PCM GT-40 owners

[nor_cal_01super]

New user hoping I have finally found a site that actualyl is knowledgeable enough to help we out here with some soild input.
General questions for you all as this is the first year (out of 3) that I have had any motor probs and it is getting annoying!
Check engine light came on at the end of last year in the middle of a session at the end of a long day of riding. After 3 attempts with a mechanic over winter and a diagnostic tool it ended up being a oil pressure switch. I hear this is common for our motor, have you had to change yours yet?
So that was a long drawn process but in the end I was happy as had my boat back. Now recently similar "limp Mode" issues have bene happening in the middle of a session, check engine light pops on motor cuts back to 2500 rpms, I let off, get back in neutral, light goes off and I can take off again no probs. I am not stoaked on that by any means but since it goes away I just deal with it. If you have had this prob and have a suggestion for solution please post.
Now on my last run my temp gauge was dead, does not move a mm, have any of you had any of these issues, I only have 120hrs on an 01 GT-40 and feel that i am having alot of small things happen and want to know if anyone else with this motor has some pointers and some proactive ways to keep this motor charging strong as it is the most BADA$$ ride out there!!!

[Johnsongc]

RE: PCM GT-40 owners

There has been some recent posts, including the one I started for a friend of mine whom is having the same "limp mode" problem as you on his '99 SN w/ the GT-40. We will probably change both the temp sensor and oil pressure sensor this weekend and will keep you posted.

On another note - I have a '01 SN and have had intermitent engine temp gauge problems that just recently became a permanant failure just as yours. I am picking up a new gauge on Sat and will install to see if thats the problem. Otherwise I might be replaceing two temp sensors this weekend. I will keep you posted as to progress and potential solutions.

Good luck!!

Greg

[nor_cal_01super]

RE: PCM GT-40 owners

Thanks for the reply Greg. Have your gauges being dead effected the motor from performing at full potential, or are they causing it to go into limp mode?

[NautiqueJeff]

RE: PCM GT-40 owners

You guys are on the right track. Only two things will cause that light to come on - temperature and oil pressure.

[Johnsongc]

RE: PCM GT-40 owners

I was writing about two different boats. My temp gauge is dead in my '01 SN, but boat performance is excellent. My buddy's '99 SN is being sent into "limp mode" just as is sounds like your is, but his gauges seem to be operating normally. We will be trying to fix this weekend. Where in Nor Cal are you? My buddy is actually my neighbor out here in Discovery Bay.

Greg

[DavidF]

RE: PCM GT-40 owners

Keep in mind that the temperature gauge is controlled by the temperature sending unit. The temp sending unit does NOT control limp mode. Limp mode is controlled by the coolant temperature switch (and the oil pressure switch).

To check for a faulty coolant temperature switch, simply disconnect the wires from the switch. If the limp mode problems goes away or does not resurface, then you have found the problem.

[Johnsongc]

RE: PCM GT-40 owners

David,

Thank you for the heads up. Do you happen to know where the coolant temp switch is?

Best,

Greg

[nor_cal_01super]

RE: PCM GT-40 owners

I live out in Lincoln. I have never checked out Discovery bay but here alot of good things about that area.
We are heading out to Oroville this weekend (my fav Nor Cal Spot) for a houseboat trip.
I did another run last night and even though (as mentioned aboveby Dave and Jeff) my temp gauge does not register anything my check engine lights stayed off.
I will prob have to run it this way the rest of the year and will get it all dialed back in over winter when I am not spending $300/mnth in gas on Big Red!!!

[DavidF]

Re: RE: PCM GT-40 owners

David,

Thank you for the heads up. Do you happen to know where the coolant temp switch is?

You know, I cannot recall which is which. But, you should be able to locate the switch as it will have the same color wire as the oil pressure switch. The CT switch is wired in series with the oil pressure switch.

[lukeduke95]

RE: Re: RE: PCM GT-40 owners

Are you sure if you disconnect it it will go away? I know the higher the voltage that passes through it is what causes it to go off, but if there is no signal, it is still fine??

[BobbyGagnon]

RE: Re: RE: PCM GT-40 owners

I have the same annoying/prolonged problem with my 98 Sport. The guys at this site told me if my temp is above 170, check my engine cooling line. I changed out my impeller and all the bladed have been broken except one, i went ahead and checked my thermostat, it was pretty rusty and just $10. I found all of my broken impellers inside the thermostat housing clogged up in the metal part of the housing where the raw water house connects. I haven't yet run the boat to see if this is the fix.

[Johnsongc]

RE: Re: RE: PCM GT-40 owners

On the '99 Ski with the limp mode problem - we disconnected the temp sensor (the one on top of the main water pump) and the problem went away. We ordered a new sensor, but will also be changing the impeller (due to the fact that I just found out that he has never changed it) and probably the thermostat as well. Thanks for everyone's help.

BTW- on my '01 Ski, I just put in a new engine temp gauge and all is well. i also swaped the crappy digital speedo and tach gauges with the faria analog replacements that run of the paddle wheel. I couldnt be more happy with them. It took about 4 hours but was well worth it. Probably could have done it faster if I was more technically inclined.

-Greg

[9797NUAT]

RE: Re: RE: PCM GT-40 owners

I have a 97 gt-40 and the same problem when i first got it it turned out to be the oil pressure switch got a free one from the dealer and never had problem since.
The oil sending unit and pressure switch are are on the right side lower front corner of the block, And the temp stuff is on the top left side. The pressure and temp switches are the smaller of them also be carefull when changing the the brass fittings are very fragle as i found out the hard way. but napa had some new ones and i was back in business hope this help

Rick

[9797NUAT]

RE: Re: RE: PCM GT-40 owners

sorry those position were looking at it from the front side of the motor Yellow_Flash_Colorz:

[nor_cal_01super]

RE: Re: RE: PCM GT-40 owners

SWeet, i was going to ask people if they have swapped to those Faria style units. How much was the temp gauge? I have been quoted $150 for the Faria gauges, and 4 hrs labor. Look slike you have been through the fun parts on the same boat I ahve so I will prob just score them this fall and hit you up if and when I get stuck. Anything in particular hold you up on the install?
ALso was that Temp gauge pretty simple?