Two Engines - Two Different Problems

[perkie43]

We just purchased a Manta 42 - year 2000 with Volvo Penta MD2030 three cylinders. Both engines have starting issues, but different.

Port engine -
The previous owner replaced the port engine starter due to faulty relay switch and burning up the starter prior to delivery. We have only been able to start this engine twice - after cleaning the battery terminals (nasty) and replacing the relays; the relay showed signs of high heat. As I was engaging the glow plugs, I didn't observe the glow plug display at the helm. The oil light illuminated, the audible alarm came on and I allowed the plugs to warm, assuming they were powered up.

The engine did start and we motored for several hours. Observation of the glow plug display at the helm while running showed long and/or short intermittent on/off. The next weekend we have been unable to start this engine, it exhibits the same exact symptoms as before cleaning the battery and replacing the relay - slow cranking, unable to catch and unable to start. I have not inspected the relays again, but would believe if the system is burning through relays, the cause lies elsewhere.

Starboard engine --
Started the very first time. I let the engine idle for 10-15 mins, then turned it off. Immediately tried to restart, but all I heard was a loud clicking sound. I tried rotating the battery switch around 360 several times and then the engine did start. Have experienced the same thing the second weekend.

Also noticed that the helm glow plug display didn't illuminate. And that the tachometer varied 500rpm (+/-) while the engine was idling at dock, but didn't notice the change in engine speed sound.

We want to take her out for our maiden sail with us, but don't want to leave the dock until we have rectified these problems and have two reliable engines.

Many thanks in advance,
S/V Galileo

[Unicorn Dreams]

Welcome Aboard

[noelex 77]

Welcome to the forum.
I think you probably just have a poor contact somewhere. The good news is that’s cheap to fix.
Measure the voltage at the engine when starting. This will confirm the diagnosis and show an improvement when you have fixed the problem.
If you know how to use a multimeter measure the voltage drop (measure the voltage drop with the glow plugs on this provides enough current, and saves cranking the engine) at each connecter and this will tell you where the problem lies.
As an alternative heat is always a bit of giveaway. Crank the engines and feel all the contacts such as the battery switch. The high resistance one will get warm
Or just clean all the contacts (negative and positive) in the starting circuit.

[colemj]

It sounds like bad power - either bad batteries or bad connections. Make sure to clean the engine ground and make sure it has good contact to the starter/engine block.

The glow plug light shouldn't be on while the engine is running. Are you sure it wasn't the alternator charging light? The tach is controlled by the alternator and if the alt or regulator was failing you would have a squirrelly tach, a red light on the panel and a low battery (without other charging sources).

When you rotate the battery switch on the starboard side, it parallels the house bank to the engine. This is also evidence of bad power.

Which Manta did you buy?

Mark

[perkie43]

Thanks for the responses and welcomes. Very much appreciated and will begin troubleshooting the next time we're there.

Any follow up information/education will be welcome too.

Manta 42 hull #66

S/V Galileo

[perkie43]

Both starting batteries have been removed, thoroughly cleaned, volt meter checked and reinstalled with fresh terminal grease. New relay switches have been installed as well. Both port and starboard engines will start, but unreliably. Last weekend I started each engine a dozen or so times over the day, letting them run for 10 minutes or more each time before shutting them down. The last attempts that afternoon were unsuccessful and I waited until the next morning to try again.


The starboard engine starts more reliably than the port. When it does not start, a loud clicking sound from the starter motor is observed with very slow rotation of the pulleys and belt. I waited until the next morning and it started fine. I restarted it several times and then the starter clicked and it would not start the rest of the day.


The port engine started without hesitation after the battery reinstall. Restarting throughout the day was fine, until late afternoon when it cranked but would not fire. When the port engine does start, a fair volume of smoke is emitted from the exhaust.


While my wife turned the key to the glow plug position, I listened for the relay switches in the engine rooms and tested the glow plug bus for voltage. All seemed fine.

Observations at the helm –


The starboard “dummy” lights and tach seem to be in error. After turning the key to warm up the glow plugs, the tach goes to 4K and then back to 0, which I think is fine. But then it quickly decreases to 2K and oscillates between 4K and 2K – the engine is in glow plug mode at this point. The glow plug lamp does not illuminate (I checked voltages on the glow plug bus on the engine and they are receiving power), then the oil lamp comes on with the audible alarm. The helm instruments go through this routine whether the engine starts or not. If the engine starts, the tach settles on 850rpm after a minute or so of running.


The port glow plug “dummy light” lamp does not illuminate either, except once the engine has started and then it remains illuminated until shutting the engine down. The tach is unstable the entire time the engine is running, yet the sound of the engine is stable.

Each engine compartment has a HEHR Power System box. The starboard unit flashes a green LED on/off every second with a low volume audible alarm. The port unit is not illuminated except when the glow plugs are on. No audible alarm is noted.


We want to go sailing, but not until we determine the source of these problems and have reliable engines. Any assistance is very much appreciated.


S/V Galileo

[itdave5]

The load clicking sound is the bendix which is thrown out when you turn the ignition key to the start position. you should be able to adjust it.
Have you stripped and cleaned both starters?
The one that makes the clicking sound can be checked quite easily (if you feel brave enough) by taking it off the engine and then earthing the business end to the engine block and holding on to it very firmly and then getting some one to crank it over. if the bendix throws out and spins easily it's a wiring fault. Check the cables being used are big enough to carry the amps required to run the starter.
If the bendix does not throw out or throws out then stays out and clicks like before you need to clean it and the solenoid and possibly adjust it as well.
I had to do this with mine, it's a dirty job but well worth the effort when your engine starts on the button.
Good luck. Dave.