Losing Coolant - advice needed

[Agronaught]

Hi all,

I bought my GU several weeks ago, a GU TB48 @ 200,000km. Pre-purchase I had an inspection done by a mechanic chosen by me, and apart from the clutch plate being closer to the replace side of life no issues were found. This inspection included a pressure test, checking for coolant in the exhaust, oil in the coolant etc. Again no issues found.

In spite of this I'm losing > 1L of coolant per 100km with no obvious leak. I've had the car pressure tested by a different mechanic and we found the radiator had a crack in the top tank under higher than normal pressure - this was replaced on Thursday at NatRad and the pressure test repeated.

I've just driven 150km to ensure everything is OK, the system was pressurised, the level in the expansion bottle increased as expected, and everything was hunky dory. Then less than 1 km from home the temperature gauge started bouncing (air in the system) and I found the system wasn't pressurised, and one cool 1L of coolant was required to top up the radiator on top of what had been pulled from the expansion bottle.

A short test drive and the system has pressurised as it should.

I did find the bottom of the radiator cowling had broken off and was 'swining', I've now removed this (forcefully) so the cowling will need to be replaced. I could see some coolant under the car, but this could be a remnant of the radiator replacement on thursday.

When the temperature started bouncing I did note that the engine was oscillating between 800 and 1800rpm. This behaviour is what alerted me to the problem.

SO


* I have a car that has had the cooling system tested by 3 different mechanics including NATRAD and declared OK.
* I have replaced the radiator (natrad, new), and replaced the cheap radiator cap with a new nissan cap this morning.
* The radiator levels were checked this morning and I added 1 cup of coolant, as the radiator had been replaced I've assumed this is simply air that hadn't been bled from the system.
* I ran the heater etc to ensure the system had been bled.
* I did note the lower coolant pipe is spongy and will obviously need to be replaced - but it doesn't appear to be leaking.

So...

Where do I go, and what do I do to get to the bottom of this ?

Any recommendations ? Is Nissan the best bet (BTW - in Sydney).

J.

[threedogs]

Might be wrong here but see how we go. You may have an air lock if running gas most likely. Have you changed radiator cap?.
This it the way I used to do it. Park 4x4 nose up, higher the better . Cut the butt off a plastic drink bottle and when running invert this in neck of radiator.
All we are trying to do is increase your fill point, well trick it really. while topping up coke bottle squeeze hoses forcing water around system, loosen clamps on gas condensor you'll see bubbles. just repeat it till only water /no bubbles in coke bottle. If still no good you may have stuffed the head,

Heater on full too please

[Agronaught]

Thanks Threedogs, I'll do that. I picked up a genuine thermostat this morning so will take the opportunity to install it and a new genuine radiator cap was put on the radiator this morning.

Trapped air/air lock is an option, although 1 Litre seems excessive (to me).

I'll revisit bleeding the system in the morning, Thanks.

Cheers.

[threedogs]

Another member here found he was losing fluid from the top return hose outlet ,it was cracked, cheap fix

[BigRAWesty]

I'm loosing about 1L every 500Km, but my hoses are nearly 24 years old.. Lol
I'm hoping it's a high pressure leak out of one of the hoses and not a head issue..
No coolant on the ground.
But I've just noticed the water pump bearings sound a little rumbly, so I may do it all at once



Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[threedogs]

Easy to check water pump is grab it and see if any movement ,if there is its shagged. water will drip from it

[BigRAWesty]

Easy to check water pump is grab it and see if any movement ,if there is its shagged. water will drip from it

Yep. Planned for tomorrow. Only just started to hear it this morning on the weekly walk around..
Possible is my coolant loss issue to.
But need to get bearings, hoses, belts and would love to do my endless air while it's apart..
Money hay... Never enough..


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[threedogs]

Money might be worth spending elsewhere. endless air awesome, it'll take a day to fit. if you intend using rattle gun etc
compressor and tank on chassis perfect for weekends and lockers. endless air is awesome though

[nissannewby]

Sometimes its hard to pin point a water pump leak as it can evaporate on the hot engine block before you actuallly see any sort of fluid on the ground. Normally a give away is like a white snail trail of where it has run before it has dried up.

[Robo]

Sometimes its hard to pin point a water pump leak as it can evaporate on the hot engine block before you actuallly see any sort of fluid on the ground. Normally a give away is like a white snail trail of where it has run before it has dried up.

X2 on this and,
Worth getting a inspection mirror and fully looking the motor over for with tell-tail stains.
X2 the inverted bottle in radiator filler trick.

[threedogs]

Gotta laugh Newby "WHITE SNAIL TRAIL"
I was way off lol

[Agronaught]

I'll do the bottle trick and will elevate the front as suggested. The lower radiator hose is soft so I'll order replacements, install the thermostat (no separate gasket?) and failing that look to a new water pump.

I do get white smoke and a few drops of what I assumed was condensate when starting th engine cold... Now I have to wonder.

Once the above is tried I guess it's time for the head to come off... I'm hoping it won't need to and will see if the problem persists.

If (god forbid) the head is cracked. Is it worth putting a new head on a 200,000k tb48 engine or should I go the rebuild/replacement?

[BigRAWesty]

If it gets to it, rebuild and turbo..
But that's another thread..


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[Agronaught]

OK..

I spent *far* more time than it should have taken with the front wheels up on ramps and the old coke bottle jammed in the radiator until I was unable to solicit any mor bubbles, just shy of 1/2 L of liquid fed into the system this way with the engine running and me squeezing every pipe I could reach.

Once filled I took the car for a 20 minute drive and noted on return system pressurised and coolant had flowed into the expansion bottle. There was also the smell of burnt coolant from the engine, so a leak is possible if only I could find it. There was also a slow but steady bubbling into the expansion bottle, - approx 1-2 bubbles per second.

I've left the car for a couple of hours and the coolant hasn't been drawn back into the radiator, albeit the engine is still a little warm to the touch. I did break the seal (just now) and the amount of liquid missing from the radiator is easily accounted for in the expansion bottle. (yes, I'll have to manually fix this... tomorrow after work).

All in all... no result :(

still getting bubbling into the cooling bottle, but the car smells like a coolant leak.

I need to find a 4WD mechanic in the inner west of sydney, no more generic mechanic's.

J.

[threedogs]

No result , badluck but less for your mechanics to look for. when he finds whats wrong, post results here if you could please

[BigRAWesty]

Could try a new radiator cap??


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[Agronaught]

Already done on the radiator cap.

Time to find another mechanic.

J.

[Robo]

Where are you located

[BigRAWesty]

Well an update on mine..
Just checked my pump, the bearings are on there way out, a little movement in the bearings but no leaks that I can see..

I'm struggling to find any details on bearings and if they can be changed in the pump. I prefer $20 of bearings over $100 for a new pump..


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[Agronaught]

Found a local mechanic... like this one... is a patrol owner himself :)

Tested the system and the thermostat was replaced along with a number of checks as it was definitely faulty. I've also learnt where the bleed point is for the engine to that's one task that will be simpler. No evidence of blown gasket or head but we know how that one plays out... I'll take it in for an LPG service as that won't be helping with overheating and the water pump will need to be rebuilt/replaced.

Otherwise... not sure we have a solution at this stage, I'll replace the pipes and go from there.

J.

[Robo]

Well an update on mine..
Just checked my pump, the bearings are on there way out, a little movement in the bearings but no leaks that I can see..

I'm struggling to find any details on bearings and if they can be changed in the pump. I prefer $20 of bearings over $200 for a new pump..


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)
Your pic is gq patrol assume your talking the same here TB 42 try around $80 retail at local auto shop

[BigRAWesty]

Yea TD42, was a typo. Meant to put $100.


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[Robo]

Bro,
A double row bearing as used in a water pump with extra good seal, (pretty tough environment).
seriously doubt the bearing would cost less than $50.
half the price of a complete new pump.
that's hoping you dont damage something pulling it apart, or impella re-fits securely.
not to mention the running around, it would surely cost as much if not more than a new pump.

ok up-date,
Just out of curiosity I rang local bearing guy I use alot and he said to me.
"water pump bearing replacement is a thing of the past.
buy a complete new pump these days".
just dont do em anymore
and cost would have been around $50+ as suspected.
cheers

[BigRAWesty]

Thanks for that info Robo. If that's the case then a new one it is..


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[threedogs]

Not so much an impellor but a pressed metal fan, Was a GURU here in Vic now retired that machined an actual impellor for most
water pumps, and put the thermostat in the bottom hose. With his system near on impossible to overheat any 4x4. Pity
all this technology retired with him. Seems such a waste.

[Robo]

No wuckin fuwries.

Had often wondered this one myself, now we both know for certain.

[Agronaught]

Well he car had a visit to the LPG guy today and he found a number of small leaks under the bonnet and the exhaust analysis was off the chart. That fixed, retuned, and a leak-down test and it seems I actually have a 'good' motor, assuming we can fix the coolant issues anyway. All I'm waiting on is a new water pump, new hoses and it should be done... Hopefully :)

Unexpectedly - I actually have a 115L LPG tank which is good, especially if the tuning fixes the gas consumption.

Now... to order a temp gauge, oil pressure and pillar mount so I can keep an eye on it.

J.

[Agronaught]

2 steps forward, 3 steps back...

Just checked the coolant, needed to add a litre. The really sad part of this is the car hasn't travelled more than 5km between the mechanic on Tuesday and the LPG service today, only being run when being worked on at both places. They *did* run the car for an extended period on Tuesday to check for problems, I can only assume they didn't check the coolant levels - only the engine temps - during and after the run.

Starting to feel really... ticked... about this.

[Bulbous]

Few years ago, I had a BMW 325i with a broken radiator seam. It was losing about a litre of coolant every time I went anywhere, I couldn't for the life of me find the leak.
When the car/engine was cold, the radiator was sealed and didn't leak.
When the car/engine was hot, then it had all expanded and sealed - didn't leak.
I had to carry a gallon of coolant everywhere, but couldn't see where it was going.
It was really strange cos it lost the same amount every time, didn't matter whether you drove 10 miles or 100.
Found it by accident one day after a shortish drive where the coolant got just warm enough to open the thermostat and dump hot water into the radiator. The resultant luke warm mix caused the seam to pop open and allowed the coolant to pour out.

[Agronaught]

Already replaced the radiator, and that was one of the issues just not the whole problem.

Took a drive today and im sure i smelt a couple of occasions when coolent was released from the system. In all cases the temperature was stable (although still waiting on a gradiated gauge so i know the actual temp). while im still waiting for the water pump and hoses, i have my own theory.

My suspition is a blown gasket or more likely a cracked head (cylinder 5 if what ive read about these engines holds true).

Ill replace the water pump and pipes and test again just in case, and the water pump is worn so it is a possible culprit. Failing that i guess its time to lift the head... I think ive discounted everything else.

If It is, a new head hardened for LPG and bottom end rebuild should have me out in the bush. Im just incredibly impatient to get out there.

Cheers
J

[threedogs]

Agron a little while back a member was losing fluid and doing all you've done then some ,pulling hair nd teeth out.
after lifting the head the coolant was leaking into the cavities in the head, no wonder you're frustrated as everything he did
drew a blank. Now I think this may be common to 4.5 and 4.8 petrols, frustrating as it is hopefully you're on top of it now.
keep updates coming. There should be a sticky just on 4.5 losing coolant, would be less bald men around. LOL

[Agronaught]

That's my thinking, just need to confer with my mechanic to see if he agrees or not. I have a quote for a 'new' engine (i.e. complete rebuild, all new parts, warranty) thats not _too_ exxy. Ill compare to getting the head reworked/replaced and the bottom end refurbed... although the drive-in, drive-out quote would save a *lot* of running around. Unfortunately this doesn't include a head that's LPG hardened so I'm not so sure there.

Cheers
J.

[threedogs]

They are just stainless valves and seats I think, Maybe if you can find the thread called replace or repair head I think it was called
Maybe a bit of a port job as well might aid efficiecy

[BigRAWesty]

If all else fails it could possibly be the head gasket leaking internally..
Is the oil nice, black and silky? Or does it have a creamy tinge to it?


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[Agronaught]

Actually the oil looks and feels like new... LPG.

I've confirmed with the mechanic that from what he has seen it's either the gasket or head, and given it's been on LPG for most of the 200,000km he would put money on the head.

I'm not going to waste any more money on what is on the balance of probabilities a dud engine, and at 200,000km I don't believe it's worth replacing the head without rebuilding the bottom end.

As a result, I've just booked in to have the engine replaced as I'm reasonably happy with the cost and will certainly get the value out of the car.

J.

[Agronaught]

Confirmed, cracked head in cylinder 5.

Joy.

[BigRAWesty]

Bummer.. Not cool


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[BigRAWesty]

Well I've had some development with mine. After a quick start yesterday I noticed quite a large wet patch above the pump. Looks to me that the alloy thermostat housing gasket is leaking..
So I'm wondering is this a single gasket? Or is that part incorporated into the head gasket??
I'd like to fix it properly but I don't really feel like pulling the head off..


Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[Agronaught]

New engine installed, and even though I'm taking it easy for the run-in it has *WAY* more power than the old one and sounds... quiet! Almost too quiet compared to the old engine.

SO yet another cracked head due to poor maintenance/lpg/add reason here.

Now... lets get the bloody thing offroad!

[threedogs]

Great to hear, never been a fan of gas on petrol engines, but 200K was a fair run I suppose

[johno90]

Glad you sorted it out, but on a side note be cautious of any engine that has an egr cooler, common problem on a bt-50, cooler leaks and goes in through egr passages. Ive seen this problem mis diagnosed as a head gasket many times.

[Agronaught]

I'm actually still debating weather I keep the LPG on it or not... This is a weekend car only so fuel availability and range are more important to me at this stage, the lpg is also due for tank inspection in 18 months combined with an EFI upgrade (should be done) so if I keep it on gas there's a couple of grand... for now I'll get an upper cyl lubricant added as I don't need to rush the decision and with 8c per litre off LPG at the moment (coles) it doesn't cost that much more than my subaru to run.

[johno90]

Is your lpg injected or mixed? if its the injected type then it will most likely be worth keeping

[Agronaught]

Mixed unfortunately. If i stick with lpg i would consider upgrading.

[johno90]

lpg with injected would be great if you plan on doing any long trips. Just hit the petrol button if you plan on doing an overtake.

[Robo]

FYI .
LPG Injected tuned correctly makes more power than petrol.
in standard guise that is.