67 skylark overheating...

[soul player]

Question

on the 67 GS340 I just recently bought I changed the water pump,hoses,180 thermostat,and a new radiator. As i drove around everything would be ok according to the temp. gauge however, when i come to a stop (fastfood places, train tracks, long stop lights) the temp. would creep up slowely to 200-210 eventually..

i changed the thermostat today to a 160 thinking maybe I had a faulty thermostat but it still tends to creep a bit. I know when you stop the fan is not moving as fast but it seems to keep rising

what am I missing?? are these cars prone to this, should I be worried?? how hot is too hot?

thanks for any help

[BillK]

Soul,
First of all, the car should not be running hot, if anything the older cars ran cooler than the new ones.
Now ... usually when a car runs hotter at slow speeds and idle conditions, it is an airflow problem. Does the car have a fan shroud on it ? If not, that is the first thing to be installed. Second, if it has a clutch type fan, make sure the clutch is good. A good test is to get the engine good and hot, then have someone turn off the key while you watch the fan. If the clutch is working properly, the fan should stop turning almost instantly when you shut off the engine. If the fan keeps spinning for a few turns, the clutch is your problem.
Hope this helps,

[soul player]

Billk,

thanks for the reply, it ia a automatic, funny you mention it though, my fan shroud is intact but a piece was cut off on the bottom portion of the shroud by a mechanic that i had work on the car when i first bought it. after changing the oil pan seal and supposedly changing the rear main seal he could not mount the fan shroud back on right.... (see post "new to the forum just bought a buick")

I would not think that even part of the bottom piece would effect the air flow but now that you mention it, It looks like it could. I guess i will have to buy a new one. thanks again

[soul player]

could it be anything else if it was not the fan shroud?

[Tom Gallagher]

[img]graemlins/wavey.gif[/img] Hi Soul Player

Do You have a Clutch Fan or a Fixed Fan Blade? I don't mean to be a Smart Alic, but I don't want to leave any stone unturned. When You Filled the Radiator did You put in a Rust Inhibitor, the right mix of Anti-freeze and a Water Pump Lubricant? Also when Filling the Radiator (I know this is Summer) Did You let the car run and heat up and did you turn the heater on. Turning on the heater lets you add more fluid, but increasing the Volumne and Capacity of the Cooling System, making it more Efficient.
Most Failures in cooling are caused by blockages in the Radiator. You Said that You put in a New Radiator. Is it the Correct size and Capacity? You wouldn't be the first person that received the wrong part from a Vendor/Supplier. I'm just playing the Devils Advocate here. It sure sounds like You are doing all the right things and your car shouldn't be running HOT. I'm just trying to pin-point the problem, in hopes of correcting your situation.
[img]graemlins/clonk.gif[/img] [img]graemlins/smash.gif[/img]

Tom Gallagher [img]graemlins/shield.gif[/img]

[Tom Gallagher]

[img]graemlins/wavey.gif[/img] Hi, Soul Player,

Just Following-Up.
Did You find what was causing the Over-Heating Problem? [img]graemlins/thumbsup.gif[/img] [img]graemlins/thumbsup.gif[/img] [img]graemlins/beers.gif[/img]


Tom Gallagher [img]graemlins/shield.gif[/img]

[the skylark]

My guess would be shroud/clutch, but not meaning to be a smarta##, but here some thoughts that surprised me. and some that didn't. Overheating occurs when the coolant turns to steam, and is no longer able to carry the heat away. 50/50 AF/water mixture at 15 lbs. pressure (66 lasabre would've been 12 or 15, not sure) raises boiling point to 268 deg. Most newer cars are running 16 lbs or more, and since his rad. is new I think that would be safe. Engineering studies have shown that best thermal efficiency occurs when coolant is in the 215 degree range. If money is not a big object, I recommend new fan shroud and new fan clutch, maybe 16 lb cap, and after making sure it stays cool at long idle, 195 thremostat.
Theskylark62

[the skylark]

Oops, sorry,
forgot to mention installing antirust and 60% AF/water mix (up to 70% is acceptable according to AF lables, but no higher because efficency drops off sharply above 70) and maybe a coolant enhancer. It's all about controlling the movement of heat.
Dan

[Bob]

Just as another tag on cooling...

I have found that, if a major cooling loss occurs and the person does a repair and fills the rad with straight water, failing to add a rust inhibitor for several days or a week, a rust coat can develop in the block which will inhibit the movement of heat to the coolant enough to cause overheating. A good flush can be tried, but in many cases the coating can only be removed thoroughly by disassembling the engine and "hot tanking".

[Tom Gallagher]

[img]graemlins/wavey.gif[/img] Hi, Fellow Buick Enthusiasts,

Another Element, that I Strongly Recommend is Do Not leave Anti-Freeze in the Cooling System for over a Year. After a years time a Chemical Reaction takes place and starts Eating Away at the Soldier Joints in the Radiator. In Colder Climates it is even More Important since a Higher Percentage of Anti-Freeze is used. Living in a Northern Colder Climate Around Thanksgiving I Flush out the Entire System and refill with the Correct Anti-Freeze Mixture for my climate about 20 below.I also add water Pump Lubricant and a Rust Inhibitor. Around Easter I drain the fluid off for a 20-30 degree climate. and that should take you till Turkey day, when you flush the entire system.
Also a Reminder The New Red Antifreeze and the Standard Green Antifreeze DO NOT MIX. They are made of different Chemical Composition and Compounds. If Your Newer Model Car cam with RED Anti-Freeze Stick with it. It is Good for 5 Year and 100,000 Miles. For Older Cars, used only the Green. The Subject Matter may Seem Insignificant, but it is Very Important. [img]graemlins/thumbsup.gif[/img] [img]graemlins/thumbsup.gif[/img] [img]graemlins/beers.gif[/img]

Tom Gallagher [img]graemlins/shield.gif[/img]