Replacing waterpump...tips & tricks ?

[MrMoparCHP]

if it ain't steamin it ain't overheating.


Alan

 

[luigi164]

Well... That's not overheating. That's just running a little warm.

Lot's of things could cause it. Air flow for example.... Are all the stock splash shields in place? That old fan clutch is a likely suspect too. Have a fan shroud?

You could change to a 160 degree thermostat. That may or may not make any difference, although it did with my car.

Everything is stock and intact: splash shields, hood to cowl seal, fan shroud. I'm gonna replace the clutchfan with the Hayden 2747. Thermostat is a 180 F. According to the FSM it should be a 195F so I already cut it down...and, as Snotty says:

I said to a friend of mine once, and it can be true here: "If you still had nothing but the idiot lights instead of an actual gauge, the temperature wouldn't bother you at all."

maybe I'm overreacting and shouldn't worry about it. I indeed started to worry áfter I got the gauges installed..ánd during a long 200 mile trip last year and ending up in a few traffic jams, the idiot light indeed lit up !!
I know it's not comparable with the old iron we are driving but my daily driver (VW Golf) stays at 195 F all day, wherever I drive..so I would be happy if the Newport would stay around 185 - 200 F..

 

[david hill]

After starting engine and let it warming up at idle it stays at approx 190 F. It goes to 210-215 F when I start driving. Highway or country roads, it doesn't matter. Temp goes up and stays.



While rad was of I inspected and flushed it (again) : no signs of blocked tubes or crud. I do have a fan shroud and checked rad temp with a temp-gun. At top of rad about 215 F to 220 F sometimes, at bottom about 160 F and meassured at different spots on the rad.

I'll try to get those drainplugs out.

After you remove the block drains you may find the holes partially blocked up. Open them up W/ a coat hanger doubled on the end about a 1/4 inch. Reach up in the water jacket as far as you can in all directions w/ the hanger. Next pull the thermostat to confirm its condition, any rubbing or polished marks make it a candidate for replacement. Refill and flush this 2x Times. Warm eng. to oper. temp. Stay close to home and drive it till it is at the 210-215 temp. Return home and monitor eng temp. while spraying the rad. w/ water. Note how fast the temp drops from top to bottom or rad. Slow rate of change = partial plugged rad. Immediate temp change w/ a greater than 30 degree change from top to bottom. Rad. is ok check fan clutch oper. Note: Radiator and fan clutch partial failures are very possible. Please post results

 

[fury fan]

Keep in mind that higher coolant temperatures translate into higher oil and ATF temperatures, too. I don't like anything of mine running over 200F on a consistent basis, but on a few of mine it was typical to get to 210-220 when in stop/go traffic.

I have 2 stories regarding steaming, overheating, and idiot lights vs gauges:

On my white Fury, when its original 318 was nearing end of life at around 180k, all was well on the dash temperature gauge and the oil light. But it had plugged up the heat riser passages for the 3rd time (this time down in the heads as well as the intake) and I didn't realize the head(s) were plugged until after it was all reassembled (cleaning the intake was always sufficient in the past). I wasn't going back in a 4th time, so I elected to crutch for a little more carb heat by going from a 180 t-stat to a 195. It helped a little, and a replacement engine was awaiting its turn anyway.

The immediate side effect of the T-stat was that at hot idle the oil light would flicker (and that's maybe a 7psi switch?) but the temperature on the gauge didn't change all that much IIRC (it was maybe 5/8-3/4 to hot?). So how low was my OP with the 180, how worn was my engine?

A 2nd prime example -
My 300L had a rebuilt engine when I got it, but it had some blowby so I suspected it was a backyard job. But it ran nice, so I left it alone. And the oil light didn't work, so I left that alone too. I feared why it was unhooked -- I assumed OP was lower than I would want, but I could drive it as much as I wanted if I was blissfully ignorant. Maybe 5 years /3000 miles later, I back it out of the garage one day and all is normal. When I try to restart it later, it turns over very slowly and makes a terrible squeaking sound as if a bearing shell is spinning around. I presume what I had long suspected, OP was gone and that the prior restart didn't build up enough oil film on the crank to make it one more time.

So I put a spare engine in, a well-verified one that I had running on my test stand (this is pertinent), I get everything swapped over, and install the mini-starter from the car's 413 (this is pertinent too). Imagine my emotional state when I hit the key and hear the same slow turning and squeaking. If I had an OP gauge on that car I would've known to diagnose the 413 further (but I'd never experienced a starter failure like that before, either).

The morals of my raqmblings -
On 50-year-old cars, esp if they are running on old parts in non-renewed/non-verified systems, better to know what's really going on than be blissfully ignorant - and improve it if opportunity affords it. Esp if it's a car you care about.

 

[fury fan]

After starting engine and let it warming up at idle it stays at approx 190 F. It goes to 210-215 F when I start driving. Highway or country roads, it doesn't matter. Temp goes up and stays.

While rad was of I inspected and flushed it (again) : no signs of blocked tubes or crud. I do have a fan shroud and checked rad temp with a temp-gun. At top of rad about 215 F to 220 F sometimes, at bottom about 160 F and meassured at different spots on the rad.

I'll try to get those drainplugs out.

I'm going to over-generalize, but in my experience when a car overheats in traffic it is usually a flow problem - usually air, but perhaps coolant.
Overheating at highway speed, when engine is making more heat, means a capacity problem - due to blockages and or faulty components.
(but yes, there is some overlap in those 2 characterizations).

1. I have always used the rule of flowing the garden hose in the radiator - fill it up with the lower hose on, keep the hose going, and pop the lower hose off - if it flows the full hose without ever backing up, IMO the problem is elsewhere. (Obviously this is a generic rule, as you could have a /6 radiator flow the garden hose, but we all know it would not be enough to cool a Hemi.)
2. Based on your temp-gun readings I would say your radiator is not the culprit.
3. If overheating at highway RPM, make sure the lower hose has a spring in it to keep it from collapsing. Reportedly the pump can create enough suction to collapse a hose, and a pump can't move fluid if it can't get fluid. FWIW, I am undergoing some cooling system repairs on my white 68 Fury, and discovered it has no spring. But it is a good-condition hose and has decent stiffness - this car tens to run hot in traffic, and is OK at highway speed, so I don't think mine is collapsing. But an older hose wrapped around the oil filter, softened by PS pump drippage - that might collapse? How is your hose.
4. Be aware that thermostats can only be rated for a temperature for when they open - not much else. If the cooling system (heat transfer out of the engine block/heads, pump flow, airflow, and radiator heat transfer -- the whole system) exceeds the engine heat output, the thermostat will cycle slowly and keep the temperature 'at' its rating (temperatures in the heads and block will vary higher than that temperature). If the cooling system is under-capacity, engine temperature will rise above the T-stat's initial cracking event, and keep on going. In such a case maybe the T-stat cycles quickly, maybe it just stays open, each system might behave differently. In a case like this, a 180 T-stat will only make the car take a little longer to overheat vs a 195, because it starts cooling off sooner. But if under-capacity, either T-stat will allow an overheat condition. (and say 'overheat' or emphasis, what I really mean is the engine's equilibrium coolant temperature at steady state conditions)
5. At highway speed the radiator fan is not required as much due to the airflow increase over the radiator, so I would look elsewhere from fan and clutch. It is possible that if the clutch did not loosen up properly at high temps/speeds that it could act as a restriction, but that's too much of a stretch here?
6. So - I would be looking at insufficient coolant flow/fan belt slippage for a high-speed temperature increase.
7. Cleaning out the crud in the bottom of the engine block is always going to benefit, but the amount is unknown and it's tough to do it thoroughly with teh engine in the car -- you really need to have the freeze plugs out and good access with a stout screwdriver and maybe a hammer because that crap rust-fuses together. And also consider that the crud is at the bottom of the coolant area, furthest away from the heads and top of the cylinder, where the temperature is the hottest. Yes, cooler cylinder bottoms will conduct heat down from the heads, I'm just saying I don't think this will make a night/day difference, it's more of a feelgood thing.

That's probably enough of my spouting for now...

 

[fury fan]

Oh, one more thing - ignition timing and fuel mixture should be looked at too. Those affect how much heat the engine makes, and ignition timing can affect whether that heat goes more to the coolant or into pressure to push the piston down. Ignition timing at TDC is ideal, however the less efficient the cylinder head, the more timing advance is needed, and more time for the combustion heat to start to escape to the coolant while the piston is still rising (ignition timing advance in an older engine is a necessary evil). Esp consider that the sooner it is done, more cylinder wall is exposed and more 'cold' surface area to suck off heat.

 

[fury fan]

Doggone it, another thing I noticed upon re-reading all of this:

As I mentioned, I'm mid-way thru some repairs myself. I heard some belt-drive noise thru the hood, and discovered a bit of play in the water pump, so took it off. It is an older 'high-flow' pump I got from Summit prob 10 years ago, in effort to get my 440 a little cooler in traffic (it didn't help much).
So I reviewed the used pumps I had, 1 an 8-blade in non-suitable condition, and a 5 or 6-blade that seemed usable. So I put that one on, along with going from a 195 t-stat to a 180.

My car started out at normal warm-up (idling only), then each cooling cycle was 3-4 degrees higher than the last, until it was getting up to 215. Raising engine rpm didn't help much, so I assumed it would overheat in driving, so I aborted. I simply didn't believe it would stay cool enough in driving operation.

That pump I installed is similar to the one you posted, Luigi. I did make 2 changes to my system, but I believe the fewer-blade pump isn't flowing enough. It was about 93F ambient that day, but I've driven this car in days hotter than that in the past, and this pump definitely showed different behavior.

So I am going to a new pump, either an 8-blade OEM, or a 6-blade with anti-cavitation plate similar to the High-flow pump I removed (I have both types on-hand now) and also a high-flow 180 T-stat. I want to see what those changes do, and after that I am researching an aluminum radiator upgrade. I'd like my car to run 190-195F max in stopped traffic, I'm tired of seeing 210-215F.

Perhaps next week I can give some feedback on what my pump changes do for me, and that may guide you?

 

[fc7_plumcrazy]

Luigi: I had a similar symptom in the past: a 440 GTX was fine when idling but got up to 210 when driving on the autobahn. The faster I drove the hotter it got. When driving slower again the temperature fell. When driving in a traffic jam: It was down to 180F (t-stat). Engine was rebuilt not to long ago, lower rad house had a spring. The radiator looked clean with no dirt coming out. We put in a new net into the old frame: Problem solved. The rad was stuck from inside

 

[68PK21 440.6bbl]

For what's it's worth, my 1968 PK21 with a 440 would puke when shut down after a long hard run. Didn't matter if coolant level was high or low. Now this was back in 1971/on so clogged up cooling system would not apply as the car/engine was less than 4 years old.
about it, after one flat out test run with the speedo pinned for pretty much the whole run round the beltway (100+ miles), dash temp gauge just fine even with the slow drive on secondary roads home, sit in driveway idling for 10 minutes, no temp increase, shut down, PUKE.
Arrrrrgggggggg!

 

[luigi164]

Thank you all for the responses on my "overheating problem" but...I believe it's solved

First I replaced the pump with the Gates 8 blades and also replaced the clutch with the Hayden 2747.
Test drive showed a little lower temp than before the change but still went up to 205-210 F after a long drive. So I was not satisfied yet. I thought to myself: what next? Pulling the drainplugs ? or should I first be sure that the radiator was not clogged? Decided to do the easy thing first and brought the radiator to a radiatorshop which is here in town for almost 50 years. After I picked it up the man said it was indeed clogged up at some passages and that he was able to clean it up but not completely. Gave me the advice to try it and see what happens. If necessary he could put another core in it.

So, put the radiator in and went for a ride. Guess what, temp was around 185-195 F all the time, never got above 200 F ! So thank you Carsten for your tip, I really thought my radiator was clean but apparently not !

So now I drive around with confidence with a nice temp gauge showing the right temp
Again all..

Luigi

 

[fury fan]

For what's it's worth, my 1968 PK21 with a 440 would puke when shut down after a long hard run. Didn't matter if coolant level was high or low. Now this was back in 1971/on so clogged up cooling system would not apply as the car/engine was less than 4 years old.
about it, after one flat out test run with the speedo pinned for pretty much the whole run round the beltway (100+ miles), dash temp gauge just fine even with the slow drive on secondary roads home, sit in driveway idling for 10 minutes, no temp increase, shut down, PUKE.
Arrrrrgggggggg!

I would say that is due to the heat still transferring to the coolant after the engine shuts off, and with no circulation thru the radiator, and no airflow, the water sees about as much heat and expansion as it ever can. The hottest water's heat 'floats' from teh heads, water housing, thru the T-stat and into the radiator, and the heat in the radiator's coolant is floating up as well, making the top tank the hottest part - right where the cap is. Your hi-speed highway run was under high load, but it also had high airflow to compensate. That's just my speculation for explanaation, though.

Engines start to cool down instantly when they are shut off (the heat source is extinguished) but heat transfer still continues, so coolant temperature starts to immediately climb.