engine temp gauge troubleshooting

good morning everyone. I have a 97 rinker 182 with 4.3 merc alpha 1. I have only had it now for about two months. It has a new motor with about 12 hours on it. everything works and runs well. I am only having two small snags to dig into that i am looking for some trouble shooting tips on.

1. My temp gauge dosnt work. it dosnt do anything. just sits all the way to the left. Is there a way to test to see if its the guage or the sensors?

2. Tach works, but after running abit or stopping and restarting it shows a higher rpm then the engine is actualy doing. sometimes it gets stuck at 3000 while idling shows maxed out when you give it some gas and may return to normal in a minute or two. i am guessing bad tach but i would like to trouble shoot to make sure first.

3. if i have to replace these gauges where can i find them?

thanks robert.

p.s. dont go full roller rockers. push rod went through the rocker. converted back to stock rockers at dealer for $.

Re: engine temp gauge troubleshooting

Ayuh,... #1, ground out the sender wire at the t-stat housing, the gauge should go to Full Hot...

#2,... It's junk, replace it...

#3,... Right here at iboats megamall of course...

Re: engine temp gauge troubleshooting

Your temp gauge could be as simple as someone used a standard automotive gasket on the thermostat housing instead of the special Merc one. The Merc one has a couple of brass eyelets in it for grounding. Yes, I know the housing bolts SHOULD ground it, but they don't, just put the Merc gaskets on....

Tachometer.... Check all the grounds on the instrument panel are clean and tight... Check the coil is grounded properly.

If there's still a problem, revert to Bond-o's advice....

Chris........

Re: engine temp gauge troubleshooting

Check out the main engine harness connector. When troubleshooting my temp gauge, I found out it is pretty much junk. Somebody previous actually cut the rubber closer to the metal connectors to try and get it a better connection. I have to torque it around to get good connections on everything. It'll be replaced this winter.

Like was already said, ground the sensor wire at the engine and see what happens. If nothing, then you have a gauge/wiring issue. Ground the sensor wire at the gauge - if nothing happens then, it's the gauge. If it pegs hot, then it's a wiring issue.

Re: engine temp gauge troubleshooting

Struc said:

Check out the main engine harness connector. When troubleshooting my temp gauge, I found out it is pretty much junk. Somebody previous actually cut the rubber closer to the metal connectors to try and get it a better connection. I have to torque it around to get good connections on everything. It'll be replaced this winter.

Like was already said, ground the sensor wire at the engine and see what happens. If nothing, then you have a gauge/wiring issue. Ground the sensor wire at the gauge - if nothing happens then, it's the gauge. If it pegs hot, then it's a wiring issue.

Click to expand...

If it pegs hot when grounding the wire at the sender, then the sender is kaput or the thermostst housing isn't grounded or someone put teflon tape on the sender threads when installing and insulated them.. If it stays at cold, then gauge / wiring / (grounding wire that goes to the sender, at the gauge, will tell you if it's at the gauge or after it).

Re: engine temp gauge troubleshooting

Does anyone have a diagram of the thermostat housing here. There is a single screwed in sensor with just a one wire to it on each side. The colors bolth appear tan in color.

Re: engine temp gauge troubleshooting

That is the audio warning sensor! The other side is analog temp sender. Replace the gauge!