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Milky Oil in throttle body!!!! Please explain.

9K views 10 replies 5 participants last post by  reeder139 
#1 ·
Hi Guys, I fear the worst but with no other running problems/symptoms of nasty things happening, what are the possible reasons for the fact that the little drop of oil I always find in my throttle body has changed from nice pure oil to the dreaded milky mixture???

I hope there is a nice explanation. A bit of background. These pictures were taken two days ago. I cleaned it off and will check again tomorrow. There are no other symptoms of anything wrong going on. There was some coolant around the rim of the expansion tank the other day. I checked everywhere for leaks and concluded that there aren't any, I had topped up the day before and it must have been some spillage.

The pictures:-




Any opinions welcome but if its bad, try to break it to me gently.
 
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#2 ·
Its probably due to air temp dropping causing denser condensation????

Have you done the usual 'test' re possible hgf?

Sniffed the header tank? Checked oil filler cap? Checked oil level? Water droplets or rainbow slick on dipstick? Engine runner hotter than normal? Heater on hot but air is cold from the blowers/vents?

Get an oil catch tank for around £25 with all necessary nuts and bolts etc to fit it and two sizes of screw in fittings to suit various sizes of breather pipes. Some thin wall flexi pipe is included but for a few quid you can buy specifically rated hose for fuel and vapour. (have a trawl through my previous post on the forum to find pics and links of the catch tanks I fitted)
 
#3 ·
Indeed I have, none of the below occurring. Could it just be condensation?

Ps: I have the oil catch tank ready to be fitted. I think I'll do it tomorrow. I have always got a little bit of oil in the throttle body but naturally became a little concerned when I saw this!


Its probably due to air temp dropping causing denser condensation????

Have you done the usual 'test' re possible hgf?

Sniffed the header tank? Checked oil filler cap? Checked oil level? Water droplets or rainbow slick on dipstick? Engine runner hotter than normal? Heater on hot but air is cold from the blowers/vents?
 
#4 ·
I'd say so if all else checks OK.

Supposedly the breather that enters the throttle body 'air-box' side of the throttle valve is more likely to supply oil mist if the car is driven at higher revs for longer than usual. I can only guess that if you like a 'spirited' drive then there's a higher chance of oil in this part of the throttle body??? I also wonder if the higher the engine oil level the less capacity inside for oil mist to settle thus more mist pumped/sucked through the breather system????
 
#5 ·
Hi Guys, I fear the worst but with no other running problems/symptoms of nasty things happening, what are the possible reasons for the fact that the little drop of oil I always find in my throttle body has changed from nice pure oil to the dreaded milky mixture???

I hope there is a nice explanation. A bit of background. These pictures were taken two days ago. I cleaned it off and will check again tomorrow. There are no other symptoms of anything wrong going on. There was some coolant around the rim of the expansion tank the other day. I checked everywhere for leaks and concluded that there aren't any, I had topped up the day before and it must have been some spillage.
Any opinions welcome but if its bad, try to break it to me gently.
I would not worry too much, just yet!
The milky colour comes from water vapour mixed with oil. There could be a quite innocent reason for that, that you drive short journeys and the car does not get warm.
On the other hand, (as any good economist would say) there is a possibility that the water comes from the cooling system. I would check under the oil filler cap for signs of mayonnaise, which is usually the first place to notice it. Check on a fully warmed up engine.

If you have to top up with water, how can you conclude there are no leaks??? Obviously there is (are) leaks, otherwise you should not have to top up! (I am not allowed to say "what are they teaching you at school" so I won't:bgrin:, but logic does not seem to be a front contender.!)

Never mind, in the meantime, check your water level often, don't overfill, and check that on a stone cold engine, parked level in the same place, so you can compare. Do also check the oil filler cap on a hot engine, you should not have any mayonnaise then. If the last check is clear, I would not worry much, just continue to check the water level.
 
#7 ·
If you have to top up with water, how can you conclude there are no leaks??? Obviously there is (are) leaks, otherwise you should not have to top up! (I am not allowed to say "what are they teaching you at school" so I won't:bgrin:, but logic does not seem to be a front contender.!)
Thanks for the Sarcasm Kaiser. I meant, I concluded there were no leaks around the expansion tank that could explain the coolant on the rim. I didn't conclude there are no leaks at all.!

Other than that, thanks for the informative reply.
 
#6 ·
Hi, i had this as well, i fitted a oil catch tank which picked up some water at 1st and 10k later no water or oil, but at the time of fitting the tank i did found the larger breather pipe to be blocked with milky oil.

I think mine was just a build up of condensation.
 
#9 ·
If indeed there was (is) residue around the filler cap, then this is where (some of) the water has gone. There is no special conduit for water ejected here, it just flows through the cap.
Make sure you don't overfill, as this will get spat out here, and make sure you check oil filler cap and water level.
Then take it from there.
 
#10 ·
I have owned two KV6 engines both produced water/oil/rubbish like this from the breathers ending up in the area of your pics. Do not panic I have never had HGF I suspect its just combustion by products including water.

Older owners will remember cars that simply had a vent pipe from the engine, which after a long run could be seen steaming.

Ps I friend of mine bought a 75 and when we looked in the intake it was full of this so that we had to scoop it out - the car had done 4000 miles a year, he drives 20000 + and its all gone (and no HGF)

Bob
 
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