Sludge in coolant.

[CCCMikey]

G'day

Every now and then I cop a bunch of sludge in the overflow bottle, but have no other effects such as water in oil or tranny fluid.

It seemed to start about 7 years ago when it boiled once. (Radiator tank burst.)

I put a flush through, and attempted to change some of the coolant today. Also took the time to clean the bottle and flush the hose from the radiator to the bottle which was somewhat blocked. This crud might be ancient. Forced water out of the bleed hole by pushing an old sprinkler over the radiator opening, which worked well since I wasn't set up to remove the knock sensor to drain the block.

Car has 410,000km on it.

 

[theghostoftime1978]

G'day

Every now and then I cop a bunch of sludge in the overflow bottle, but have no other effects such as water in oil or tranny fluid.

It seemed to start about 7 years ago when it boiled once. (Radiator tank burst.)

I put a flush through, and attempted to change some of the coolant today. Also took the time to clean the bottle and flush the hose from the radiator to the bottle which was somewhat blocked. This crud might be ancient. Forced water out of the bleed hole by pushing an old sprinkler over the radiator opening, which worked well since I wasn't set up to remove the knock sensor to drain the block.

Car has 410,000km on it.

could be either mainfold gasket blown or head gasket gone. Either one will mix coolant with oil and cause that sludge. I just changed my manifold gasket the other week and when i took off the manifold you could see sludge in the coolant galleries and had to scrap it out with a screw driver. Oil floats on water to it ends up in the overflow bottle, mine was and still is a bit sticky and red like.

 

[PlenumBiscuit]

salute to the 400,000 kms beast

if intake gasket your probably blowing heavy white smoke, but i think thats the opposite - coolant in your oil (im no pro)

2 days labour coming up for you or 4-5 hours plus parts for a mechanic

 

[CCCMikey]

Well, strange thing is it never turns up anywhere else. Exhaust is always invisible, oil is never milky and transmission fluid is still red. My best guess is that on one of the occasions when it did overheat, a gap formed large enough to let some oil out, and sealed up again as it cooled.

22/5/07 [203466]: Hose clamps (overheating event) CEL, Cooolant.

On rare occasions when climbing the Dorrigo Mountain (10kms of 2nd-3rd gear 40kph climb) it can develop a loud ticking sound, but if I ease off it goes away. (Temperature can reach two from top.) I've thought it might be the exhaust manifold since I remember my '71 Kingswood making a similar noise.

Re 400,000km, I do wonder what will end up breaking to stop me. I just do the usual maintenance and replace things as needed; but I guess one day something internal has to give. It was my late partner's car (initials VS too funny enough) so I'll be sad when it dies. I do about 100km a day.

 

[PlenumBiscuit]

so u reckon only when theres extreme pressure on the engine, a leak opens up and oil gets into coolant?

maybe

maybe check intake manifold bolts are all tight (firm), i checked mine once and they were finger loose omg

in tightening these though there is a sequence most recommend to follow, and torgue tightness etc

youd have sludge under your radiator cap too yea?

 

[moneypit]

It will be the lower intake gasket just starting to go. You will start to see a cupfull of coolant dissapear for no reason here and there, maybe a tiny bit of moisture under the oil filler cap. Be really carefull if you are gaining a small amount of oil, as mentioned it floats on water, my oil looked ok till I drained it, you could see there was moisture in it then, looked fine on the dipstick.

Personaly I would not disturb LIM the bolts unless I was going to change the gaskets, sounds like they have not been touched for some time, as they should have sealer on them, if they are disturbed it may leak worse.

 

[CCCMikey]

Hi again

Yes, there was some of that sludge on the radiator cap, and a fair bit partially blocking the hose to the overflow bottle.

I do my own oil changes every 5,000 and have never seen anything unusual in it, which makes me think the oil under high pressure might be getting forced into it on rare occasions. I've just flushed and changed the coolant this weekend (my first time) so will take a look and see if any has turned up again.

I agree 'moneypit' that I will let sleeping dogs lie until it becomes a problem

 

[Datvp]

Hey guys
Have a 92 vp with Buick 3.8l
Just wondering if anybody else has one and if they have a thermo fan running for the aircon condenser aswell as radiator?

 

[JL1]

for what it’s worth, I read somewhere that sludge in the coolant happens as a result of a vacuum created in the engine when it is switched off.

I had this problem for awhile and thought there may be problems with the engine. At the time I’m switching the engine off at red lights. I stopped doing this and the sludge disappeared.

Hope this helps.