V8 cooling heating????

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scarr

scarr

New Member
Posts
25
2000 V8 Discovery 2 NO LPG
I’m having problems getting my heater to constantly blow hot air whilst the engine is ticking over. Blows nice and hot when engine is revved but within 30seconds of dropping down to tick over heater starts blowing cold no matter what setting the climate control is on!
This started about 2 month ago along with coolant loss and white smoke from exhaust, HEAD GASKETS I hear you all shout. And you’d be right but
I had both done last week and both heads reconditioned, including composite head set, pressure test, skim, and valves re-ground, new valve stem oil seals and new head bolts. Full oil flush, and cooling system flush new oil and filter new coolant, all is fine stopped losing coolant no more smoke
I was getting a gurgling noise from heater matrix so bleed system as per Rave CD to the letter TWICE the gurgling has stopped so I think I have got all the air out, but still cannot get constant hot air.
PLEASE help am I missing something?
 
Thanks for the input.
Water does seem to be circulating ok I disconnected a heater pipe with the engine running and the flow looked good, and as the engine heats up the pressure builds nicely top hose get hot and hard?
The pump doesn’t look that old (I’ve owned the car 8 month) but will probably change that along with thermostat this weekend
Cheers
 
There is an air bleed pipe from the right hand top of the radiator to the header tank. It enters the coolant in the header by a very fine stainless steel needle with a hole in it.

Its sole purpose appears to be to take out air in the top of the header tank that accumulates above the top hose level.

Check that the needle hasn't become clogged up, it took a 100 psi airline to blow mine out, previous owner had used a stopleak capsule.

Peter
 
Quick update
Seen as the water pump looks relatively new I changed just the thermostat this morning (cheapest option first). However this hasn’t made any difference the heater still blows cold when engine is ticking over! So my next question is

Is it possible for the water pump to be weak, so that when not under load it doesn’t work well enough to circulate water fast enough or with enough pressure to the heater matrix but works well enough to stop the engine over heating? My train of thought with this is the heater matrix is the highest point the water goes so when the pump is only spinning in tick over the pressure isn’t as strong as when the engine is revved , hence the heater working fine once the engine is revved. Could the impeller be slightly loose?

Also am I best going for an OEM water pump or are the pattern part copies on eBay any good?

I’ve been looking at 2, 1 states its OEM
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=390152656886&ssPageName=STRK:MEWAX:IT

The other is half the price
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=390035138767&ssPageName=STRK:MEWAX:IT
Or am I best just paying the stealer price

Cheers
 
Hi did the water-pump solve this?? I've just fitted a water-pump today and still have the same problem. I know its not the thermostat, so the only thing I can think is that the heater matrix needs flushing. Anybody have any other idea's???
 
smurphy said:
Hi did the water-pump solve this?? I've just fitted a water-pump today and still have the same problem. I know its not the thermostat, so the only thing I can think is that the heater matrix needs flushing. Anybody have any other idea's???
Click to expand...


Hi smurphy

NO, new genuine water pump and like you I still have the same problem?
I’ve also tried another new thermostat but still no change. I’m completely stuck, unless I have porous block problem which I doubt as I have never heard of a 4.0l with block problems then I don’t know what it is?
The complete cooling system is new, radiator, water pump, thermostat, and new head gaskets the only exception is the heater matrix which isn’t leaking or blocked
I’ve sent it for a sniff test, just in case the heads haven’t sealed properly, but will keep you updated if and when I get sorted
Cheers
 
scarr said:
Hi smurphy

NO, new genuine water pump and like you I still have the same problem?
I’ve also tried another new thermostat but still no change. I’m completely stuck, unless I have porous block problem which I doubt as I have never heard of a 4.0l with block problems then I don’t know what it is?
The complete cooling system is new, radiator, water pump, thermostat, and new head gaskets the only exception is the heater matrix which isn’t leaking or blocked
I’ve sent it for a sniff test, just in case the heads haven’t sealed properly, but will keep you updated if and when I get sorted
Cheers
Click to expand...

How do you know the matrix isn't blocked?
Also do you have loads of pressure in the hoses and when you take off the cap on the header tank?
I have a spare matrix so going to swap that I think
 
smurphy said:
How do you know the matrix isn't blocked?
Also do you have loads of pressure in the hoses and when you take off the cap on the header tank?
I have a spare matrix so going to swap that I think
Click to expand...

I’ve disconnected both the inlet and outlet to the heater matrix and connected to a garden hose and flushed in both directions and the flow is good and water coming out has no contaminants.
 
remind me-because I can't remember-do the hoses come off timing chest like 3.5 or not, the holes on those blocked occasionally with crud and corrosion if the antifreeze was shagged. sounds like a restriction type issue, what about water control valve to matrix as the coolant is less pressure than hose pipe.
 
fanatic said:
remind me-because I can't remember-do the hoses come off timing chest like 3.5 or not, the holes on those blocked occasionally with crud and corrosion if the antifreeze was shagged. sounds like a restriction type issue, what about water control valve to matrix as the coolant is less pressure than hose pipe.
Click to expand...

I have LPG fitted so I know that it s flowing round just not though the heater matrix unless I'm moving or hold the revs up to 2000rpm.
The thermostat is new, now I've removed a good water pump n fitted a new one , so there's only one thing left really.
 
Last edited:
You could be right that block is porous, but if you have lpg conversion is it possible a flow restrictor is not fitted to balance flow.
Bear in mind I have not seen your setup
 
fanatic said:
remind me-because I can't remember-do the hoses come off timing chest like 3.5 or not, the holes on those blocked occasionally with crud and corrosion if the antifreeze was shagged. sounds like a restriction type issue, what about water control valve to matrix as the coolant is less pressure than hose pipe.
Click to expand...

The inlet hose for the matrix comes from the inlet manifold, and I’m pretty sure there is no restriction anywhere in the system, it’s been flushed it really well in every direction including being run with Wynn’s coolant system flush in
From what I know and have found out the 4.0L doesn’t have a control valve to the matrix it runs hot all the time?
The heater does blow hot when the engine is under load but not on tick over
I’m beginning to think the heads gaskets still have a problem, or the block is porous but the guy that did the heads (local independent) said he’s sure the block is good, it’s back with him now and he’s doing a hydro test at this morning,
I’m hoping he’s right and the block is good then that means it must be the heads then it’s his problem to sort as I paid him just shy of £900 to fix them less than 2 weeks ago!
 
Last edited:
scarr said:
I’m completely stuck, unless I have porous block problem which I doubt as I have never heard of a 4.0l with block problems then I don’t know what it is?



The complete cooling system is new, radiator, water pump, thermostat, and new head gaskets the only exception is the heater matrix which isn’t leaking or blocked
I’ve sent it for a sniff test, just in case the heads haven’t sealed properly, but will keep you updated if and when I get sorted
Cheers
Click to expand...

well, you now have the pleasure of meeting your first 4.0 owner who has suffered a slipped liner. And I've met and spoken to somewhere in the region of 30-40 others who have had simular problems. 4.0, 4.5, or 5.0, it doesn't seem to make much differance once you get above 3.5 litres.

I had exactly the same issues as both of you chaps did. Changed everything except for head gaskets before stripping the motor down and realising all I had was a V8 shaped anchor.

Your best bet is proberbly to take it to someone who knows RV8s well and aint going to take your trousers down, like TVR Power or John Eales, but I aint including RPI in that list.


Good luck with it.
 
How many 3.9's get it? I wonder if the problems is the tooling for the v8's got older and more fooked as time went on rather than any change , as aparently the 3.9 and 4.0 are the same blocks??
 
fett said:
How many 3.9's get it? I wonder if the problems is the tooling for the v8's got older and more fooked as time went on rather than any change , as aparently the 3.9 and 4.0 are the same blocks??
Click to expand...


mine is the same, just got a longer stroke thats all'
now i wished i could find a girl to put that in writing. :D
 
Disco Moneypit said:
well, you now have the pleasure of meeting your first 4.0 owner who has suffered a slipped liner. And I've met and spoken to somewhere in the region of 30-40 others who have had simular problems. 4.0, 4.5, or 5.0, it doesn't seem to make much differance once you get above 3.5 litres.

I had exactly the same issues as both of you chaps did. Changed everything except for head gaskets before stripping the motor down and realising all I had was a V8 shaped anchor.

Your best bet is proberbly to take it to someone who knows RV8s well and aint going to take your trousers down, like TVR Power or John Eales, but I aint including RPI in that list.


Good luck with it.
Click to expand...

What with no coolant loss, no over-heating, no over pressurising in coolant system, no sings of water in the oil and no excess steam from the exhaust???
 
Disco Moneypit said:
well, you now have the pleasure of meeting your first 4.0 owner who has suffered a slipped liner. And I've met and spoken to somewhere in the region of 30-40 others who have had simular problems. 4.0, 4.5, or 5.0, it doesn't seem to make much differance once you get above 3.5 litres.

I had exactly the same issues as both of you chaps did. Changed everything except for head gaskets before stripping the motor down and realising all I had was a V8 shaped anchor.

Your best bet is proberbly to take it to someone who knows RV8s well and aint going to take your trousers down, like TVR Power or John Eales, but I aint including RPI in that list.


Good luck with it.
Click to expand...



Thanks you’ve just made my day! I was starting to feel better and that it had to be a cheap fix gas there is nothing left to change!
However mines been stripped (well the heads have been off and the gaskets done) and I’m assured from the local independent who did them that the liners haven’t slipped, he’s ex land rover main dealer with 20 years experiences so I’d would hope he knows his way around a rover V8 but I’m still living in hope that when he did the heads he’s not sealed them properly. It’s back with him at the moment and he assures me he will put it right. Let’s hope with it costing me anymore of my hard earned

Cheers
 
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