[karthikd21]

Hi Guys,

I have been facing a problem on my Gurkha (2016, BS3 model) during off-roading.

It first happened during the very first OTR I went for after purchasing the pre-owned Gurkha. Had been to Crazy Drivez in Bangalore with a few friends. There were all kind of Obstacles, Water wading etc and Gurkha performed reasonably well on the HT tires. While driving back from OTR, I noticed the engine temperature shooting up after around 10 kms into the drive. Stopped and found that there was a leakage in the radiator. Got it towed to the FNG near my house and rested for the day. Next day, we could see the problem.

Radiator fan was damaged


The Damaged Blade in-turn had damaged the Radiator


The radiator had extensive damage and the fan, well was not repairable. So, the FNG sourced both and fitted them back.

Post this, had been on many more OTRs and there were no issues. Thoroughly enjoyed the way Gurkha was able to handle anything thrown at it.

Fast forward to last weekend. Same problem reoccurred. This time the Radiator fan lost all the blades and the Radiator incurred minor damage and is being fixed. We were initially clueless. But, one of the more experienced buddie's pointed out the only commonality between the two incidents. It was water wading!

It looked like in waters deep enough to submerge the Radiator Fan, its just not able to take the pressure. In the First OTR, I do remember driving it fast in water as it was the very first time and I was super excited. In the last weekend OTR however, it was not fast. But, I had to revv the engine high since I had to reverse in the water and the car was not moving.

I spoke to the Lead Mechanic at Force Bangalore service and he says this doesn't usually happen unless you revv the engine high.

We are clueless as to what exactly is happening:
1. If Revving high is a problem, how do we do it if its struck in water. i.e. Struck here means, not like needing recovery. But, needing a bit of momentum which makes us push the Accelerator peddle
2. Mechanic says, you should be slow on water wading. I think I did this mistake the very first time
3. Force says water wading depth is 700 mm. I am sure, I was well under this limit the first time. But, cant remember the 2nd time. It might have been a bit more than 2 ft.
4. Does the theory of not revving high make sense? if so, I have seen Gypsies speeding in rallies even through water. How do they handle?
5. The fan that I had replaced the first time this happened was an after market one. Could that be a reason? Perhaps, the previous owner had done the same as well?

I was reading through some of the Australian 4x4 forums where people have experienced similar issues on older Defenders and Nissan Patrols and they recommend to disconnect Radiator fan/Fan belt during water wading. This sounds sensible, but not a permanent solution.

Can knowledgeable members bring forward their thoughts? Is this an engineering flaw or am I doing something wrong?

I had even planned to buy MT tires and a relative of mine(dealer) had sourced. But, I had to put this on hold for wanting to understand the problem better before investing further

I could not find similar issue being discussed on the form. Hence, creating a new thread. Kindly merge if found duplicate

[Kosfactor]

700mm is ~2 Ft, will 2 ft standing water hit the blades ? I doubt that.

Check your engine mounts once, at full load it may not be holding the engine in place properly.

[Shubhendra]

Originally Posted by karthikd21

The radiator had extensive damage and the fan, well was not repairable. So, the FNG sourced both and fitted them back.

Was land flat while these incidents happened? This generally happens in offroad vehicles while articulation because of vehicle flex.
it would be good to check radiator mounts, engine mounts to rule out this cause. Also did the fan hit shroud during this process? There might be a possibility of fan hitting shroud and in turn damaging the radiator.

[Jaggu]

Originally Posted by Kosfactor

Check your engine mounts once, at full load it may not be holding the engine in place properly.

+1

Check engine and gearbox mounts, and how is the clearance between fan and radiator.

Yes going in fast can cause such issues, one can always use a water blanket arrangement in front of the radiator to avoid that. But not sure if that will help if the issue is due to water at blade level and while vehicle is submerged. If it is poor quality plastic of the blade then a metal blade is the solution

But I guess there would be an auto clutch at blade which will stop it in case it faces stopping force against it.

[karthikd21]

Originally Posted by Kosfactor

700mm is ~2 Ft, will 2 ft standing water hit the blades ? I doubt that.

Check your engine mounts once, at full load it may not be holding the engine in place properly.

I might not have been precise. But, the 2nd time at one point it could have been more than 2 ft. Probably a few more inches.
I have asked the mechanic to check all the mounts. Will know more tomorrow when I visit

Originally Posted by Shubhendra

Was land flat while these incidents happened?

it would be good to check radiator mounts, engine mounts to rule out this cause. Also did the fan hit shroud during this process? There might be a possibility of fan hitting shroud and in turn damaging the radiator.

Land was not flat and was in a forward decline mode. So, front 2 wheels were more in water than the rear. At that point, I realized it might have deeper than needed and started reversing. just before reversing, water entered the cabin floor for a few seconds.

The first time, there were a lot of shrouds. But, 2nd time water was more or less clear.

Originally Posted by Jaggu

+1

how is the clearance between fan and radiator.

Yes going in fast can cause such issues, one can always use a water blanket arrangement in front of the radiator to avoid that. But not sure if that will help if the issue is due to water at blade level and while vehicle is submerged. If it is poor quality plastic of the blade then a metal blade is the solution

But I guess there would be an auto clutch at blade which will stop it in case it faces stopping force against it.

There is enough clearance. Must be more than 2 inches between the fan and the radiator

Yes, I could see that the damage was less to the fan the first time(on the pics above). But, the 2nd time, one would not be able to make out if a fan was present. All the blades were missing completely!

From what I heard from the Mechanic, the Fan runs all the time in the Gurkha like Ambassadors.

[karthikd21]

Originally Posted by Jaggu

If it is poor quality plastic of the blade then a metal blade is the solution

Has anyone tried a metal Blade? How to procure it? Obviously OEM won't have it. So, custom order? Since the Metal blade would be heavier, would it not cause other issues?

[dhanushs]

Your fan and radiator must be very close to provide optimal cooling. However, the drawback is the fan hitting the radiator on jumps/water wading etc..

The solution is to move the radiator a bit forward. Also, check if your fan clutch is working. It's supposed to let off the fan when cold/faced with resistance.

Lastly, if you intend to water wade frequently, get an electric fan.

[Tejas@perioimpl]

Splashes while going fast are great for photographs and give a lot of likes on facebook and instagram.

BUT! You need to go slowly and create a bow wave in front of the vehicle.

The bow wave pushes water in front of the car and thereby reduces the water behind the pushing part so that the fan doesn't come in contact with the water.

Any fan will disintegrate when in contact with the water at high speed RPM.

The idea of the tarp is basically to help push the water and prevent debris from choking the radiator.

If your vehicle doesn't have a viscous coupling for the fan, you may physically need to remove the fan belt and prevent the fan from rotating.

Personally, I strongly dislike water wading and given a choice, I would just not do it. Water is the worst, not only for engine, but also for exposed body parts, washes away lubrication etc.


EDIT:

Originally Posted by karthikd21

We are clueless as to what exactly is happening:
1. If Revving high is a problem, how do we do it if its struck in water. i.e. Struck here means, not like needing recovery. But, needing a bit of momentum which makes us push the Accelerator peddle

Revving doesn't give traction, rather over revving breaks traction. Remember that saying, as slow as possible, as fast as necessary?

2. Mechanic says, you should be slow on water wading.

He is correct

4. Does the theory of not revving high make sense? if so, I have seen Gypsies speeding in rallies even through water. How do they handle?

Every car is different. Where you in 4L or 4H?

5. The fan that I had replaced the first time this happened was an after market one. Could that be a reason? Perhaps, the previous owner had done the same as well?

NO. The blades hit the water and shattered. The fan doesn't even have to be submerged. Even 1" of water above blade diameter is enough to break it.

I was reading through some of the Australian 4x4 forums where people have experienced similar issues on older Defenders and Nissan Patrols and they recommend to disconnect Radiator fan/Fan belt during water wading. This sounds sensible, but not a permanent solution.

Agree. Get a viscous coupling. Where? I don't know. Google it.

Can knowledgeable members bring forward their thoughts? Is this an engineering flaw or am I doing something wrong?

Not a flaw IMO. Known fact during wading.

Only thing you can do is to maybe add a metal rat mesh between the radiator and fan so that in the future you might just break the fan and not damage the radiator. But best is to avoid water!

[karthikd21]

Originally Posted by dhanushs

Your fan and radiator must be very close to provide optimal cooling. However, the drawback is the fan hitting the radiator on jumps/water wading etc..

The solution is to move the radiator a bit forward. Also, check if your fan clutch is working. It's supposed to let off the fan when cold/faced with resistance.

Lastly, if you intend to water wade frequently, get an electric fan.

Visited the Service center today. There is about an inch gap between the fan and the Radiator. Its not an easy task to move the radiator forward. Radiator mounting Bolts are welded to the chassis and also the intercooler is placed ahead of the radiator. So, that would be a full on customization. He also did not recommend it as it could cause overheating issues. Electric fan again is not an easy one.

Originally Posted by Tejas@perioimpl

BUT! You need to go slowly and create a bow wave in front of the vehicle.

The bow wave pushes water in front of the car and thereby reduces the water behind the pushing part so that the fan doesn't come in contact with the water.

If your vehicle doesn't have a viscous coupling for the fan, you may physically need to remove the fan belt and prevent the fan from rotating.

Personally, I strongly dislike water wading and given a choice, I would just not do it. Water is the worst, not only for engine, but also for exposed body parts, washes away lubrication etc.

Revving doesn't give traction, rather over revving breaks traction. Remember that saying, as slow as possible, as fast as necessary?

Only thing you can do is to maybe add a metal rat mesh between the radiator and fan so that in the future you might just break the fan and not damage the radiator. But best is to avoid water!

Read a lot about water wading and the best practices post the incident and understand Slow and Bow wave is the best recommendation

Mechanic showed me exactly what you are saying about the repercussions of water wading on other parts
1. Car was recently greased, have to get it done again as it was low on some parts and suspension was making noise although it is in good condition
2. Wheels were jammed

So, will just attempt water wading when necessary and not for fun going forward. If there is more routine maintenance required because of water wading every time, I will avoid it. There are so many other kind of obstacles Gurkha is excellent in. Will have fun with those

Also, the Mechanic pointed out that there is a housing around the diameter of the fan to make sure the air direction is more focused towards the Radiator. This is making the water to produce more pressure allowing it to be not going out easily when the fan rotates under waterSee, marked in red below


Also, marked in red here and the fan visible, marked in yellow

He suggested to remove it and try. Seems like this is a regular one done by them on many vehicles under these circumstances

Its also the Mechanic's theory that only 1 of the fan blades partially broke during the first incident because its OEM and it broke because of usage for the last 72k kilometers and the part has become weak due to heat from the engine. The 2nd time, it was an aftermarket part and all the 6 blades broke and washed away beyond recognition. This also answers my doubts about why Force is advertising Gurkha that it could water wade up to 700 mm(almost bonnet level) if mine is failing despite the engine, radiator and fan mounts being not weak. Yes, it can work with OEM parts. But, parts could get damaged like any other car in the longer run due to wear and tear. So, I don't believe newer Gurkhas would see this and might see some time later in their future.

Thanks everyone for your suggestions and comments. Lots of learning. Will keep you posted. Gurkha will be back tomorrow

[bharatbs]

Radiator fan breaking is a common problem in off roading, if you hit the water or drive through water at higher speed.

Even if the water level is low, it will create a bow wave that rises when you drive through it at higher rate of speed.

[Ravi Parwan]

I have had a similar experience many years ago with a premier padmini!!!
Actually I was going through a water crossing, the kind we have in smaller roads crossing streams. Being a novice driver, I gunned the engine so it would not stall.

I ended up shredding the radiator with the plastic fan. Within 2-3 km the car started overheating. I drove for about 10km stopping every 2 km to refill the leaking radiator and allowing the car to cool down.

What happens is that the plastic ( I believe it is ABS plastic) bends and flexes abnormally when it has to pass through water, instead of air, which is its normal medium. when it does, it will rub against the closest thing, which is the radiator.

This has lesser chance of happening in a electric fan setup since the thermostat is attached at the bottom of the radiator and is the first thing to come in contact with the (normally) cold water. That stops the fan, thereby lowering the chance of such damage. A belt driven fan will never have that escape route.

Hence I would put much credence to the advice given, to disconnect the fan before water wading, or going the electric fan route.

[DirtyDan]

I am wondering if Mahindra was forced to address this problem on the M550 jeeps it has sold to the Indian Army. My thinking is that You could copy what Mahindra did to the M550.

Of course, that assumes that Mahindra does NOT have that problem.

[karthikd21]

Thanks Everyone for your advice and suggestions regarding the right ways to water and also on various options to fix. to Summarize:

Advice:
1. Avoid water wading and restrict to cases only when necessary. Water wading causes other issues like grease wash off, tires do not rotate freely and require regular maintenance after every session of water wading
2. If needed to go through water, make sure to do it slowly creating a bow wave. High torque is generated in lower gears. So, avoid high revving
3. Disconnect fan before water wading - Mechanic advised against this as the same fan is tied to many more functions and also difficult to do this without removing the radiator and the fan in Gurkha

Suggestions to Fix:
1. Installed OEM fan blade
2. Trying to see if I can fit a rat mesh between the fan and the radiator. This would avoid radiator damage at the very least
3. Add a viscous clutch if available - checked and saw that even newer versions of Gurkha(did not check 2022 model, but this is not available even on 2017+ models) don't have this
4. Remove the fan housing so that there is space for water to splash around and doesn't hit the fan back - I have got this removed. Now, need to observe the temperature gauge on highway drives to see if there is any detrimental effect. If temperature goes northwards, will get it fitted back
5. Replace with metal fan - not trying this as this might cause more damage to the radiator than the current plastic fan
6. Move radiator further away from the fan - Not going with this one as it requires extensive custom work. Radiator mounts are welded to the chassis and intercooler is just next to it

Now that I have worked on a few things, mind says should do a test sooner than later. But, brain says to avoid it. So, will avoid and leave it for the monsoon to automatically create a necessity during off-roading sessions which is when I will make sure to be extra careful and apply the slow, high torque principle, carry an extra fan, ask Mechanic to be on backup just incase

Will keep you all posted.

Moderators, kindly close/keep open the thread as necessary. I will talk about the actual experience on next water wading on my Gurkha ownership thread. Alternatively, if you can merge this thread if possible there, that would be great as well. Here is the link to the same https://www.team-bhp.com/forum/test-...-review-2.html (My pre-worshipped Force Gurkha Explorer 4x4 3-door Review)

[Tejas@perioimpl]

I would not remove the housing / shroud as mentioned in point number 4.