Oil Contamination to Cooling System?

I flushed the cooling system yesterday.. pic 1 of the excess sludge is after letting it sit and ooze for a few hours.

Pic 2 is today, about 18 hours later. I saw a little of that oily line mixed in with the iced coffee sludge inside the jacket drain holes, wiped/soaked up enough with some rags to leave the holes clear until any remainder sludge could ooze back down... about 30 to 60 seconds later, what is in the pic has accumulated, and generally stays at that level for each cylinder jacket.

No dark mix of fluid like that from the hole leading to the thermostat (drain **** assembly removed), and the sludge drip from what remains in the radiator is also straight iced coffee coloured.

I've been hoping it was just a rust issue inside the radiator, but today's discovery has me accepting the reality that it could be far more involved than just throwing a new radiator into the mix.

So, my questions if anyone knows... what to do? What could have caused this? How bad is this in the scheme of repairs? How bad could it possibly be; ie worst case scenario?

Apologies if this has been covered before, closest information I could find pointed to a water pump rebuild but didn't involve a dramatic build up of sludge like this.

I will be riding her all week mind you, and I do expect to have to flush next weekend, possibly Wedneday too... seeing the ride home in the afternoon make the temp gauge rise near the end of a 20-30 minute ride as I hit the suburban traffic choke points.. possibly turn the bike off at a couple of red lights as it creeps to a nose hair from the red zone (the cooler wintery morning ride doesn't go above 3/4 on the gauge mind you).

Could be simple as a waterpump rebuild, coolant crossover joint oring, or as bas as a head gasket (though not as common to leak IN TO the coolant).

A minor oil leak into the coolant tank is normal with some bikes.
This doesn't hurt anything. It stays in the top of the fill tank and
doesn't circulate. One of my bikes does this and runs fine.
It's not really a lot and I never find water in the oil. Considering
that you seem to have an excess going to the coolant. Follow
Sean's Leads.

Water in the oil would be a problem

Bloodbite said:

I flushed the cooling system yesterday.. pic 1 of the excess sludge is after letting it sit and ooze for a few hours.

Pic 2 is today, about 18 hours later. I saw a little of that oily line mixed in with the iced coffee sludge inside the jacket drain holes, wiped/soaked up enough with some rags to leave the holes clear until any remainder sludge could ooze back down... about 30 to 60 seconds later, what is in the pic has accumulated, and generally stays at that level for each cylinder jacket.

No dark mix of fluid like that from the hole leading to the thermostat (drain **** assembly removed), and the sludge drip from what remains in the radiator is also straight iced coffee coloured.

I've been hoping it was just a rust issue inside the radiator, but today's discovery has me accepting the reality that it could be far more involved than just throwing a new radiator into the mix.

So, my questions if anyone knows... what to do? What could have caused this? How bad is this in the scheme of repairs? How bad could it possibly be; ie worst case scenario?

Apologies if this has been covered before, closest information I could find pointed to a water pump rebuild but didn't involve a dramatic build up of sludge like this.

I will be riding her all week mind you, and I do expect to have to flush next weekend, possibly Wedneday too... seeing the ride home in the afternoon make the temp gauge rise near the end of a 20-30 minute ride as I hit the suburban traffic choke points.. possibly turn the bike off at a couple of red lights as it creeps to a nose hair from the red zone (the cooler wintery morning ride doesn't go above 3/4 on the gauge mind you).

Click to expand...

I had some of that trouser glue action, new water pump kit sorted it.unk:

Got my parts on order, should be able to get it done this weekend. I'll take pictures just in case.

It's still behaving oddly. Now it leaks from the thermo-to-drain-**** seal in the morning...just an ambient temp change, but still takes a lot of the fun out of riding what with constantly monitoring the temp gauge.

Sent from my Nexus 7 using Tapatalk

Just a brief update. Been in damage control since the weekend. Seems like I cracked the ceramic head on the mechanical seal, so upon pouring fluid into the system it just pissed straight back out the seep hole. Even with a test warmup... definitely not a seating issue.

The source of contamination is still yet unproven as I found a dirty build up at all steel piping connection points (each pipe from the joint and the two that flow from the cylinder jackets... found this while installing the new silicone hoses).

So... new parts on order again, and feeling naked having to take 4 wheels to work until the weekend rolls around.

Successfully installed the mech seal on Saturday, no weeping from the water pump hole this time.

I have not yet looked under the rad cap, but so far it seems to be promising. Even though it's cool down here now, hitting traffic lights after a decent ride only gets up to half on the temp gauge (though a newer, larger radiator is on there too). More importantly the temp doesn't creep slowly up at the lights. But I'll confirm if this is fixed by the end of the week. Hopefully the only sludge to come out now is the residue that was sitting in the corners of the cooling jackets.

Running straight distilled water, just like the prior runs that produced sludge.

As for the pictures:

1. The sludge in the water pump, even after having let it ooze for over 24 hours... this is after having poured hot water through the system to encourage the sludge to flow during the extensive flush-ooze-reflush-etc.
2. The amount of sludge that had built back up in the system after the initial post's photos of being almost completely sludge free.
3. The presence of oil from what here has oozed out of the detached radiator
4. The build up of filth from one of the joint pipes. This same type of filth was present when probing the pipes leading into the cylinder jackets.
5. Joint pipe after being wiped clean/dry of the greasy filth
6. Exposed water pump area... no contamination of the oil system thankfully
7. This is the condition of the original mechanical seal, sludged up in the spring
8. And this is the impeller side of the mech seal set
9. Part of that decayed seal cut/scraped out (it was kind of melty soft)
10. Seal completely removed and a minor scuffing of the flaked rust build up with some steel wool

That looks to me like it needs a serious ****** job maybe two ...

I put about 20 litres of boiling hot water through it... hose squirts after letting it cool from the hot water too. Took about 6 hours before I let the final day long ooze occur to try and catch what was still possible to get out without the flow of a proper pressurised run.

That was more effective than any of the vinegar runs ever were to this point.

I just blast a garden hose from the radiator cap with the lower radiator hose off. I flush the radiator separately for no particular reason other than it gets full hose pressure when done by
itself. Any sludge/sediment in the water jacket would be blown out or carried out by the volume of water coursing through the motor.

Yeah see I did the garden hose too... it could only push so much out. Even the strategically alternating squirts into the jacket weep holes... over and over surprise junk would come out after letting it sit even for just a few minutes.

Okay, a week's long riding and a weekend flush.

The bike didn't move past half on the temp gauge until Friday afternoon. It never overheated, but the fan diidn't come on either at the appropriate temp.

The flush resulted in a very decent amount of sludge coming out, and when the drain **** was detached, the mass of sludge that was desperate to escape explained why the fan wasn't coming on. Clearly the thermostat wasn't being allowed to open.

Unlike previous oozings, a layer of oil settled with the sludge fairly quickly, and the reservoir bottle had next to no sludge backwash-buildup.

Which leaves 2 conclusions. The sludge build up is from the 1st broken mechanical seal that allowed a swish of oil to enter the system and just needs to have a chance to sludge up the last drop and get out of there... or it was a dual leakage where the main leak was from the waterpump, but possibly still leaking oil into the system from elsewhere.

I don't think I'll be able to confirm the first options chances for at least another 2 weeks worth of rides and flushes.

It has been nice though, riding without worrying about the temp gauge.

Sounds like you're getting there anyway

Looks like the problem has improved, but not been solved.

Week 1 riding was sludgy, but should have been enough to transform any remaining oil that had been sitting in the new radiator into sludge and thus expelled during the extensive weekend flush I put the bike through.

Week 2 involved riding to work over 3 days. A far more spirited riding style too (pushing up to the red line on occasion through traffic). I found the bike heated up very quickly after a foray into vboost territory for more than a second or so (those moments tended to last up to 5 seconds). The fan doesn't seem to trigger incidentally, haven't had a chance to determine if that's an issue with the wiring that had been removed/reattached during the previous cleaning process of the joint... despite that... day 1 and 3 morning rides ended with a burbling in the overflow bottle the moment the bike was switched off. Day 1 night ride home almost overheated and needed topping up before the following day's ride (just a couple of splashes mind you). Day 2 was fine, never went above 3/4 on the temp gauge even with crappy traffic. Day 3, half way through the work day I went and dismantled the side cover to check beneath the rad cap... thick and gooey all through the neck. Even stuck my finger in there and it was all sludge sitting up at the top. Ride home Day 3 started to creep towards red... it maintained its high temp at the lights, but would creep up after take off as the pressure increased the flow of fluid and sludge again.

I let the bike cool down enough to drain Thursday night after that last ride... what came out was clouded water from still being relatively hot/warm. Some frothed up sludge remained in the cylinder jacket holes before I left her to sit while I did other things. Not much of a sludge experience in contrast to having stuck my finger into the joint earlier and had that.

This morning I checked the cylinder jacket holes and saw some minor oil build up behind what sludge had settled at the bottom. The picture included is from this afternoon after coming home. The oil build up is almost twice what it was since morning as a point of reference.

So... I think it's safe to say that oil layer in the picture is the cause of the continued sludge build up. And if my amateur mech logic is right, the more spirited riding means at higher revs, higher oil pressure... higher chance for oil to successfully squeeze through wherever it is leaking from... is that right?

If so... for the oil to slowly seep down into the cooling jacket after drainage and general cooling of the oil itself... is it possible for that to be residue from the head gaskets, or is there a possibility that it could be a lower point? There is that hose point in the radiator assembly parts diagram that sits between the cylinders on the right side of the engine that takes 2 gaskets. I don't know what that thing is actually called... is it possible that could be the cause?

Since I won't be attempting the installation of a jet kit myself, I figure head gaskets are best left to a professional while the carbs have been pulled apart for rejetting. So should I consider regasketing that radiator assembly part I mentioned as well to be safe?

Are there any other possible sources for a leak?... barring heart breaking theories like actual casing cracks?

Bloodbite said:

There is that hose point in the radiator assembly parts diagram that sits between the cylinders on the right side of the engine that takes 2 gaskets. I don't know what that thing is actually called... is it possible that could be the cause?

Click to expand...

That is where I would look next myself, and the highest of the two seals has an integrated O-ring that keeps high pressure oil from both the crankcase breather and coolant system

johnpclynch said:

That is where I would look next myself, and the highest of the two seals has an integrated O-ring that keeps high pressure oil from both the crankcase breather and coolant system..

Click to expand...

Yeah that's the part. Is it safe to dismantle that part alone and install the new seals without tearing apart anything above it like the airbox and carbs?

After reading through all of the posts related to this issue and many have supplied good info, I would go back to the fact that you never mentioned any oil weeping from the water pump weep hole? So this rules out any type of water pump oil seal issue. The breather housing can be one the causes as mentioned but being the fact that I'm somewhat of a lazy type of person I would remove both water cross-over manifolds first & inspect them for cracks/damage. replace as required but make sure at the very least you replace all of the "O" rings three per each manifold. Part numbers:

Manifold 26H-12469-01-00 X2
Small "O" ring 93210-16629-00 X2
Medium "O" ring 93210-18322-00 X2
Large "O" ring 93210-21631-00 X2

If this fails then go after the breather housing but this will require you to remove the carb rack & all intake manifolds to remove the housing properly.
Good luck & keep us posted.

Well since replacing the water pump seals, the sludge build up has reduced dramatically. What took a week (10x half hour rides on average) of sludge build previously came about after just 1x of those rides. It hadn't been weeping anything at that point.

There are also orings on the crossover tubes located in the heads (look behind one of the spark plugs on each head).

Would it be possible the head cover's gasket could leak too?

I'm somewhat sick of this whole process. I think I'll have all the relevant gaskets and o-rings replaced just to be safe. That way I can ride her over 100,000km and not worry about the cheap arse legacy of the previous owner.