Nissan X-Trail Forum banner
1 - 20 of 23 Posts

·
Registered
Joined
·
195 Posts
Discussion Starter · #1 ·
Despite me not having recently topped up my coolant level, my car has discharged coolant four of five times now via overflow on hot days with puddle on ground.

- Car is NOT overheating, at least according to the temp gauge. Has never gone above halfway.
- However pipework around radiator / engine does appear to get very hot - maybe that's normal?
- Level is NOT above MIN on header tank when car is cold.
- Spring loaded radiator cap is as it should be, takes quite a bit of thumb pressure to compress.
- However when I remove radiator top cap, I cannot see a coolant level (never have).
- Coolant is clean with no dirt and is green / blue in colour.
- Engine oil appears fine (would indicate cylinder head problem if otherwise?).
- I have never heard my fan(s) come on.
- There are no other leaks in system.
- Hot air blowers appear to be working (though might not be heating up as much as they used to).
- No loss of engine power or increase in fuel consumption.
- No other noises or obvious problems.
- Started to do this last couple of summers, whereas first summer I had car it never threw out coolant.
- Coolant system and related components have never been touched or worked on during my ownership.
- Car always driven easily, never over-revved or pushed hard apart from a once per month drive at around 2500rpm to ensure DPF stays good.

Something weird just doesn't add up!!!

Any thoughts / possibilities welcome.
 

·
Registered
Joined
·
524 Posts
My coolant level is always low when I take rad cap off ,funny as checked it yesterday .As long as coolant level is on max in expansion tank then all good.You could try and change the thermostat for a new one .Just wondering if it's sticking then popping open quick ?
 

·
Registered
Joined
·
2,871 Posts
Mine is above max, i filled to the rim and now it stays about 2 cm over max.
Could be head gasket leak, or egr cooler leak.
 

·
Registered
Joined
·
195 Posts
Discussion Starter · #4 ·
Further to my initial post above, I have confirmed that my cooler fans are both running fine. The reason I was never aware of them is that they run almost silently and stop when car ignition is switched off. Even with bonnet opened and engine running, I had to use my finger (carefully) to convince myself that the fans were spinning which they were.

Also looking again at my radiator cap, its impossible to see the coolant level as my filler is offset from the radiator itself blocking the view vertically down into the actual radiator.

Ahto42 and Leafy - My expansion reservoir coolant level sits almost at the bottom (way below minimum mark) when car is stopped, but when engine is running the level fluctuates dramatically. If I top it up to the MIN or MAX marks, it just throws the coolant back out again onto the ground next journey on a hot day.

I should also state that it doesn't do this when I am driving, but appears to throw the coolant out in one pulse at end of a journey just before or just after the engine is switched off. Only does it on hot days.

I don't fully trust my temperature gauge on the dash. I need to find out where it takes its reading from as I am convinced, based on smell and feeling pipework around radiator, that the system is running very hot on warmer days.

I will need to focus on my thermostat, water pump, or perhaps a silted up radiator? Maybe I will need to give system a good flush soon, and when doing so look at those components?

I don't believe it can be the cylinder head (gasket) as the problem has been around for over a year now and 15K miles. If it was the cylinder head gasket, it would have become much worse over that time period. Also I can see no contamination in either the engine oil or the coolant itself.

In the meantime, I'm doing around 50 miles daily and car is otherwise driving fine. No loss of power, and trip computer fuel consumption is sitting at 37.8 mpg which I am very happy with, and that's with a mix of town driving and my daily commute to work 20 miles each way.
 

·
Registered
Joined
·
191 Posts
A basic obd reader will show you the temperature for sure. Leave it plugged in and you can see the temperature as you're driving.

Sent from my moto g(8) power using Tapatalk
 

·
Registered
Nissan X Trail Columbia 2.2 DCi 2006
Joined
·
686 Posts
Sounds like thermostat. When engine is turned off, water pump stops circulating coolant and localised boiling occurs. The coolant hoses will be hot as nowhere to go if thermostat stuck. Ambient temperatures have been higher lately which will not have helped either.
 

·
Registered
Joined
·
195 Posts
Discussion Starter · #8 ·
Colster - You might be on to something there as indeed the pipes to / from the radiator become very hot at end of each journey, especially as you say on hot days.
 

·
Registered
Joined
·
195 Posts
Discussion Starter · #9 ·
....and Ahto42, yes I will consider that possibility as well. Albeit I did my engine with Wynns EGR cleaner last weekend. It produced no obvious smoke so I believe that my EGR was not very dirty.
 

·
Registered
Joined
·
195 Posts
Discussion Starter · #11 ·
Latest thinking:

My cabin heater is blowing good hot air when engine warms up, so I believe my water pump is circulating coolant as it should. No obvious fault there.

When engine heats up, the large coolant hose leading to my radiator becomes very hot as it should, suggesting that my thermostat is opening correctly /fully also.

However, I do notice that despite my fans running when engine is hot, my radiator itself isn't becoming hot. In fact, the bottom of the radiator is staying completely cold almost all the way along it. There is just a little warmth in the vicinity of the inlet and outlet pipe and down that part of the radiator between the inlet and outlet pipes.

So I am beginning to think that my radiator may need a good flush? I have not had this done during my ownership of the car which is a period of 3 years, and from 81K to 117K miles.

I also notice that my system has green / blue coolant, but is it not supposed to be the red mix? Could this be the reason my system may have built up so much sediment? Maybe I am wrong there about the colours, just going by what my motor parts guy said.

Anyway, looks like I need to investigate my radiator?
 

·
Registered
Joined
·
195 Posts
Discussion Starter · #13 ·
I am satisfied now that my thermostat is working fine.
Pipes to / from radiator remain cold until engine warms up, after which they become very hot. So thermostat is opening exactly as it should.

My problem very much appears to be a partially silted up / blocked radiator.

Could others kindly feel their radiator after a journey and see if it feels cold / warm / hot / very hot.
On pre-facelift T31, a large portion of the lower radiator, wider than your hand, is exposed low down through front bumper and is very each to reach.

Many thanks.
 

·
Registered
Joined
·
399 Posts
After a journey my radiator is warm but not excessively hot - the coolant is red/magenta which I believe is the correct stuff not green/yellow/blue - that sounds wrong and could be blocking rad by not providing correct inhibitor??
 

·
Registered
Joined
·
195 Posts
Discussion Starter · #15 ·
Slowly piecing this puzzle together, many thanks for all inputs however small.

Yes, Jim, I thought coolant was supposed to be red, not the green / blue that has been in my car for my 36K miles, plus the 14K since previous service with last owner in service book. And, by the way, that was a provincial Nissan dealer service! In fact, all recorded services from new under the car's previous owners are Nissan dealer. Oh dear, this could be my problem, causing radiator to silt more than it should.

I haven't had a chance to take matter further yet as I need a day off work, and need to have everything I'm going to require sitting ready, including new red coolant, a decent quantity of distilled water etc. Also I want to be well read up on the process, and whether I might need to purchase some other product to help clean out the interior of my radiator if full of sludge, hopefully not.

In the meantime car as I say is driving fine, and throughout all of this, my temperature needle has never budged above the middle mark, so I don't have an engine overheating issue (yet!) Trip computer fuel consumption is currently showing 38.4mpg, based on 40 miles daily commute on fairly good class B roads at 50 to 60mph and a little town driving.

Will post further here in due course.
 

·
Registered
Joined
·
399 Posts
Since reset last week after new squib fitted my mpg has crept up again to sit at 44.3 average :roll:

I haven't as yet seen it dip below 40 apart from towing a rather large trailer with car on it when it dropped to mid 30's!! On a nice run it will push and go past 50!!! I must be doing something right and do wonder if the re-map has helped as I don't change gear as often.......... doesn't help you though...............
 

·
Registered
Joined
·
195 Posts
Discussion Starter · #19 ·
Latest update..... I spent Saturday afternoon doing a coolant flush and replenish. My first on this car.
(Remember car has had green coolant for a long time instead of the recommended red.)

It took TEN flushes to get all the green out and return to completely clear water. I just used tap water for the main flushes as it would have taken a colossal amount of de-ionised water to do so many flushes. I also poured in a small carton of Holts Speed Flush coolant system cleaner and went for a drive to heat up engine before starting first drain.

(Remember from radiator drain, you cannot drain the complete system, only what is on the radiator side of the thermostat. I could only get out approx 3.5 to 4.0 litres at a time despite the system holding a total of 8.4 litres. This is why so many flushes were necessary.)
I do not suggest draining the engine block, as how do you refill the engine block again after your thermostat has closed, which it will immediately? You would then have to start taking pipes off. I didn't take any pipes off anywhere.

Zero sediment or dirt of any kind came out, just bright green coolant! So no evidence of clogging, silting, rust or damage / deterioration, which was one of my motivations for doing a flush in the first place, so thankful for that. It appears that the wrong green coolant hasn't done any harm over the 4 years and 40K miles minimum that it has been present.

From about flush no. 8 I started using the de-ionised water, then did two further flushes with dionised water and started putting in the red concentrated coolant. I put in around 4.0 Litres of the new red coolant.

Apart from the time consuming aspect of draining, filling, running engine until thermostat open, cooling down, and draining each time, the job went very smooth.

Just remove your large black plastic under engine guard panel, then look for the central hole in the forward steel cross member. There is a small rubber pipe visible if you can look up into that hole, and the drain plug is just a small black plastic plug up inside. It simply screws out with a large cross head screwdriver. Opens very easily as no corrosion will be present due to it being plastic. It has a tiny O-ring which I didn't replace as it looked fine and I didn't have one the right size at hand. Only remove your radiator cap and reservoir cap after you've removed your drain plug to increase flow.

To fill each time, I just poured slowly into the radiator and reservoir tank alternately, a little bit in each one at a time. I had NO issues with air bubbles or air lock. Just don't dump the lot in at once, do it more slowly and you can hear the air bubbles escaping. I did not remove any pipes.

I was able to complete the fill / drain cycle quite fast eventually, as I discovered that each time I got the engine hot enough to open the thermostat, the drain coolant wasn't dangerously hot after about 5 minutes sitting with engine stopped.

Will see how car performs now. However I still notice quite significant reservoir level changes between engine cold and engine hot, but I can live with that if it doesn't overflow and I don't have any overheating issues.
 

·
Registered
Joined
·
2,871 Posts
Norfolk Jim said:
British mpg obviously :)
I use L/100km, but when i swith to mpg, british, not so great, and when switch to US mgp then ridicusly high mpg.
 
1 - 20 of 23 Posts
Top