Michael Yount
Mustang Master
87ttop - how did it cool down to 145 with a 180 t'stat? If it really did, then your t'stat isn't working like it should.
electric fan vs HD fan clutch
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I don't know, I was measuring temperature of the water at the fill hole and inside "V" portions of cooling fins- don't know much about thermostats, how quickly do they open and close? Or is mine faulty? 
P.S.-Appreciate all the fan info you post, helped me out a lot!
P.S.-Appreciate all the fan info you post, helped me out a lot!
i knew i should've replaced the water pump at the same time as the radiator, but i was cheap and thought this would work just fine. my cooling system was completely shot i guess, well i didnt know until like 1-2 weeks ago. i pulled the radiator and the core was like rotted, and im pretty sure i still have the stock fan clutch and now the water pump.
sometimes i want to roll the car off a cliff, other times im pretty happy w/ it.
back to my water pump dilema. it only leaks when the car is on and the belt is turning so i dont think it's the seal. when the car is off it stops dripping so it must be cracked or something?? then again coolant expands so i dunno. it wouldnt be because i put too much coolant in, right? correct me if im wrong but it would just go into the overflow tank...
sometimes i want to roll the car off a cliff, other times im pretty happy w/ it.
back to my water pump dilema. it only leaks when the car is on and the belt is turning so i dont think it's the seal. when the car is off it stops dripping so it must be cracked or something?? then again coolant expands so i dunno. it wouldnt be because i put too much coolant in, right? correct me if im wrong but it would just go into the overflow tank...
ok, im needin some more info cuz im dumb. are ya familiar with the weep hole that Michael was talkin about? if not, look underneath the pump. you will see a small hole (manufactured into the pump). when the seal inside goes south, water will leak out of the hole. it normally leaves a telltale stain down the pump body. then it will drain down whereever gravity takes it.1991vert said:
i would really clean the pump and surrounding area up and start it and watch (be real careful and watch fans, pulleys, belts, etc). look for a fresh trail of coolant. if it is the weep hole, probably better off with a new pump - ive never entertained trying to put a new seal on it, so i dont know about that (since you have a nice pump).
good luck, bud.
87 T-Top, i agree with ya totally - we all appreciate Michael's knowledge with cooling systems, amongst all the other areas.87TTopGT said:I don't know, I was measuring temperature of the water at the fill hole and inside "V" portions of cooling fins- don't know much about thermostats, how quickly do they open and close? Or is mine faulty?
P.S.-Appreciate all the fan info you post, helped me out a lot!
i agree with Michael (remember when folks called him Guru?) about the readings you got. the only way i can think of that you could read 145 is from meter error or: if you were playing with the pyrometer and checked temps after the coolant had been in the radiator and cooled down, just before it gets recirculated into the motor (basically at the coolest point while in the radiator before goin back into the motor). i dont know how much a rad/fan will cool coolant down, though.
once coolant which is cooler than the temp of the stat, reaches the stat, the stat should close. i dont think they close real fast (just like they dont open super fast - not like a light switch). but i would not think you could cool it down that much w/o closing the stat (im thinking it should be closed by 175-180. but im talkin out my rear and will learn a lot when Michael corrects me.
BTW, i often run at 170 (aftermarket gauge in the stock sender location). i chalked it up to the difference in temps at the sender vs at the T-stat. or gauge error. always made me wonder though (80-90* day, been driving for quite some time - motor is as warm as it will get). anyone else notice the same thing or have comments, since we are tossing this stuff around?
Michael Yount
Mustang Master
Hissin/87tt - that explains it. The t'stat does open/close relatively slowly over a range of 3-5F degrees. But if working properly, it will keep the coolant at the open/close temp -- if measured right at the t'stat location. That's always at the outlet of the engine -- which will be the hottest location. If you measure elsewhere, it will be cooler - which is what occurred. When you said it cooled to 145F I thought you meant on your car's temp gauge (which also measures near the t'stat housing - the hottest part). I measured the 180 t'stat in my car - it began opening at 182F and was fully open by 185F. So they're all a little different.
Michael Yount said:
So, water is going into the engine at 145*- wonder what the delta is coming out of the thermostat housing? Too bad the only way to check is sticking the needle into the radiator hose! Might be fun to find out when I get ready to replace that hose... of course there are a lot of variables, water pump flow rate, radiator condition etc.- while you have your Guru hat on, is it possible to outflow a radiator? How much water can flow through a 2 row or 3 row in new condition? Any industry ratings for this? What happens when you pump water faster than the radiator flows?
Michael Yount
Mustang Master
I tend to think of it more as temperature gradients rather than deltas. Temps vary throughout the block and radiator from top to bottom, side to side and front to back (the front row of the radiator is cooler than the rear row because the rear row is 'cooled' by hot air coming off the front row). The temp at the t'stat housing should be within 3F degrees of the t'stat rated temp. Also, with the cap off, the system doesn't pressurize, so that impacts temps as well - under running conditions you'd measure different numbers.
The t'stat controls temp and limits flow/velocity in the system. I wouldn't worry about outflowing the rad with a t'stat in place. ANd the bypass hose allows the pump to circulate coolant in the block even when the t'stat's closed.
The t'stat controls temp and limits flow/velocity in the system. I wouldn't worry about outflowing the rad with a t'stat in place. ANd the bypass hose allows the pump to circulate coolant in the block even when the t'stat's closed.
since it was touched upon, where on the spectrum is the ECT in terms of relative temps. what im asking is, if im reading 170 at the stock sender location, have a Mr G 180 stat, is it likely that im in closed loop? my foggy recollection is that the ECT needs to be at 178* to enter closed loop. any guess or thoughts?
Michael Yount
Mustang Master
I believe closed loop operation relative to coolant temps is a bit of a myth. The issue is simply whether or not the O2 sensors are warm enough to start generating voltages for use by the ecu. The ceramic material in the sensor must be at least 570F before it starts working correctly. Consequently, it can take as long as 90-120 seconds for an unheated O2 sensor to get warm enough to start working properly. In most 88-93 eec systems, the O2 sensors are heated to get them operating more quickly. A heated sensor may be hot enough in 10-15 seconds to generate voltage and allow closed loop operation. So, a minute or two at the longest, a few seconds at the shortest and you're in closed loop. All this according to Probst book on the Ford ECU. Verified on my car which had no problem achieving closed loop (19 mpg city/26 mpg hwy) with a 170F t'stat - even in our occasional 5F-10F cold mornings in Jan/Feb.
1991vert said:
Minor quibble: The FMS aluminum radiator (M-8500-C) is a 2 row/core radiator. It is very wide because the cores are 1" wide, but it is not a 3 core.
Anyway, if the temp rises only when you are stopped, that is a sure sign of lack of airflow across the radiator. Try spinning your fan blades with the engine off. If the fan spins freely with little to no resistance, it's time for a new fan clutch. An OEM unit is the way to go. I've tried parts-store fan clutches in the past and been unhappy.
An upgrade to an electric fan would help, as well.
As has been pointed out, most OEM electric fan setups will work well, but the most popular are the 3.8 Taurus, Lincoln Mk VIII, and SN95 electric fans. The control from www.dccontrol.com also seems to be the way to go as far as controlling it.
Good luck,
thank you very much for the insight, Guru.Michael Yount said:
that is something i always wondered about. i know with the Chevy motors, the lambda function was, as you stated, a result of the sensor being properly hot from exhaust gas alone. in here i have read about the ECT (thus coolant temp) having something to do with closed loop entrance.
with the SBC's, they run the factory 180 stat, and the rediculous fan switch (on at 226*) - the latter for emissions perhaps. but no one ever worries about being 'too cold' with those, but we do.
that really makes a lot of sense, Michael. thanks a bunch.
BTW, i would think the exhaust is up to 570* way before i ever get 180* coolant.
does the lambda input coming-on occur about the same time as it car goes out of fast idle? with the times you listed, that seemed about right, or pretty close (i have not timed fast idle duration, nor done pyrometer testing on the exhaust). just my foggy recollection.
thanks again - i need to get one of Chuck's books so i can stop buggin you about stuff like this.
many thanks!
miamifiveoh said:
eh, i dunno about that one...http://www.mustangsunlimited.com/itemdy00.asp?T1=M8005C+01 and i've emailed/spoke with a few distributors and they all said it was a 3row/core. anyways, the radiator isnt the problem anymore. it's the water pump. will a stock replacement be fine for my useage?
I've seen the misprint in the Mustangs Unlimited catalog and a few other places, too....www.summitracing.com for one...
I have the same radiator you do, aluminum core with the plastic tanks, and it is most definitely a two core. Look inside through the cap opening and you will see 2-1" cores.
Anyway, the stock pump should be fine for your application. I have HEARD about Edelbrocks suffering the very fate you described too often to buy one myself.
However, before you go changing the pump, make sure it isn't a loose hose or something. I thought my water pump was leaking once, and it turned out to be the lower radiator hose wasn't as snug as it should have been going into the water pump. A couple of turns of the clamp and all was well.
Good luck with it,
I have the same radiator you do, aluminum core with the plastic tanks, and it is most definitely a two core. Look inside through the cap opening and you will see 2-1" cores.
Anyway, the stock pump should be fine for your application. I have HEARD about Edelbrocks suffering the very fate you described too often to buy one myself.
However, before you go changing the pump, make sure it isn't a loose hose or something. I thought my water pump was leaking once, and it turned out to be the lower radiator hose wasn't as snug as it should have been going into the water pump. A couple of turns of the clamp and all was well.
Good luck with it,
well i had random coolant spots last year and never thought twice about it. the other day after i got my radiator situated i took it for a ride and went back home. right when im back in the garage, my dad told me i was leaking and popped the hood. it's coming from the bottom of the water pump. i put a pan under it and went out cuz i had plans and when i came back there was like 2-3 tablespoons of coolant in the pan. it only leaks when the car is on i guess.
oh well if it's a 2core, i guess it's just as good
gotta love false advertisement i guess. gonna pick up the stock pump tomorrow for a whopping $30 w/ discount included. it's funny, little things like this annoy me, but doing a big job like a tranny swap is actually fun to me .
i thank EVERYONE for all of you help/advice!
Chris
oh well if it's a 2core, i guess it's just as good
gotta love false advertisement i guess. gonna pick up the stock pump tomorrow for a whopping $30 w/ discount included. it's funny, little things like this annoy me, but doing a big job like a tranny swap is actually fun to me .i thank EVERYONE for all of you help/advice!
Chris
Michael Yount
Mustang Master
Nelson - on the clutch test, I'd offer a different perspective. The clutch works based on temperature. That is, as the air coming off the radiator gets hotter, and the fan clutch gets hotter, it gets to a point where it locks up and drives the fan. The clutches work just like a cars t'stat does. Consequently, if the engine is cold, and you walk up and spin the fan - it should freewheel. That's how the clutch is designed - to freewheel as long as the engine is below a certain temp. Now, drive the car around, and get it good and hot - sit in some traffic to be sure it's completely warmed up. Now, shut it down and try to spin the fan -- with the engine good and hot, you shouldn't be able to spin the fan. Cold it should freewheel, hot it shouldn't -- that's the clutch test.
Michael,
I agree with you to a point. Your logic is flawless, and I'm certain the method you describe is more accurate than the one I use.
However, in my experience, the fan should never truly freewheel, even when cold. In my experience, the fan should spin fairly easily when spun by hand, but once that hand is removed, it should barely complete a revolution (if even that much) on its own. Any more, and I'd say the clutch is shot. At that point, I'd say its ability to lock up when hot has also been greatly diminished.
I agree with you to a point. Your logic is flawless, and I'm certain the method you describe is more accurate than the one I use.
However, in my experience, the fan should never truly freewheel, even when cold. In my experience, the fan should spin fairly easily when spun by hand, but once that hand is removed, it should barely complete a revolution (if even that much) on its own. Any more, and I'd say the clutch is shot. At that point, I'd say its ability to lock up when hot has also been greatly diminished.
Michael Yount
Mustang Master
Nelson - I'm with you; free-wheeling is a relative term. Even when cold, there is some resistance to movement - it's not like you can spin it and it will just keep on spinning. But you should be able to easily turn the fan with your hand. And when hot it will be extremely difficult to turn. In failure mode, I've seen them lock up when cold, and fail to lock up when hot; more often (my experience) they fail by locking up all the time. And you get the Boeing 747 on take off sound if you rev the motor above about 3 grand. Of course, when that happens, it's the noise and power drain that are the problem, not overheating.
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