Wet Gray Sludge on Radiator Cap?

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pdee4t

Hey guys. When checking my coolant today, I had noticed a bit of sludge on the bottom of my radiator cap. The coolant itself though, was clean as a whistle, with no traces of oil in it.
Wondering if this could of been somehow caused from when I got water into the engine/oil? or from combustion gases mixed with water leaking into the engine due to the water that got into it from the air box??

Aside from that, I have no coolant loss, nothing is leaking out of the radiator overflow hose, it is not blowing white smoke and it is not overheating(also have a temp gauge fitted, which never goes passed 90 degrees Celsius unless I'm doing very slow riding) and no milky oil. So based on the fact it isn't overheating and lack of other symptoms to suggest a cracked head gasket or cracked cylinder head, I am doubtful of that being the cause.

Also had just done a fresh rebuild on it 14.7 hours ago(hour meter) with a brand new head gasket, I had the blocks checked for cracks at the time of the rebuild and all came back clear, and the radiators and radiator cap is fairly new also.
This is a week or so after I had gotten water into the engine through a deep stream crossing(to me, seems ironic)....this is the 1st time i've checked the coolant/taken the cap off since the rebuild.
I also always flush out my cooling system properly before re-adding coolant.

Just wondering what else a possible cause could be?
 
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Mihylo33

Mihylo33

Pics please.
They often help in identifying the material/sludge in question. It might just be residual assembly lube that collected.
 
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pdee4t

here's what it looked like though. the wet stuff on the side of the cap in this pic.

IMG_0382.jpg
 
Mihylo33

Mihylo33

bummer.... hopefully it won't reappear but if it does...pics pics pics.... then more pics! :thumb:


yes that's oil building up inside the motor. keep an eye on it
 
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pdee4t

so if it doesn't occur again, what could it of been? or why would it of occurred?
im wondering if it could've been water mixing with oil up above the cylinder head gasket, from when water got into the air box, because there's an oil line that goes straight up into the cylinder head and squirts oil everywhere.
 
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pdee4t

im also thinking of putting that door seal foam stuff around the filter wall, where my air filter will sit against, to try and stop water from getting into the air box via the filter. Give it that extra little bit of seal.
Anyone done that before?
 
Mihylo33

Mihylo33

pdee4t:
im also thinking of putting that door seal foam stuff around the filter wall, where my air filter will sit against, to try and stop water from getting into the air box via the filter. Give it that extra little bit of seal.
Anyone done that before?
Click to expand...


don't do that.... it wsill get sucked in and you'll be in Barney..
 
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pdee4t

Lol yeah.
Seriously though, is it ok to use or not?
Why would it get into my air box if its stuck to the air box surface with that sticky shit?
 
O

ossagp

If I am reading this right I can't see any harm if it does get sucked in. I use it for gaskets Ina non motorized application. It sticks very well.
 
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ossagp

An old trick for flushing oil out if a cooling system involved the use of Calgon dish washing soap. The stuff you put in a dishwasher. Named in Detroit Diesel manuals when I learned of it. It works.
 
2strokesteve89

2strokesteve89

ossagp:
An old trick for flushing oil out if a cooling system involved the use of Calgon dish washing soap. The stuff you put in a dishwasher. Named in Detroit Diesel manuals when I learned of it. It works.
Click to expand...

I used palmalave in a 4 cyl. Renault diesel engine with a cracked head in a jeep Cherokee to get the old diesel oil Outa the cooling system....it worked better than I could have imagined. And yeah I did say diesel jeep Cherokee, they made a few of those derelict bastards n the mid 80's.
 
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