Isuzu Engine Alarm

[Jay Knoll]

Hi everyone

One bit of "excitement" that occurred on our last cruise was the moment that I looked down and saw that we didn't have any oil pressure! Considering that I had just worked with a mechanic replacing some leaky oil lines that ran to the engines filter I was a bit surprised to say the least.

Opening up the hatch I saw that the lines were dry and pulling the dipstick I saw that there was plenty of oil in the engine. So I pressed on, with several stops along the way to check oil level.

I figured it was a bad sender but since I am not a great mechanic when we got to Fernandina Beach I was able to locate a mechanic that was willing to come to the boat on a Sunday! It turned out to be a bad connection, the sender was ok, but during the testing process he noted that he didn't hear an alarm when we started up the engine. Then I recalled that I had never seen the warning light illuminate since I owned the boat. Duh! Nothing

He tried to order a warning kit from Port Supply, it didn't arrive at the promised time and when he checked with them they said there had been a recall. We continued on with our cruise without incident other than the crook in my neck from checking the gauge every 30 seconds or so for the next 2 weeks. LOL

So I'm now getting ready to remedy the situation. I can't find anything on the web regarding a recall so I don't know if the customer service person was blowing smoke. Does this product make sense or are there others I should consider?

http://www.jamestowndistributors.com/us ... ?pid=13312

Thanks for the guidance

Jay

[Beta Don]

It could be that you have no light or alarm because their senders were removed when someone added gauges to the instrument panel - It's not that easy to have both if the engine didn't come set up for both gauges and lights/alarms from the factory

It's a great idea, but may it be difficult to do since you already have the gauges . . . . unless you're willing to give up the gauges. They don't mention anything about the senders for this unit - Wonder if they come with it? For $27, I kinda doubt it

It would require (I think) an additional sender for low oil pressure and to keep your gauge, you would probably have to go with a Tee arrangement of some kind so you can use both senders. It would also have to use something I've never heard of before - A sender which recognizes both coolant too hot and coolant too cold. I guess you could forget about the too cold and just install a conventional 220 degree heat switch so you'll know when it's too hot. That would probably require another Tee arrangement so you can keep your temp gauge

I would inquire about the senders and how they intend for you to install it, since you already have gauges - I'm guessing this thing was designed for engines which have neither a traditional temp or oil gauge

I would also hazard a guess that your Isuzu engine block is threaded with BSP pipe threads (most all Japanese engines are) and most aftermarket senders and Tees come with US NPT threads, so ask about the availability of a sender with the correct threads for your engine. When adding two senders together with a Tee and then an adapter to go from BSP to NPT you may wind up with a fairly long, relatively heavy (with both senders out near the end) collection of soft brass pieces which will run the risk of breaking after years of heating/cooling and vibrations. If it ever did break, you'd have 5 quarts of oil in the bilge and none in the engine very quickly and that would always be in the back of my mind. A collection of senders and adapters to get everything installed in the one available port on the engine isn't the best way to go, IMO

If you decide to do this, I would suggest hunting up senders with BSP threads so all you would need is a BSP Tee (which will also be difficult to find) but then you'd have much less risk of a collection of brass pieces which might break

Also, there are 'dual senders' which have both a resistive element (for the gauge) and a low pressure switch (for the light or buzzer) together in the same sender, but finding one of those which would work with your current gauge (the resistive element would have to match your brand of gauge) AND be threaded for BSP threads might be difficult

One note of caution - A friend re-engined his Shannon sailboat with a new Yanmar diesel which came with the standard Yanmar 'A' panel - No temp or oil gauge, just lights and a buzzer. He told the yard doing the install that he wanted to add gauges too. No problem, they said. They knew nothing about the BSP threads on the new engine, cross-threaded a standard Tee into the block (for both senders) which promptly leaked oil and coolant. They tried re-threading the block with an NPT tap, but because of the impossibly tight working conditions, they broke off the tap in the engine block. This required removal of the engine to get the tap out and then rethreading the block for both senders which I am sure probably got some metal bits from the threading into the engine . . . . .

Be careful who does this job for you!!

Don

[Jay Knoll]

Thanks for the detailed explanation Don, the engine panel on my boat has both gauges and the warning light.

I thought that I could just add the wire leads for the alarm on top of those for each sender, thus having a "belt and suspenders" warning system -- gauges and audible alarm.

I can't find a wiring diagram anywhere so I don't know if this is possible or if the unit requires dedicated senders.

Guess I'll be contacting customer service departments tomorrow

Jay

[Beta Don]

. . . . the engine panel on my boat has both gauges and the warning light.

If it came that way, maybe you already have a dual sender for oil pressure and it could be as simple as a wire not connected somewhere or a defective sender switch. How many wires are there on the sender? If it's more than just one, it could be a dual sender

An eBay search for 'Isuzu 3 terminal sender' makes it look like dual senders for Isuzu engines are pretty common, so it could be what you need is already there - Maybe you need a new sender? Checking it with an ohmmeter both with the engine running and with it off should tell you if you have a working make or break switch on two of those terminals. A wiring diagram would be really helpful. Maybe someone else here with an Isuzu powered boat could help you out

Don

[WillieC]

" They knew nothing about the BSP threads on the new engine, cross-threaded a standard Tee into the block (for both senders) which promptly leaked oil and coolant. They tried re-threading the block with an NPT tap, but because of the impossibly tight working conditions, they broke off the tap in the engine block. This required removal of the engine to get the tap out and then rethreading the block for both senders which I am sure probably got some metal bits from the threading into the engine . . . . ."

YEEEAAAAHHHH!!!! I'll keep stripping my own threads and filling the crankcase with detritus. No need to pay a professional to do that. Took the family car one time into the dealership to have them listen to the clunk in the automatic transmission. Kept it overnight, one of the techs drove it home. Couldn't hear it. Asked if we wanted the oil changed since it was due and we were there. Sure, why not. Tranny problem was intermittent so I knew it was a bit of a long shot. Oh, and a dealer. Went for test drive with mechanic to see if I could replicate the noise. Driving across the dealer parking lot, I asked the mechanic if the oil light should be on. "Turn around and drive it right back into the bay!" He exclaimed wiping the egg salad sandwich off his face. I replied cool as a cucumber, "No effing way, pal. You go get the oil and bring it out here." Thinking the whole time I should just floor it and see how long it would run. The car went up on the rack and was drained just before closing time. The next morning it was lowered from the rack and parked outside. Huge, long story, but after two months of wrangling with the criminals, I got $2000 out of them just to shut up and go away. And I can't talk about it, either. So I'm done.