flush methods after head gasket fix??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**tkeduk8r** · 12-17-2003, 06:49 PM

What is the best way to flush a cooling system after a head gasket failure where oil gets into the cooling system. I have already flushed the system with Permatex industrial flush, but my heater still doesnt blow very warm and Im wondering how to get the rest of the oil (if there is any) off the cooling fins of the radiator and the heater core w/o taking all the components out and getting them cooked. Thanks for al the help..
--Mike

Rooster's 67 · 12-17-2003, 06:52 PM

How much oil was in the coolant, if it was a small amount dont worry about it.
If there is a good amount use prestone radiator flush and follow the instructions, then flush thougholy with clear water the fill to specsn

BLAZERMAN · 12-17-2003, 07:33 PM

I would be much more worried about anti freeze in the crank case, I would change oil, run the motor a few minutes and change again. Use cheap oil if you want for the first few changes and your regular oil on the last. Anti freeze reeks havic on bearings.

**old Rusty C10** · 12-17-2003, 07:58 PM

to expand on what blazerman said what i did was to first change the oil with cheap oil and run the truck for just a tad ( maybe twenty minutes) and changed it again. I then changed the oil with my regular brand and ran it for like 1000 miles then changed it again and back to my regular maintenance schedule

Gordo · 12-17-2003, 08:39 PM

A old time radiator shop told me to flush the best you can with water then refill with water and one cup of Lestoil, run/use/drive the vehicle for a day or so then flush again. If need be repeat until it drains clear/clean. In my case it was the trans cooler built into the radiator that let go and pumped quite a bit of ATF into the cooling system. I've used that procedure several times with good results.

cdowns · 12-17-2003, 09:03 PM

first off i doubt you have oil on the cooling fins of your radiator or heater core !! the fins are on the outside and no liquid circulates thru the fins it circulates thru tubes that the fins are attached to
i suggest you run a 190degree thermo if that doesn't supply heat then you've either got a blocked heater core or a phlenem box that's filled up with debris either of which will require taking out and replase/repairing the heater core

walker · 12-17-2003, 10:50 PM

I would remove the heater hoses and check out the inlet outlet barbs. Then flush out the core through the hoses with a garden hose. May as well replace the hoses while you got 'em off too. Odds are there is a piece of gasket or sealant blocking one of the hoses or fittings. Make sure you have the hoses routed so the you have one routed to a port on the outlet side of the water pump (engine side) and one on the return side( on the pump at the lower hose or to the radiator), as it takes pressure differential to circulate water. Also, make sure your air is circulating through the right ducts, as outside air intake dilutes your heat. I think the vaccum operated duct on the P/S of the engine compartment is apt to fail and leave you sucking outside air.
There is also the possibility that your t-stat is stuck open not allowing your system to heat up.
Oh, and if you think you still have oil in there you may consider mixing some simple green in plain water to emulsify the oil. Mild mix should do it, but I don't think that is your problem.

mrein3 · 12-17-2003, 11:03 PM

Stupid question - did you burp the system before you started using it again? You may have a slug of air in the coolant system.

Bowed · 12-18-2003, 01:58 AM

Quote:

Originally posted by mrein3
Stupid question - did you burp the system before you started using it again? You may have a slug of air in the coolant system.

That's not a stupid question , it happens a lot of times . tkeduk8r Just back off a heater hose and let any air purge . Also I have read that any amount of oil in a cooling system will cause lime deposits to accumulate over time so maybe it would be wise to follow the advise above on flushing . Just my .02

**tkeduk8r** · 12-18-2003, 10:13 AM

Thanks guys... Well i guess i should have said this b4, but this car is a mint 93 spirit (2.5 L) that was given to me with a blown head gasket ( great milage comapred to our trucks!!!) so i fixed the gasket, put in a new 195 tstat, and flushed the sys and ran water through till clear... my symptoms are the car runs well, but only blows luke warm heat. The temp gauge will rise and fall back to just above cool so im assuming the tstat is operating fine. im just afriad to remove the heater core cuz it is in a BAD spot... most of the dash has to be removed to get it... ugh... BUT i do only have less than 100 bucks wrapped up in it so far too,a nd put about 400 miles on it... 24 mpg even with the heating prollem... thanks for the info and keep it coming with more xperience... and i know im gonna catch s*** for it being a chrysler product

--Mike

12-17-2003, 06:49 PM	#1
tkeduk8r Senior Member Join Date: Apr 2001 Location: Alexandria, MN Posts: 1,462	flush methods after head gasket fix??? What is the best way to flush a cooling system after a head gasket failure where oil gets into the cooling system. I have already flushed the system with Permatex industrial flush, but my heater still doesnt blow very warm and Im wondering how to get the rest of the oil (if there is any) off the cooling fins of the radiator and the heater core w/o taking all the components out and getting them cooked. Thanks for al the help.. --Mike __________________ 63 C20 2WD, 230/SM420/4.11 73K 68 C30 dump truck, 327,SM425,4.56 66K original 68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes 68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79 69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi... 70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP 72 Chevy K20 4x4 350/350/205/4.56 donor 72 Vette 350/M21/3.70 posi, triple black and super fast 84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's

12-17-2003, 06:52 PM	#2
Rooster's 67 Registered User Join Date: Sep 2003 Location: DFW Posts: 765	How much oil was in the coolant, if it was a small amount dont worry about it. If there is a good amount use prestone radiator flush and follow the instructions, then flush thougholy with clear water the fill to specsn __________________ The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?

12-17-2003, 07:33 PM	#3
BLAZERMAN Currently Blazerless Join Date: Apr 2000 Location: St. Joseph Mo. Posts: 4,826	I would be much more worried about anti freeze in the crank case, I would change oil, run the motor a few minutes and change again. Use cheap oil if you want for the first few changes and your regular oil on the last. Anti freeze reeks havic on bearings. __________________ 1972 C/30 133" W.B. C&C 1970 GMC 3500 157" W.B. single wheel C&C

12-17-2003, 07:58 PM	#4
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,281	to expand on what blazerman said what i did was to first change the oil with cheap oil and run the truck for just a tad ( maybe twenty minutes) and changed it again. I then changed the oil with my regular brand and ran it for like 1000 miles then changed it again and back to my regular maintenance schedule __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

12-17-2003, 08:39 PM	#5
Gordo Registered User Join Date: Jan 2001 Location: Killingworth, CT. USA Posts: 3,378	A old time radiator shop told me to flush the best you can with water then refill with water and one cup of Lestoil, run/use/drive the vehicle for a day or so then flush again. If need be repeat until it drains clear/clean. In my case it was the trans cooler built into the radiator that let go and pumped quite a bit of ATF into the cooling system. I've used that procedure several times with good results. __________________ 1971 C10 swb stepside 350/700R4/3.73posi (retired as of 4/22/03) 1998 S10 short bed 2002 S10 Blazer 1942 Oldsmobile 1958 Massey Harris Pony 1951 Wife Killingworth, Connecticut May those who love us, love us, any of those who do not love us, may God turn their hearts. And if God is unable to turn their hearts, may he turn their ankles so we may know them by their limping. A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and his heart is an artist.

12-17-2003, 09:03 PM	#6
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	first off i doubt you have oil on the cooling fins of your radiator or heater core !! the fins are on the outside and no liquid circulates thru the fins it circulates thru tubes that the fins are attached to i suggest you run a 190degree thermo if that doesn't supply heat then you've either got a blocked heater core or a phlenem box that's filled up with debris either of which will require taking out and replase/repairing the heater core __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

12-17-2003, 10:50 PM	#7
walker Registered User Join Date: Jul 2003 Location: north of Phx AZ about 30 miles Posts: 698	I would remove the heater hoses and check out the inlet outlet barbs. Then flush out the core through the hoses with a garden hose. May as well replace the hoses while you got 'em off too. Odds are there is a piece of gasket or sealant blocking one of the hoses or fittings. Make sure you have the hoses routed so the you have one routed to a port on the outlet side of the water pump (engine side) and one on the return side( on the pump at the lower hose or to the radiator), as it takes pressure differential to circulate water. Also, make sure your air is circulating through the right ducts, as outside air intake dilutes your heat. I think the vaccum operated duct on the P/S of the engine compartment is apt to fail and leave you sucking outside air. There is also the possibility that your t-stat is stuck open not allowing your system to heat up. Oh, and if you think you still have oil in there you may consider mixing some simple green in plain water to emulsify the oil. Mild mix should do it, but I don't think that is your problem. __________________ Andy,Phx AZ '67 C-10 (Ahhh, done at last. Well there is that disk front end I want to put in and...) "23 C-Cab-sold '48 Ford 8N tractor(still working) '67 Scout(Now on the road) '70 MG B.-sold Last edited by walker; 12-17-2003 at 11:01 PM.

12-17-2003, 11:03 PM	#8
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,253	Stupid question - did you burp the system before you started using it again? You may have a slug of air in the coolant system. __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

12-18-2003, 10:13 AM	#10
tkeduk8r Senior Member Join Date: Apr 2001 Location: Alexandria, MN Posts: 1,462	Thanks guys... Well i guess i should have said this b4, but this car is a mint 93 spirit (2.5 L) that was given to me with a blown head gasket ( great milage comapred to our trucks!!!) so i fixed the gasket, put in a new 195 tstat, and flushed the sys and ran water through till clear... my symptoms are the car runs well, but only blows luke warm heat. The temp gauge will rise and fall back to just above cool so im assuming the tstat is operating fine. im just afriad to remove the heater core cuz it is in a BAD spot... most of the dash has to be removed to get it... ugh... BUT i do only have less than 100 bucks wrapped up in it so far too,a nd put about 400 miles on it... 24 mpg even with the heating prollem... thanks for the info and keep it coming with more xperience... and i know im gonna catch s*** for it being a chrysler product --Mike __________________ 63 C20 2WD, 230/SM420/4.11 73K 68 C30 dump truck, 327,SM425,4.56 66K original 68 C10 2WD SWB Stepper, 250/3-tree/3.73 66K.... Wifes 68 Buick Skylark Custom Conv., 350/TH400/2.56 In our family since '79 69 GMC 1500 SWB 2WD, 350/TH350/3.73 posi... 70 K10 SWB 4X4 4-sp,ps, pb, tilt, buckets, console, sliding back window (Need AC parts) WIP 72 Chevy K20 4x4 350/350/205/4.56 donor 72 Vette 350/M21/3.70 posi, triple black and super fast 84 Olds Cutlass Brougham 350/2004r/4.11 was Dad's



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