Been a while since I’ve looked for some info on a problem but I could use some now. I took 470 JW Regal out for a spin and the temp gage read 120 when I left then 3 miles down the road the gage was heading for 280 so I turned around quick and got back home. The gage would go down to 220 but wouldn’t stay just went back up. Opened the hood and got just a bunch of steam and none of it from the radiator over flow port couldn’t see any spray. After a short time the steam cleared and I could see a pin sized spray of coolant coming from the upper corner passenger side of the timing chain cover with some steam just behind the gasket. Lower hose was hot upper was cooler. After letting it cool down I opened the radiator cap and saw that the coolant was 8” low, it was 2” low when I left cause I checked. I’m thinking I have a hole in the lower hose I can’t see yet, I can’t believe the water pump going out would cause that much coolant lose if it just stopped pumping. I’ll start by checking that hose before tearing into anything else. So I have 2 questions 1 if I find either a hole in a hose or a bad water pump should I tear it down and replace that timing chain cover gasket or will it hold up when there is normal pressure in the engine and 2 will it be alright to fill the radiator again and run the engine long enough to see if there is water circulation and rule out the water pump as the problem. Any information is welcome and thank you in advance. Roger On The Eighth Day God Created Buick
If the engine temp was 280 and the upper hose felt cool then its likely your thermostat is stuck or you're not getting flow for a different reason
Thanks for that response 436’d skylark, that is something I totally over looked and a very inexpensive and fast fix. Good starting point and probably the problem I’m hoping. Thanks again Roger On The Eighth Day God Created Buick
"I could see a pin sized spray of coolant coming from the upper corner passenger side of the timing chain cover." If the timing chain cover gasket is leaking, yes you have to take the cover off and replace the gasket. I'm with Joe, it sounds like your thermostat stuck closed.
I too in my daily driver have had a pin hole leak that in only 15 minutes of drive time took a gallon of coolant out of the system. Keep in mind that once the coolant level gets low to a certain point the pump though still spinning can not pump steam ! water pressure is what overcomes steam pressure and turns the steam back into a liquid that the pump can then move thru the cooling system again. it’s the same thing that a A/C system does, but with opposite temperatures. This is why expensive coolant like Evans which has no water content to it works so well in extreme conditions that with other coolants would have you pulled off onto the side of the road waiting for a flatbed!
Thanks Larry I guess I knew the answer to that before I asked just didn’t like the thought of tearing down the front end. Oh well I got the inside bolt to the fuel pump been stripped and leaking oil so I can fix both problems at the same time. Stuck thermostat is the easy fix. Thanks guys Roger Stevem thanks for the explanation on how the water was lost. On The Eighth Day God Created Buick
Yup, went through that 2 years ago. https://www.v8buick.com/index.php?threads/uhhh-timing-cover-leak.360985/
I would like to caution you on something. The top end of your motor having been at 280 f is dam hot! When you get it back together don’t drive it too far from home, go around your block or whatever 20 times if need be to get the motor fully up to normal temp, stay close to home. I say this because many times when a motor has take place to it what has happened to yours the head gaskets let go once the motor gets close to normal temperature again, and you do not want to be far from home if things go south on you! If the motor starts to run hot, do not pull over and add more coolant if it needs it because the temperature difference will surly crack one of the heads. It’s better that it runs a little hot and gets you back home. If the motor does gets you back home without issue and goes thru another cool down and heat up session then your ok.
On the plus side, these old beasts will take some abuse and you were not operating the car for a sustained period. I think Steve ‘s caution is warranted but fingers crossed it cooled down without issue and will be fine. That said, I would be very cautious that your repair is truly successful and that you don’t accidentally repeat that stress as you test it after the repair.
Well I’ve got the engine back together and running between home projects but I’m a bit puzzled. Replaced timing cover gasket and thermostat engine fired right up and ran good but the coolant wasn’t moving in the radiator like I expected and never dropped and the temp gage wasn’t moving so I shut it off after running it for approximately 1 min. I’m wondering if the water pump is bad. The snout turned without grinding or moving it did turn stiff but the weep hole never leaked. In anyones experience do these pumps go bad without any relative sign to speak of ? Thanks for any replies Roger
No coolant will move in the radiator until the thermostat opens. That takes a lot more than 1 minute.
I have never had a problem with air in the cooling system. Run the engine with the radiator cap OFF. After the thermostat opens, you will see coolant flowing in the radiator, and the level will drop. Fill the radiator to 1" below the opening. Have a helper rev the engine to 1500 RPM and hold it there. Fill the radiator to the very top, and put the cap on. Then have your helper release the throttle. Fill the overflow to the proper level, DONE.
My suggestion is to drill 2 1/16th." holes on each side of the thermostat. It will bleed the air with no other problems. Replace a regular thermostat with a safety stat. When it fails it fails OPEN. These are the ONLY stats NAPA carries now. MANY engines have been destroyed because of defective old style stats. Tom T.
This will be easy enough to do tomorrow. Thanks for the help I’m just a little cautious hoping I didn’t damage the head gaskets. The engine is running and sounds good.
No thermostat engineer drills big damned holes in the flange. Some of them put a jiggle-valve that CLOSES when the water pump starts flowing coolant. And Robertshaw has a very tiny air bleed stamped into the flange, but it's nowhere near big enough to upset coolant circulation prior to thermostat opening. It's big enough to bleed air, but not big enough to slow engine warm-up. That's a complete misrepresentation of what that "safety stat" is supposed to do. It's impossible to design a device to fail in a certain way. The whole meaning of failure is that it doesn't perform like it's intended. The Moto-Rad "Fail-Safe" thermostat is intended to lock open if SOMETHING ELSE in the cooling system causes overheating. https://motorad.com/tech-tips/fail-safe-thermostats/ But what's the point? A normal, non-defective thermostat will be fully-open at that temperature anyway; and may not have to be replaced when the REAL problem is fixed. Once the Fail-Safe thermostat locks open, it's scrap. www.napaonline.com still shows "Economy", "Standard" and "Premium" thermostats in addition to the Safety Stat and a couple of "Robertshaw" designs. https://www.napaonline.com/en/search?text=Thermostat&referer=v2 Don't bother. They're useless, but at least they're expensive.
