Range Rover P38 4.6 - Overheating on LPG

Hi there. Hope someone can help me with my overheating questions. I have read the other posts on this popular topic, but cannot find anything relating specifically to a 4.6 RR with multipoint LPG, which has my symptoms.

Basically, the temp needle on my 1997 rangie seems to sit right in the middle when running on petrol. Drove 200 miles with this when i collected it the other week. However, when I switch on the LPG, the temp rises quite quickly until it is almost in the red. I do know that LPG makes the engine run slightly hotter, but I wouldn't have thought that is would overheat on LPG but not overheat on petrol. When you change back to petrol, the engine cools back down to half way within a minute or so.

Also, I noticed that when ticking over at a standstill for 10 mins (running on petrol), the temp also rises to just under the red. Cools down again when driving.

Lastly, there does appear to be some pressure in the top rad hose (much harder to squeeze than when cold). Hope this isn't cead gasket etc??

Any thoughts would be welcomed.

Thanks and regards.

p.s. haven't yet had chance to try the obvious, i.e. flushing and cleaning the rad etc

hello mate re your overheating problems forget trying to clean out or flush the radiator , its a waste of time ..............stick a new one on it ,
rick.

Hi there. Thanks for the tip. Will try that if all else fails.

Hi there,
I always understood that LPG gave a cooler engine! Anyway if it is OK on petrol and not on LPG you have a problem with the LPG. I run a 4HSE on gas and my temperature needle sits halfway (even when towing). On the odd occassion I have run on petrol I saw no real change. Hope this helps.
Ian

Foxxy said:

Hi there,
I always understood that LPG gave a cooler engine!

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nope - LPG always makes an engine run hotter.

I run a 4.6 with multi-point LPG and have never seen any change on the temp gauge which ever fuel I run on. I assume the stat opens a bit further to compensate for the higher temps generated. I would think there is a more underlying problem than the type of fuel.

Nigel

Dorset VogueSE said:

I run a 4.6 with multi-point LPG and have never seen any change on the temp gauge which ever fuel I run on. I assume the stat opens a bit further to compensate for the higher temps generated.

Nigel

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ditto, i too have a r/r 4.6 hse on gas (1996) with multi point gas injection and have never noticed the temp gauge to be any higher, dont bother changing the rad, if its not over heating in petrol then it shouldnt on gas, it may well run hotter on gas but the temp difference is minimull and probably not noticable on the standard temp gauge anyway.
my thoughts are to it running too lean (weak) on gas and therefore running hot! get it checked out by a reputable gas installer (not corgi ) to see if it is the case!!
i think theres some sort of ecu for the gas, maybe this could be playing up as well, first things first get it looked at by a decent gas guy! oh and reset the plugs to .7mm the gap for petrol is too big for gas.

Thanks for the advice folks. Yes, I did read somewhere that if the LPG mix isn't properly set up that is can make it run too hot. So I'll take it to a specialist to get it looked at. Thanks once again. These forums are great!!