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[tigers_gonads]

Ok, after lots of buggering about, the car is running on LPG and running very nicely   

But true to form, the car has developed a weird noise while accelerating.
It seems to be coming from the drivers side of the engine bay.
You can also feel a vibration threw the accelerator peddle.

The only way I can describe it is it sounds like a power steering  pump which is low on fluid.

Should add that the LPG reducer is bolted to the inside of the wing on that side.

Reducer gas pressure is a tad low (1 bar) but the car revs to 6000 rpm plus with no errors recorded or hesitation 

Any ideas please 

[allen25]

I don't have the answer but have been thinking about what you've said. Is the noise specific to LPG or happening on both fuels?

[tigers_gonads]

Good point Allen 

Its happening when running on gas only I believe.
Running on petrol vapours at the moment so not in a position to compare when hot until later.
Also the hotter the coolant, the nosier is seems to get.
Only happens when the engine is under load and the noise seems to disappear above approx. 4000 rpm.

[05omegav6]

Is everything tightened up as it should be? When was the cambelt/waterpump last changed... bit of play somewhere

Does it happen at the same engine speed in each gear, or is it related to road speed?

[tigers_gonads]

Is everything tightened up as it should be? When was the cambelt/waterpump last changed... bit of play somewhere

Does it happen at the same engine speed in each gear, or is it related to road speed?

Everything seems nice and tight.
With me being a ham fisted barsteward, things are liable to be over tight
Cambelt / waterpump should have another 15K / 18 months left (if the service documents are to be believed)
The car was bought as spares or repair as a project for me to tinker with.

Noise seems to engine load related.  In other words, the harder I stamp on the gas peddle, the nosier it is until around 4K revs when it disappears

[Entwood]

It's not the regulator vibrating is it ?? As there's a diaphragm inside it's a possibility .... ?

[tigers_gonads]

It's not the regulator vibrating is it ?? As there's a diaphragm inside it's a possibility .... ?

With the gas pressure a little low 
mmmmmm
Could be.
With the vibration being transmitted threw the inner wing and peddle box 
i'll get my hand on it and  if I can feel anything later when it stops raining 

Also, the plenum has been off / throttle body's water pipes have been off a fair few times over the last week.
I'm wondering if I've a little bit of air in the reducer 
Thanks 

[05omegav6]

It's not the regulator vibrating is it ?? As there's a diaphragm inside it's a possibility .... ?

With the gas pressure a little low 
mmmmmm
Could be.
With the vibration being transmitted threw the inner wing and peddle box 
i'll get my hand on it and  if I can feel anything later when it stops raining 

Also, the plenum has been off / throttle body's water pipes have been off a fair few times over the last week.
I'm wondering if I've a little bit of air in the reducer 
Thanks 

Try running it for a while with the cap off the coolant bottle and the cabin temp set to Hi on both sides. Should make sure there's no air in the system, just to rule it out

[tigers_gonads]

It's not the regulator vibrating is it ?? As there's a diaphragm inside it's a possibility .... ?

With the gas pressure a little low 
mmmmmm
Could be.
With the vibration being transmitted threw the inner wing and peddle box 
i'll get my hand on it and  if I can feel anything later when it stops raining 

Also, the plenum has been off / throttle body's water pipes have been off a fair few times over the last week.
I'm wondering if I've a little bit of air in the reducer 
Thanks 

Try running it for a while with the cap off the coolant bottle and the cabin temp set to Hi on both sides. Should make sure there's no air in the system, just to rule it out

Will do 

[Entwood]

It's not the regulator vibrating is it ?? As there's a diaphragm inside it's a possibility .... ?

With the gas pressure a little low 
mmmmmm
Could be.
With the vibration being transmitted threw the inner wing and peddle box 
i'll get my hand on it and  if I can feel anything later when it stops raining 

Also, the plenum has been off / throttle body's water pipes have been off a fair few times over the last week.
I'm wondering if I've a little bit of air in the reducer 
Thanks 

Try running it for a while with the cap off the coolant bottle and the cabin temp set to Hi on both sides. Should make sure there's no air in the system, just to rule it out

Will do 

A few hard squeezes on the large hose whilst doing that might help as well .. it tends to shift any airlocks or stubborn bubbles

[tigers_gonads]

Right, now confirmed it the reducer that's squealing 
Engine is smoother then a babies bottom when running on petrol.
Also i've got a faint smell of gas but that may be a pipe 
System well and truly burped so pretty sure there is no air in there.
The reducer is a KME Gold.
Has anybody on here had any problems with theirs ?
Squealing or other wonderful noises ?

I've also had a good sniff of the coolant bottle.
I can't smell any trace of gas so I presume its not leaking gas into the coolant.


Edit to say ................ it only happens when its warmed threw

[Andy H]

How rigid is the support of the vapouriser? If it is a bit springy it might be resonating. I would try providing a more rigid support. If that doesn't work, rubber mounting the vapouriser to isolate the vibration from the car body.