Overheating and Heating Issue

[Ben Griffith]

Hi Gents

Have a weird one on my 2009 Titanium 2.5L diesel. Ive done a lot of town driving today running my kids around, absolutely no issues. Then this evening driving down the highway I noticed the heat out of the cabin vents started blowing cold air. Shortly after, the coolant temp rapidly climbed to 120deg. Pulled over, had a preliminary look for leaks or hoses, couldn't see anything obvious. While idling the temp went back down to around 95, limped it for a little while in 2nd and the coolant temp very slowly started rising until 105, so pulled over again, again in idle temp settled back down all the way to 90 after about half hour. Didn't risk it, had it towed home to deal with in the morning. I'm not a guru, coolant level seems fine, no engine lights or fault codes. What should I be looking at for both no cabin hear AND overheating engine temp?

I would be very grateful for any hints and tips.

Cheers fellas

 

[Old.Tony]

Sounds like either an air pocket, a damaged thermostat, a blocked radiator, a failed water pump or a blocked heater matrix. If you're not losing coolant it probably isn't a cracked head.

With the engine running and warm, see if the BOTTOM radiator hose is getting warm. If it is, the pump is probably ok. However, if the thermostat has failed, this could also block the flow of coolant. If the bottom of the radiator is cold, it's probably blocked.

Park the car with its nose up (about 300-500mm above the rear) and when cool, crack the radiator cap. Try filling it. Replace the cap and let the engine idle for 30 seconds or so, repeat until you can't fill the radiator any more - this should get rid of any air pockets.

One final thing it could be: the pesky viscous hub (fan clutch, the stupid thing has a squillion names but it's the aluminium widget on the front of the water pump that the fan is bolted to). Test it: with the engine at NORMAL temp (over 90C), have someone turn the engine off while you watch the fan - it should stop almost immediately. If it spins and spins, the silicone oil inside is stuffed, you can buy a bottle for $18 at a Toyota dealer, crack yours open and pour the whole bottle in (has to be done on a bench if you're having trouble making the car stand on its tailgate to keep the hub level).

 

[Soflegee]

I had a similair problem with my l200, couldnt find any leaks in the coolant system, but kept loosing coolant, then the vents would blow out cold air... possibly air pocket like tony said, try taking the front coolant cap off (engine cold), and running the engine from cold on idle for a while whilst engine slowly warms and keep an eye one it, see if you can manage to push the pocket out if thats the case. You'd be loosing coolant if there was a leak/cracked head... im not a proffesional mechanic but this helped me release an air pocket before!

Charlie

 

[Ben Griffith]

Sounds like either an air pocket, a damaged thermostat, a blocked radiator, a failed water pump or a blocked heater matrix. If you're not losing coolant it probably isn't a cracked head.

With the engine running and warm, see if the BOTTOM radiator hose is getting warm. If it is, the pump is probably ok. However, if the thermostat has failed, this could also block the flow of coolant. If the bottom of the radiator is cold, it's probably blocked.

Park the car with its nose up (about 300-500mm above the rear) and when cool, crack the radiator cap. Try filling it. Replace the cap and let the engine idle for 30 seconds or so, repeat until you can't fill the radiator any more - this should get rid of any air pockets.

One final thing it could be: the pesky viscous hub (fan clutch, the stupid thing has a squillion names but it's the aluminium widget on the front of the water pump that the fan is bolted to). Test it: with the engine at NORMAL temp (over 90C), have someone turn the engine off while you watch the fan - it should stop almost immediately. If it spins and spins, the silicone oil inside is stuffed, you can buy a bottle for $18 at a Toyota dealer, crack yours open and pour the whole bottle in (has to be done on a bench if you're having trouble making the car stand on its tailgate to keep the hub level).

Thanks for the prompt reply Tony. That is some good info to carry out some fault finding.

One thing I noticed was that in the coolant reservoir, it's it's about just over the min. Now I've only had the Nav since last October and I have no idea which coolant the previous owner was running in it. I dipped it with a clean white paper towel to try and see what colour it was, it was almost transparent, with a slight yellowish colour. Now to me it looks like someone maybe have been topping it up in the past and now it is so diluted, or could even be someone's only been using water in it? Because I live in a cold climate (it's currently -3 at 8:45am as we speak) I reckon I should flush it out and put new coolant in it, because if that is just water no wonder I'm having issues. Is there a recommendation for which coolant to put in it?

Cheers

 

[Old.Tony]

Nissan will tell you that you should only use their own coolant, but then Mitsubishi and Toyota will say the same thing, and it's all just rebadged stuff - like the Navara's fuel filters are made by Mann and rebadged.

So just pick a good brand and mix it up - you'll need about 10 litres for a full change, and somewhere between 33% and 50% is a good mix. Coolant is actually not as good at transferring heat compared to water - but coolant is great at extending the range of freezing/boiling points and reducing oxidisation.

 

[Ben Griffith]

So on closer inspection, the coolant in the radiator was low (about 4 litres only), and I topped it up with water to test, and found this join (see attached) to be pissing out.

Again, I'm no guru - is this part of the heater coil for the cabin heater, and does anyone know the part number? The rubber appears to be split.

 

[Ben Griffith]

So after some more farting about, and some googling, it looks like this is the heater core hose and the plastic link is a common failure point. No wonder, a bit of plastic like that running near 100 deg water regularly AND right behind the turbo heat shield won't last very long. The thing is brittle as an old lady's bones, basically crumbled when I tried to turn it on the pipe. It looks like it's stamped on there too, not actually a thread, which is an absolute dog move by Nissan to make that hard to remove, probably want people to have to buy the whole pipe.

Anyone know a quick way to get it off, or a retrofit? I don't see why the hose can't be replaced altogether with a rubber/silicone hose and piss that stupid elbow off altogether.


Cheers

 

[Old.Tony]

I'd replace the elbow with something else, for sure. Wrap it in heat tape too, just for good measure.

I might have to look at mine! If you're replacing it, does it need to come off "clean" ?

 

[Ben Griffith]

Because that doesn't appear to be a thread, I'm probably going to destroy it and then just get the right diameter hose and replace that whole hose and slip it over the aluminium and some clamps. Unless anyone else can suggest why that is a bad idea?

Really annoyed about how such a pov thing has caused such a major issue. Also annoyed that there was no fault code or warning indicator that came up for low coolant. To me it seems like entrapment by Nissan.

 

[Old.Tony]

That's been an issue that has been raised here a few times - the lack of water level indication in the radiator. Some people have installed a device to provide an alarm - I can't remember what was chosen, a quick search reveals several products that are available.

I can't think of why your solution would be a bad idea at all.

 

[Ben Griffith]

Well thanks for the help and advice Tony and I'll let you know how I get on.

Cheers

 

[basher57]

Hi Gents

Have a weird one on my 2009 Titanium 2.5L diesel. Ive done a lot of town driving today running my kids around, absolutely no issues. Then this evening driving down the highway I noticed the heat out of the cabin vents started blowing cold air. Shortly after, the coolant temp rapidly climbed to 120deg. Pulled over, had a preliminary look for leaks or hoses, couldn't see anything obvious. While idling the temp went back down to around 95, limped it for a little while in 2nd and the coolant temp very slowly started rising until 105, so pulled over again, again in idle temp settled back down all the way to 90 after about half hour. Didn't risk it, had it towed home to deal with in the morning. I'm not a guru, coolant level seems fine, no engine lights or fault codes. What should I be looking at for both no cabin hear AND overheating engine temp?

I would be very grateful for any hints and tips.

Cheers fellas

Any air bubbles coming out of rad with cap off from cold..if yes head gasket

 

[Scott52]

So after some more farting about, and some googling, it looks like this is the heater core hose and the plastic link is a common failure point. No wonder, a bit of plastic like that running near 100 deg water regularly AND right behind the turbo heat shield won't last very long. The thing is brittle as an old lady's bones, basically crumbled when I tried to turn it on the pipe. It looks like it's stamped on there too, not actually a thread, which is an absolute dog move by Nissan to make that hard to remove, probably want people to have to buy the whole pipe.

Anyone know a quick way to get it off, or a retrofit? I don't see why the hose can't be replaced altogether with a rubber/silicone hose and piss that stupid elbow off altogether.


Cheers

YD25.com sell an upgrade kit and they note the plastic tee is a common problem. The kit includes a replacement brass tee.

http://yd25.com.au/index.php/yd25-s...oducts-4/yd25-d40-r51-heater-oil-cooler-hoses

 

[cesanneo2]

I saw some aftermarket kits and this T joint was brass so does not crack anymore. Possibly on yd25.com.au. Let us know when you have the diameters of the T joint - possibly can be found in aquarium or home improvement shops for peanuts Cheers

 

[Ben Griffith]

So Gents,

I ended up cutting the aluminium pipe, removing the short hose, and running a length of heater hose instead. A bit messy in the engine bay but solved the issue without having to resort to Nissan's ripoff buying the whole assembly. I watched a YouTube vid where a guy did this, and I basically copied him. You can have a look here:

Parts needed for the above : 5/8" heater hose - $8 per metre from Supercheap auto, I used about a 50cm length, a couple of jubilee clamps (just better than reusing the pinch type) and if you don't have a pipe cutter I got a small one from Bunnings that's cuts 3mm-20mm pipe for under $10. Did the job nicely with a smooth cut.

I got chatting with another guy in a Facebook Nav thread, and he sent me the info for the brass replacement couplings you can use. If you changes the elbow to brass you will still need a bit of heater hose and cut that aluminium pipe as the old plastic piece is stamped on by Nissan and can't be removed (dicks). The second T piece I am looking to replace asap with the brass fitting and it looks very easy being 3 hose clamps only. See attached photo for the brass part numbers from Reece.

I'm glad I can pass this info on, it was an absolute dog so I hope it helps someone else before you get stranded on the side of the road and paying for towies.

Cheers for the advice also.

 

[Old.Tony]

Superb job, thanks for sharing it with us!

 

[Chapster]

Yeah I'm pretty sure when I replaced mine it was a brass elbow from Tradelink then a couple of clamps and short length of heater hose from Supercheap. Plus a pipe cutter if you don't already have one.

Just bear in mind if you lose that breather/indicator above the existing elbow you need take care when replacing coolant not to get air stuck in there. I resolve this by driving onto ramps to make radiator the highest point but even a decent gutter would probably do the job. And fill slowly.

 

[pistol-W]

So on closer inspection, the coolant in the radiator was low (about 4 litres only), and I topped it up with water to test, and found this join (see attached) to be pissing out.

Again, I'm no guru - is this part of the heater coil for the cabin heater, and does anyone know the part number? The rubber appears to be split.

Different to mine which just fell apart.. in my search on youtube there was a guy doing a quick and cheap fix for that problem, sorry I didn't save clip.. Good luck.