Brown scum in coolant
05-09-2005, 02:15 AM
#1
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Brown scum in coolant
I recently changed the coolant in my 88 and noticed a brown oily scum floating on the water.
Anyway a few days later it's back - most noticeably in the reservoir.
The engine doesn't use any oil, holds normal temps and doesn't bubble through the overflow reservoir or blow it's pressure cap so I'm a little perplexed as to where this is coming from.
I'm wondering if it's exhaust gas that's leaking into the coolant - is there a way to test this? Surely the pressure from the gas would cause other problems.
Any ideas?
Anyway a few days later it's back - most noticeably in the reservoir.
The engine doesn't use any oil, holds normal temps and doesn't bubble through the overflow reservoir or blow it's pressure cap so I'm a little perplexed as to where this is coming from.
I'm wondering if it's exhaust gas that's leaking into the coolant - is there a way to test this? Surely the pressure from the gas would cause other problems.
Any ideas?
05-09-2005, 02:28 AM
#2
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St. Jude '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21-'22-'23-'24
Did you pull the overflow tank and clean 'er out good?
05-09-2005, 04:59 AM
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I had the same problem, made me concerned that I might have a failing head gasket, but, oil checks out nice and clean so I flushed out my cooling system and refilled with new coolent.
05-09-2005, 10:29 AM
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St. Jude Donor '05
Originally Posted by 93JetJocky
Ya know there are tablets that are added to the coolant system for sealing and conditioning. They make the green coolant turn to a brownish look.
Whent eh coolant is changed per the manual, there are leak stop tablets put in the reservoir that will cause some brownish discoloration. Its normal, and expected. So says the L98 section.
05-09-2005, 10:35 AM
#9
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Originally Posted by stevec4
I recently changed the coolant in my 88 and noticed a brown oily scum floating on the water. Any ideas?
If this is back after a proper drain/flush/refill, then you have a head gasket issue.
Did you use a radiator flush when you changed coolant??
Larry
code5coupe
05-09-2005, 11:37 AM
#10
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I did remove the collant reservoir and flushed that good but I guess I didn't do a very good job of flushing the system - just drained the bottom hose and reverse flushed the radiator (it looked pretty clean inside anyway). So there may have been some left over from the heater/block.
I'll clean the overflow again and see if it keeps coming back but I'm glad that others have seen the same thing.
Thanks all
I'll clean the overflow again and see if it keeps coming back but I'm glad that others have seen the same thing.
Thanks all
05-09-2005, 01:33 PM
#11
Team Owner
may have been left overs in the block? How about WERE left overs in the block...
your best bet is to get a bottle of prestone coolant flush. Drain the coolant, replace with water and flush. remove the t-stat. The idea is to make sure the goo gets out, not trapped somewhere.
Run the engine for a while, force the heater core valve open (on the heater core feed pipe) and then let it do it's magic.
After you have run the engine (30 minutes or so), drain the entire system, and hose it out.
Remove the knock sensor to drain the block. If your 88 is like bastet44's 87, it will have an oil heater on it - runs coolant through a housing between the filter and the block. I bypassed that brilliant idea... There is also a drain there. By bypassing those lines, I was able to get rid of a lot hosing that gets nasty over time.
Replace the rubber heater lines, and, run some hose water through the heater core, just to be sure.
with the lower hose off, the radiator, install a hose, let it run, and start the car. Keep all block drains open. This will flush out the last of the goo in the block and such.
button up the various block drains (you can get a fitting to block of the oil heater line from the block and replace the t-fitting hose with conventional hose.
replace the rubber hoses to the heater core, and you should have a near spotless cooling system.
refill with distilled water and good coolant. I also suggest a bottle of Redline Water Wetter. Cool stuff.
your best bet is to get a bottle of prestone coolant flush. Drain the coolant, replace with water and flush. remove the t-stat. The idea is to make sure the goo gets out, not trapped somewhere.
Run the engine for a while, force the heater core valve open (on the heater core feed pipe) and then let it do it's magic.
After you have run the engine (30 minutes or so), drain the entire system, and hose it out.
Remove the knock sensor to drain the block. If your 88 is like bastet44's 87, it will have an oil heater on it - runs coolant through a housing between the filter and the block. I bypassed that brilliant idea... There is also a drain there. By bypassing those lines, I was able to get rid of a lot hosing that gets nasty over time.
Replace the rubber heater lines, and, run some hose water through the heater core, just to be sure.
with the lower hose off, the radiator, install a hose, let it run, and start the car. Keep all block drains open. This will flush out the last of the goo in the block and such.
button up the various block drains (you can get a fitting to block of the oil heater line from the block and replace the t-fitting hose with conventional hose.
replace the rubber hoses to the heater core, and you should have a near spotless cooling system.
refill with distilled water and good coolant. I also suggest a bottle of Redline Water Wetter. Cool stuff.
05-09-2005, 02:01 PM
#12
Le Mans Master
Originally Posted by 93JetJocky
Ya know there are tablets that are added to the coolant system for sealing and conditioning. They make the green coolant turn to a brownish look.
Chances are you are seeing sealing tab residue and not rust. I have it in mine and I am not gonna lose sleep over it.
05-09-2005, 04:32 PM
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Originally Posted by eschoendorff
Chances are you are seeing sealing tab residue and not rust. I have it in mine and I am not gonna lose sleep over it. My '92 did the same thing after I plopped those radiator pellets in there. Nothing to worry about if that's what it is...
05-09-2005, 04:40 PM
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I just did another check and there is definitely no bubbling in the rad or coolant reservoir so I'm guessing you are correct.
I might try bogus's suggestions however to give it a really good clean through.
I might try bogus's suggestions however to give it a really good clean through.
05-09-2005, 09:56 PM
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Cleaning the reservoir
Thought I'd throw this in.. I cleaned out my overflow bottle today.. Found a basting brush in the kitchen w/ a long flexible handle .. Worked great.. Gotta go buy my wife a new basting brush 
...Bye.
...Bye.
05-09-2005, 10:00 PM
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Originally Posted by rufneck
Thought I'd throw this in.. I cleaned out my overflow bottle today.. Found a basting brush in the kitchen w/ a long flexible handle .. Worked great.. Gotta go buy my wife a new basting brush ...Bye.
...Bye.
05-10-2005, 07:16 PM
#18
Drifting
Originally Posted by vettefun
Just go rinse it off, it'll be fine!
I use the toliet bowel brush to get in the tight spots between the tire spokes in my wife's car, what they don't know won't hurt them any 
