Truck won't come up to operating temp after rad install

[Andrew]

I'm currently trying to understand why my truck will not come up to operating temp. I recently installed a griffin rad (1st gen s10) The original rad was a dual core and quite small. This griffin rad is much larger, aluminum and a triple core I believe. Ever since the install my truck will not come up to full operating temperature when I'm driving. If it's sitting there idling in the driveway it will very slow come up to 190-200F and then the electric fans come on. When I'm driving it will barely ever creep over 160F. I've replaced the thermostat twice (third on now) and that is definitely not the problem. The current thermostat is rated at 192F. I've tried blocking off the rad almost entirely with cardboard just to test it and the temperature will not rise above 160 while driving. I'm kind of at a loss at the moment. The engine is a roots blown 3.2, if that makes any difference. I feel like I'm having a can't see the forest for the trees moment here and would love some input/suggestions.

[Vegas69]

Have you verified the coolant temp with a gun? Stock thermostat or aftermarket? Some aftermarkets flow before they open. You may have over done it with that radiator.

[Sieg]

What is responsible for your temperature readings?

As Todd noted you may have went overkill on radiator size.

Would it be possible to slow or reduce flow to the radiator via water pump speed, impeller design, inlet/outlet reducers?

[Vince@Meanstreets]

What is responsible for your temperature readings?

As Todd noted you may have went overkill on radiator size.

Would it be possible to slow or reduce flow to the radiator via water pump speed, impeller design, inlet/outlet reducers?

They do make flow restricters that go inline transfer hoses.

Andrew, Ain't broke why fix it?

[samckitt]

What is responsible for your temperature readings?

As Todd noted you may have went overkill on radiator size.

Would it be possible to slow or reduce flow to the radiator via water pump speed, impeller design, inlet/outlet reducers?


Unless I am missing something,
Regardless of radiator size, water temp inside engine should be at the temp that the thermostat is rated for. It will not open until temp reaches that value. The thermostat is your flow reducer.

[Andrew]

my apologies for the lack of information.

I have shot the thermostat housing and also just below the thermostat on the intake with an infrared thermometer. Temp reads 169-172 f. I really appreciate the input.

Vegas, it's a stock replacement thermostat but I'm leaning towards that possibility or that coolant may be seeping around the outside of the thermostat? It seems unlikely but I'm at a loss.

Sieg, I have a gauge in the dash that takes a reading of the coolant in the head. I have verified this reading with an infrared thermometer. When cruising or driving at any speed the truck will not get up to anything more then 170ish. Thermostat is rated for 192.

Vince, I'm not quite sure what you mean. Why go to a bigger rad? or ?


Samckitt, this is what I always thought. So I'm pretty stumped at the moment.




I have a 180f thermostat made by STC, going to try that just to see if anything changes. Will report with the results.

Thanks again for the input.

[Andrew]

Just installed the 180 for curiousities sake. Drove it around a bit brought it up to temp, then got out and shot the thermostat housing. Gauge in the truck reads 160. Infrared thermometer reads 158-163 on the thermostat housing. So I'm consistantly running 20f cooler then I should be with the 180 and the 192.

Both thermostats have the same profile sitting in the intake. It appears there is maybe 1/32 or slightly more of a gap between the housing and thermostat. My next train of thought is put a thin rubber gasket under the thermostat and try and space it up to close that gap?
Please if I'm missing something here, don't hesitate to point it out to me.

http://i223.photobucket.com/albums/dd164/kyboshh/IMG_5904.jpg

This is the recess I'm talking about. I just don't see how coolant could work it's way around it unless it was floating up.

http://i223.photobucket.com/albums/dd164/kyboshh/IMG_5908.jpg


So to reiterate.
With a 192F thermostat I'm only reaching an operating temp of 170.
With a 180F thermostat I'm only reaching an operating temp of 160.

stumped at the moment...

[Andrew]

Going to pressure test the system tomorrow. Nothing to lose. I remember reading that every psi loss is 3* temp loss as well? find out tomorrow.

[Andrew]

Pressurized rad to 16 psi, let it sit for 15 mins no pressure loss at all. I just tried changing rad caps to confirm the rad cap hasn't failed. No change in temperature at all.

At a total loss at the moment.

[Sieg]

How about a picture of the engine compartment. Just because. It's acting like the thermostat is being bypassed. :headscratch:

[ErikLS2]

You made a change, now have this symptom that you didn't have before, I'm just curious why you are not condemning the change (the radiator)? I work on cars for a living and I can't tell you how many times I fixed something and when done a new problem presented itself and I convinced myself it was nothing I did, it HAD to be a new problem. Well, 99.9% of the time it was something I did, or at least put my hands on. I would bet lunch that the radiator is simply too big and would suggest you put the old radiator back in and see if it does the same thing, besides, you've eliminated the thermostat and the fans aren't on all the time, there's really nothing else it could be but that radiator. You're just overthinking it.

[Vince@Meanstreets]

My point was its not broken. Its not over heating its not being symptomatic why bother trying to fix it.

Where is the sender located and did you verify temps infrared temp tool at the same area?

You said it gets up to op temps at idle parked right? Sounds like a very efficient cooling system to me. :RunninDog:

[Andrew]

Erik, you are completely right. I changed the rad because the old stock one was cooked,

http://i223.photobucket.com/albums/dd164/kyboshh/Feb4th%202009%20and%20on/2cf80731.jpg

I figured while I was rebuilding everything else why not upgrade my cooling system and eliminate the clutch fan while I was it. Yes it's overkill for this motor, but the plan is to swap out to an ls one day in the future. So rather then buy two cooling systems I opted for one.

You are right though I was overthinking it. Definitely made a big step today correcting it. Well the big problem was definitely a cant see the forest for the trees moment. The water pump was spinning in reverse. I had modelled my build off of another guy online. I failed to notice the way he and I routed the serp belt was reversing the water pump.

This is the way I originally had it set up

http://i223.photobucket.com/albums/dd164/kyboshh/thumb_IMG_5912_1024_1.jpg

http://i223.photobucket.com/albums/dd164/kyboshh/2010/DSC03100.jpg


This is the way it should of been

http://i223.photobucket.com/albums/dd164/kyboshh/00E32735-95FA-41AF-AE62-C21C946D5228.jpg

http://i223.photobucket.com/albums/dd164/kyboshh/0BA6F14A-F174-43BE-A8EB-ADB204CAD237.jpg


I just thought ok smooth side of the belt to the smooth pulley, perfect! Not exactly though, it was definitely spinning backwards.

Sieg you are completely right, the water pump flowing reverse was just simply opening the thermostat all the time and the coolant was constantly flowing.

As you can see above I rerouted the belt so now the pump is flowing in the right direction. That took a few mins to figure out.

Now onto the "but"
but the truck is still running cool. With the 192f thermostat I'm still only hitting 165f on the thermostat housing and just below it. I'm looking into different thermostats. I'm still suspicious that the air bleed vent is allowing enough coolant to slip by that it may be enough to drop the engine temp.

Vince, I hear you it is definitely a great cooling system. The reason I'm after this is hopefully regain a little bit of fuel economy.

[Sieg]

Well done Andrew! :thumbsup:

[Andrew]

Thanks Sieg, I'm not totally solved yet but definitely a step in the right direction.

I really appreciate everyones input. Just to have someone to bounce ideas off of or get another point of view really makes such a difference.

I was just reading about motorad thermostats. Apparently the spring in them in is really weak and then tend to crack open at an earlier temperature then they are supposed to. I'm remaining cautiously optimistic but I think opting for a different brand with a stronger spring may solve my problem. Will report back in the morning.

[Andrew]

Went out this morning and bought a stant 195f thermostat and a new gasket.
I am losing my mind. The engine is running the same temp, 155-160 at the thermostat. Fourth thermostat now so I can say without a doubt that the thermostat is not the issue. I'm guessing it's bypassing the thermostat. The heater core is a closed circuit, the water pump draws coolant through it from the intake and then back to the pump. It never had the ability to cool the truck 30f below the thermostat rating before I can't see that would be the problem now.

suggestions on where to go next would be so greatly appreciated. I feel like I've covered everything and am getting nowhere quickly.

[Andrew]

I'm just trying way to hard and to close to the problem. I need to take a step back and rethink everything.

I just realized rerouting the belt was a total waste of time in terms of reversing the water pump. It made sense in my head and sounded like it was the fix but in reality the water pump is still spinning the same way.....

http://i223.photobucket.com/albums/dd164/kyboshh/F9C1AD45-D198-4FDC-8516-598FD6917146.jpg

on the plus side with the new routing I get much better wrap on the blower pulley and the tensioner is at a better angle.


I'm still not convinced it's spinning the right way however. I'm going to flip the thermostat over just for ****s and giggles. If I flip it over and it performs properly then I know the water pump is reversed and was just blowing the thermostat open.


edit: well as I'm sure most of you guessed that did nothing at all. I just confirmed water pump is rotating the proper direction. I followed the inlet hose from the thermostat housing to the rad with the infrared thermometer. At the thermostat 160 and gradually declining to 145 at the rad. Then shot the lower rad hose, at the rad and followed it the water pump inlet. Temp of the hose at the rad was 90 and gradually increased to 92 at the inlet. So without a doubt coolant is flowing in the right direction. Hot coolant coming in and cold moving out to the bottom to the water pump.
Taking a break, I'm totally lost and out of ideas.

[Vegas69]

You have a monster V8 radiator on a V6 which means you are probably over cooled by 25%, minimum.

[Andrew]

I hear what your saying vegas. My thermostat doesn't open at all until 195f confirmed by bring water to a slow boil also confirmed closing at 185f by letting it cool in the water. My thermostat is not even getting up to 170f therefor it's not even beginning to let coolant through. This leads me to believe it's being bypassed. I just have no idea how.

I just clamped off the heater core lines to make sure they weren't in some way cooling the thermostat. Nothing changed.

I am at the point where I really don't know what to check next.

[ErikLS2]

I don't understand why you keep skipping over the radiator as the problem? Put one of these in it and save the Griffin for the V-8

https://shop.performanceradiator.com/index.php?route=product/product&path=1_8381_11136_11158_11160&product_id=3395

[Sieg]

I don't understand why you keep skipping over the radiator as the problem?

:G-Dub:

[andrewb70]

I am not saying that the radiator is not the problem, but if the thermostat is not opening, and it is not being by-passed, how is having a radiator that is too large causing his problem?

Andrew

[Andrew]

It's because I don't believe it's the problem. I may very well be wrong.
Regardless this mystery will go unsolved. I currently live 5000km's away from where the truck is kept and was back home on vacation for 3 weeks. Thought I could figure it out in that time. The truck broke down on me today (ignition issues) I'm Flying back home to bc tomorrow . It will have to wait until I have another chance to work on it.
Thanks again for everyones input. Sorry there was no happy ending yet.