Help! Overheating badly.

[PeterH]

I spent a day under my 2001 HSE 4.6 today, replaced the starter motor, as well as a couple of hoses that were showing signs of leaking.
I have been losing coolant lately, which prompted me to check the hoses.
Got the new hoses on and refilled the coolant, left it idling for about 30 mins to check for leaks...all good so far.
Took it for a test drive to the service station to fill the petrol up, on the way back home it I saw the temp guage climb rapidly, so I pulled over straight away.
Opened the bonnet to find coolant eveywhere, and steam coming out of the cap.
Checked all the hoses with no obvious signs of leaks.
Once it cooled down, I topped up the coolant and took off again, only for it to overheat again after about 1km of driving.
Stopped again, same story, after cooling down again, managed to limp it home ok.
I felt something binding while driving, I'm suspecting the bearing in the water pump.
What is the best way to test the water pump on a P38?
Anything else I should be looking for here?
Thanks, Pete.

[seano87]

Slipped liner/s?

That'll be my first guess on that engine, and is a pretty good explanation of seemingly untraceable coolant loss and frequent overheating.



Sent from my Galaxy Nexus using Tapatalk 2

[wayneg]

If you did not have overheating issues before the work I would suggest you did not get all the air out of the system on refill. This should be done over a good few hours in my experience. Raise the front of the car as best you can. Fill the tank to the cold level and start the car with cap off. Let the car run whilst watching the level and as soon as it starts to rise turn the engine off and leave to cool down. Repeat until the cold level does not drop after being left to cool. Also ensure that the small hose from the top of the rad to the expansion tank is not blocked, with the engine running there should be a steady flow through the hose into the tank.

[jezza89]

+1 on air pocket in cooling system.

I have not done the RR coolant change yet, but most cars I have done this on have a special fill procedure similar to what Wayne has described to prevent air pockets.

[PeterH]

Thanks for the replies.
It certainly could be air in the system, I'll give your method a try tomorrow wayneg.
I did have coolant loss related overheating issues prior to doing the work, which is why I went looking for leaks.
I am suspecting the water pump, but any other suggestions will be most appreciated.

[jezza89]

RAVE also mentions to help rid the cooling system from air, run the car with the cap off the filler tank, and rev to ~2000rpm and then bring back to idle, fill and replace cap.

[RGD129]

hi mate

i have been through similar problems with the wife’s p38, to test the waterpump take off the top radiator hose and start engine, if plenty water shootsout the hose from the top of your engine then the water pump is probably fine. Itwould more likely have a broken shaft rather than a locked up bearing.

Does rangie overheat while idling, while driving slowly or when on freeway?

Regards brett

[slug_burner]

Coolant loss can mean a few things slipped liner is one already mentioned, head gasket, leaks external to the engine including water pump. Most coolant leaves slight telltale sign of colour where the leak has been occurring. Check out the possibility of leaks and airlocks but I suspect that you will be pulling this engine down after a pressure test.

[Keithy P38]

X3 for air lock! As mentioned, full to cold level, start her up, once the thermostat starts to open the level will drop, add enough coolant as not to let the reservoir lose level out of sight. Once thermostat opens, give her a few revs up and down, then turn it off as the level begins to come up. Let it cool for 30mins, top up to cold level again and repeat the procedure a few times. After the third or fourth time let it sit, too it up, cap back on and away you go!

[PeterH]

I'm certainly hoping I don't have to go pulling the engine down.
RDG129, it seemed fine while idiling, I let it idle for a good 30 mins before driving.
I was driving at about 60 kmh when the overheating hapenned twice in a row.
I will try the airlock procedure first as suggested and see what happens, I have my fingers crossed!
Failing that, I'll try to test the pump as described by RDG129.
I'll keep you posted!
Thanks for your help, it is most appreciated.

[wayneg]

If you think your water pump is suspect and you car has done 200000k`s or there abouts just change it. Easy job and very cheap from the UK. Just make sure you know how to get the fan off. It could be leaking past a warn bearing.

[PeterH]

Yes it is approaching 200000km, could be water pump time.
I have never had to remove the fan on mine before, is that a tricky job?

[DT-P38]

Agree with air block - burp it!

[Keithy P38]

It's quite easy if you have done it before! You need a 36mm spanner and either the land rover tool or in my case, a large flat head screwdriver!

Use the screwdriver to stop the fan pulley from turning, place the 36mm spanner on the fan nut and spin it anti-clockwise (looking at the motor from the front of the car).

Wear gloves or use wrags, your knuckles will thank you for it.

[edit] It is also advised to remove the shroud first, including the shroud over the air con compressor clutch.

[PaulP38a]

Burping the coolant system is fairly easy with the front of the vehicle raised, and the rear lowered to bumps.

Here's a tip... if you are topping up the coolant through the expansion tank, make sure you replace the cap before switching the engine off. Otherwise, you may end up with coolant sprayed everywhere.

[PeterH]

I will definitely try the burping, will keep you posted!
One thing I just remembered, I saw what looked like steam coming out of the exhaust.
I just thought it was condensation at the time, but if it was steam, that would explain the coolant loss.
Would that be pointing towards head gasket or slipped liners?
I'm dreading that for an outcome.
Just thinking worst case, would slipped liners mean a complete engine rebuild?

[Keithy P38]

Steam is game over! Head gaskets at the very least. If its a slipped liner I would suggest a rebuild rather than just replacing the suspect. Top hat liners definitely and maybe a stroker kit if the budget allows!

[RGD129]

hi peterh

the problem could be as simple as a blocked radiator (inside or outside) ora thermostat that is playing up or slow to react. If re bleeding the system doesn’twork i would try cleaning or replacing these two items before removing heads. Iremoved springs from my thermostat and jammed thermostat wide open and put backin my rangie while I was doing testing for overheating problem and this ruledout the thermostat as the main problem and it kept engine cooler while I wasdoing testing.

There are only 4 water gallery’s in the block (one at frontand rear either side) so if it was a head gasket that was blown and lettingwater in, it would be in cylinder 1,2,7 or 8 and you may be able to see waterweeping out near one of these cylinder. Also the liners in the block are dryliners which means they are not in direct contact with the coolant so if it wasa slipped liner there would also have to be a crack in the bore In the blockthat surrounds the liner.



How does the engine run? Does it idle poorly or misfire? Is itabnormally noisy?



Regards brett

[PeterH]

OK, I have spent the morning bleeding the cooling system properly, thanks everyone for the valuable input there.
It starts and runs perfectly now, no unusual noises.
I pulled the spark plugs out and thay all look fine.
After bleeding the system, I did have a coolant leak from the new hose that connects to the top of the water pump, I noticed it had moved slightly, probably due to the pressure from overheating yesterday.
I have re seated that and taken it for a small drive, all ok so far.
RDG129, the radiator is only three months old, so I'm not suspecting that, but the thermostat is a good suggestion to consider.
I'll take it for a longer drive this arvo and see how she goes!
Thanks again for all the great responses everyone, they have been a huge help.

[radste]

Hi,I had a similar problem & it turned out to be a sticking thermostat,replaced with a new one problem wen't away for a while only to return once but I refilled water in radiator & bled all air out & it appears to be fine now.
Steve

[PeterH]

Thanks for sharing your experience radste, I will keep the thermostat in mind.
Bit of an update for you, after bleeding the air out of the system yesterday, I was still noticing rapid coolant loss when driving with the motor up to temperature.
Topped it up today and took a spin, pulled over when it got up to temp, and low and behold, the new hose at the top of the water pump was leaking coolant past the spring type hose clamp. I put a traditional screw up hose clamp on and that seems to have solved the rapid coolant loss/ overheating issue.
I am still seeing very faint steam coming from the exhaust though, not sure if it's normal condensation or actual steam from the motor.
I put my hand over the end of the exhaus pipe and noticed a few droplets coming out.
Anyway it seems I can drive it for the time being without overheating.
As much as I hate using mechanics, I may have to take it in for a check over.
Will keep you posted.
Thanks, Pete.

[Keithy P38]

My old P38 used to leave a few droplets from the tailpipe. It was not using coolant, I put it down to unburnt fuel. My current P38 has no such issues.

[PeterH]

Update for those interested, took it for a longer drive today, up to 100kmh, no coolant loss, no overheating! I don't want to jinx myself, but it's looking good so far!
No steam to be seen, I'm hoping it was just a bit of condensation in the pipe.
Interesting that yours did that keithy P38, I'll keep an eye on it.
Cheers, Pete.

[DT-P38]

Update for those interested, took it for a longer drive today, up to 100kmh, no coolant loss, no overheating! I don't want to jinx myself, but it's looking good so far!
No steam to be seen, I'm hoping it was just a bit of condensation in the pipe.
Interesting that yours did that keithy P38, I'll keep an eye on it.
Cheers, Pete.

Hopefully, successfully burped.

Pat it on the back every now and then to be sure!!!

[poleonpom]

Good to hear

[PeterH]

OK finally got to the bottom of the overheating problems.
RGD129 and radste were right on the money, it seems the thermostat was the underlying problem afterall.
It must have been partially sticking and not allowing enough coolant flow through, causing overheating.
While at $200 the thermostat is certainly not cheap (as far as thermostats go), it is much cheaper than pulling the engine apart.
I'm happy it's all sorted now, big drive tomorrow to check it out properly.
Hope this is of help to someone!
Cheers, Pete.

[Keithy P38]

I buy my thermostats off island-4x4.co.uk for $20... You got ripped off mate!

http://www.island-4x4.co.uk/thermostat-4046-pem101130-p-384.html

[PeterH]

Keithy, $20 would be for an after market one, I don't know if I'd trust the quality.
I got two quotes for genuine and they were both about the same.
I use aftermarket parts for some bits, but this is one part I felt better having a genuine one fitted.
Each to his own!
Cheers, Pete.

[radste]

Good to hear that it was not more serious than just a thermostat.

Steve.

[PeterH]

Thanks radste, I was pretty happy that's all it was, I would hate to have to deal with head gasket or worse!
Thanks for the help, Cheers, Pete.

[radste]

No worries,glad to help.

Steve

[Keithy P38]

I use them, travel to very remote places and have not had an issue after 2yrs so far. As you say though, each to their own!