Cooling System Rehab - Any Pointers?

[grrlscout89FJ62]

As I mentioned a while back, the crew at my local garage spotted several leaks in my rig (surprise!). Since I'm moving down to Phoenix, and will have a long commute, I decided to address the radiator one first. They didn't say exactly *where* it was.

As it is now, most days, it runs pretty cool -- the temp usually hangs around somewhere between the 1st and 2nd hash mark on the gauge. After 30-60 minutes of regular driving, the needle usually tops out a quarter of the way up.

But some days, if I have a lot of stop-n-go, towing, climbing, or speeding, the temp climbs. Other times, it seems totally random. Turns out, I usually just need to dump a half gallon of coolant in. Sometimes it seems to do fine with the coolant. Other times, it eats it up.

And a funny thing, on those bad days, the temp rises most when I'm idling.

So, I bought 5 gallons of coolant, a flush kit (the Prestone T thingie), some sort of flushing liquid, ordered replacement hoses, a new rad cap, a t-stat, a t-stat housing & gasket -- as the nipple that comes off the housing is all corroded, and the hose doesn't fit so tight.

I bribed my buddy with dinner and some cash, and he'll be coming over Wed or Thurs to work on it.

I'm asking him to drain the system, flush it, replace the hoses and other parts, and fill it. While he's tooling around in there, is there anything else he should check (fan clutch? water pump?), and do you have any handy pointers for him on this job?

TIA!

 

[agent orange]

Id be a bit concerned about having to refill the radiator so much. Do you keep the overflow bottle full? If youre losing that much fluid, i would have your buddy pull the radiator and have it pressure tested. That way, if there is a problem you can take care of it now while the radiator is out, not down the road when its hard as s*** to get to. Ive never changed a t-stat on my rig, but from what ive gleaned from here there should be 2 gaskets for the tstat, not one.

Matt

 

[grrlscout89FJ62]

Id be a bit concerned about having to refill the radiator so much. Do you keep the overflow bottle full? If youre losing that much fluid, i would have your buddy pull the radiator and have it pressure tested.

When it's cool out, I usually only need to add that much about every 2 months. I'll do it when I notice that it's regularly running slightly warmer that usual -- say about, halway up the gauge. It's like a slow seep.

I keep the overflow bottle filled to the line (about 1/3?). But when I looked at it on Sunday, it was almost full. Will it even out on its own, or do I need to get some fluid out of it somehow?

I think the plan is to visually check for rad leaks when it's being flushed, and I *think* he can pressure test it. If he finds any leaks, he'll pull it, and we'll go get it soldered.

 

[brett76]

yah the thermostat hs two gaskets one under the housing and a little one that sits on top of the thermostat. everything else sounds good.

 

[tpattyII]

it heats up when you idle because there isnt any air flow.

 

[grrlscout89FJ62]

yah the thermostat hs two gaskets one under the housing and a little one that sits on top of the thermostat. everything else sounds good.

Thanks! I just checked with NAPA and they do indeed have two for me.

 

[rusty_tlc]

Unless you have done it since you owned the rig or know the PO did it I'd suggest pulling the radiator and having it flushed and re-cored. It usually dosen't cost that much and it is worth the peace of mind. Flush the system first so you don't pump nasty stuff back into your clean radiator.

It's normal for engines to get hot at idle, that is when the air flow over the radiator is the least.

There should be two fill lines on the overflow tank, hot and cold.
If you fill to the hot level when the engine is cold you will lose coolant when the engine heats and the expanded radiator coolant is dumped into the overflow.


5 Gallons of coolant is a lot for a 2F block, remember the coolant is mixed 50/50 with water.

In general your friend should check for play in the water pump, as well as the general condition of the belts.

Hope this helps.

 

[grrlscout89FJ62]

it heats up when you idle because there isnt any air flow.

That's what I was thought. But I thought it sounded so simple, it couldn't possibly be the answer.

 

[grrlscout89FJ62]

Thanks, rusty!

Unless you have done it since you owned the rig or know the PO did it I'd suggest pulling the radiator and having it flushed and re-cored.

Hmm... I don't know. I could check the records.

There should be two fill lines on the overflow tank, hot and cold.
If you fill to the hot level when the engine is cold you will lose coolant when the engine heats and the expanded radiator coolant is dumped into the overflow.

I'm pretty sure I filled it to the cool level. I always do it to the bottom line -- about 1/4-1/3 the way up.

5 Gallons of coolant is a lot for a 2F block, remember the coolant is mixed 50/50 with water.

The 5 gallons is pre-mixed 50/50. FSM said 17.2 quarts. Figured that to be roughly 5 gals.

In general your friend should check for play in the water pump, as well as the general condition of the belts.

Will do!

 

[tpattyII]

i just had my rad redone here at a local shop. it only cost about 40 bucks. its well worth the money.

 

[grrlscout89FJ62]

Grr. NAPA just called, and they can't get my t-stat housing.

CDan is out of town until tomorrow.

I just e-mailled my local-ish stealer and asked them for a price -- we'll see.

I was really hoping to have this done before I drive to Phoenix on Friday for my interview. But it might not happen that way.

Would it be worth it to do everything else for now, and come back to it? Or would that old corroded housing just release crud into my cleaned up system?

 

[bhk]

Grr. NAPA just called, and they can't get my t-stat housing.

Cruiserparts.net has one listed for $45. Maybe they can overnight it.

 

[Toadhopper]

If your rig is heating up at idle, a fan clutch check is is order also. It should engage the fan when the engine is hot, and disengage when its cold.
Toad

 

[grrlscout89FJ62]

Thanks again for the info guys!

I have one more question. Which thermostat should I get:

Thermostat - OE-Specified Temperature 192 - 195 Degree

or

Thermostat - Optional High Temperature 180 Degree

and then this one says:

Thermostat - OE Standard Temperature 180 Degree

HUH?

 

[grrlscout89FJ62]

UPDATE: my local stealer can get the upper housing for $43.50. I just have to drive over the mountain (an hour each way) to go pick it up. The lower was $130, so I decided to skip it. It was really the corroded nipple (ew!) on the upper I was worried about anyway.

Hope there's enough time for my rig to cool off before Bill starts working on it!

 

[grrlscout89FJ62]

Tonight's the night!

A guy from work even volunteered to go pick up that t-stat housing for me at the stealer's -- sweet!

Last night, I finally opened up the box of service records that the PO gave me, to see if the rad had ever been re-cored. Looks like nothing's been done to the cooling system whatsoever.

There was one receipt from a parts store that had an unidentifed core charge, from about 5 years ago. I have no idea for what part.

Funny what a difference there was between the receipts from the original owner and the PO. The OO was meticulous for the 10 years he had it. All sorts of receipts for belts, shocks, ceramic brake pads, starter, oil sender, blah blah blah. Took it to the dealer for all the regular maintenance. Noted the odometer readings every year -- I have 6 mini notebooks full of the numbers! He also kept the sales brochure and the window sticker.

The PO's receipts were from Circuit City (Viper alarm), Best Buy (stereo, speakers, all that jazz), Maaco, and an auto detailling joint. Different priorities I guess. Actually, he did have the cat and 02 sensors replaced so it would pass emissions.

 

[bigbrowndog]

Check your fan, this link may help.https://forum.ih8mud.com/showthread.php?t=79661
When you drain the radiator drain and flush the block as well. When refilling open and run the heater and make sure there is not an airpocket blockage in the engine block. cheers.

 

[TremorX]

If your rig is heating up at idle, a fan clutch check is is order also. It should engage the fan when the engine is hot, and disengage when its cold.
Toad

Crap. My fan engages when the truck is off for 5-10 minutes, regardless of temperature, and is never heard again while running, also regardless of temperature (which is wont to rise if I run over 2500rpms for very long, but will cool down a bit if I run lower). Is this the normal, tell-tale sign of a dying clutch?

 

[FJsixty2]

i'm wondering about this '5 gallon' capacity myself. i just finished the same procedure (new upper and lower hoses, new thermostat, new radiator cap, gaskets, drain plug, 'T' in the inlet hose, full flush, etc.) and i was only able to get 2.5 gallons (10 qts) in the system, so far. the FSM calls for 20+ qts and i'm not seeing it. i have already filled it (with 'T' off), run for 10 minutes and topped off and that's what got me to 10 qts. is this what most people find they take? i did a full drain of the radiator after the flush.

 

[60wag]

Crap. My fan engages when the truck is off for 5-10 minutes, regardless of temperature, and is never heard again while running, also regardless of temperature (which is wont to rise if I run over 2500rpms for very long, but will cool down a bit if I run lower). Is this the normal, tell-tale sign of a dying clutch?

- different fan. The electric carb fan only runs when the engine is off. The larger belt driven fan behind the rad has a fluid coupled clutch that can fail after 15 years or so. Rising temps at idle can indicate a weak fan clutch. Don't bother with aftermarket replacements - go OE.