Over heating problems or not?

[John C]

Hi all
Not sure how to explain my problem, but here goes.
The engine bay has been getting very hot of late, so hot that when you put your hand on the bonnet passenger side towards grill it is extremely hot, lifted the bonnet all hoses to and from turbo extremely hot including air box.
Have had cooling system checked out and all OK, had coolant changed anyway, new fuel filter, now about to change air filter. Car runs fine plenty of boost.
Car smells hot when you stop. [Town running]

John

 

[Old.Tony]

I'd be querying the coolant temp if you're overly concerned about it. The bonnet paint might get affected if the temps are too high - that's part of the reason why there's matting under the bonnet. There's a picture of my engine bay in my garage and the dark area at the top is the mat I'm talking about. It should pretty much cover the entire bonnet underside - is yours intact?

Temps under bonnet WILL get high. There's a turbocharger sucking in exhaust gas between 500C and 700C depending on how hard you're going (sometimes higher!). Coolant temps are anywhere from 90C to 100C and the fan will draw gobs of air through the radiator to shed some of that heat.

There's enough heat in there to raise the air temp inside the air box by 20C in the short time it's there (I've measured the difference between ambient and the MAFS output). That could be all you're seeing.

Good way to check: find another, see what it feels like. You could also grab an OBD2 bluetooth (ELM327) adapter and an Android app called 'Torque' (or 'Torque Lite' to try it out) then measure coolant and MAFS temps yourself.

 

[John C]

Hi Tony
The people that checked the coolant temp said it was reading 91c when at normal operating temp. The matting under the bonnet is intact and in good condition, after they changed the coolant and fuel filter I then changed the air filter. I am now going to do a full ECU reset.

Bought the car new six years ago and has performed with out fault. [ 2008 D40 ST-X duel cab Auto trans] its my first 4x4 and first turbo diesel, I bought it for towing the van.
Will follow your suggestion on OBD2 blue tooth adapter

John

 

[kernels]

Does the Navara run hotter when it's trying to do a burn-off of the DPF possibly ?

 

[Old.Tony]

DPF burnoff (regeneration) results in diesel being injected in the exhaust stroke while the valve is open so that the fuel goes straight out the back and lands on the DPF. It gets a little hotter - some have said EGTs rise by about 100C during a regen - and that will translate into noticeable heat, but I'm not sure it's going to feel so hot that the bonnet is "extremely hot".

Pity you're more than a couple of hours' drive away. I have a infrared temperature sensor that reads 0-1100C, we could point that at the bonnet and get a precise reading. Ask a mechanic if he's got one and can take a reading.

91C is absolutely normal. Nothing wrong with that at all.

 

[John C]

Not knowing when the dpf is doing a burnoff I cant tell if it gets hotter or not. As for the infrared temperature sensor sounds brilliant will try and find some one who has one close to me

 

[John C]

Thanks tony and kernels for your input much appreciated

 

[camo.b]

How high should a d40 get when towing? I saw 98 today...34° air temps tho...towing this.photo has no relevance...just showing off really

 

[Iceman]

Good question. How hot is too hot?
I have seen 105 deg once or twice when blasting up a long hill at 100+ with a heavy trailer.
Went straight back to about 88 once i eased off at top of hill. Pistons were probably turning to liquid!

 

[camo.b]

Hahah not a nice thought tho.
Mine went back to 91 once the road leveled off..wondering about a rad flush?

 

[John C]

I like the one on the trailer Camo.b

 

[camo.b]

Like it too...Just come back from a woodwork tighten up and some fresh timbers here and there.my uncle loves timber...i however like steel and only steel.will be driving soon!

 

[Old.Tony]

I've got a clean radiator with newish tanks and a recently replaced fluid couple. When towing our 2.5T van, temps generally sit (flat ground, cruising) around 96C. When hillclimbing, they'll head north fast - straight to 100C then a steady climb past 105C if I let it. I usually back it off once it reaches 103C so that the engine load figure falls below 55% which seems to be the magic point in my car for heating the coolant.

 

[camo.b]

Thats good to hear Old.Tony. seems mine is quite normal then.

 

[John C]

It has also helped me enormously, Thank you one and all

John

 

[steel d40]

Likewise seems normal.
Changed thermostat to Tridon Hi flow. Temps drop a lot faster and don't seem to peak so high. Made a bigger difference than expected.
Also sealed and shortened air tract (bypassed duct on front of air box) and intake air staying much cooler even stopped in Perth traffic on 40 degree day.
All measured on my trusty scanguage.

 

[camo.b]

Likewise seems normal.
Changed thermostat to Tridon Hi flow. Temps drop a lot faster and don't seem to peak so high. Made a bigger difference than expected.
Also sealed and shortened air tract (bypassed duct on front of air box) and intake air staying much cooler even stopped in Perth traffic on 40 degree day.
All measured on my trusty scanguage.

Tridon high flow...have you run this in winter also? Any adverse effects?