Overheating engine, radiator fan stays on.

[shreeshar7]

Okey,so after a lot of unsuccessful diagnosis the engine still isn't cooling sufficiently.
The entire engine is rebuild as the older one seized.
Old parts used are:

Cams.
Cam chain.
Oil pump.

For the test, we took two identical rc 390s, mine and another one.
Started both of em and let them idle.
Obd was plugged in, on both the bikes, the fan came on at 96 degrees, and the temps started to fall.
On my friend's bike the fan turned off as soon as temps reached 89, mine hovered around 90-91 and didn't cool any further. As the engine gets hot, its loosing power.

Things ive replaced,
Thermostat.
Coolant.
Fuel injector
Fuel filter
Throttle body.

 

[zaster]

I feel your pain.
Mine does the same and the dealer can not diagnose the problem.
Mine has a Yoshimura exhaust, BMC air filter and used to have a PCV with auto tune module installed.
It ran absolutely flawless for 800 plus miles and started to overheat on a cool morning coming down from a mountain.
I checked the fluid levels and the fan which where all fine.
I brought the bike to my dealer and they could not replicate the overheating and started to blame the issue on the PCV.
Going through the trouble of totally uninstalling the PCV, the overheating reoccurred when I let my nephew ride it on the track who never even rode a street bike before.
Back to the dealership

 

[shreeshar7]

Sad,unfortunately .
Now the bike is bare stock and still there's this problem.
Now it shows low battery if I leave the bike ignition on for. A while, ive installed new battery and still theres this error.
Could it be the ecu?
Bad coolant impeller?
Bad oil pump?
Lean?.

There's this cracked air box issue and mine is one of it. Could it be that?
Too tight ring clearance?

Ive even bled the cooling system.

Also theres this hesitation at higher rpms in top gears.
After it struggles and almost hits redline in 5th gear at 155kmph and I shift to 6 th the speed doesn't go any higher. Not enough torque.

I'm tired of doing trips to ktm service mahn..

They've told they'll get back to me by Monday.
I shall keep you updated too.

 

[cornerslider]

Okey,so after a lot of unsuccessful diagnosis the engine still isn't cooling sufficiently.
The entire engine is rebuild as the older one seized.
Old parts used are:

Cams.
Cam chain.
Oil pump.

For the test, we took two identical rc 390s, mine and another one.
Started both of em and let them idle.
Obd was plugged in, on both the bikes, the fan came on at 96 degrees, and the temps started to fall.
On my friend's bike the fan turned off as soon as temps reached 89, mine hovered around 90-91 and didn't cool any further. As the engine gets hot, its loosing power.

Things ive replaced,
Thermostat.
Coolant.
Fuel injector
Fuel filter
Throttle body.

Wow..... While I never experienced the failures that your bike did, I did have some cooling issues. I noticed after about 800 miles, that my fan would kick on in less than 10 seconds if I was stopped at an intersection. I knew that wasn't right. I did some research, and tore into it. First thing I noticed was that the radiator was only about 1/2 to 3/4 full..... That would explain the cooling issue- my my cooling efficiency was down 25-50%!!!! I bought higher (1.6 bar) radiator cap. That keeps the coolant in the radiator better. I also switched to "Engine Ice" coolant, which probably helped too. I also changed the radiator fan (which is prone to failures). I went with a SPAL 5.2 inch radiator fan. Look around this site for the part number, as a lot of folks are using this. I think I got mine brand new off Ebay for around $40.00. The OEM fan has this really dumb "shroud" around it that makes no sense to me? Once you see it you will know what I mean..... It looks like it really restricts airflow across the radiator. Long story short, by changing those three things, I have no more cooling issues. I do about 50/50 street/track on my RC. The fan rarely kicks on while street riding, and has NEVER kicked on while track riding. What that tells me is that the coolant/radiator capacity are sized about right for the motor. If I can run mine hard, at high RPM, for long periods of time without the fan kicking on, that's a REALLY good thing. My personal opinion is that KTM did the coolant/radiator cap, and fan "on the cheap"..... I've also noticed that the majority of the people that post cooling problems on this site are street riders, and most of the racers/track riders have very few cooling problems. Hope that helps you out-

 

[shreeshar7]

Wow..... While I never experienced the failures that your bike did, I did have some cooling issues. I noticed after about 800 miles, that my fan would kick on in less than 10 seconds if I was stopped at an intersection. I knew that wasn't right. I did some research, and tore into it. First thing I noticed was that the radiator was only about 1/2 to 3/4 full..... That would explain the cooling issue- my my cooling efficiency was down 25-50%!!!! I bought higher (1.6 bar) radiator cap. That keeps the coolant in the radiator better. I also switched to "Engine Ice" coolant, which probably helped too. I also changed the radiator fan (which is prone to failures). I went with a SPAL 5.2 inch radiator fan. Look around this site for the part number, as a lot of folks are using this. I think I got mine brand new off Ebay for around $40.00. The OEM fan has this really dumb "shroud" around it that makes no sense to me? Once you see it you will know what I mean..... It looks like it really restricts airflow across the radiator. Long story short, by changing those three things, I have no more cooling issues. I do about 50/50 street/track on my RC. The fan rarely kicks on while street riding, and has NEVER kicked on while track riding. What that tells me is that the coolant/radiator capacity are sized about right for the motor. If I can run mine hard, at high RPM, for long periods of time without the fan kicking on, that's a REALLY good thing. My personal opinion is that KTM did the coolant/radiator cap, and fan "on the cheap"..... I've also noticed that the majority of the people that post cooling problems on this site are street riders, and most of the racers/track riders have very few cooling problems. Hope that helps you out-

In mine the overheating issue is basically when the bike is at low rpms. I.e at idle and at high rpms >7500.
After 8000 rpms it feels like the bike has lost torque since it no longer pullls hard after that and when I stop the motorbike after a run like that, the temps skyrocket.
If I turn it off for a few mins and just turn on the ignition, the temps show even higher.

It overheats during track style riding.

 

[cornerslider]

In mine the overheating issue is basically when the bike is at low rpms. I.e at idle and at high rpms >7500.
After 8000 rpms it feels like the bike has lost torque since it no longer pullls hard after that and when I stop the motorbike after a run like that, the temps skyrocket.
If I turn it off for a few mins and just turn on the ignition, the temps show even higher.

It overheats during track style riding.

*I mean no disrespect*, but what you are describing sounds normal for a modern liquid cooled motorcycle..... Low RPM usually translates into stopped, or moving slowly. Either way, there isn't enough air moving over the radiator to cool the motor. When the temp gets high enough, the bike calls of the fan to kick on so the radiator gets more airflow over it, cooling the motor. After 8,000 RPM, most RC's "flat-line" in regard to torque. It's just the nature of the beast...... When you turn it off, and let it sit for a couple minutes after a hard run, and then turn on just the ignition, the temp gauge will always show sky-rocketing temps- this normal. When you run the motor hard/high RPM, the motor obviously produces more heat. When you are running it hard, the coolant is doing it's job- keeping things as cool as it can. Your temp gauge doesn't read the "engine temp", it reads "coolant temp". The temp of your cylinder head gets MUCH higher than the temp of the coolant. When running at high RPM the engine is producing much more heat, but you don't see it on the gauge, because the coolant is doing it's job- keeping things cool. When you shut down the motor after running it hard, the motor is still really hot (from running at high RPM), but now it doesn't have the coolant circulating through the radiator to cool it down. The coolant just sits there next to this REALLY hot motor, and picks up all that latent heat. This completely normal. Every bike I've owned over the last 25+ years does the exact same thing.

 

[shreeshar7]

*I mean no disrespect*, but what you are describing sounds normal for a modern liquid cooled motorcycle..... Low RPM usually translates into stopped, or moving slowly. Either way, there isn't enough air moving over the radiator to cool the motor. When the temp gets high enough, the bike calls of the fan to kick on so the radiator gets more airflow over it, cooling the motor. After 8,000 RPM, most RC's "flat-line" in regard to torque. It's just the nature of the beast...... When you turn it off, and let it sit for a couple minutes after a hard run, and then turn on just the ignition, the temp gauge will always show sky-rocketing temps- this normal. When you run the motor hard/high RPM, the motor obviously produces more heat. When you are running it hard, the coolant is doing it's job- keeping things as cool as it can. Your temp gauge doesn't read the "engine temp", it reads "coolant temp". The temp of your cylinder head gets MUCH higher than the temp of the coolant. When running at high RPM the engine is producing much more heat, but you don't see it on the gauge, because the coolant is doing it's job- keeping things cool. When you shut down the motor after running it hard, the motor is still really hot (from running at high RPM), but now it doesn't have the coolant circulating through the radiator to cool it down. The coolant just sits there next to this REALLY hot motor, and picks up all that latent heat. This completely normal. Every bike I've owned over the last 25+ years does the exact same thing.

I've been riding this bike for 14000kms.. The engine seized at around 12k and then rebuild and all these issues.
Ive ridden the bike quite long enough, so I do know the way this motor behaves and i tell you, hot..real hot it gets.
I am,well aware of the fact that temps read a bit high when coolant is stagnant but its max by 1 or 2 bars.
I regularly do trips to the same spot in Hills and this didn't used to happen before, I can also feel the power loss accompanied by increased engine braking (fishtails in 2ND gear when I let go off throttle).
Once hot it takes longer to reach Rev limiter in each gear.

 

[zaster]

Sad,unfortunately incompetent ktm engineers.
I used the powertronic piggyback for a while too. Now the bike is bare stock and still there's this problem.
Now it shows low battery if I leave the bike ignition on for. A while, ive installed new battery and still theres this error.
Could it be the ecu?
Bad coolant impeller?
Bad oil pump?
Lean?.

There's this cracked air box issue and mine is one of it. Could it be that?
Too tight ring clearance?

Ive even bled the cooling system.

Also theres this hesitation at higher rpms in top gears.
After it struggles and almost hits redline in 5th gear at 155kmph and I shift to 6 th the speed doesn't go any higher. Not enough torque.

I'm tired of doing trips to ktm service mahn..

They've told they'll get back to me by Monday.
I shall keep you updated too.

Please do.
I will contact my dealer on Tuesday and let you know how things turn out.

 

[Diploman]

I would very carefully check your airbox for cracks and/or leaks, and repair anything abnormal. A leaking airbox can very easily lead to an over-lean air/fuel ratio that can cause the engine to run hot enough to cause damage. It is not impossible that the engine seizure you experienced might be due to an airbox leak.

I think your comments about "incompetent KTM engineers" are misplaced. If the bike and all components are in good condition and operating properly, the cooling system of the 390 is quite adequate and the engine does not overheat. The design is well-engineered. I think your bike has some defective component that is causing: 1) the engine to overheat; or 2.) the cooling system to underperform.

 

[shreeshar7]

I would very carefully check your airbox for cracks and/or leaks, and repair anything abnormal. A leaking airbox can very easily lead to an over-lean air/fuel ratio that can cause the engine to run hot enough to cause damage. It is not impossible that the engine seizure you experienced might be due to an airbox leak.

I think your comments about "incompetent KTM engineers" are misplaced. If the bike and all components are in good condition and operating properly, the cooling system of the 390 is quite adequate and the engine does not overheat. The design is well-engineered. I think your bike has some defective component that is causing: 1) the engine to overheat; or 2.) the cooling system to underperform.

Hey..thanks for the inputs.. Will get that checkd carefully again. And about the ktm engineers being incompetent, I mean the service engineers here.

They tried to blame me because I was using engine ice coolant ( these guys have never heard of it), later upon realising it exceeded their standards they mellowed down a bit, then they tried to blame the after market adjustable levers and again they realized it was built for ktm and then..... A Lotta time is being wasted because these guys don't know what to do, for them step 1 is to blame customer, step 2 is to change some spare that is almost unrelated and cheap and try to get rid of the issue..

About the airbox crack.. Yes mine does have a crack near airbox where the breather pipe attaches..almost 70% of bikes here that are older than 1 year have this problem.
From what I saw on the Internet the outer box doesn't directly go to the throttle body and there's a path/tube inside, so this crack should make such a difference.
I have already told them about the crack too and they're hesitant to change it under warranty.
Very bad service staff here man.!

 

[cornerslider]

I've been riding this bike for 14000kms.. The engine seized at around 12k and then rebuild and all these issues.
Ive ridden the bike quite long enough, so I do know the way this motor behaves and i tell you, hot..real hot it gets. View attachment 3330
I am,well aware of the fact that temps read a bit high when coolant is stagnant but its max by 1 or 2 bars.
I regularly do trips to the same spot in Hills and this didn't used to happen before, I can also feel the power loss accompanied by increased engine braking (fishtails in 2ND gear when I let go off throttle).
Once hot it takes longer to reach Rev limiter in each gear.

Sorry to hear of your problems....... I seriously meant it when I said "I mean no disrespect" in my earlier post. It sounds like you are doing everything right on your end. I wish I could help everyone with problems with their RC. I have been fortunate in having very little REAL problems with my 2016 RC390. Please keep us posted on how this plays out. I'm very curious.......


Sent from my iPad using Tapatalk

 

[shreeshar7]

Sorry to hear of your problems....... I seriously meant it when I said "I mean no disrespect" in my earlier post. It sounds like you are doing everything right on your end. I wish I could help everyone with problems with their RC. I have been fortunate in having very little REAL problems with my 2016 RC390. Please keep us posted on how this plays out. I'm very curious.......


Sent from my iPad using Tapatalk

Definitely.. I'll keep you updated.

 

[zaster]

Hey..thanks for the inputs.. Will get that checkd carefully again. And about the ktm engineers being incompetent, I mean the service engineers here.

They tried to blame me because I was using engine ice coolant ( these guys have never heard of it), later upon realising it exceeded their standards they mellowed down a bit, then they tried to blame the after market adjustable levers and again they realized it was built for ktm and then..... A Lotta time is being wasted because these guys don't know what to do, for them step 1 is to blame customer, step 2 is to change some spare that is almost unrelated and cheap and try to get rid of the issue..

About the airbox crack.. Yes mine does have a crack near airbox where the breather pipe attaches..almost 70% of bikes here that are older than 1 year have this problem.
From what I saw on the Internet the outer box doesn't directly go to the throttle body and there's a path/tube inside, so this crack should make such a difference.
I have already told them about the crack too and they're hesitant to change it under warranty.
Very bad service staff here man.!

Sounds like my dealer experience

 

[shreeshar7]

Been to the dealer..
They replaced coolant pump impeller and radiator fan. Still the issue is there.
I asked them to do a oil pressure test.
It stays at 1.5 bars idle and 1.85 bar at 5000rpm.

What could be wrong?

 

[amirossi21]

Same problem here

I too have this overheating problem. My fan failed me twice. Had it change. I asked the dealer why our fan having problem and they said that our fan is overworked. To me whatever. I have changed from Evan coolant back to normal water coolant. Same issue again. Engine fan will never off even my temp had drop to normal engine temp. The only way that I do now is stay away from traffic lights. Using the highway more and also ride fast. Using air cooled makes the difference.

Sent from my A33f using Tapatalk

 

[shreeshar7]

Oil pump

Same problem here

I too have this overheating problem. My fan failed me twice. Had it change. I asked the dealer why our fan having problem and they said that our fan is overworked. To me whatever. I have changed from Evan coolant back to normal water coolant. Same issue again. Engine fan will never off even my temp had drop to normal engine temp. The only way that I do now is stay away from traffic lights. Using the highway more and also ride fast. Using air cooled makes the difference.

Sent from my A33f using Tapatalk

Been to a different service station.
They claimed the "oil pump failure"
Replaced oil pump.

Now will check and update.

 

[amirossi21]

Been to a different service station.
They claimed the "oil pump failure"
Replaced oil pump.

Now will check and update.

Had my oil pump replace too. Seems like a bit better. After sometimes, it seems like back to usual. Overheating again. At last discovered that my airbox is cracked. Had it change n seems like the fan did not off when the temp is cool down.

Sent from my A33f using Tapatalk

 

[shreeshar7]

The KTM Duke 390 Ownership Experience Thread - Page 204 - Team-BHP

 

[ss4dmk]

I've been having issues my RC 390 here as well. I stay in Chennai, India and I've driven my bike approx. 20k kms. Have done occasional long rides, driven my bike through insane amount of traffic before, but the bike never overheated back then (maybe after I switched off the bike for a while in signals, temp. climbs 1 point above min. temp, but cools down after i switch the bike back on). Since the last week, my bike has been overheating insanely, and switches itself off like every 3 kms. The overflow valve is broken, but I don't think that is much of a problem, from what i've seen in a few threads. Went to a nearby service center to check on the overheating, had the temperature sensor, thermostat and coolant changed (from Evans to Motul, on the service manager's recommendation). Service manager said the radiator and fan were working fine.Got the bike yesterday and drove the bike approx. 75 kms after that, no issues then. Today, the same annoying issue showed up. Radiator turned on 5 minutes after driving, and bike turned off another 5 minutes later.

I mean, are there any other possible reasons why the bike would overheat? A cracked airbox, clogged coolant passage. etc? Because i have to drive 15 kms just to the service centre and its so fucking tiring, and I'm getting really pissed with the service quality here. If there are any other possible reasons, please cite them to me so that i could discuss them with the service manager (could rather take that fucker's job myself, cuz he suggested me not to put Engine Ice when i talked to him about it -_- ).

 

[Deleted member 452]

I thought I fixed this problem with Evans coolant but it just started happening again. Pukes coolant when not hot and then temp creeps 2 bars when you shut off the bike to add fuel and restart. Oh and it's a blistering 50 degrees fahrenheit in Seattle, WA, USA.

Power Commander (12.7 AFR @ WOT)
Head gasket
water pump
SPAL fan
Evans waterless coolant (tried Engine Ice before that)
1.6 bar radiator cap