Dreaded fan failure....

[Kiwibrett]

Hi all, so it's happened, the radiator fan on my 2015 has decided to stop working on me, got a bit warm sitting at a stop sign the other day, so decided I'm not mucking around iv ordered the spal fan to upgrade, and plan on changing to engine ice as well since its drained. While its apart I'm thinking I'll heatwrap the front part of the exhaust which should help reduce some of the heat close to the radiator I'm hoping.
Is there anything else you guys suggest doing that will also improve things while I'm in there

Cheers,
Brett

 

[thunderrun53]

A higher pressure radiator cap isn't a bad add on either. Check out the 1.6 bar or 1.8 upgraded cap. You can get a lot more in depth with Samco hoses and removing the thermostat.

 

[Formula390]

If you aren't living in a zone which sees hard freezes, I would also recommend you just forgo engine ice and just use straight distilled water. As long as the bike lives in a garage which doesn't hard freeze, or lives outside in a race trailer perhaps, then straight water will ALWAYS outperform any other coolant. The additives to prevent freezing aren't contributing to cooling the motor, so straight water + an upgraded radiator cap are my standard swapout... but I also live in Central Texas where freezing temps are pretty rare and almost never longer than a day or three. Residual heat that leaks into the garage tends to keep the garage at least +20F over what ambient is in the winter.

 

[John390]

respectfully,(for real, you know your shit, clearly) I disagree on running straight water. There are other additives in commercial coolants. They stop galvanic action, they lubricate, they prevent evaporation, they stop rust and other corrosion, and many of them have limited but useful leak stop properties. Also most of them also boil at a much higher temp than straight water.

I have raced a car on a track that requires water/water wetter only. I have done it, then swapped it back to coolant when the last race was in the books. Short season, so no problem.

I also have a theory on higher pressure caps, especially on ones that already have a fairly high pressure cap. These bikes (especially the earlier ones) have issues with head gaskets. Adding more pressure in the cooling system can possibly add to this problem. No specific data to back that up, but I do know that an overpressured cooling system can cause issues.

I fully agree on a better fan however, especially on the older ones. Those are a crap design even when they are working correctly, which is not all the time apparently.

 

[Kiwibrett]

Evening all, so my fan arrived yesterday, fitted it up and reassembled everything, filled and bled cooling system and everything good.
Took the bike for a test run today after work and was running great, sat 3 bars shy of the line the whole time (15 min run around town) got home and let it idle for a good 10 mins or so to check the fan was working effectively and yup sure enough it did its thing, works a treat. However the ecu has thrown a code of 17 which is lambda sensor. It did this after idling for some time. Is this normal to do this?

 

[m3hl]

Not normal. Shouldnt throw any codes. May want to poke around a bit and diagnose...

 

[John390]

did you possibly disconnect the sensor? or bump the wires/connector? possibly route the wiring too close to the exhaust?

Or, its just coincidence,and it was going to throw a check engine light anyway.

 

[Kiwibrett]

Ok so I had a poke around last night, sensor is all still connected etc and wiring hasn't been moved, took it out for a run today and all working fine, no code at all today so who knows, I'm going to assume all is well and it just had a strange moment last night. Bike is definitely better with the spal fan and exhaust heat wrapped

 

[marcusjake]

Hi all, so it's happened, the radiator fan on my 2015 has decided to stop working on me, got a bit warm sitting at a stop sign the other day, so decided I'm not mucking around iv ordered the spal fan to upgrade, and plan on changing to engine ice as well since its drained. While its apart I'm thinking I'll heatwrap the front part of the exhaust which should help reduce some of the heat close to the radiator I'm hoping.
Is there anything else you guys suggest doing that will also improve things while I'm in there

Cheers,
Brett

Mine has just did it so orderd a new fan kept getting high coolant temp message on dash when I looked down my fan wasn't going anywhere

 

[Formula390]

respectfully,(for real, you know your shit, clearly) I disagree on running straight water. There are other additives in commercial coolants. They stop galvanic action, they lubricate, they prevent evaporation, they stop rust and other corrosion, and many of them have limited but useful leak stop properties. Also most of them also boil at a much higher temp than straight water.

I have raced a car on a track that requires water/water wetter only. I have done it, then swapped it back to coolant when the last race was in the books. Short season, so no problem.

I also have a theory on higher pressure caps, especially on ones that already have a fairly high pressure cap. These bikes (especially the earlier ones) have issues with head gaskets. Adding more pressure in the cooling system can possibly add to this problem. No specific data to back that up, but I do know that an overpressured cooling system can cause issues.

I fully agree on a better fan however, especially on the older ones. Those are a crap design even when they are working correctly, which is not all the time apparently.

Higher pressure cap for water pressure for higher boiling temps will in no way contribute to headgasket failure. A 1.4bar radiator cap isn't even CLOSE to the pressures of the combustion chamber. The head gasket failures were largely being caused by two things:
1) The heads were machined flat without enough coolant. This caused the aluminum to swell with heat, which was then machined flat. Then, the metal cooled, and you now have a concave surface. I've taken BRAND NEW heads out of the box, laid a machinist square across them, and you could see light between the flats. This was a problem with QC at the factory.
2) Many of the OEM head bolts stretch after being torqued. I also suspect that the factory isn't applying any lubricant to the bolt heads, which is also contributing to erroneous torque values due to the friction of the bolt head. This results in a head which isn't torqued to spec, and.... failure. To torque the heads down, you really need to use an analog strain gauge torque wrench. This allows you to see what the torque applied is based on the bending arm. You torque the bolts down, let it sit for 10 minutes or so, then go back and check them. If they move before you reach the previously torqued number, that's a junk bolt. Pull it, throw it away, and use another new bolt.
3) Crap OEM head gaskets. The OEM gaskets themselves aren't all that great. They have improved with time, and the initial issues with common failure from a bad gasket are largely no longer happening.

Almost never have a head gasket failed simply due to warping. It's almost always caused by the 3 issues above, in that order of problems. Bajaj was just doing a large number of things wrong and have questionable QC.

 

[B7ACKTHORN]

I would echo F390's points. All the points he'd mentioned are true to the dot. Bajaj had its hands full dealing with the complexity of the engineering and making sure its vendors are upto scratch. In fact it was a learning curve for the entire Indian automotive suppliers, as this was the forebearer for what India stands today in manufacturing world-class brands' sub 500cc motorcycles. They've come a long way in improving quality and sadly as it would may be, cutting costs to keep the pie affordable. But overall, someone's gotta learn somewhere and the current 399 cc Duke is simply one KTM hit it out of the park.

 

[Fawxa67]

Higher pressure cap for water pressure for higher boiling temps will in no way contribute to headgasket failure. A 1.4bar radiator cap isn't even CLOSE to the pressures of the combustion chamber. The head gasket failures were largely being caused by two things:
1) The heads were machined flat without enough coolant. This caused the aluminum to swell with heat, which was then machined flat. Then, the metal cooled, and you now have a concave surface. I've taken BRAND NEW heads out of the box, laid a machinist square across them, and you could see light between the flats. This was a problem with QC at the factory.
2) Many of the OEM head bolts stretch after being torqued. I also suspect that the factory isn't applying any lubricant to the bolt heads, which is also contributing to erroneous torque values due to the friction of the bolt head. This results in a head which isn't torqued to spec, and.... failure. To torque the heads down, you really need to use an analog strain gauge torque wrench. This allows you to see what the torque applied is based on the bending arm. You torque the bolts down, let it sit for 10 minutes or so, then go back and check them. If they move before you reach the previously torqued number, that's a junk bolt. Pull it, throw it away, and use another new bolt.
3) Crap OEM head gaskets. The OEM gaskets themselves aren't all that great. They have improved with time, and the initial issues with common failure from a bad gasket are largely no longer happening.

Almost never have a head gasket failed simply due to warping. It's almost always caused by the 3 issues above, in that order of problems. Bajaj was just doing a large number of things wrong and have questionable QC.

Pb blaster make a decent enough lube to get the correct torque value you think? I'm fixing to tear into mine and go over everything, got high compression gasket kit from gray area I'm going to use

 

[Formula390]

Pb blaster make a decent enough lube to get the correct torque value you think? I'm fixing to tear into mine and go over everything, got high compression gasket kit from gray area I'm going to use

You can use anything for lube when torquing the bolts. Grease, Olive oil, personal lubricant, just something.

 

[B7ACKTHORN]

Spal, Engine or No Ice, it doesn't matter as long as the system is flushed and bled properly, using a good quality radiator cap (stock is built to a cost) this should keep you in peace and temps in check for a long time to come.