Oil Pressure alarm in 2001 Z275ST with 6.2L
 

Hello! Just bought this boat and after a short 15 minute run and then a short idle back, the oil pressure alarm went off and the oil pressure gauge showed almost 0. I pulled the dipsitck(which is obnoxiously long) out and the oil is very clean and full. No burning smell and no knocking sounds. Any ideas? Thanks in advance.

Chris

2001 Mariah Z275ST Center Cabin
6.2L Bravo III duo prop

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

Could very well be the outdrive oil, not the engine oil. This is the next check, there is a reservoir for this near the transom somewhere near the rear of the engine compartment.

Someone correct me if I am wrong but this alarm is just as critical from what I understand.

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

Actually, this is what the original owner told me and I didn't believe him! I might sound stupid right now, but doesn't the oil pressure gauge measure the oil pressure in the engine block?

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

Someone much more educated than me should answer this, although what you said is true, there is still a low fluid level alarm for the drive fluid. I do not know if they are linked or separate completely, but they both exist.

If the previous owner alerted you to it, that may be a significant indicator to the fact that it had been low before and he refilled the fluid and the alarm went away???? I would definitely look into the drive fluid system and make sure it is all just right, there may be a loss of fluid from something not yet identified. First thing though is to fill and see if no alarm.

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

the oil pressure uses a sending unit on the motor and the oil pressure gauge. Before I got too worried I would try a manual oil pressure gauge on the motor. I'm not sure but a lot of low pressure alarms are based off the reading on the guage if the guage isn't being sent the right signal it will set off the alarm.

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

bought my z203 this past fall. first time out the oil alarm went off. found that the resi back of the motor just below minimum level. changed fluids and never came back.

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

The engine alarm can go off for any of the three systems it is linked to. Low engine oil pressure, engine overheating, or low oil level in the drive oil reservoir. Each has its own sending unit. These sensors can go bad, and give a false alarm. You need to find out which sensor is triggering the alarm, and if there is a legitimate reason for the alarm, or if it is just a defective sensor.

Check the drive oil reservoir first. If the oil is low, add some to the full mark. Next check the engine oil level on the dipstick. If your oil pressure gauge in the dash was indeed showing "zero" when the alarm went off, you have good reason for concern! You need to have the gauge and the oil pressure "gauge sensor" checked as well. [Yes, that is another sensor] It is quite possible you have more than one defective sensor.

When you are running the boat at cruising speed, what does the oil pressure gauge in the dash read?

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

My alarm would stay on, (so much that the previous owner disconnected the piezo!) When I found this out and reconnected it, and noticed the annoyance of the alarm beeping every 2-3 seconds, it turns out the drive lube reservoir sensor had gone bad. It's sold as one part with the reservoir, and it was about $46 at the Merc Service facility. Unfortunately I ended up paying over $450 in service and diagnostic costs to finally get it fixed. :eek_animated:

There's only 3 things on the alarm circuit, and all the sensors are easy to locate, they're the only tan wires with a blue line on them. Let us know what you find out!

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

Chris -

You are correct about the oil pressure gauge on the dash - that measures the engine oil pressure and has nothing to do with the drive lube. I would figure that one out before I cranked the engine again. It is very possibly nothing more than a sensor or shorted wire but I wouldn't ignore it.

Three things will sound the alarm on your engine - low drive lube, low engine oil pressure or high engine temperature.

Re: Oil Pressure alarm in 2001 Z275ST with 6.2L
 

Thanks for all the replies! I haven't been to the boat since last Sat. I am hoping to haul her home this weekend and then I can really take a look at the sensors and report back what I find. What test would you do on the sensors? Just a straight resistance check? Or watch for fluctuating voltage?