Oil pressure drop on Detroit 8v71TIs today

[tomrealest]

My mechanic and I were sea trialing the boat after changing trim tabs and havibg the props redone. When were coming in the oil pressure on one engine dropped to 10 lbs.

I want to bring in the best detroit mechanic recommended here on the forum for the Ft Lauderdale area. How about some recommendations and phone number.

 

[Boatnut]

Contact Dave Captddis here on the forum and bring him over. Excellent mechanic.

 

[RT46]

im pretty sure that 10psi at idle on a warm DD is WNL.

 

[tomrealest]

We were on our way in at 1400 rpms. Usually carries 40 psi

 

[bobk]

Was that low pressure on an electrical or mechanical gage? Did the alarm sound?

Bobk

 

[MikeP]

After you noticed the gauge reading was there any unusual noise from the engine, any unusual smoke, any unusual vibration? If not, and, as stated earlier, if the reading was based on an electrical gauge, before spending any serious money jetting in experts, connect a mechanical oil pressure gauge and verify the pressure.

If a mechanical gauge verifies the low reading, THEN calling in the cavalry might be a consideration!

 

[86Hat41]

If indeed the reading is from an electric gauge it's scary that your "mechanic" didn't suggest hooking up a mechanical gauge immediately. Electric gauges are about as reliable as politicians. Flying someone in to check oil pressure is going a little overboard. You can hire anyone with any basic automotive knowledge to do that.

 

[rsmith]

After you noticed the gauge reading was there any unusual noise from the engine, any unusual smoke, any unusual vibration? If not, and, as stated earlier, if the reading was based on an electrical gauge, before spending any serious money jetting in experts, connect a mechanical oil pressure gauge and verify the pressure.

If a mechanical gauge verifies the low reading, THEN calling in the cavalry might be a consideration!

Yes put a test gauge on it. But even my mechanical gauges have clogged up with crap and would stick sometimes. I had 40PSI one time after the engines were shut down.

 

[Cinphil2]

If you decide you need a mechanic, I would highly recommend Fran, the owner of Competition Diesel in Ft Lauderdale. His number is 954 931-2846. I have found he does what he says, doesn't create work, and is reasonable. Feel free to tell him I recommended him. Good luck.

 

[RT46]

I really don't think 10psi on a hot day after a long run at idle is a big deal for a DD.

 

[SeaEric]

I really don't think 10psi on a hot day after a long run at idle is a big deal for a DD.

I agree. But the OP said it was at 1400, not idle.

 

[RT46]

10 pounds at 1400 would be a concern

i would first confirm the reading with a mechanical gauge

 

[tomrealest]

Thanks for all of your help. The gauge was the mechnical gauge in the engine room as well was both electrical gauges. I will talk to my mechanic about putting another mechnical gauge on it to check it again. There were no noises, smoke or anything out of the ordinary.

At breakfast this morning the boat mechanic read where there is a pressure gauge inside the pump or somewhere close by. We'll have to drop the oil pan probably. She was due for an oil change anyway. It's just a reminder not to be complacent at the helm and to keep your eyes scanning the gauges.

Thanks again

 

[chris45]

Just curious as to what happened? Did a new mechanical gage confirm low oil pressure? Was it one of the by pass valves in the oil pan or something else.

 

[johnjen50]

Tom, did you ever figured out he oil pressure problem?

 

[hromberg]

I love this place. Whenever I'm about to pop in and ask a question, somebody pops in and asks it early enough for the answer to be ready for me when I get here. 8v71TI oil pressure change at idle after a nice run explained.

 

[jmagel]

We had a low pressure alarm last weekend on our starboard DDEC 8v92TA. But really low -- 1 and 2 PSI. It was warm start after about an hour running at 800rpm. No unusual noise or smoke. I brought it home on one engine to be safe. Started it the next day and alarms went off again, but pressure steadily rose 1 - 9 PSI (alarm stopped at the 7PSI mark as expected), then jumped to 20+ suddenly. Upped RPM and got a normal pressure reading in the 30 - 40's. Seemed stuck or something.

Based on what I read in this thread, looks like this is fairly common (except our pressure reading was really low). I will have the mechanic confirm the pressure, but I'm not sure what the most prudent next step is. I don't want to spend unnecessary $$, but seems like I should install mechanical gauges in the ER (i don't have them). I would ideally like to install full sets for each engine over the winter, but now I don't trust the pressure readings on that engine. Maybe I could just have one temporary pressure gauge installed for peace of mind. I can't imagine it's too costly. Any other suggestions? Should I just disregard the alarm on warm starts if engine is operating normally?

 

[MikeP]

Installing a mechanical gauge is not at all difficult and is well worth the piece of mind. Here's a pic of the gauges/start button I installed in our ERs some years ago. If you just wanted oil pressure, it would be very easy and takes very little time.

http://i208.photobucket.com/albums/bb84/mikeP996/DSC_1896.jpg

 

[jmagel]

Installing a mechanical gauge is not at all difficult and is well worth the piece of mind. Here's a pic of the gauges/start button I installed in our ERs some years ago. If you just wanted oil pressure, it would be very easy and takes very little time.

http://i208.photobucket.com/albums/bb84/mikeP996/DSC_1896.jpg

That looks great.

I actually just got a text from the mechanic. all is well -- just need to replace a bad sender. i think i'll spec out the full set of gauges and get them installed sooner than later, but hopefully the new sender will give me more reliable readings in the interim.

 

[Genesis]

Yeah, one of the first things I added to Gigabite was a panel right at eye level at the hatch (when you were standing on the ER floor) for each engine that had oil pressure, coolant temperature and pyrometer (both banks) along with an ER start switch for the engines key interlocked (so you had to enable it with a key before it would work.) All three gauges were mechanical (self-powered for the pyros) and thus had no reliance on electrical power or the vagaries of electrical connections. It was well worth it.