Optimax 150 2004

[molo_30]

Hi guys,

I need some ideas. My optimax 150 is getting a low water pressure alarm which in turns cuts in the guardian system. I have replaced the impellor and housing and there is heaps of pressure out the tell tale.

The sensor is reading 0 psi at idle and the mechanic did not try it a higher rpm. My thoughts are that the block water pressure sensor part # 8M0059531 is to blame as I removed the little grey water hose that feeds the sensor and a continuous stream of water is coming out.

Do you think it is the sensor that has failed and if so does anyone have a parts diagram that actually shows the part number?

Can this sensor be bypassed as the telltale is a pretty good indication of block water pressure?

 

[Chris1956]

Re: Optimax 150 2004

You might check the poppit valve and thermostats. The thermostats would not normally cause a 0 PSI reading, but it never hurts to see if they are stuck open. The poppit would cause low water pressure at idle and up to 2000RPM, if stuck open.

Why not check the water pressure with a known working gauge? I had my dashboard water pressure gauge freeze and the guts cracked. One also corroded (solid brass), so the needle would not move. A telltale can be an indicator of good waterpressure, but remember those motors only have a few PSI at idle, when they are working right.

 

[molo_30]

Re: Optimax 150 2004

You might check the poppit valve and thermostats. The thermostats would not normally cause a 0 PSI reading, but it never hurts to see if they are stuck open. The poppit would cause low water pressure at idle and up to 2000RPM, if stuck open.

Why not check the water pressure with a known working gauge? I had my dashboard water pressure gauge freeze and the guts cracked. One also corroded (solid brass), so the needle would not move. A telltale can be an indicator of good waterpressure, but remember those motors only have a few PSI at idle, when they are working right.

I think from memory it is only supposed to have 1-2psi at idle. I know the telltale is certainly pumping nicely. But I am more concerned with the alarm and guardian system kicking every time I try to get on the plane. Can this sensor be bypassed or will it need to be replaced? Any ideas as to a parts list for it?

 

[Faztbullet]

Re: Optimax 150 2004

Check the strainer that's screwed into adapter plate, its on the port side and attaches to fuel rail.

 

[molo_30]

Re: Optimax 150 2004

Check the strainer that's screwed into adapter plate, its on the port side and attaches to fuel rail.

Hi guys,

finally changed the pressure sensor, poppet valve and water pump. Cleaned the strainer and am still reading 0 psi at idle.

Any more ideas?

 

[tomibach]

Re: Optimax 150 2004

Hi guys,

finally changed the pressure sensor, poppet valve and water pump. Cleaned the strainer and am still reading 0 psi at idle.

Any more ideas?

The gauge?

 

[molo_30]

Re: Optimax 150 2004

The gauge?

Ok, just a follow up on this. Good news, it was a simple fix once taken to the dealer. The plug that fits into the water pressure sensor had a faulty wire. Problem was it was inside the actual plug fitting so could not be seen. Maybe I should have done continuity testing of the wiring but wasn't to sure how to do it. Opti now has excellent pressure at idle.

Thanks everyone who offered opinions. Thats what makes the site a wealth of info.