HELP! overheating 3.8

I frequently read this group and feel that someone out there could help with a problem I have with a 1990 T-bird. The car has the infamous 3.8, non supercharged v6 and is overheating but does not have the telltale signs of blown head gaskets. There's no water/coolant in the oil nor does it smoke or run rough, it simply overheats. Just after I bought the car the water pump started leaking and I had to replace it. I don't recall if the car overheated prior to that or not. I've replaced the thermostat and even removed the stat. It's almost as though the pump is not circulating the water properly and I believe there is only pressure on the top rad hose and not water. When the car is running with the radiator cap off coolant is coming out as though it is being pushed from the bottom as opposed to being sucked into the motor from the bottom. Also when the vent is loosened coolant will escape but again it doesn't appear to be running though the top hose. Could this be a sign of air lock, incorrect water pump(wrong rotation) or the ever dreaded blown head gaskets? Would it be worth my time to replace the pump again, bypass the heater core in case it's blocked and causing air lock or simply set the damn thing on fire for the Fourth of July?

Thanks, Jay

I own a black 1989 LX 5.0 hatchback, so I'm thinkin' I'm ok with postin' about a T-bird

Reply to
Jay Orcutt
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AFAIK, unlike the 5.0, the 3.8 water pump only turns in one direction - reverse. I don't think you can get the wrong part. Getting all the air out is crucial, and difficult. Make sure the filler neck is clearly the highest point. If you put the thermostat back in, be sure and drill a 1/4" hole in the plate. I think there's a fitting in the back of the manifold that goes in to the water jacket. I think there's a temp sensor in it. Take that out, and allow the air to escape. If all that fails, find a shop that has a vacume filler tool, and pay them a few bucks to do it for you. Or spend about $150 for the tool and do it yourself.

Reply to
boB

These symptoms all point to a radiator that needs replacement. Of all the cooling problems I've ever seen, 95%+ were due to a partially/fully plugged up radiator, and they were all 10+ years old.

You can test this theory by removing the radiator and stuffing a garden hose into the top, using a towel to seal the opening. Turn it on full-blast. Chances are, very little will come out of the bottom, and most will shoot back into your face from the top.

When you look into the filler opening with a flashlight, do you see corrosion buildup alongside the tubes? This is a dead giveaway to a plugged radiator problem as well.

-JD

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Reply to
JD Adams

I agree with JD on the plugged radiator.. Borrow / rent a high PSI (I like

2000psi) and pressure wash the heck out of the radiator (AFTER unhooking the hoses from it and properly draining and disposingof the coolant). You'll crap at all the brown water that comes out. Do the heater core and the engine with a garden hose. You can do the heater core w/the pressure washer, but be gentle. If you are pretty spray-happy, cover the alternator and distributor with plastic bags before starting the procedure..

Does the heater work before it overheats? Does turning on the heater lower the temperature? If the heater gets hot, then coolant is circulating..

HTH

Carl

Reply to
Carl Saiyed
2000psi ? Won't that blow up the radiator ? The radiator is supposed to work with about 16psi, putting 2000 psi on it will kill it for sure I think.

You might be better of doing a chemical flush (a REALLY strong one) OR (if possible) take the radiator to a radiator shop and have it rodded.

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Reply to
Rein

I've seen this too, and it's usually too late. The engine has already overheated and needs work.

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Reply to
Rein

new radiator is like $75. cheaper than repairing the old one. //Jeff

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Reply to
orangespawn50

$75 ?? for a new one ? wow, that's a bargain. Forget trying to fix it then.

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Reply to
Rein

(Some snippage......)

I thought I would listen to some of the replies before I did, so here goes....

I've got an '88 Cougar that I purchased new. It now has 265K miles on it and the valve covers or oil pan has yet to be removed. It's got a reliability record that would be the envy of any car. It's also got the 3.8 engine that still does not use oil between oil changes. I also want to say that I am a mechanic and that is my occupation, not a weekend sideline. In the last year, it has gotten to the BORDERLINE of overheating. Yes, I've replaced the radiator. (I've got the $99 dollar radiator. I guess I missed the good deal of the $75 dollar radiator. :-) I know these engines have air pocket or air bleeding issues, but I think in my case, the head gaskets are on their last leg. The thermostat didn't fix my car either. Anyway, it's now down to the duty of my work car and when it rolls over and dies it will probably just go to the wrecking yard. In it's lifetime, the water pump has been replaced three times. (I think) I love the lifetime warranty pumps, too bad installation isn't included. Anyway, I just thought I'd give you my $.02 worth. I hope your car has minor repairs instead of major, but I know my car's repairs will be terminal when it happens. Good luck.

Reply to
Kruse

The car has the infamous 3.8, non

Best case scenario: Plugged Radiator Core! Worst Case Scenario: Head Gasket compression.

Reply to
Mr. Ford

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