Heater / water loss problem

I have a 2001 4.6 with LPG.

Its had a problem with the LPG so its not been used for while on LPG. I spent many hours in the car the other day stuck on the motorway and after a couple of hours the heater stopped blowing out hot air. I turned up the temp to max and after a minute the book symbol came up but still not hot air. When the traffic was cleared and I got going again after a few miles the heater started blowing hot again. Once the car was stopped and turned back on the next day the book symbol had gone. So I ignored it as a one off.

Now a week later I got into the car and down the road the temp guage shot up and the light came on. I slowed right down and the temp came down but everytime I turned a corner the temp shot up. Stopped the car after half a mile of this and there was a bubbling / gurggling noise from the front. Checked the water this morning and the header tank was pretty much empty so have topped this up. Its been running fine all day now so what could be wrong?

i would get the coolant pressure tested, there is a leak somewhere. any overheating in a petrol rangie is bad news and could lead to more serious problems later on. also if your not using the lpg take it out of the coolant link as this is where the airlocks seem to originate on lpg rangies. the v8 rover engines are very fickle and there are lots of cases of airlocks and overheating discussed on here. don't drive it till youve got it sorted as you may do more damage.

got a bit more time now so some more info if its gives anyone any ideas.

The day the heater stopped for a while I had been driving for around 6 hours then got stuck on the motorway for another 3 hours (yes long day ). All this time it was running on LPG with no problems.

The next day I got in the car and it wouldnt run on LPG properly, this has since been diagnosed as a broken temp sensor on the LPG system which is why I'm not usinng LPG at the moment. This is due to be fixed next week. However as mentioned it had been running on petrol for a week after this with no problems and I have done around 300 miles in that week.

Since topping up the water I've only been on short trips so not really got it up to temp for any period but its been fine so far. Will take it a bit further today and see what happens.

Could it have been down to an air lock from the LPG system due to the faulty temp sensor which has taken a while to work its way round?

it 'could' be, but i would first check for leaks, do it whilst engine is up to temp and sealed. air locks are a pain to get out but not impossible. i don't think there will have been an airlock if you had no trouble before!! but there maybe now if you have had a leak

on mine, the coolant was pressurizing and blowing water out of the overflow and forced its way out of the joints. mines got a porous block which is an expensive fix. thats the far extreme of the scale.

pourous block i have heard about this. iv just had to do the head gaskets on mine. new rad new thermostat but struggling to get air out, get the steady stream of water from pipe on header tank but never had briliant heating in the car always look warm but as soon as you put the cap on and drive it top hose preshurizes, heads up me arse with this one. ready to save up for coscast bottom end. what do you think

Well I think I have found it. There is a split in one of the hoses that comes from the heater hose to the LPG system which shows signs of having water leak out.

I've had to put some more water in and will replace the hose tomorrow to see if thats the problem. Did 10 miles in it today and used 1 litre of water.

Would I be right in thinking I'd notice if that much was going into the cylinder, it shoudl run like a dog on one if its got that much leaking in.

Oh well fingers crossed tomorrow.

Well had a look at the hose today and its definately leaking so that looks like the problem. Its a hose that goes from the heater line to the bulkhead and taps from there over to the LPG system. My guess is that when I lost heat in the cab it split and that caused the LPG system to play up including the LPG temp sensor. Since then it caused an air bubble and thats why I have had to top it up. Got a new hose now and will replace once it stops raining.

As I'll loose a lot of fluid changing it is there a right way to re fill the system avoiding air locks?

mate im on the very same problem now my self. had a sniff test done on mine to see if carbon in header tank from cylinders or poris block and showed nothing. so was happy. till i spoke to some one the day that also did sniff test on theres and showed nothing in system but his block is knackered. how ever he has used ceramic sealer and has sorted his. before i godown that path its booked in to garage sat. to have water system put on one of them machines that force the coolant in gettin air out. iv replaced rad, therm, rad cap, so really asking for massive air in mine, why not a bleed valve!!!!

dave_r said:

I have a 2001 4.6 with LPG.

Its had a problem with the LPG so its not been used for while on LPG. I spent many hours in the car the other day stuck on the motorway and after a couple of hours the heater stopped blowing out hot air. I turned up the temp to max and after a minute the book symbol came up but still not hot air. When the traffic was cleared and I got going again after a few miles the heater started blowing hot again. Once the car was stopped and turned back on the next day the book symbol had gone. So I ignored it as a one off.

Now a week later I got into the car and down the road the temp guage shot up and the light came on. I slowed right down and the temp came down but everytime I turned a corner the temp shot up. Stopped the car after half a mile of this and there was a bubbling / gurggling noise from the front. Checked the water this morning and the header tank was pretty much empty so have topped this up. Its been running fine all day now so what could be wrong?

Click to expand...

sounds like headgascet gone sorry

dave_r said:

Well had a look at the hose today and its definately leaking so that looks like the problem. Its a hose that goes from the heater line to the bulkhead and taps from there over to the LPG system. My guess is that when I lost heat in the cab it split and that caused the LPG system to play up including the LPG temp sensor. Since then it caused an air bubble and thats why I have had to top it up. Got a new hose now and will replace once it stops raining.

Click to expand...

I know of this!!

i have lpg and the coolant was taken from a pair of tees in the heater pipes and then run over the rear of the plenum to the lpg vaporiser, a stupid idea i though AND it looked horrible!
A drop in coolant due to losses would result in the lpg system not working as the pipes to vaporiser where the highest in the system and therefore suffered first! im guessing next may be heater matrix flow?
I had a leak from the tees, the clips constantly needing to be tightened up and then a hose split, this i put down to the heat from exhaust manifold causing expansion and contraction of said clips so i decided to change the set up!
I got 2 straight pieces of pipe to replace the tees in heater hoses to revert it to standard.
Next i had planned to remove the coolant supply to the throttle body as i want it to stay as cold as poss so the small bore pipes that fed that now feed the lpg vaporiser, you could quite easily retain a heated throttle body and just take a supply from the hard small bore pipe from inlet manifold o lpg, then from lpg back to throttle body!

Its heats up and switches to lpg just as quick as before, theres no stupid pipework going over or behind the plenum chamber and theres no jubilee clips located over the exhaust manifold to keep having to tighten!

After this mod i found the heater to blow out much hotter air, i assumed this to be due to the hot coolant supply to the matrix no longer being shared with the vaporiser so theres now a greater through the matrix!

Reducers at vaporiser


New hose from manifold


Connection from hard to new soft hose, to vaporiser.

Well, replaced the split (which was definately leaking) hose and have done 300 miles since with no loss of water at all.

dave_r said:

Well, replaced the split (which was definately leaking) hose and have done 300 miles since with no loss of water at all.

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Hows the heater temp?

Hi

Heater temp is good and car runs at half way on temp guage as it used too.

Counting myself very lucky. Although my warranty company said they would have covered head gasket or slipped liner. They've already paid for a new rear diff, LPG injectors (all 8) and are covering the LPG temp sensor (it was the best thing I ever bought )

what warrenty company is this? many thanks

Hi

Its a company called warranty direct. There are several conditions to it and they only sell privately so you cant get it from a garage.

Car must have less than 100,000 miles at the start of the policy.
Must have been serviced within the last 12 months by a VAT registered garage (you need to provide the receipt for any claim).
Must have an MOT
Car must be less than 10 years old

Its not a cheap warranty (£600 -£700 a year) but does cover wear and tear items after the first 3 months as well. But looking at it, its now paid out over £1k to me for the work I've had done so far and they are very helpfull.

Well it would seem that you have found the problem. Ignore for the minute, the scaremongers crying "porous block" and "head gasket". My opinion is all you need to do is to ensure you bleed correctly after topping up. It is all to easy to get an air lock which will produce the symptoms you have. Do a search on bleeding to get the correct method, or look it up in the Rave. The small pipe from the top of the rad to the expansion bottle is crucial in the process.