Engine Overheated! Need to change oil??

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742
Location
Lake Anna, VA
Well my mother's 98 Monte Carlo Z34 3.8L overheated a few days back to 260 degrees due to a broken tensioner pulley that snapped the belt which then stopped the water pump. When she noticed the coolant temp gauge in the red she pulled over and shut it down and a tow truck pulled it the rest of the way. It was running Schaeffer 10W-30 PAO blend with a Supertech oversized PF52 oil filter. Both had around 2000 miles of running time on them. Should I change the current oil with fresh oil or would the current oil still be fine. With the coolant temp at 260 degrees the oil would be well over 200. Other than a higher insolubles level and probably shorter oil life would it be okay to continue to run the Schaeffer's or fill with new? Opinions?
 
Messages
453
Location
Galveston, TX
quote:
Originally posted by Ryan00TJ: Well my mother's 98 Monte Carlo Z34 3.8L overheated a few days back to 260 degrees..... It was running Schaeffer 10W-30 PAO blend....
Relax, Ryan. 260 degrees is nuthin'. A piece of cake for Schaeffer Supreme 7000 blend. I have run Ford v-6 and v-8's till all the oil disappeared because of cooling system failure, I mean 100% total loss of all cooolant fluid. I did not take the temperature, but I am sure it was more than 320 F. Just re-filled the dry engine with my usual Castrol GTX 10w-40 or 20w-50 and carried on as usual. Needless to say, I no longer drive Fords. Don't need to have all these "adventures" with the cooling system.
 
Messages
450
Location
Louisville, KY
If 260 is oil the temp then no problem. If thats coolant temp then a lot higher temps were in the oil, especially in hot spots. During overheats all bets are off I would change it. Fred.. [Smile] [ December 30, 2003, 02:45 PM: Message edited by: palmerwmd ]
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
quote:
Originally posted by Dr. T: My car just overheated last week from a water pump failure and I've been contemplating the same thing...seems like the 10W-60 I had in there held up good...
OUCH, I bet it wasn't cheap to fix a water pump on that BMW V12 engine either!! [Eek!] It cost me almost $1000 for a new water pump in my 95 Firebird Formula last winter (put on by a GM dealer, and that price even included a slight discount on the price of the water pump too!!)
 

Al

Messages
19,166
Location
Elizabethtown, Pa
quote:
Originally posted by palmerwmd: If 260 is oil the temp then no problem. If thats coolant temp then a lot higher temps were in the oil, especially in hot spots. During overheats all bets are off I would change it. Fred.. [Smile]
I agree-If there is no warped heads or other damage-don't screw around. Change it. Also I would get an oil sample kit and take a sample after 500 miles or so to check for coolant leak. You could use a cheaper oil for this [Smile]
 
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2,480
My car just overheated last week from a water pump failure and I've been contemplating the same thing...seems like the 10W-60 I had in there held up good...looks the same as it did the day before....will see how it does in the next little while. If it's thickened I'll get the dreaded cold lifter knock...and I'll change it out.
 
Messages
9,448
Location
USA
If she pulled over right away it is a non-issue. The oil would smell very burnt if their was an issue with it. If she drove any distance and the heads warped or the lower intake manifold warped all bets are off. At this point if oil looks and smell good and does not show any signs of coolant contaimanation you could leave it in. If this was my car I had no doubts about the oil I would leave it in for another 500 miles and then test it. I can not see puting in fresh oil just to see if you have a bad head gasket. A coolant temp of 260 would put the oil at around 310 degrees witch is cooler then the piston crown or top ring! I would imagine though that the dealer at least checked the cooling system for pressure holding, checked the cooling system for exhausght gas and the tail pipe for coolant. Have them do a vaccum test on the car too. If eith of the intake manifolds has let lose it would show up right away on vaccum test! So you do want to change it soon but no need to cancel you plans to do it if the above is true! If you motivation is cost I would not let that be an issue. It is always safer to change out anything in doubt!
 

Ryan00TJ

Thread starter
Messages
742
Location
Lake Anna, VA
Thanks everyone! I've decided on letting the oil stay for a hew hundred more miles then sampling for a UOA. The oil looks fine smells fine and was exactly on the full mark just as it was the last time I checked it.
 
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