Overheated tonight.....

Good evening to all you knowledgeable experts.....

Had to come over to Northern Ireland and been driving my P38 v8 4.6 with LPG through town. She's not used to city centre traffic, ie stop and start with heavy traffic flow. Also had to queue for hospital car park for about 30 mins today.

So on way home noticed a waft of steam from under bonnet, right in front of me so around the expansion tank. Needle had gone slightly higher than normal. Couldn't stop so carried on until I was able to safely pull into a garage forecourt. About the same time needle made a jump to top of scale.

So stopped, lifted the bonnet and plenty of steam coming from the expansion tank but no sign of leaks/coolant loss elsewhere. After letting her cool topped up the coolant - about 4 litres. Completed journey with no problems in heavy traffic but as soon as I put some power on (dual carriageway and uphill) needle started to climb above mid point again. Pulled into layby and, with engine ticking over, needle dropped to centre point, so set off again with no problem cruising about 50.

As I said no sign of other water leak, no sign of water in footwells (although handbook has been showing for ever with not a lot of inside heat), no sign of mayo in water or oil.

Will have some time to check over in morning in the light.....but what else should I be looking for?

Know I will be doing same journey again tomorrow so a tad nervous.

Never had overheating problem before and have towed 1000 miles in a week around our clogged motorways. So all a bit out of blue. (And she runs beautifully until I'm away somewhere)

Silted radiator, stuck thermostat or duff viscous fan unit....???

Saint.V8 said:

Silted radiator, stuck thermostat or duff viscous fan unit....???

Click to expand...

The v8 rarely silt up the rads
The viscous fan is possible as is failed water pump but the dreaded headgasket is always at the front of my mind with these engines

Guys, thanks.

Head gasket was my immediate thought but would have expected some signs or forewarning? Might be a problem because it overheated.
Fan seemed ok on tick-over but will try to run engine up to some speed in morning and thermostat or water pump would fit with lack of heat?

Hoping it's something simple as don't have a lot of tools with me, need to visit hospital (so all the traffic) each day and no decent work place

Looking on bright side at least it's all looking at straightforward mechanics.

Thank you for reassuring me of why I love old-design engines (apart from the obvious joys of a V8)

Trevt, where you in Belfast....was up there myself today, there are a couple of indies not far, addresses of use?

P

Parisien

Addresses and a recommendation would be brilliant, just in case. I'm in Newtownards but going up to Royal daily so fighting the traffic.

Not bothered about travelling a bit if they're good (last time I was away and had a breakdown I went to a indie in Kendal. Plugged in the scanner and told me I needed a new ABS unit at £3000 + labour. It was ABS pump thermal switch - £75 from scrappy, 3 nuts and a pipe union was a much better option )

Belfast has gone to the dogs for early and late pm traffic....hold on will rustle up


P

Not used these myself....but recommended on PH forum....by ciscodisco!

Land Rover Specialists - Ballynahinch, Downpatrick | BLRC
BLRC Ballynahinch
88 Listooder Road
Saintfield
Ballynahinch
County Down
Northern Ireland
BT24 7JX

Telephone: 028 9751 1763
Mobile: 07774 732 098
Email: [email protected]


Others listed......

This guy is in Banbridge, a bit further....recommended too

Al is a good contact for land rover repairs and spares. His number is: 07824763098

Hope these are of use


P

Really appreciated and many thanks

First thanks to the guys last night for advice.

Topped up and checked coolant this morning. ran engine up to temp with no signs of leaks etc. then shje started to struggle on tick over as I noticed the LPG defuser (?) had gone a nice icy white. coolant pipes leading to and from it were solid - as if coolant was frozen inside. All other coolant pipes had no pressure issue.

I'm assuming this shouldn't freeze and this is a symptom of bad water circulation?

Think i'll run on petrol today and see what happens....

Trevt said:

First thanks to the guys last night for advice.

Topped up and checked coolant this morning. ran engine up to temp with no signs of leaks etc. then shje started to struggle on tick over as I noticed the LPG defuser (?) had gone a nice icy white. coolant pipes leading to and from it were solid - as if coolant was frozen inside. All other coolant pipes had no pressure issue.

I'm assuming this shouldn't freeze and this is a symptom of bad water circulation?

Think i'll run on petrol today and see what happens....

Click to expand...

Water pump gone?

A quick update, drove to town today on petrol (gulp) without issue. On way home decided to put heater up to full and turn on. Within a few minutes needle started to climb. Turned down to minimum and got home with no problem.
Putting everything together I think I have an airlock in the cooling system and, by some miracle or freak of nature, it was disguised as I always keep heater low. Combination of me turning heater up and city traffic has exposed an underlying issue. If it isn't that it is either water pump or thermostat not circulating water.
Diffuser icing up is another symptom because it's not getting a feed of hot water (hoses run from the heater pipes).
So plan for the morning is to refill and coolant and bleed properly (after reading how to do it already) and see what happens.
If that doesn't work then time to check water pump etc.....but will need to understand how I lost coolant to get an airlock in the first place.

you said in first post it took 4 liters of coolant, surely you didn't fill it correctly and created a new airlock.

Spend some time on getting the filling right, it can be tricky on these beasts

Keep filling expansion tank right up to neck with engine running, make sure wee return hose from radiator is clear (I leave it off till thermostat opens and all air is out) maybe bleep revs - squeeze top hose and when it takes no more coolant stop and let everything cool right down, top up if needed, check level after the first couple of drives after cooling down to be sure.

Hope your car has never had come into contact with K-seal or similar killers

Trevt said:

A quick update, drove to town today on petrol (gulp) without issue. On way home decided to put heater up to full and turn on. Within a few minutes needle started to climb. Turned down to minimum and got home with no problem.
Putting everything together I think I have an airlock in the cooling system and, by some miracle or freak of nature, it was disguised as I always keep heater low. Combination of me turning heater up and city traffic has exposed an underlying issue. If it isn't that it is either water pump or thermostat not circulating water.
Diffuser icing up is another symptom because it's not getting a feed of hot water (hoses run from the heater pipes).
So plan for the morning is to refill and coolant and bleed properly (after reading how to do it already) and see what happens.
If that doesn't work then time to check water pump etc.....but will need to understand how I lost coolant to get an airlock in the first place.

Click to expand...

Turning the heater up or down does not affect the flow of coolant through the heater matrix. I think you have a problem with the LPG side of things.

Could be a leaking vaporizer - best to get it checked by an LPG specialist.

air lock in the pipes to LPG Vaporiser can stop the flow of water and water freezes in the pipes and restricts the flow further so the vaporiser has to be bled as well when filling the water

Ovalanderover - you got it.

And unfortunately mea culpe - I drained some coolant a few weeks ago doing another job and, clearly, didn't bleed it properly. I've only been doing local driving so never warmed up enough to show. Sitting in city centre traffic exposed it.

Bleed the system as per directions (thanks) and has driven sweetly today with no problem at all. Just need to do it all again tomorrow so I can top up the antifreeze.

Lesson learned the hard way. And thanks to all the useful suggestions and advice. It really is good to know so many out there willing to help and bounce thoughts of.

A virtual pint to all