y5mgisi
1 ton status
On trucks without rear heat, there is no valve of any type for the heater hoses.
CK5
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Cooling System Overhaul - Stumped and Frustrated
- Thread starter dhcomp
- Start date
The ones I'm seeing pictures of are all vacuum controlled in any case, so that rules out non-AC trucks no matter what.
My 1991 w/o Rear Heat does NOT have any valve.
At least on Rockauto they list them on the K5's even back to 1987, so methinks the parts listings are wrong.
Even with rear air, whats the difference between front AC and the way the rear air was setup? I'm not putting the pieces together as to why it matters if "hot" coolant was going through the entire system. If anything it would help cooling simply due to the length of the hose/pipe run.
Even with rear air, whats the difference between front AC and the way the rear air was setup? I'm not putting the pieces together as to why it matters if "hot" coolant was going through the entire system. If anything it would help cooling simply due to the length of the hose/pipe run.
So, the rig finally got a tuneup.
Plugs, cap, rotor, fuel filter, timing set to 0. AC delco plugs gapped to .035
Truck runs a bit better, but still climbs above 210 at the hint of load on the motor.
WTF.
The only thing left to really try is removing the trans/oil coolers in front of the radiator, and seeing what happens.
Plugs, cap, rotor, fuel filter, timing set to 0. AC delco plugs gapped to .035
Truck runs a bit better, but still climbs above 210 at the hint of load on the motor.
WTF.
The only thing left to really try is removing the trans/oil coolers in front of the radiator, and seeing what happens.
Try it, at this point, what's left? 
Try it, at this point, what's left?
Oh, and forgot to mention that I replaced the radiator after it sprung a leak, so radiator, hoses, etc. are all new.
Forgive me, only post #587, was that a new radiator already? The Champion?
Champion was a new one not too long ago. Forget when. They warrantied it, split at the tank to core.
But, a pain none the less, as the heater hose fitting was different.
Made new mounts to make sure it wasn't tweaked or unsupported.
But, a pain none the less, as the heater hose fitting was different.
Made new mounts to make sure it wasn't tweaked or unsupported.
Well, I finally made some diagnostic progress.
Need to drive down to the bay area this weekend, and tow a boat back up the hill. Temps shouldn't be over 60 or so, and figured this was a good time to see what impact my trans cooler was having on my radiator.
Removed the trans cooler, which will give a lot more airflow to the radiator. I have matching oil/trans coolers in front of the radiator, so its pretty blocked. We'll see if this makes the difference I need.
If it does, not sure where i'll remount the cooler. Where are you guys running them besides in front of the radiator?
Need to drive down to the bay area this weekend, and tow a boat back up the hill. Temps shouldn't be over 60 or so, and figured this was a good time to see what impact my trans cooler was having on my radiator.
Removed the trans cooler, which will give a lot more airflow to the radiator. I have matching oil/trans coolers in front of the radiator, so its pretty blocked. We'll see if this makes the difference I need.
If it does, not sure where i'll remount the cooler. Where are you guys running them besides in front of the radiator?
WhiteKnight3153
Registered Member
Hey darren i am assuming you will let us know how it went. If you are still having problems there are only two things I can think of that could be your problem even after all that you have done. I own a 1990 GMC 1500 4X4 Suburban and have a 6 inch lift with 38" MTZ stuffed under it (barely fitting) and have towed just about everything under the sun with it with A/C on and have never had a problem with temp ever. I will be waiting for your post. And if you are still having problems we will talk.
Driving it unloaded tomorrow, and then towing monday. will let you guys know!
Got some questions about my radiation mounts. Just opened up the stock ones and added angle on both sides to support the radiator, with some rubber stuffed in. 
OK, yeah I had to do that when I put the 4 core is so I guess I'm already set for the new champion.
Thanks.
Thanks.
So, it seems to have helped.
I was only 65 or 70 when i was towing this weekend, but the motor didn't heat up.
Trans did without the cooler, as expected.
So, what does everyone recommend? I currently have the stock oil cooler in front of the rad, and need to decided where to put the trans cooler.
Options:
Remove oil cooler, replace with passive trans cooler.
Leave oil cooler, mount passive trans cooler elsewhere
Leave oil cooler, mount active integral fan trans cooler in front of rad, hope fan helps.
Leave oil cooler, mount active trans cooler elsewhere.
Am i missing other options?
Who is running the stock oil cooler? Do i need it?
Let's discuss.
Thanks guys!
I was only 65 or 70 when i was towing this weekend, but the motor didn't heat up.
Trans did without the cooler, as expected.
So, what does everyone recommend? I currently have the stock oil cooler in front of the rad, and need to decided where to put the trans cooler.
Options:
Remove oil cooler, replace with passive trans cooler.
Leave oil cooler, mount passive trans cooler elsewhere
Leave oil cooler, mount active integral fan trans cooler in front of rad, hope fan helps.
Leave oil cooler, mount active trans cooler elsewhere.
Am i missing other options?
Who is running the stock oil cooler? Do i need it?
Let's discuss.
Thanks guys!
I don't think you are going to get much more than opinion on engine oil temp...from all I've found, it's not nearly as well documented as trans temps. GM ran them on some applications (are both your engine and trans coolers factory?) and on some Corvette applications oil temp WAS being monitored. I don't believe they did it to sell as bling to people who could then boast about having an oil cooler, but I don't know that for certain. There are plenty of people who have removed them and towed that claim no ill-effects, but unless you know oil temp not sure that is a given.
Trans is a no-brainer IMO...do whatever it takes to keep that temperature under control. I'm sure there is a happy medium in terms of how much cooling the trans needs vs. how the cooler operates. What kind of temps are you talking about without the cooler?
How is the trans cooler plumbed? If presently its run through the radiator first, plumb it without going through the radiator at all? That would keep some of the heat from going into the radiator but almost certainly increase trans temp....but who knows how much? Certainly less than not having a cooler at all.
Trans is a no-brainer IMO...do whatever it takes to keep that temperature under control. I'm sure there is a happy medium in terms of how much cooling the trans needs vs. how the cooler operates. What kind of temps are you talking about without the cooler?
How is the trans cooler plumbed? If presently its run through the radiator first, plumb it without going through the radiator at all? That would keep some of the heat from going into the radiator but almost certainly increase trans temp....but who knows how much? Certainly less than not having a cooler at all.
That supports my idea. All the coolers in front of the radiator are giving you problems two ways.
One, they are inferring with air flow, which would tend to cause higher engine temps, plus they are actively dumping heat into the radiator.
In other words, in the case of the transmission cooler, you are transferring heat from the transmission to the engine.
In my opinion, the best way for results, is a remote transmission cooler with its own fan.
This gets more and cooler air through the radiator, and still cools the tranny.
The problem is, what fan? One like goes on the radiator moves plenty of air, but is too big to fit a regular transmission cooler.
You need something like a muffin fan out of a computer, but most of them do not move enough air.
I have seen some pretty powerful ones though, I will go through some of my resources.
As to where to mount it, I would think about taking it out of the engine compartment entirely unless you have a good space with access to cool air.
Maybe somewhere in the back where it can get air. Up high under the body somewhere.
Shame you are not up in the frozen north. You could put it in the cab for an auxiliary heater........
One, they are inferring with air flow, which would tend to cause higher engine temps, plus they are actively dumping heat into the radiator.
In other words, in the case of the transmission cooler, you are transferring heat from the transmission to the engine.
In my opinion, the best way for results, is a remote transmission cooler with its own fan.
This gets more and cooler air through the radiator, and still cools the tranny.
The problem is, what fan? One like goes on the radiator moves plenty of air, but is too big to fit a regular transmission cooler.
You need something like a muffin fan out of a computer, but most of them do not move enough air.
I have seen some pretty powerful ones though, I will go through some of my resources.
As to where to mount it, I would think about taking it out of the engine compartment entirely unless you have a good space with access to cool air.
Maybe somewhere in the back where it can get air. Up high under the body somewhere.
Shame you are not up in the frozen north. You could put it in the cab for an auxiliary heater........
Yeah,some Isuzu trucks and box trucks with Deutz air cooled diesels use an oil cooler for the heater core...
I've seen a few aftermarket transmission coolers mounted on the radiator support off to one side,and they punched out the air duct "plug" the air cleaner snorkel would have been mounted too,so the airflow passes through the cooler..
They say nothing cools better than a trans cooler thats in the radiator though..water transfers the heat much better than air alone..
I've seen a few aftermarket transmission coolers mounted on the radiator support off to one side,and they punched out the air duct "plug" the air cleaner snorkel would have been mounted too,so the airflow passes through the cooler..
They say nothing cools better than a trans cooler thats in the radiator though..water transfers the heat much better than air alone..
it also heats it up to 195, etc better than anything else.... 
my air-cooled only trans never got up to a decent temp easily (in the dead of summer, it never got over 185), and the sub 100 degree, forever, winter warm-ups killed the 700 in short order..
so, I'd say the great "cooling" aspect of "in rad" is bunk... whereas the getting it over condensation temp due to antifreeze temp was of much more importance..
my air-cooled only trans never got up to a decent temp easily (in the dead of summer, it never got over 185), and the sub 100 degree, forever, winter warm-ups killed the 700 in short order..
so, I'd say the great "cooling" aspect of "in rad" is bunk... whereas the getting it over condensation temp due to antifreeze temp was of much more importance..
