928 S4 Coolant flush
#1
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928 S4 Coolant flush
Just bought my first 928, an S4 1989 auto, Euro.
The coolant has oil in it due to an internal oil cooler leak into the radiator.
Any tips on best way to flush it out completely ?
Can I run a strong detergent mix or will that damage waterpump seals etc ?
The coolant has oil in it due to an internal oil cooler leak into the radiator.
Any tips on best way to flush it out completely ?
Can I run a strong detergent mix or will that damage waterpump seals etc ?
#2
Congrats on the purchase.
1st thing to do is remove the two block plugs on each side of the engine......small screw in plugs that will drain coolant out of the engine block. With these plugs removed flush some clean water thru the block, then replace the plugs.
Had the same problem on a previous '89. Ran a couple of tablespoons of dish washing detergent (NOT DISH SOAP......dish detergent used in dish washing machines) and plain water thru the system, then drained (including block again), flushed with clean water again and again. Really cleaned the reservoir and then filled with coolant and water mixture. System came out very clean without a drop of oil. Use at your own risk, but it worked very well for me and came from a trusted 928 mechanic of all places.
1st thing to do is remove the two block plugs on each side of the engine......small screw in plugs that will drain coolant out of the engine block. With these plugs removed flush some clean water thru the block, then replace the plugs.
Had the same problem on a previous '89. Ran a couple of tablespoons of dish washing detergent (NOT DISH SOAP......dish detergent used in dish washing machines) and plain water thru the system, then drained (including block again), flushed with clean water again and again. Really cleaned the reservoir and then filled with coolant and water mixture. System came out very clean without a drop of oil. Use at your own risk, but it worked very well for me and came from a trusted 928 mechanic of all places.
#3
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Double check the integrity of both rad coolers if you are in a 'repair' rather than 'replace' mode for the rad - and assure that it was not the trans cooler that was leaking; If the latter was possible, a complete trans drain is in order ASAP, as will be done on the engine oil ( coolant remains pressurized after engine shutdown, so can migrate in reverse to operating conditions).
Consider a wrap of pipefitters teflon tape on the block drains on reinstall - after removing them, that tip will be more apparent .... good luck with the new shark!
Consider a wrap of pipefitters teflon tape on the block drains on reinstall - after removing them, that tip will be more apparent .... good luck with the new shark!
#4
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Originally Posted by Garth S
Double check the integrity of both rad coolers if you are in a 'repair' rather than 'replace' mode for the rad - and assure that it was not the trans cooler that was leaking; If the latter was possible, a complete trans drain is in order ASAP, as will be done on the engine oil ( coolant remains pressurized after engine shutdown, so can migrate in reverse to operating conditions).
Consider a wrap of pipefitters teflon tape on the block drains on reinstall - after removing them, that tip will be more apparent .... good luck with the new shark!
Consider a wrap of pipefitters teflon tape on the block drains on reinstall - after removing them, that tip will be more apparent .... good luck with the new shark!
Did my collant flush before I left to Venezuela. I used Dex-Cool and RedLine Water Wetter- Strange but my 928 is running hotter than before when I was running the green stuff and mostly water!
#5
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Originally Posted by DoubleNutz
Did my collant flush before I left to Venezuela. I used Dex-Cool and RedLine Water Wetter- Strange but my 928 is running hotter than before when I was running the green stuff and mostly water!
I would be confused too, for there is no good reason to suspect a loss of heat exchange efficiency with a coolant flush - unless the flush stirred some crap out of hiding and casued a restriction in the rad core flow. There are the usual checks for fan operation and the variable flap contraption ( if present on your car); however, the heat exchange efficiency of any coolant mix should not be noticibly different: pure water is the best, but is little degraded by the essential antifreeze mix.
#6
USMarine
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Originally Posted by Garth S
Strange ..... hotter by the mickey mouse gauge? .. or by an actual squeeze of the hoses, face near the block reality check? Nothing can beat an infrared gun to be sure, but my tool kit is lacking ...
I would be confused too, for there is no good reason to suspect a loss of heat exchange efficiency with a coolant flush - unless the flush stirred some crap out of hiding and casued a restriction in the rad core flow. There are the usual checks for fan operation and the variable flap contraption ( if present on your car); however, the heat exchange efficiency of any coolant mix should not be noticibly different: pure water is the best, but is little degraded by the essential antifreeze mix.
I would be confused too, for there is no good reason to suspect a loss of heat exchange efficiency with a coolant flush - unless the flush stirred some crap out of hiding and casued a restriction in the rad core flow. There are the usual checks for fan operation and the variable flap contraption ( if present on your car); however, the heat exchange efficiency of any coolant mix should not be noticibly different: pure water is the best, but is little degraded by the essential antifreeze mix.
I am at that point Garth where I am about to drain all the coolant and put in just water (which incidentally my car seemed to run cooler on when my mixture of the green stuff was less that 10% and 90% water).
#7
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Originally Posted by DoubleNutz
I am at that point Garth where I am about to drain all the coolant and put in just water (which incidentally my car seemed to run cooler on when my mixture of the green stuff was less that 10% and 90% water).
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#8
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I am at that point Garth where I am about to drain all the coolant and put in just water (which incidentally my car seemed to run cooler on when my mixture of the green stuff was less that 10% and 90% water).
#9
USMarine
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Originally Posted by Flott Leben
Not much beats water as far as heat transfer capabilities. Antifreeze reduces that capability but it does add rust inhibitors and will prevent freezing, to a point.
#10
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Originally Posted by DoubleNutz
OK I dumped 2.5 gallons of of my 50/50 Dex-Cool mix (with water wetter) and replaced it with just plain old water... wow ...what a difference in the temp. The temp gauge needle is directly down the center of the guage in the stead of being directly over the 3/4 mark before it runs in the red.
#11
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The coolant includes some essentials like lubricant for the water pump seal, and some pH buffers that help in the long run. Coolant raises the boiling point some, with some help from the pressure cap. The 'Water Wetter' has some pump lube in it, probably plenty if you run two bottles in the large-capacity 928 system.
If you live where there's any chance at all of the engine getting down to freezing, you will need to run some coolant.
If you are straining the heat dissipation capability of the car with coolant, you need to clean the radiator and try again. Just a thought.
If you live where there's any chance at all of the engine getting down to freezing, you will need to run some coolant.
If you are straining the heat dissipation capability of the car with coolant, you need to clean the radiator and try again. Just a thought.
#12
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Originally Posted by dr bob
If you are straining the heat dissipation capability of the car with coolant, you need to clean the radiator and try again. Just a thought.
Today removing the 2.5 gallons of coolant mix and just adding plain ol' water made a huge difference.
The Porsche maintenance manual reccomends a 50/50 mix of water to coolant for the temp environment I live in (PacNW it rarely ever gets down to ice freezing conditions in Portland). Correct me if I am wrong but I suspect that even one gallon of coolant to the capacity of the 928's cooling system would require winter temperatures to fall far below 32degrees for an extended period of time before it would freeze the coolant in the block.
#13
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DNutz.............most coolant containers have the mix ratios printed on them and the ratio is temp dependant. Where we're at with temps below -30C in deeep winter we require 50/50 (antifreeze/water).
When I was racing we had to replace all coolant with straight water ( you think oil is slick on a race track, you should see what antifreeze does) and some of the guys would use water wetter which increased the engine running temps...........perhaps this was your issue.
When I was racing we had to replace all coolant with straight water ( you think oil is slick on a race track, you should see what antifreeze does) and some of the guys would use water wetter which increased the engine running temps...........perhaps this was your issue.
#14
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Nutz
3/4's to red on the temp gauge for a 50-50 dexcool + water wetter seems quite hot...also since it isn't as hot where you live? How old is the radiator? Does it show any corrosion on the inside? Or maybe you have a "optimisticly hot" gauge?
Brian
3/4's to red on the temp gauge for a 50-50 dexcool + water wetter seems quite hot...also since it isn't as hot where you live? How old is the radiator? Does it show any corrosion on the inside? Or maybe you have a "optimisticly hot" gauge?
Brian