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Topic: engine running too cool *solved- installed non failsafe tstat (Read 17327 times) previous topic - next topic

engine running too cool *solved- installed non failsafe tstat

Reply #15
because i know the stat isn't going to fix anything.
i can take the upper hose off and with a light i can see that eventually the tstat closes when things cool down.

ive change the tstat like three times in 2015 troubleshooting this.  including rad cap.

the heater core is NOS put in a couple years ago,, all hoses are new also.

its barely tolerable in the car with this wonderful weather.

engine running too cool *solved- installed non failsafe tstat

Reply #16
Gotchya. I didn't know you had already swapped it. There has to be coolant getting by somewhere where it shouldn't be.

My old crown vic wagon started spraying coolant out of the water pump nipples. When I removed the water pump I found no antifreeze, just straight rust colored water and no blades on the water pump. It never did overheat until the coolant leak.

With the new water pump it started to overheat randomly and then I would get big orange chunks in the radiator that were solid and hard but looked like a sponge. No matter how many times I tried flushing it, I kept getting them in the radiator. I eventually just decided to ignore it and it kept putting along until my sister messed up the axle hitting a curb. Then it kept eating axles and rear wheel bearings and I junked it and bought my cougar. I checked the radiator before I drove it the the junkyard and it looked like someone filled the whole radiator with expanding foam.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

engine running too cool *solved- installed non failsafe tstat

Reply #17
My money's on the w/p being bad...
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6

engine running too cool *solved- installed non failsafe tstat

Reply #18
The way to test for good flow through radiator is with coolant down approx six inches, there should good streams flowing from visible cores(open thermostat of course)... Also cold heater hoses are a giveaway flow is minimal at best... Of course could indicate core is plugged but usually the inlet hose will be hot...

I had a 3.0 Aerostar around here for awhile that had bad water pump impeller, would idle and generally drive OK till at least till the A/C was on, then it overheated...

engine running too cool *solved- installed non failsafe tstat

Reply #19
How old is the water pump? If it's original; A:  that's impressive and B: yeah it probably doesn't work very good at all. Water pump replacements are cheap but a pain if the bolts get stuck in the timing cover. I always cover the bolt threads that go into the timing cover with thread sealer (the white ARP or Permatex stuff is fine) to keep them from sticking if the pump ever has to come out.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

engine running too cool *solved- installed non failsafe tstat

Reply #20
Use heat on those bolts Scott...and go back and forth with them. You probably know this though. I got luck on my project engine, but it was easy to do since it was on a stand and not in the car. Heat, back and forth, patience, and knowledge that if I snapped a bolt, I'd be in a pickle. Lou is on it too....I used ARP as well on the reassembly. Used it on all of the w/p bolts, for that matter.
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6

engine running too cool *solved- installed non failsafe tstat

Reply #21
All signs lead to water pump. I had a similar situation in a 99 expedition 5.4 liter. No heat, everything cool/cold to the touch, no overheating. After many flushes, including the heater cores (rear heat on this one) there was little to no coolant flow. Pulled the water pump and there were no fins left at all. Ironically, when you'd take the engine over 3500 rpm the heat at the vent would crest over 65 degrees. Replaced pump, topped off coolant, heat output at the vent jumped to borderline uncomfortably hot.  Problem solved after an afternoon of frustration.
41 Dodge Luxury Liner Sedan
78 F-100 2wd flareside
84Turbo Coupe
84 Thunderbird Élan
85 Thunderbird 3.8
88 Turbo Coupe
88 Mustang GT
90 Stang LX 5.0 5spd
93 F-150 4x4 ext cab
96 Mustang GT
98 Mustang GT
99 SVT Cobra
06 Fusion SEL
14 Fusion Sport

engine running too cool *solved- installed non failsafe tstat

Reply #22
IM second owner,, but I cant say the water pump "isn't" original. 

guys, now that you mention it,,  on my trips weekly up north I sometimes stop to just simply check under the hood and no matter how many miles I put behind me, im able to take off the rad cap with no pressure.,,,, I forgot to watch for flow tom like you mentioned,, and this stupid radiator doesn't have the petpen 15 with a drain nipple like the other.... so.. ill check flow anyway.

but......... anyway, I actually wondering why I don't build pressure at all.    hell who knows, its staying cool so why should it build pressure right?

yep, will heat bolts and wiggle them out.  I got lucky I guess on the bronco, the timing cover bolts came out real nice, used anti-seize when they went back in.

I hope I can do a pump this weekend but maybe the winter wonder land has other plans for me.

engine running too cool *solved- installed non failsafe tstat

Reply #23
Pump on my old Comet 302 had frozen bolts on passenger side, shanks were rusted in place inside the timing cover... Was obvious they weren't coming out without breaking, so I used my small 12v battery Dewalt impact to rattle them for awhile... Took a couple minutes of back and forth but they finally gave up and came out...

I won't apply heat a aluminum timing cover unless I'm going to pull it, don't trust the cover to block gasket after it's been heated...

engine running too cool *solved- installed non failsafe tstat

Reply #24
Do you have water coming out of the small hole on the waterpump?
If yes, change it. Happened to both me and my father on the exact same summer aswell.

engine running too cool *solved- installed non failsafe tstat

Reply #25
If his impeller is corroded away, the pump will still be bad but not bleeding out antifreeze...


And again, my money is on the pump being bad. Had the same thing happen happen too many times to my own stuff to see it being elsewhere.
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6

engine running too cool *solved- installed non failsafe tstat

Reply #26
If Scott hasn't already swapped the pump, it may be awhile... They got 20" of snow up that way on Saturday..

engine running too cool *solved- installed non failsafe tstat

Reply #27
Well, got the bolts out with natural heat instead of artificial heat.

changed the pump and was surprised.  it was a Reman,, professionally stamped as such with some odd ball numbering reman stamping.

impellers were in tact,  looked totally brand new.

I felt like packman after taking a drive,,  you know where the ghost eats packman,,, still same problem.

Update though,, on the way up to pa today, I felt the upper hose and it had pressure  !!!


so,, back to the cardboard game till spring I guess.

if its warm this week I will dig into the ductwork and see if something is fubar there.  Ive been wanting to take out the blower anyway and clean the squirrel cage for the first time ever.

I pretty much totally give up.

even the radiator is still cold on the bottom half and warm on the top.

maybe if it stays warm it wont matter,, and by spring the problem will go away lol.... till next winter.

engine running too cool *solved- installed non failsafe tstat

Reply #28
I saw the thread title in the main listing for last-posted-in and I thought "I know EXACTLY who the thread starter HAS to be" :rollin:
And then saw the date. Kinda jogged my memory and then I realized I didn't partite in the discussion. Don't know why this didn't get a rise out of me back then.

Do you have an IR thermometer gun? I'd definitely be pointing it at everything. Is the radiator stock or did someone upgrade it in years prior?
If the car's temp gauge isn't BS'ing you...in the winter especially doing a lot of highway I wouldn't be terribly surprised if things generally feel cool in the engine bay. Even exhaust...headers I'd expect to be red hot but manifolds probably insulate fairly well and their rough texture and surface area conduct heat into the air far better than tubular headers.

Coolant control valve OK? I feel like that hasn't been mentioned yet. I unplugged that long ago in my 20th, it does have EATC. Always annoyed me that this wouldn't let coolant flow to the heater until some setpoint (don't know what that point is). But either that's just barely not being satisfied or the valve failed shut. You should get SOMETHING out of the vents. Does air even move at all out of each discharge position? Foxes don't seem to blow too hard out of the dash except for the one right between the clock and instrumentation. But the air should at least be warmer than whatever is in the interior already. Heatercore isn't getting anything. Can't be. Or the blend door is stuck on cold.
1987 20th Anniversary Cougar, 302 "5.0" GT-40 heads (F3ZE '93 Cobra) and TMoss Ported H.O. intake, H.O. camshaft
2.5" Duals, no cats, Flowmaster 40s, Richmond 3.73s w/ Trac-Lok, maxed out Baumann shift kit, 3000 RPM Dirty Dog non-lock TC
Aside from the Mustang crinkle headers, still looks like it's only 150 HP...
1988 Black XR7 Trick Flow top end, Tremec 3550
1988 Black XR7 Procharger P600B intercooled, Edelbrock Performer non-RPM heads, GT40 intake AOD, 13 PSI @5000 RPM. 93 octane

engine running too cool *solved- installed non failsafe tstat

Reply #29
Quote from: ZondaC12;453607
Coolant control valve OK? I feel like that hasn't been mentioned yet. I unplugged that long ago in my 20th, it does have EATC. Always annoyed me that this wouldn't let coolant flow to the heater until some setpoint (don't know what that point is). But either that's just barely not being satisfied or the valve failed shut. You should get SOMETHING out of the vents. Does air even move at all out of each discharge position? Foxes don't seem to blow too hard out of the dash except for the one right between the clock and instrumentation. But the air should at least be warmer than whatever is in the interior already. Heatercore isn't getting anything. Can't be. Or the blend door is stuck on cold.

Uh the EATC doesn't have a valve that shuts off flow to the heater core. The sensor in the heater hose actually just keeps the blower fan from turning on until the coolant circulating through the core is around 120*. It doesn't block coolant flow at all. You can override the sensor by just turning the fan from "AUTO" to "HIGH", "LOW", or "MEDIUM".
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.