Prowler26

Need some help. I have a 2000 Sonic Prowler with 2000 454 Mag MPI. Before Labor day I began having problems with a miss. I went ahead and replaced the plugs and everything ran fine. Then the same day my oil psi was alarming after I came down from a run. Talked with numerous people from around the annapolis region and all said change to a 40 weight motor oil and replace sensor which I did. The motor continued to alarm. The motor has 427hrs on it with 50 of them coming this year in salt water. I have also noticed the starboard stock exhaust manifold steaming up which tells me their is a restriction somewhere. My question to the ones that can help, Is the motor just tired and need to be upgraded? Has anybody had a problem with the alarm before?

I have never had a problem with the boat and flushed after every run and have done all services. If I need to refresh the motor I have a couple of options:

A: Replace the motor with a Rebuilt 454 Mag MPI fresh water cooled

B: Replace the motor with 496 Mag rebuilt with 100 hrs on it

If I replace the motor should I remove the Corsa quick and quiet? Which of these motors would be best replacement for my orig. Also does the wiring harness go with the 496?

Pwrbt33

iTrader: (2)

Its good you changed the engine oil. Did you happen to look at the oil and see if it was glittery or had metal in it? also did you install an oil filter? if so good. The sensor that you replaced, was it large or small? the alarm sensor is a small sensor. It should have a tan with a blue tracer wire going to it. Just curious as well, how do you know its oil pressure thats your problem? Did you or someone with a computer scan the engine? Could be a faulty drive bottle alarm. Even though the bottle is full it can be bad and setting an alarm. The easiest way is to unplug the alarm wires 1 at a time until the alarm goes away. Then you have your culpret.

Good Luck!!
John

Prowler26

John,

We did not change the oil filter. All fluids and filters were change at the start of the season. We had a synthetic blend in the motor and one the problems began we change to the current 40W. The oil was clean and saw no glitter. We replaced the lower large sensor on the port side of the engine. we did not change the alarm sensor. We did though check all connections for corrision and found nothing. We also checked the sweep of the gauge and found no issues. We did not check all other alarms that you mentioned. We also put a mechanical gauge on the motor and when we came down from a run it dropped to 14-15psi. The electric gauge showed a slight difference but nothing noticable. with the stock exhaust starting to steam and be noticably hotter then the port we thought that it was a refreshening issue. We are going to place after market exhaust on the winter but with the oil pressure issues it through a wrench in the mix. Thanks for your help.

George

Prowler26

John,

I'm also from Frederick, Md and do most my boating on the bay. Would you be interested in looking at the boat? I would rather look at it and see if its electrical before I spend 10k grand for a simple electrical issue. Also we never put it on a scanner. Thanks

George

PatriYacht

Was the water temp high after the run? Sometimes oil pressure drops after a run because it is hot. The steaming exhaust suggests that water flow through the engine may be low. 15 psi after a run is low but will not hurt your engine. Did the pressure come back up at all after idling for a few minutes? Don't run right out and get a new engine until you are certain something is wrong.

Prowler26

The water temp of the boat was about 160 to 180, never wnet higher or showed any signs of overheating. The oil pressure did return to about 20 on the guage and the alarm would stop once I bump the idle up or waited a few minutes. normally only took about 30sec to a minute to come back up but their were those few times were it didn't come up unless I increased the throttle.

ezstriper

try a good 20w50 conv oil and quality filter(not fram) and give that a try...not a uncommom problem...what OP do you see @ 3000 & 700 hot ? what temp are you running ?

pachanga

Perhaps your oil cooler is clogged or the oil line to it is kinked?

PatriYacht

Good point. It's not uncommon for the oil filter to fail internally and partially block the oil flow. Change it with a good oil filter (hint NAPA Gold is a Wix) to make sure.

jeffswav

If you got water in the oil, then continued to run it not knowing, you could have damaged the mains or rod berrings. I run 15psi at idle after a hard run, that is OK, 10psi or less is bad. What did the oil look like that you removed? Definatlly change the filter, I use Amsoil 40wt and Amsoil filters.