Now It's My Turn for Help

[Roscoe]

Matt,
Check out the troubleshooting I did in the beginning of the thread. We did a leak down, pressure and dye test of the cooling system to check for head gasket leakage. No foreign stuff in the oil or coolant. No exhaust gasses in the cooling system. No white smoke at all.

I still suspect that water pump.

Thanks,
Roscoe

[Okiesnake]

Roscoe,
Out of curiosity and troubleshooting by the process of elimination, have you tried running the car without a thermostat in place? It may not have anything to do with the problem but is would only take a few minutes to confirm.

[Jack21]

Rosco,

The seals on the water pump will prevent it from free wheeling. This is normal. Are you using an OEM pump or one of the high volume aftermarket pumps?

What kind of pulleys are you using? If March, the street rod ratio works better on street motors than the Hi Po ratio.

What kind of fan are you using? Although, at speeds over 30 MPH, your fan shouldn't come on at all. If fan isn't doing its job, motor will run hot, or overheat at low speed.

What kind of lower water crossover are you using? Any chance of it collapsing and restricting flow? Long lengths of lower hose need to have those funny looking springs inside to prevent collapsing. Exhaust tubing makes good lower water crossover. (Pump inlet on drivers side, radiator lower outlet on passenger side)

Air, or exhaust in the coolant. Any bubbles in coolant when you hold upper hose up with engine running and garden hose keeping radiator full? Coolant in oil? Water condensation on dipstick? breather? PCV?

[Roscoe]

OKIE: That's about the only thing I haven't done. Although I did cycle it with boiling water and even put a new one in. Worth a try I guess.

JACK: Remember that everything was running well for a year before I had problems.

I'm using a Milodon high volume alum pump. March pulley, Derale high output fan.

With the new radiator I am running -16AN crossover and only about 2 feet of stainess braided hose.

We did a dye test in the coolant and that was negative. No coolant in oil or visa versa. Nothing on the dipstick and the oil is clean.

Roscoe

[Dang]

How MUCH drag is your water pump making? The 0.5-3 horse pumps I worked on were capable of melting their own impellers onto their shafts if they lost coolant. Never had one melt due to bearings, BUT these pumps had automatic heat protection. I imagine that an all-aluminum impeller spinning at high rpm with plenty of HP could heat the water nicely.

Edit: Squeaking means something is rubbing together. When your water pump is squeaking at 4000 rpm with 400 hp on it, I bet it'll get hot (or broken).

[Roscoe]

Dang,
If I hold the pump in my hand and spin the shaft it can go about half a turn. The squeaking stopped after sitting overnight on the bench.
Roscoe

[wadesdad]

Roscoe,

I spoke with someone yesterday who accidently re-routed his belt the wrong way on a serpentine system. It caused the pump to work backwards. The result is what you are experiencing.
He was man enough to admit it. I've done similar things myself.

[Dang]

1/2 turn sounds decent. And turning the pump backwards would definately cause a problem! Is the impeller clogged?

[Denny S.]

I had the same type of problem and the cure was to remove the temp guage sender and fill the coolant from there and then fill
the radiator. That solved it. It was air somehow..

[Curt C.]

Play with the pump impeller a bit. This exact same thing happened to me durring a 306 build up for my 95 Mustang Cobra. Brand new Stewart water pump broke the compression fit where the impeller goes on. Impellar would sometimes spin, sometimes not. Reving the motor increased temp dramatically. Someone earlier suggested running the motor with the upper radiator hose off and pointed up to see if water or air / nothing comes out. Just remember to stick a water hose in the radiator to keep water flowing into the motor. Also, do it while it is cold because when hot, expansion will force the water out by itself.

Curt

[Roscoe]

I took the pump over to a couple of mechanics I know and they both checked it out. All say it is fine.

Well I even boiled the pump in our pasta pot and it still works. I did block off the heater hose bypasses and installed a petcock in the intake manifold outlet as a bleed.

Might get to give it another go today.

Roscoe

[Roscoe]

Well I put everything back together. Made new upper hoses which provided a less restrictive flow. No Thermostat.

50/50 mix, new belt, bleeder on the intake manifold. Filled it with the car up on jack stands, the front up at least a foot off the ground. Checked fluid lever after bringing it off the jacks and it was fine.

Idled for about 10 minutes with a few revs and worked itself up to about 150. Seemed to raise quicker after each rev session.

Water pump inlet hose was just warm. Drivers side of rad was warm (normal).

I got in the car and brought the tach up to 2700-2800. Within three minutes or less it worked its way up to 220 and I shut it down. Opened the bleeder on the intake and no air.


I'm stymied. Other than pulling the intake and heads I am at wits end!!!

Roscoe

[Steve R]

Bummer buddy
Roscoe wish I had something to ad that would help.......just thought of this: Did you look at the tops of the pistons through the sparks plug holes? Usually the piston is steam cleaned if there if any funny business with coolent/ cylinder interaction.
Steven

[Roscoe]

Steve,
Did not do that but I did pull the plugs and they looked ok.

Roscoe

[RACER X #99]

Roscoe,

PULL THE HEADS

Cranky

[Roscoe]

Cranky,

Yeah! I should have done that along time ago but I've been in denial, I guess. I always had it on the list but kept putting it off hoping that it would be something else.

Roscoe

[Steve R]

Roscoe,
Nothing wrong with that. I agree. It's time.
Steven
"Count to one hundred backwards.... Scalpel please....."

[John Poling]

Let's keep in mind that Roscoe said he had been driving his car for a year with no issues as far as overheating and then it started to heat up. All of the testing and experiments he has done discounts pretty much any possible engine mechanical problems.

Roscoe, a few posts back Jack21 suggested the lower radiator hose being a possible culprit. I would look here BEFORE removing any more engine parts. I don't believe that I saw anything in this string suggesting that you have replaced it. My suggestion would be to fabricate as much of the lower hose out of hard (steel or aluminum) tubing as you possibly can. The lower radiator hose in a normal x-flow radiator is under a "vacuum" of sorts when the engine is running and under a more extreme "vacuum" at off idle conditions. As your componants age so does the rubber on your hoses which weakens them in the process causing the hose to partially collapse if not fully collapse if it does not have an internal spring coil for support. Even if you have the spring there, it doesn't mean that it is doing what it is supposed to. In my 20 or so years of playing with cars, I have run into this more than once, of course after I had gone through everything like what you have been.

Again, PLEASE try this before tearing into your engine deeper and eliminate this possibilty.

John

[Roscoe]

John,
The lower hose is new. The new radiator has AN fittings so I fabricated a new hose when I installed the radiator.

WAIT! I'M NOT PULLING MY HEADS. I'VE FOUND SOMETHING!

This may be a stretch and unrelated but some people tell me it may be the cause of my problem.

Here goes: While I was waiting for the new radiator I took off my two fuel filters to clean. The filter that goes between the tank and the pump is a System 1 9" inline with a reusable stainless 45 micron filter screen (non restrictive). Next is the pump, a Holley black 140gph, then a Canton Mecca small canister with an 8 micron paper filter, then the regulator to the carb.

The 9" inline had some dirt and stuff in it but that is normal. However when I pulled the filter out of the Canton canister it was loaded with clear silicone! And I mean loaded!. Now I don't own any clear silicone. I've heard that when some of these gas tanks are fabricated they are 'touched up' inside with a bead of silicone. If this is the case, and it looks like it is, this silicone worked it's way into my fuel system.

So now I test the pump. This pump is supposed to put out 140 gpm which comes down to about 1.165 gallons in 30 seconds. Well I turn on the pump and it pumps less than a pint in 30 seconds!!

This starving condition (under load remember?) could be leaning the engine out so much that the engine just heats up.

I disonnected the line from the tank at the 9" filter and took everything apart, including the pump and regulater. Other than some gravel in the pump screen everything else was ok. I tore down the carb and blew everyting out. However, when I put everything back I still could only pump less than a pint in 30 seconds.

I'm borrowing a Holley blue today and will swap it out and try it. If it is the same than I suspect the regulator.

Almost ready for the Funny Farm,
Roscoe

[John Poling]

Roscoe,

Good to hear you found another possibility. BTW are you ready for the cow tip'n yet? Keep us posted.

John