Oil in water again!

[Barrieb]

Guys, need some motivational support (it's been a bad few days here in Blighty) and I'm near to giving up on my k100rs!

Last year when I got the bike the seller advised it needed a new head gasket as their was oil in the water (bike has only done 66k)
I questioned this on the forum and surely enough advice was that it was more likely to be the seal on the fuel/water pump, this was correct as the seal was completely knackered.  I was lucky enough to have a spare pump in perfect condition from a newer bike and this was fitted.  I have run the bike numerous times since then and all was good.

Since then I have sorted, brakes, forks and clutch lever seals whilst doing general cleaning and repainting also replaced the clocks, which got all the warning lights working.
Just replaced clutch and throttle cable and noticed small amount of coolant on top of the engine.  I thought (optimistically) this might be from when I topped up the radiator, I checked the level and it was down about 2 inches, topped this up and carried on with getting rest of bike together.

Today I just happened to look inside the radiator cap and there is oil sludge present, keeping in mind I have not run the bike since topping up.

Is it possible this is sludge from before I changed the pump and after having run the bike up to warm has found its way to the top or am I looking at the whole head gasket change again?

The ask here, is can you suggest a systematic approch in order of checking? I would imagine drain water/oil first or run engine up to see if any coolant appears on top of the engine?  At this minute given time and effort on the bike, I'm starting to loose heart, but I don't want it to end up being yet another abandoned project

Note: just corrected my auto spelling errors and should point out, that this is the first time the rad cap has been off since the pump change, when I topped it up the other day the oil could have been sitting on top of the coolant where it was not visible

Thanks guys

Barrie


,

[John Lang]

Coolant on engine and oil in coolant are likely unrelated. It is quite possible nothing serious is wrong other than coolant leaking from somewhere above engine. Sludge in rad could be remnant of bad seal. It might take several flushes to get rid of it completely. This is my optimistic reading.

[Laitch]

Just replaced clutch and throttle cable and noticed small amount of coolant on top of the engine.  I thought (optimistically) this might be from when I topped up the radiator, I checked the level and it was down about 2 inches, topped this up and carried on with getting rest of bike together.

Today I just happened to look inside the radiator cap and there is oil sludge present, keeping in mind I have not run the bike since topping up.

John is right. Optimism is the way to go here.

Coolant is always "topped up" on a cold engine by looking at the level on the expansion tank gauge then adding to the max mark, Barrieb, not by opening the radiator cap and filling there. Is what you see in the tank sludge or just black liquid? If it's just black liquid, that could have been caused by a coating that was applied to new pumps and that now has sluffed off into the coolant.

In any case, you should do a complete coolant flush by draining at the pump, rinsing the expansion tank then following the Clymer procedure for replacing coolant. 60/40 water/coolant should do it. Use the recommended long-life coolant without nitrites.

[Scott_]

60/40 water/coolant should do it. Use the recommended long-life coolant without nitrites.

Also use Distilled water... not water from the tap.

+1 on the flushing again.

[Barrieb]

Nothing in the expansion tank, but it is oil sludge in the top of the radiator, I remember when flushing originally it was very hard to get the sludge out and there was a lot!

From what I can tell it only takes a small amount of oil to create sludge and with this a lot of the oil/ sludge would not have come free until the engine got up to operating temperature.

Is it a good idea to add a rad flush, run the engine up to open the stat before letting it cool and drawing them completing a second flush with distilled water only and then refilling with the correct distilled water and coolant additive?

Getting optimistic again now , just need confirmation on go/no go for a radiator flush additive.

thanks

Barrie

[Laitch]

I'm directing you to Snowbum. I suggest reading the whole article before you make a move. You may need to rest your eyes periodically during the reading.

[Barrieb]

Looks good! Think I read it when I was doing the initial pump change, but I needed a refresh!

Thanks
Laitch