Re-Radiator Strategies : '89 Automatic 2.9L 4x4 w A/C

[eightynine4x4]

I may need to replace the radiator. I am 50% certain it's rusted up inside and need to do some more investigating as to if i can salvage it's function enough. Maybe the coolant flow is decent still. The drain plug at bottom barely drips, have tried many times in different conditions and have used a bottle of breakup substance. But maybe all the tubing is in the right spots and flow is still possible. I guess the drain could be rusted shut and that's it. That would be nice! I plan to look for the engine drain plugs too. Haven't found those suckers yet.

But if go the reliable route and get a new radiator, I have come across some obstacles..
Seems lots are designed for either Manual, or for Automatic W/O AC. I have Automatic W/AC.
So I'm planning to scope the details soon in front of the truck but figured I'd ask here as well.. Are they kinda modular? In other words can I buy just a manual radiator and replace the main radiator part of mine?

Maybe the transmission cooling segment of an Auto radiator is it's own separate beast and can be left in tact?
As for the A/C factor, it seems difficult to find a radiator meant for this. My A/C doesn't even have a belt on it and it is ignored. If the physical mounting/sizing of the non-A/C radiator is the same as A/C version, maybe i just ignore this factor. But is it maybe wider/longer? I believe the A/C version could be thicker, or have multiple layers.
It would be nice to line up the proper radiator though, just in case in the future I somehow want to be cool in the summer. Sounds too luxurious.

I also plan to replace the thermostat. And I may just attempt to drain all coolant from engine plug (when i find one or both) and then do a proper flush despite not having a drain plug in radiator. I can suck a lot out with a tube.

 

[Eddo Rogue]

Maybe pull it take it to a radiator shop? a cleaning doesn't cost much....and/or they can probably find you a exact quality replacement. It might cost a few more bucks, but will save you time and hassle. Pulling the radiator yourself will also save you major time and money. They like when you do that part for them.

I replaced my radiator ordering one off Rock auto. They had many options and price ranges, including the one I needed. I actually ordered the wrong one, and exchanging it was no problem either. I'm not much of a dot com or big box store kinda guy, but have ordered quite a bit off them, mostly due to the options and user friendly site setup.

 

[racsan]

wish I could remember where I ordered mine from, funny thing is that one time I ordered a radiator for a astro van, had option of paying $50 for next day delivery, well I said no but it showed up the very next day anyhow. I got a all-aluminum radiator for a S-blazer once, very nice! hate the new stuff with plastic tanks. From what Ive seen most radiators will come with a auto trans cooler, even if you ordered for a “manual” application. One radiator I ordered wasn’t because the radiator was bad, but because it had a engine oil cooler. That engine had spun every rod & main bearing causing a pretty metallic sheen to the oil. I didnt trust just flushing the oil cooler. (that engine sounded like a diesel after the bearings spun) . So I just put another radiator in it along with a junkyard motor swap.

 

[Paulos]

A radiator for an auto trans and AC will have more cooling capacity, and the trans cooling coils are built into the radiator.
I have a manual trans in my '87 4x4, and upgraded the radiator with a 4.0 auto/AC radiator and 4.0 hoses. Your lower hose should be the same, but you would have to get the 4.0 auto upper hose and custom fit it. 4.0 radiators here with 1164 in the model # will work (others may also, IDK), and the Gates 21897 & 21623 will work for the 4.0 radiator.

 

[eightynine4x4]

A radiator for an auto trans and AC will have more cooling capacity, and the trans cooling coils are built into the radiator.
I have a manual trans in my '87 4x4, and upgraded the radiator with a 4.0 auto/AC radiator and 4.0 hoses. Your lower hose should be the same, but you would have to get the 4.0 auto upper hose and custom fit it. 4.0 radiators here with 1164 in the model # will work (others may also, IDK), and the Gates 21897 & 21623 will work for the 4.0 radiator.

This is excellent, thank you! Saves me a ton of research.
I compared the rock auto results you gave to the results for my 2.9 truck and there are two "1164" items in common. Basically two of the three 4.0 items are also listed as 2.9 items. I'll go with one of those. If i do get a new radiator, maybe i'll just order the top hose in case of fitment issue since it's cheap.

I'm going to still make an attempt to revive this radiator though. If i take it out, I can better assess the coagulation inside, whatever and wherever it is. I took the truck for a nice high-ish speed ride last night and finally heard what the engine should sound like when it's healthy, since i've been working on some timing things (different thread), until put it through some rigors up long hills and it started to sound a bit tappy again after that. I think my cooling system is very much in need of restoration and is causing the engine some stress. The temp gauge never goes above 1/8-1/4 either, no matter how much i drive the truck, so i'm thinking the thermostat in cooling system should be swapped as well.

 

[Rimjam]

Radiator shops can no longer 'rod' out radiators. In days gone by radiators had metal tanks top & bottom (or each side) that could be unsoldered & removed allowing the flues to be rodded out. Can't do that with newer plastic tanks which are glued on. Reflection of our society - throw old away (recycle) & replace w/ new. Most all chain auto stores are gonna sell you the same basic replacement radiator which will do an adequate job if the rest of the system is OK. If money is no object there are specialty shops that will build anything you wish. My buddy's '53 Willys wagon w/ Chev LS engine - $1000 for custom four flue all alum that fits in stock location.

No more engine drain plugs, at least not the petcock type. Welch plugs aka 'freeze' plugs are still used but hard to get out & even harder to replace. Most people use some kind of engine flush that you pour into the radiator, run engine a while, drain out. If your radiator drain petcock is stopped up drain radiator by removing lower radiator hose.

 

[RumPunch]

I've got a Champion for my 88 auto I removed AC. Fits nicely. Trans lines hook right up. I added an upgraded 6 row trans cooler as well. Here is the radiator. Not sure of cooling capabilities at this time, I ordered the 16" fan with it but haven't gotten truck all back together yet.

85-94 Ford Ranger 3-Row Radiator for Sale | Champion Radiators

www.championradiators.com

 

[Eddo Rogue]

Back when I was dealing with cooling issues, I went with the thicker 3 core radiator offered for explorer automatics. it was a tight fit, and it did not help cooling. I replaced it with a brand new single core, and it worked great.

 

[eightynine4x4]

Thanks for all the input!
Some results here...
I was able to unleash the brown water from the bottom tube of radiator. It was a lot and took a while, and even had some sudden spurts, so i'm pretty sure it all found its way out. This is promising news.
The bad news: My thermostat can't be swapped without turning this into a large new project. I broke the head off of one bolt. It looked healthy, no rust around it, i prep'd it with PB blaster, and went gradual with it but sure enough it snapped right off. It was in the upper right area of the housing. To see if i've now warranted my truck un-coolable, I did a quick water flow test by hooking up the garden hose to the heater hose that runs into the upper engine, pretty high pressure so that i could hopefully get some water splashing around in engine block, and nothing seemed to leak out of the thermostat area at all. I had thoroughly dried the engine area under the thermostat before doing this to see if even a single drop seeped out but it didn't. It looks like some of the bolt, but not much, is still kinda rusted to the inside of its hole in the thermostat housing, so maybe that's helping keep it all as sealed as before. I also tried gently pulling at the housing just to see if i could get it to pry apart even a smidge, or see any motion of the housing, knowing that if there was any motion at all that I'm going to have to dig in and drill a new small hole to clamp it back shut. But it didn't move, not one bit. So, I'm wondering what the PSI is of the cooling system, and if that pressure will ever push it open. But if that did happen, it would be a small leak, not a huge burst, since the other two bolts are certainly going to hold the thing pretty much flush still. That would be the worst case scenario in terms of the bolt issue if i just ignore the busted bolt and run the truck as is. It would also be pretty obvious if a coolant leak sprung, since that stuff stinks real bad.
However, now i'm stuck with this thermostat. I had just picked up a new one at the store and was ready to swap it in.
My question is.. what are the chances that this thermostat is working properly? Any real way to test it while it's installed?

I'm not going to commit to drilling 3 new holes in the engine block right now, so I'm kind of just going to have to stick with it at least until it seems worth the effort.

What is the worst case scenario with the performance of the thermostat? Could it be stuck open or stuck closed? If so, what are the consequences of each? I don't actually quite get the purpose of this device, a device that only opens and lets water flow when operating temp hits a certain level. I know that people get lower rated temperature thermostats to get water flowing sooner than later for the benefit of keeping things cooler. But that makes me wonder, why ever design a system to shut it?

In any case, I'm going to attempt a full flush soon, once i decide what the best outlet point is. I have the line going INTO the heater accessible right now, and the lower radiator hose opened up. The rest is connected. I might just reconnect that lower hose and open up the second heater house as an outlet. I think that gets water running through the whole system to and from the heater area.

 

[IIBRONCOS]

Here is some info on what a thermostat is and does.

How Does a Car Thermostat Work?

Thermostat is an integral part of your vehicle. This article will help you gain a better understanding of this component of your engine’s cooling system.

www.carbibles.com

 

[eightynine4x4]

Here is some info on what a thermostat is and does.

How Does a Car Thermostat Work?

Thermostat is an integral part of your vehicle. This article will help you gain a better understanding of this component of your engine’s cooling system.

www.carbibles.com

Good read, thanks!
It all makes perfect sense.
The thing that drives me a bit nuts is that although my coolant temp sensor is new, I’m not certain my temp gauge in cabin is remotely accurate. It moves, but it always reads quite low. So this is steering me into thinking my thermostat is stuck wide open and the engine is staying too cool.

But when doing some coolant flushes, it does seem like the thermostat is closed becuse after getting clear water out of the heater side of things with a garden hose hookup flush, the radiator water was still brown once I filled it, meaning there’s still brown smootz in the radiator despite the heater side being well flushed and clear. So I’m hoping this means the thermostat is closed and there’s separation. Also, when I started this heater hose flush, lots of thick brown water came out as if it was untouched by the radiator lower hose draining out, furthering the idea that there is separation due to thermostat being closed.

I suppose I could get a replacement temp gauge somehow and install it to see if it lives more in range that one would expect. Maybe it’s fault. I mean, if I warm it up in Park for 10 minutes, then I take it for a 30 minute drive averaging 35-40 mph, and it’s 40 degrees outside, what kind of temp range should I expect to see on the gauge? I’m only reaching just a hair above the lowest operating range marking after drives. It’s not below the operation temp range marking, just barely above it. I’m expecting something in the middle.

 

[Eddo Rogue]

Its not the end of the thermostat world. I've broken many bolts, learned to use extractors. I start off with a small reverse drill bit and work my way up to the proper size extractor. The trick is t go deeper that you think you need to, so the extractor can get a good bite. Otherwise, if there is space, I slice a slot across it and hit it with an impact screw remover. If you are lucky, you may be able to grab it from the outside using those stripped bolt sockets that grab it from the outside.

 

[eightynine4x4]

Its not the end of the thermostat world. I've broken many bolts, learned to use extractors. I start off with a small reverse drill bit and work my way up to the proper size extractor. The trick is t go deeper that you think you need to, so the extractor can get a good bite. Otherwise, if there is space, I slice a slot across it and hit it with an impact screw remover. If you are lucky, you may be able to grab it from the outside using those stripped bolt sockets that grab it from the outside.

Yep, I’ve already done some massive bolt drill out projects, for the entire right exhaust manifold, actually. Just looking to avoid it haha, or postpone it. So first I’m going to confirm wether or not my thermostat already works, becuse it very well might.
I had been confused by one thing that I just figured out.. the Haynes doesn’t have a temp sending unit/sensor shown in the electronic diagrams. I combed over those two pages many times in recent weeks, looking for targets to check that might impact my temp gauge. It’s just not there. So I went over to the truck and the first thing I saw is a blue oxidized cruddy sensor sitting right there mounted next to thermostat location. So it’s an omission in the Haynes. I went and picked up a replacement sender and will attempt to install it later today.
If that corrects my gauge issue, which is that it’s sorta moving but very low range, then maybe it will help make my thermostat activity, whatever it is, a lot more clear.
In my test drive last night, while warming it up I did at one point notice the gauge go suddenly down a smidge, albeit still in very low range. So I’m hoping that was the thermostat opening. I’m also going to do the ground test to see if my gauge peaks up with key on.
Many fingers crossed.

 

[eightynine4x4]

Successfully installed a new temp sender for the gauge.. Same gauge performance. I let it warm up at idle for 10 minutes or more and it reached the dead lower mark of operating temp and never went above, then i took it for a easy ride for 30 minutes to see if it rose much and it only crept up to maybe 1/16th the range above the lower mark and it took a while to get there. This is the same as before replacing sender. I suppose this means the engine IS within operating temp specs though, since it does rise past the C lower section and reach the operating temp "bracket" and stay at least there. So maybe it's not a serious temperature concern to drive the truck overcooled like this, so long as it's not below the operating range on the gauge?

I did also try grounding the single wire to the gauge and the gauge successfully peaks right up when key is on. So as far as i can tell, the gauge works. Also, after installing the new sender, i tried clipping a ground wire from the sender housing all the way over to the negative battery, just to see if perhaps the sender chassis wasn't grounding itself properly since the item did come with a thin layer of thread sealer wrap on it. But it didn't impact the gauge readouts, still in the cold zone of operating temp. So i think the grounding connection is fine.

Ultimately this leaves me to think the thermostat is stuck open. I'm wishing there was a way to dislodge it by doing a bunch of flushes with an aggressive cleaner. Also, how would a spring loaded mechanism ever get stuck in the open position? Seems like a solenoid opens it and is pushing against the spring, then the spring pushes it back into place when the solenoid is no longer being triggered. I must not know how it works.

If i make attempts at the two remaining bolts on the thermostat, i run a quite high risk of putting this truck completely out of commission for an unknown period of time. One of the two remaining fasteners, the upper left one, is actually just a small nut over a stud. That one looks easier so long as i douse it with penetrant for a few days first. The other bolt, at the bottom center, is a regular bolt like the one i already broke the head off of. But unlike the one i broke, it appears rusty, so looks worse. And the head wasn't the issue, it is the bolt core that's seized.

Therefore i'm looking for ways to confirm the thermostat is indeed stuck open before ripping this thing open and finding out it was some other issue like the gauge is indeed very inaccurate or something.

Here's a question... i already did a flush of the heater core until the water came out clear... How hot should the air feel when the truck is warmed up? Enough to kinda burn a little when you put your hand over the vent? Mine is warm, but not singeing. The heat is definitely enough to keep the cabin comfortable, but never makes you sweat even on full blast and wearing a coat. I could put a thermometer in there and see what it ends up maxing out at while gauge is at highest level and maybe that'll help determine if the engine is running too cool.

In summary, I'm wondering if I really should attempt this project since perhaps the temp gauge being within range, albeit the lowest mark, means it's not damaging the system to drive. The inconveniences are that i always have to let the truck warm up for at least 10 minutes.

RonD here mentioned the following in another thread a while back, making me think about how when i warm up the truck it slowly burns off condensation out the exhaust pipe for several minutes instead of just maybe a short 30 seconds. It always disappears and doesn't come back for the rest of the ride, so i'm pretty sure it's condensation and this does also lead me to think the reason mine takes so long to burn off is due to the open Tstat. But it does burn off, so again i'm wondering if I'm in the safe zone to drive it so long as i always let the truck warm up idle to the point where condensation is burnt off.

1/2 on most Ford temp gauges is 225degF, so normal warmed up needle would be 1/3 to 1/2

Yes, t-stat should be a 192 or 195degF model, engine operating temp of 200degF to 230degF will give best MPG and best lubrication.

Running an engine "cooler" sounds good but actually isn't, oil doesn't get hot enough to "burn off" water(condensation) and fuel contaminants(blow-by), and engine will run richer(lower MPG) which causes higher wear on spark plugs, O2 sensors and Cat converters.

 

[RonD]

1/2 on Ford gauge is actually 205deg, typo

Start cold engine and feel upper rad hose and heater hose, both will be cold of course
Check both again after 2 or 3 minutes of idling
Heater hose should be warming up
Upper rad hose should NOT be warming up

Heater hoses are on the engine side of cooling system so always have circulation

Upper(and lower) rad hose are on the thermostat side of cooling system so have no flow until thermostat opens
So if upper rad hose is warming up same as heater hose then thermostat is open when it should be closed