vectra lpg coolant problem

Hi there, can anybody give me a bit of advice? I have a Prins VSI system

fitted to my Vauxhall Vectra and i have been having a lot of problems
recently. It started about 2 months ago, i could run on gas but only
for
about 10 mins then it would switch back over to petrol on its own
giving
me a loud beeping sound from the switch. I thought this might be a
coolant problem because the reducer never felt that hot and i thought

this might be why it was switching back over to petrol. I flushed out
the system and replaced the coolant thinking this might solve the
problem. Now i have noticed that when it it running on petrol,
everything runs smooth and the coolant level stays pretty constant, with

the bonnet up, i switch it to LPG, give it 10 seconds, the coolant
level
rises rapidly in the expansion tank and starts to spurt out everywhere

even when the lid is screwed on! I have run the engine with the cap off

the expansion tank and the heater on full to get rid of any air locks
in
the system but this hasn`t made any difference at all. Do i need a new

Vaporiser? If so, what kind of price and does it have to be prins or
will another fit my system?
Sorry for the long essay but i wanted to get as much detail in as poss
in the hope i will find a solution quick, costing me a fortune running
on petrol!! Is it a DIY job to replace or will it need to go in to a
garage?


Thanks in advance, John

 

It would be nice to know just what engine you are talking about. I've heard
that the V6's dont always take too kindly to gas, but I've never had
experience
of them on gas to say, just gossip.

Whats your temperature gauge reading while all this is going on?

LPG-i.e. propane-burns a bit hotter than petrol does. Best guess is that you
have a head gasket on the point of failure, and the extra heat of gas is
just tipping it over the edge.

If its an old(er) car and you feel confident enough to try, have a go at
giving the head bolts an extra 'nip'. No more than 45 degrees, or 1/8th of a
turn. Make sure you observe a correct sequence on all the bolts and if
possible run the engine warm then try it (as the head bolts would have
expanded with the heat).

Thats the best I can come up with.

Mike