66 Fleetwood - runs hot after replacing everything on the front of the engine

[scotth3886]

As I think I mentioned in a couple of other threads, I had so many oil leaks on the front of the engine, which did turn out to be all original and nothing touched ever as far as we could tell, that I decided to do everything.  You all know what kind of trouble that can get you into when you start tearing into things that aren't broken.

My mechanic did everything from the block forward; chain, gears, water pump, oil pump, fuel pump, all hoses, all gaskets, 180 stat, which is what was in there. 

An issue I had is it ran too cool, which is not surprising since it's a Scottsdale car so evidently was prepped for 120 degree heat.  Temp gauge would go up to about an 1/8th.  We sure fixed that !!!!  I only got up to about 151 at the thermostat housing with an infrared heat gun.  We fixed that by about a 100 degrees. 

He finished up everything and let it run for a while then it started spewing coolant out of one of the crossover gaskets.  Temp was 250 at the thermostat housing so sumthin' a little wrong somewhere.  Dash temp gauge was at about half. 

Previous owner had installed a non-clutch fan, which I replaced with the correct fan and clutch.  It was too hot to do anything late today so he's going to dig in tomorrow morning.  I'm thinking that maybe he should install the previous non-clutch fan before things get to hot to do, after he runs it for a while.  I can always put the new fan and clutch on later if we have it cured. 

He used a vacuum to fill up with coolant so shouldn't be any air pockets.

Anything else that he should be aware of? 

[scotth3886]

I'll share the thread with Jeremy, the ace mechanic at a local small Chebbie dealer.  He has a bunch of experience working on old cars including my 63 Grand Prix, but not on an old Cadillac as far as I know.

Thanks in advance everyone.

[Cadillac Fleetwood]

I seem to recall that the lower radiator hose is supposed to have a coil spring inside, to prevent the hose from collapsing when the engine warms up.  Most replacement hoses lack the coil spring. The hose then collapses, restricting the coolant flow.  This could be causing the problem.

-Charles Fares

[scotth3886]

I seem to recall that the lower radiator hose is supposed to have a coil spring inside, to prevent the hose from collapsing when the engine warms up.  Most replacement hoses lack the coil spring. The hose then collapses, restricting the coolant flow.  This could be causing the problem.

-Charles Fares

Thanks.  I didn't think of checking that. 

In the morning.

[V63]

I am familiar with your car, and it’s prior owner Patrick. He  was very knowledgeable. He had worked at Cadillac in Detroit. Retired to Arizona. My personal policy it to eliminate all clutch fans with flex fans. They always work!   I am not a ‘fan’ of clutch fans, nor was he. While the clutch fan might give the illusion it’s pulling air when required...it may not be.

[scotth3886]

I am familiar with your car, and it’s prior owner Patrick. He  was very knowledgeable. He had worked at Cadillac in Detroit. Retired to Arizona. My personal policy it to eliminate all clutch fans with flex fans. They always work!   I am not a ‘fan’ of clutch fans, nor was he. While the clutch fan might give the illusion it’s pulling air when required...it may not be.

I've had trouble with thermal clutch fans on my 63 Grand Prix and only a mechanical (rpm), instead of thermal, clutch fan worked, which is still on there after 20+ years.

I think it's a good idea to reinstall the non-clutch fan so we don't get it hot enough that we can't put it back on later today.  I can put it back on later if I need to.  Car was only about 151 degrees at the thermostat housing so I thought maybe getting an original fan off of a 66 and a new clutch might warm it up a bit, but NOT to 250 degrees.

[James Landi]

Scott, Apparently, from your narrative, your engine began to overheat without being under load, so a restriction in the coolant flow such as the collapsed radiator hose would be the first order of diagnoses and the likely problem.  While replacing the clutch fan may be "a good idea," there seems to be something far more "out of order," especially because, again, your car was not under load and it became so hot.   Could the timing be way off, since so much additional work has been done? If not coolant flow, I'd be investigating the "tuning" of the engine.  As you know, an overly hot engine will develop pre- ignition, thus my suggestion about using a timing light on the distributor and a vacuum gauge on the intake manifold.  Hope this helps,  James

[scotth3886]

Scott, Apparently, from your narrative, your engine began to overheat without being under load, so a restriction in the coolant flow such as the collapsed radiator hose would be the first order of diagnoses and the likely problem.  While replacing the clutch fan may be "a good idea," there seems to be something far more "out of order," especially because, again, your car was not under load and it became so hot.   Could the timing be way off, since so much additional work has been done? If not coolant flow, I'd be investigating the "tuning" of the engine.  As you know, an overly hot engine will develop pre- ignition, thus my suggestion about using a timing light on the distributor and a vacuum gauge on the intake manifold.  Hope this helps,  James

Thanks.  No, not under load.  just sitting there in the service bay. 

I believe he said that he set it to 10 or 11 BTDC, which is appx where I had it.  I never had detonation.  I never saw more than 1/8th on the gauge and 150 +/- with the heat gun.   I was trying to get it into the range of 180 +/-.

I understand that Scottsdale would present a special challenge with daytime summer temps that can be near 120.  Here in Central Ohio we top out in the low 90s and yesterday it was in the high 70s.

[Jim Govoni CLC 20546]

As simple as it sounds, make sure the thermostat isn't upside down or turned the wrong way upside right to restrict the water flow. I also have a 66 Fleetwood, the lower hose does not have a spring, the 40-47 should. I have never had mine collapse and I use the correct molded hoses top and bottom.

[scotth3886]

As simple as it sounds, make sure the thermostat isn't upside down or turned the wrong way upside right to restrict the water flow. I also have a 66 Fleetwood, the lower hose does not have a spring, the 40-47 should. I have never had mine collapse and I use the correct molded hoses top and bottom.

I have the correct molded hoses.  And all this time, I thought being a elderly pimp wannabe in a triple back 66 Fleetwood was going to be so easy !!!!  Think again I say.

[TJ Hopland]

Maybe just for fun test both the old and new thermostats?   Put em in a pan of water and with your IR gun see what they do at what temps?    Maybe your original opened too soon and the new one is a dud and opening late or not all the way?

[scotth3886]

I'm heading up there now to see where are.

What I generally do when doing anything with a cooling system is start and let warm up initially with the cap off and watch for circulation and then cap on to pressurize.

[MaR]

I have the correct molded hoses.  And all this time, I thought being a elderly pimp wannabe in a triple back 66 Fleetwood was going to be so easy !!!!  Think again I say.

Like they say: "Pimpin' aint easy!"

[fishnjim]

OOPS!   
Always first suspect when coolant refilled and burps on heat up, an air pocket.   Covered this many times here and elsewhere.   It would have to have 30 lbs of pressure to reach 250F otherwise.   

[scotth3886]

OOPS!   
Always first suspect when coolant refilled and burps on heat up, an air pocket.   Covered this many times here and elsewhere.   It would have to have 30 lbs of pressure to reach 250F otherwise.

It squirts coolant.  It did.  All fixed now and car is home.  Cha ching to the tune of $4,100 this time. 

[scotth3886]

Like they say: "Pimpin' aint easy!"

Those rear tray tables sure help so one can 'eat out' in the car !!!!

[scotth3886]

Btw, it was the crossover tube o-ring went sideways upon reassemble so that was the leak and blockage.

Thanks everyone for your help.

[Chuck Swanson]

Glad it's fixed!  Typically the issue with the O-ring is leakage due to only using one vs two (better).

Also, never seen a '66 with a fan clutch.

Chuck

[scotth3886]

Glad it's fixed!  Typically the issue with the O-ring is leakage due to only using one vs two (better).

Also, never seen a '66 with a fan clutch.

Chuck

I thought just about everything with big V8s had fan clutch fans by then?!?!?!

And yes, we used two o-rings to fix it. 

[The Tassie Devil(le)]

My '72 500 doesn't have a clutch fan.  But it does have a factory flex fan.

Bruce.