marks to the AC Delco.

We will see what the Stant looks like.

 

[xj2202009]

this is the old one I took out last weeked

 

[CaptainXL]

Correction. The motorad open a bit more than the ac delco thermostat. I would have to believe the ac delco is a 210 degree stat. The motorad is a 192. The Stant will be a 190.

I just got one question. What is the correct stat temp?

 

[WarGawd]

Correction. The motorad open a bit more than the ac delco thermostat. I would have to believe the ac delco is a 210 degree stat. The motorad is a 192. The Stant will be a 190.

I just got one question. What is the correct stat temp?

Seems everyone has trouble finding data on the AC Delco 1511006 but I don't think it can be 210. The PCM controls the fan speed to fine tune the actual operating temp (I6 thermostat temp rating - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum.), which is several degrees higher than any of the standard 190/192/195 rated temps from the various OEM and aftermarket suppliers - any of these is probably functional. OTOH you may be interested in this review on Amazon that more or less echoes your exact experience with the Mexican made AC Delco

 

[CaptainXL]

this is the old one I took out last weeked

That Motorad can't be that old. Just another reason not to use the Motorad tstat.