5 hard learned lessons about D40 2.5l diesel engines

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lakesideguy

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Hi Guys,

Here's a tale of disaster, but I did find out a few things that every D40 Navara/Frontier owner should know.

One Navara has now chewed through three engines. Yes it's true. Maintained by different professional mechanics over it's life.
All different suppliers and installers (professionals).

One from from factory, which cooked itself 1 year after warranty and no-one has been able to provide a satisfactory explanation why (it suddenly had no coolant and no oil). Bad luck mate, but we can't help you.
One from HM Gem, which threw its single row timing chain a couple months after the warranty ran out (less than 30,000kms) - $13,000 wasted. Bad luck mate, but we won't help you.
One from YD25.com.au, which dropped its coolant from the oil cooler return hose and cooked the head. -$13,000. Bad luck mate, but I WILL HELP YOU!

Paul at YD25.com.au rebuilt my third engine with a double row timing chain and a couple other goodies to toughen it up. My local mechanic performed the installation. It honestly ran better than new. It was installed in January. After gaining some confidence with it, I took it for a country drive from Brisbane to Newcastle. It went like a rocket. Before departing Newcastle for the return leg, I checked coolant, oil, tyres - everything. Two hours later, I look down at my speed and notice the temperature gauge near the upper limit. I immediately slow and look for somewhere to pull off the road. It takes about a kilometre or so because I'm going through winding mountain roads.

But too late, as I'm pulling over it suffers a massive power loss. I've been here before, this is not good. I find myself parked thirty-five kilometres in either direction to the next town and no mobile phone coverage, on the side of steep hill. I pop the bonnet and cannot see any evidence of a damaged hose or water loss. Oil is fine. So I decide to let it cool right down because it is radiating heat on hot day in Ivan Milat country of New South Wales.

After about half an hour a kind senior couple stops to offer help. I swallow my remaining pride and give them my details for the automobile club and they drive on to the next town to make a call on my behalf - thank you.

I wait for a while before having another look. Still can't see any leaks from any of the hose that I can see in the engine bay and they all look in good condition (not swollen or soft) and properly clamped. In fact, it's an extremely clean bay, like there's a new engine - oh yeah it only 6 months old! Now that it's cooled down, I crawl under the truck and hope there's no King Brown snake already there. It's hard to see with all the grass, but notice a droplet hanging from the back of the engine. I reach out to get a sample on my finger and bring it to light. Its the beautiful blue-green colour of fresh coolant.

Many cars and trucks thunder past, but at this moment a local farmer very kindly stops to offer assistance in his fully functional Toyota Hilux with 4 million+kms on the clock.

Now I have back up, I crawl in further across the roadside rocks, but still no obvious signs of dramatic water loss. WTF!

Wait a minute, what's these two small hoses here at the bottom right-hand side of the engine? They are difficult to see looking back up through the engine bay into the midday sun. They are not swollen, they feel solid and are clamped well. I'm told the hoses are for keeping the oil cooler doing it's job. But, one tug on one of them causes hot coolant to flood down my out-stretched arm to pool in my armpit and begin the poaching process.

This really pisses me off. I've done everything I could to avoid exactly such an incident. Even if those hoses were transferred twice from the original engine, the vehicle only has 138,000kms on the clock.

After recoiling from under the Nissan, my new friend has a look for himself and decides it's worth having a go to try and wrap it in electrical tape to get me to the mechanic in the next town. I'm sceptical, but if a man of the land is willing to have a go, then I'm in too. Of course there is no access from above and it's very awkward from below. We can only get one hand at a time to the hose. Twenty minutes and one roll of red electrical tape later, we decide that's as good as we can do.

The Navara has cooled down now so he offers a jerry can of water, which the radiator swallows whole. I'm thinking that is not good.
We try to start the engine. It turns over, which is a relief, but only for a millisecond, because air and water are belching and coughing back out the top of the open radiator. So, is it a blown gasket (if I'm lucky) or warped head (if I have my normal luck) or hydraulically damaged bottom end as well (if this bloody 4x4 does what it normally does)!

Pressurised water gushes out of the hose directly into the ground. The electrical tape fails, but the mystery of the clean engine bay and how could this motor could get so hot, so quickly, is solved.

To cut this long story shorter, my senior Samaritans were able to call for a rescue party and a tilt tray tuned up after about 3 hours. In the following weeks, there was an almost comical amount of stuffing around with the country town mechanic/auto parts store/mayor and the insurance company - who did not come to the party.

However, and this is where the story cheers up, I finally find a trucking company who is willing to transport my vehicle for less than the wrecking cost. The Navara arrives back in Brisbane 4 weeks later at my local mechanic and I'm at my wits end. I've already gone and purchased another car I can't afford, but I know two things: the cost of a replacement engine is probably equal to that resale value of the vehicle and without an engine the wreckers will only give me $1500.

In a last ditch effort, I call my specialist engine builder Paul at YD25.com.au with cap in hand. The hose is not part of the rebuild warranty, but I've got nothing to lose. For some reason, he is sympathetic to my position and offers to replace and rebuild the head. What a bloody legend! I'm almost in shock that I've found someone who actually knows what he's doing, delivers real customer service and actually backs himself and his products with actions and not just words.

My local mechanic knows the Navara has been sitting for a few weeks and takes some initiative and has already removed the head to prevent any corrosion. Fortunately, it's not bad. I take the head to Paul at YD25.com.au and on initial glance it doesn't look too bad. No where near as bad as some of the other dead heads he has in his workshop. But, a closer look reveals that it's not flat and he explains (I apologise if I get this wrong) that if it gets that hot, then the alloy metal becomes literally "soft" and cannot be repaired. So, it's definitely a new head.

One week later I receive a call from Paul that it's done, ready to pick up and has thrown in a gasket kit. Like I said, what a bloody legend!

Now we have to put it all back together and fingers crossed the bottom end is OK. Any Christmas prayers thrown my way will be much appreciated.

So lessons to be learned for all D40 owners:

1. Your Navara engine is great, but fragile as glass and can overheat in minutes.
2. Your Navara engine is twice as expensive to fix as other four-wheel drives.
3. There are almost no replacement engines laying around because it is a global problem and that is why they are so expensive.
4. Contact Paul at YD25.com.au now for a double row timing chain kit before yours let's go. Under $3000 vs $13,000 - your call.
5. Change all your hoses after 100,000kms - Paul also has a hose kit that is half the cost of Nissan original and not made with plastic connectors that fail.

Good luck fellow Navarians and Frontierites
 
Mate that is shocking, i really feel very sorry for you and your wallet. I've been a Navara owner since 1989, never have I heard of such rotton luck. All the best for a change for the better.
 
That's a terrible experience, and I'm glad it worked out in the end. There's a valuable lesson in there and it's sending me on the search for something important: a reliable means of knowing the coolant level. The lesson: never, ever let your engine run out of coolant.

The thing is, how can you accurately measure the amount of coolant present in the engine?

Obviously if you monitor pressure you can tell when it gets far too high - that's when it's already too late and the combustion chamber is venting into the coolant jacket. Even if you do start losing coolant, the pump should maintain close to the original pressure and (especially if the leak is slow) so monitoring pressure isn't the answer.

Monitoring the level of fluid in the expansion tank may not be fruitful either, because if the pump is maintaining pressure in the system, there's no reason for fluid to flow back from the expansion tank to the coolant jacket.

So - anyone got any ideas? What else is there to do? What do you think about a flow rate meter installed in the water pump inlet or outlet?
 
Old tony, i think the best system would be the "water watch" from memory. It has a sensor that you put in your top coolant hose that sounds a buzzer inside the cab whenever it can't detect coolant in the hose. They have been mentioned quite a lot on the patrol forum from similar occurences of dumping coolant and cooking the head.


Edit, sorry, engine watchdog was what i was thinking of....
http://enginewatchdog.com/tm2.html

I stand corrected again hahaha. Apparently it doesn't require opening the cooling system at all. Just measures engine metal temperature instead of actual coolant temperature.
 
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cooland level is easily checked vie the radiator cap removal and visual inspection eg; is it full to the top plus when you start your engine whilst looking at the radiator coolant level , does the water flow when the accellerator is depressed on and off a couple of times. also its wise to allways keep an eye on the temp gauge on dash when driving.
these days many owners of vehicles hardly if ever look under the bonnet and check the obvious things like oil / cooland and battery levels, they just leave it until the next service is due. sounds like this may have occured with the guy that had no coolant plus no engine oil in the engine, waite for a service she ,ll be right.
 
jonney thats all well and good when the car is in your driveway , but if the hose splits mid trip thats a different matter . I don't check coolant when I fill up with fuel and it would be nice top get an indication if level drops. I have heard people use water sensors in the hose but not sure how to install
 
jonney thats all well and good when the car is in your driveway , but if the hose splits mid trip thats a different matter . I don't check coolant when I fill up with fuel and it would be nice top get an indication if level drops. I have heard people use water sensors in the hose but not sure how to install
this is why we must use the supplied temp gauge in dash, yes i know we can,t look at it every second but it is something you do get used to looking at whilst driving.
 
this is why we must use the supplied temp gauge in dash, yes i know we can,t look at it every second but it is something you do get used to looking at whilst driving.
The problem is, the "supplied temp gauge" is crap. It indicates "normal" from about 80c to over 110c and won't go to the red zone until it is too late. There is no audible warning, so unless you sit there looking at the gauge the whole time while driving, there's a very good chance it will have expensive damage done before you can react to it anyway.

The only way to have an accurate gauge is to fit an aftermarket one. You could also use one of the many obd2 programs on a smart phone or tablet to monitor what the ecu is seeing, whether these can be set up to give an audible warning or not, I couldn't say. But at least you can see the exact temp of the coolant, not just the "rough guess" that the gauge on the dash gives you.
 
What bods and John said.

The coolant temperature sensor sits in coolant (while you might think that's a "duh" statement, its not when you learn what can happen) and in the coolant, it can measure the temperature of the coolant.

If the coolant drains out, the sensor sits in air - and the temperature isn't going to rise quickly. What WILL rise fast is the temperature of the head - with no coolant to cool it, every combustion stroke raises the temperature of the head. Eventually, the head gets so hot, it radiates heat to the sensor and THEN you see it - but it's an alloy head, and that sort of heat cooks it.

That head temperature monitoring tool is the ticket. I am getting one. Thing is, once you see the temp rise extraordinarily, you NEED to shut the engine down FAST. There's no "cooling off". If you were boosting hard, you'll have to wear the turbocharger risking its bearings (replacement kits about $140 or so on eBay) but that's far less expensive than a rebuild.
 
I feel for you.

I have just had to replace my auto transmission on my 2011 D40 because the radiator failed where the two pipes from the transmission enter the radiator before going into the oil cooler - apparently it is a very well known issue and is prevented by doing a modification to bypass the radiator and if I had know I would have done it.

I wrote a letter to the CEO of Nissan - Richard Emery - complaining about their poor design and how it has failed through no fault of mine. I received a call from one of their spin doctors (Customer Service Managers) who basically said that it was my fault because:

1. The age of the vehicle and the number of kms - it is 4 years old and had only done 138 000 km at the time!

2. I was towing my Campertrailer - apparently this puts extra stress on the transmission - no kidding but the CT is just on 1000 kg

3. I didn't have it serviced by Nissan 'expert technicians' - true because my mechanic is Australian trained and uses quality parts and not Phillipinos on 457 visas that the local dealer employs (and has a bad reputation)

I have replaced the transmission and bypassed the radiator and added an extra large oil cooler as well as a transmission temp gauge to monitor the tranny.

But my woes don't end there. The new gearbox has a shudder that comes in between 80 - 100 km/h and Nissan say hat this is just a normal characteristic of the gearbox and it is the torque converter not knowing which gear to be in!!!! and they won't do anything to fix it and told me to 'put up with it!!!

To stop it I have to drive with the overdrive turned off. Unfortunately I can not afford to sell the Navara as I have put too much money into it but if I could it would be gone and I will never touch or recommend a Nissan to anyone :pissedoff::pissedoff:

Problem is I don't think any other make or model is any better :Gillard:

Karl
 
Yeah that's bullshit alright. I can't believe the lack of idiot lights either. Touch wood my '04 d22 has been bullet proof so took it for granted and never even thought about it till now. No coolant level light, no coolant level sensor or any provision for one. Just a check engine light (which has never had to light up, knocking wood again!!!), i dont know whether thats hooked up to an oil level sensor or what but pretty rudimentary for a vehicle such as this.
 
The check engine light is pretty basic. Will only come on if the ecu throws a code. Normally only simple stuff like crank or cam angle sensors playing up. Nothing mechanical at all...
 
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