Ideas anyone...4.5 Mystery overheating - NOT the usual suspects

[zerolux]

G'day

Got me absolutely stuffed...

Have replaced Radiator, Thermostat, Hoses, Water Temp Sensor, Coolant Sensor, Clutch fan is Ok, cooling system flushed, new waterpump, not using water, and its been 6 weeks and the patrol overheats again...

Temp rises quick, car feels sluggy, pulled over at just over 3/4 on the dial, (didnt want to cook it) let it cool down, add 4 litres to replace what boiled out the overflow and off we go again, no issues.... NOT overheating

Dont know what or where the problem went, but thats the 2nd time and the mechanic has pressure tested, gas tested, checked mixtures, timing, leak down test and cant repeat the issue.. He says try nissan to see if there's a known issue, as he's buggered, and i went to him cause it had me stuffed

So anyone, please, I need help, this is the family car and last time the missus and kids got caught on the highway (other half says it lost power, started to ping and the engine stopped, but all the steam says it was cooked :( that was the 1st time and i replaced everything), this time I was there, but I cant trust it to let them leave town, so to speak.

any suggestions greatly appreciated

Jarrod

[threedogs]

Pull the guts out of the thermostat, still restricts it but more free flowing, use your old one for this.

CRACKED HEAD???????

If you run a hose through motor with thermostat out will it flow, maybe, just maybe an internal blockage????

[zerolux]

yeh, my thought was cracked head, but no smoke, no steam, no exhaust gas in water, and no water in oil...might try the thermostat trick, but its been 6 weeks since the last overheat, so its pretty intermittent

[threedogs]

Don't you hate that, I feel for you buddy, maybe a faulty sensor somewhere??, bad earth??, cant have enough earth straps, loose connection, running out of ideas too. just throwing them out there, still thinking sensor though,

[nissannewby]

Try and get a hold of a mechanical gauge and put it temporarily so you can see what the temp is actually doing when the gauge says its getting hot. It could be a blockage in the auto cooler or the engine oil cooler on the side of the block possibly.

[threedogs]

Yo Jarrod fill out your signature so we know what you drive and what you've done to it, sometimes all info helps Edit in settings

[nissannewby]

Does it not have the recovery style cooling system on it?

[threedogs]

X2 with Nissanewby again get a external pyro reading of the radiator and see if guage says the same thing

[threedogs]

Is it dual fuel???????

[threedogs]

Yo Nissannewby what about an air lock in the cooling system, on my old truck a 350 Chev Troopy. I always inverted a coke bottle in filler on radiator to lift water level or top up an a steep slope with front of car up

[zerolux]

Thanks for all the ideas guys, so here goes with some answers....

New Sensors fitted, havent tried the mechanical sensor yet, but its hot (boiling) when the factory gauge is almost on high, system has been bled to remove airlocks including angled for the trap at the back of the block, it does have a recovery system with a new radiator recovery cap fitted and recovery system has been working fine. after the last overheat, i replaced the radiator with a 3 core 60mm alloy one, but that doesnt seem to of been the problem....separate tranny oil cooler as well as bottom of the radiator, but tranny temp light works but has never lit up..

So you've got me thinking about an oil blockage, oil is changed regular between 5000 and 8000, so i'll flush that tomorrow just to be sure, but as intermittent as it is it could be weeks before it happens again...thats whats making it hard to pinpoint, and after it overheated, refilled water and it was right, drove it home and didnt get above just below half....

Has anyone had issues with fuel and choke plate maybe sticking and leaning out the mix, or ecu issues that lean out the fuel causing overheating...just brainstorming in case the restart of the car reset the issue..got me totally buggered (I apologise for using a Toyota term here :) )

[threedogs]

Is the water pump spinning like is it tight and impellor not slipping.???

[nissannewby]

Yeah its quite possible it could be.

[zerolux]

Waterpump is new and tight...

Nissannewby..which possible you thinkin?? fuel mix??

[nissannewby]

Nuh the air lock my phone was slow to load everything so disregard that post lol. Is there any wear in your pulley for the water pump?

[97_gq_lwb]

did you use a genuine thermostat .

[Yendor]

Does the electric cooling fan work? does it come on as soon as the air conditioning is turned on?

How's the radiator cap?

[zerolux]

Yeh all genuine stuff used, tropical thermostat 72deg, radiator cap is new and good, pulley is good...

[Sir Roofy]

just a punt here is the radiator cap the right pressure not to high

and your not locked into 4x4 with out knowing it

[zerolux]

Thanks guys for all the suggestions, I'm gunna flush the oil system and hope that helps (longshot) and replace the viscous fan anyhow as its the only part that isnt brand new in the whole cooling system, and lube the throttle body linkage in case the butterfly is getting stuck occasionally and leaning out the mix (another longshot), but as of right now, I'm stumped, and i've worked on and built motors since i was a kid, mind you, none of its been this computerised, electronic, sensors driven, flow controlled, temperature modifed, bleedin heart efi crap...just frustrated as it should be ice cold with all the new stuff..

only worry was the power loss when it started to get warm...woulda said head was cactus except all testing says otherwise...

I'll let ya'll know how it goes
Thanx again everyone

Jarrod

[threedogs]

Never heard the term "tropical" is that just the heat range for your area? certainly got a unique problem but sure you'll get it sorted

[nissannewby]

Was each individual system pressure tested or just the the pressure tester in place of radiator cap? And has it only just started since its the weather has gotten colder?

[Thirsty]

X2 on the radiator cap

[zerolux]

pressure test was only in place of the radiator cap, CO tested the radiator as compression should blow into the water when running and water into cylinder when not.....New cap was fitted...took the oil cooler off today and took out some sludge buildup..So flushed the engine just to be sure..

was a fairly warm day the first time it happened and pretty cool the other day...

new viscous hub arrives monday, but have driven around yesterday and today and couldnt get it hot

checked the ECU today and got all clear on the Consult..so

I'll Just keep plugin away till I find somethin

[nissannewby]

It might be worth your while to test each system. The engine, heater and radiator if you can test all these individually and leave the pressure in the system for a prolonged period possibly even over night you could have the tiniest of cracks somewhere that hasnt shown up in previous test and could be why its intermittent.

[zerolux]

So, just an update...Thanks again for all your help, have tried everything, and just to show how intermittent this is, went to go on holidays yesterday and got 30 minutes out of town and it overheated...no lost water, no water in the oil, drove back from where it got hot to home and as long as i didnt go over 60 the temp stayed normal (although i did have the heater on full to try and draw some heat away which made the 32c day much nicer :( ) Did have the van on, so it had a fair load, but have had the van on a few times since the last overheating, so a couple of good months.

SO...Its off to nissan it goes, see if they can find an issue

Thanx again y'all
Jarrod

[threedogs]

I'd have a very good read of Goats thread on '10 model overheating.
everyone swore black and blue the radiator was ok/checked/pressure tested
by NISSAN. it still overheated, his mate rodded the radiator only half if that had water
flowing through it. Is your radiator BRAND NEW ?? or just been checked ??

What puzzles me is you don't need a fan at 100kph ,gotta be something simple
what happens over 60 that makes it boil, start the 4x4 up with cap off, let it get
warm and check for bubbles in the water

[zerolux]

Radiator is brand new, as are hoses, thermostat, coolant and temp sensors, water pump, clutch fan, have basically replaced the entire cooling system and related sensors, flushed, pressure tested, radiator has been CO tested for exhaust, engine has been compression tested, desludged and oil changed, it doesnt use water, no water in the oil, no water in the auto, power does seem a little down, but always kicks over first start and doesnt miss or knock...has me stumped and the fact that once you stop the car when its overheated and it cools down, then it might happen straight away or it may not happen for months, like when it overheated 120kms away from home, and when it cooled down, it drove back without getting past its running temp...FRUSTRATING

No bubbles in Radiator, but at this point a cracked head would be nice, at least i'd know what needed fixing

[threedogs]

Does it have a MAF sensor, still think we have all missed something

[nipagu7]

Hi Zerolux , just read thru the thread and saw that Threedogs earlier mentioned about earth connections , but i couldnot tell from your answers if you checked them or not. This would include commputer earths , battery to engine , battery to body , map sensor connections and oxygen sensor connections , and any other earth connections that seem in any way related to the ignition or fuel system . By checking them I mean loosening , cleaning and reseating , It,s amazing how just the slightest bit of corrosian can cause problems as computerised cars age. A bad earth could cause the car to start to run lean or rich and either can cause over heating .

[zerolux]

Threedogs and Nipagu7, You might be onto something there, I was thinking today that with the power being a bit down, that i'd clean the MAF as i had some good contact cleaner spray handy and as the air filter was too new to be blocked, and got some of the power back, but dont know enough about MAF's breaking down to know if it can be irregular....So tomorrow I'll check and clean all the contacts and earths, but its hard to know when it might overheat again...Did about 50 k's today without skippin a beat

As always, thanks for the input guys

[threedogs]

Got a bee in my bonnet over this, because everything you're saying GOAT said, To the point where he nearly gave up and sold the Patrol.
Any future over heating issues will now be called GOAT syndrome, Have you read his thread last count 21 pages
did you buy your 4x4 from a salty area or now live near the beach, been to Fraser lately. All your earth straps need to be removed
cleaned properly and refitted.

Is there any member close by you can swap MAFs with just to eliminate/confirm it ????

Are your hoses in good nic, they may be collapsing under throttle?

[zerolux]

So i just read Goats thread, Now i'm scared about going to Nissan on Thursday :(

The Thermostat and hoses were the first things i replaced, and have replaced the bottom hose a second time since then because i wasnt happy with it (just seemed a bit soft on the bends) All before I replaced the radiator and sensors, so if they have issues with the aftermarket 3 core radiator they'll have to think again

Only thing thats making it hard to figure is being able to duplicate the issue. Its been running fine since fridays overheat, I put another thermostat in it late yesterday (genuine this time) as when it first got warm, the moment i pulled over and sat idling the needle dropped almost instantly to normal, which i would normally say was thermostat.

Hopefully Nissan will have a voltage map for the MAF and will be able to check that..

I'd sell the thing if only I could get the scammer on ebay to part with the 2009 GU he's offering for the $13000 he's askin :)

[threedogs]

Thermostat is in the right way eh??, sounds weird as you'd think idling it would boil. I'm not 100% convinced your radiator if giving you full flow.
where did you buy it from. is your timing spot on, you saw Goats water flow from radiator, same as what you are describing. remove the thermostat
when cold, shove a hose up there flat out just to see if it comes out at the same rate, both directions

[jff45]

@zerolux, with the obvious outlay you've had up to this point, the addition of an EcuTalk readout might be a good idea.

It will show you your real temps (as opposed to putting any faith in the original Nissan temp gauge). It will display your MAF voltages, your TPS, etc., etc.

In your whole thread, I haven't seen any figure mentioned of what temperature it actually gets to. Only the mention that it overheats..

[zerolux]

Yeh John, I've got no faith in the Nissan gauge either, the first time this happened, the missus and mother in law were in the car on the freeway and they both swear the gauge didnt read above the usual running temp level, thats one reason i replaced the coolant sensor and the temp sensor, but as to what temp it actually gets to??? Best i can guess is well over 110 as the system is bubbling and steaming out the overflow, the hoses are still pressurised, the radiator cap is new...

But your right, what i've spent, a ECUTalk is going too be a cheap investment...

[Alitis007]

With my experience alloy radiators are good to look at but dont cool that efficiently, also checking your dash cluster might be an option you might need to remove it to give to give to some one to go over it. Also another option is to add a couple of extra earths from the block to chassis.

[Dashar]

Mate, those overheating prob's are tough. I had a similar issue, turned out to be a blown head gasket. Water was circulating through the hole causing overheating. It wasn't using water, and a pressure test didn't pick it up.

[shaneo]

Im going through the same process now. overheating. gu 4.5l. have replaved thermostat, vicus coupling and fan. work for a bit but found that it would fill up the overflow container and not back fill. then replaced radiator cap and fixed that problem but still it overheats. am now replacing water pump, radiator, hoses, replacing thermostat housing and various other cooling items. found that the alum items very pitted and the steel cooling pipes rusted. so once all this is replaced all should be cool i hope. wife getting sick of car parts all over back table.

[zerolux]

Well!!!

Took the car to Nissan last week having been booked in to have the issue "fixed" They rang the missus in the afternoon said it's ready to go..They girl at Nissan Service couldnt tell her over the phone what was done, just that it was $70.00 and the mechanics could fill her in when she came to pick it up.

So when I heard, I rang nissan cause it bugged me what could be fixed for $70 that i missed, turns out that they did a diagnostics and as it said nothing, i could come get the car..F#@ktards... I'd sent it in with a list of what's been done and whats been happening, so went in and told them it was there to get fixed, and I already knew something was wrong, and they said Duh, we "think" its the head...

Heads come off, had to really, nowhere else to go......... looks like its lifted enough to stretch the head bolts which were loose, like Dashar, it looks like a hot spot where the head gasket has let go, so no water usage, and pressure tests ok, but still not sure that that explains how intermittent the issue has been.. But am getting the head reco'ed, new gaskets and bolts and hopefully back on the road mid week...

Lets see how it goes after that.

Thanks again y'all for the assistance
Jarrod

[threedogs]

Weird but great info for others, make sure you up date results here, should be interesting reading

[PJHarps]

hi guys i am having the same issues with my 4.5L GU the mech today said he has found nothing wrong replacing the thermostat rebuilding the water pump, he has ordered new temp sensors and is redoing the clutch fan even though he said it's working at about 80-90%, i have all the same symptoms loss of power, intermittent overheating but just a bit more frequently, and i have a small amount of bubbles in the coolant but no loss of water. will be good to see the results after you have the head done. please update.

[threedogs]

PJharps I'd say you've done the head. the coolant shouldn't cavitate to cause bubbles, thermostsat needs to be OE

Might want to post an intro if you haven't already just procedure

[kevin07]

has anyone taken off the exhaust manifold and have a look in there see if theres any white or tried listening to the exhaust,is there any popping or is it all smooth idling. it all adds up to head to me

[shaneo]

all new items fitted, and no over heating yet. the engine seems to sound better as well.

[PJHarps]

zerolux hows the car going with the head reco'ed?

[JoseM]

Definitely a blown head gasket. Not at all an odd occurrence. With this you will not find water in the oil, nor water consumption, and most of the time, not even compression leakage. If done correctly, it will be fine after you are done with the reco and new head gasket.

Since we are talking about this, be specially careful with the heater hoses, if they go, you will loose watter so fast that the temperature will go sky high way before you even notice, which will definetly end up on a bent head. Yeah, it happened to me :(

Good luck with your fix mate

[PJHarps]

Hey mate how did u go? Did u find ur issue?