twin engine slight difference in pressure

[TimB1]

Hi,
Looked at a twin engine boat recently.

One engine was showing slightly less pressure than the other. Is that normal. Visually both looked clean with no obvious leaks.
Obviously if we decided to buy boat, would get a proper mechanical/engineer check.

 

[RobWales]

I'm presuming you refer to oil pressure?
If so swap the guages or wiring to them and confirm original findings....

 

[rlw]

Could be just difference in corrosion on the terminals as they measure resistance. Once limped in on one engine after what I thought was an overhead after banging of a wave.
No obvious signs so checked the wiring. Reseated the spade connector and the the temp dropped down again. No carry a IR heatgun to check if it really is a temp problem. (after having a similar problem)
Oil pressure from memory works the other way. increased resistance gives a lower reading. If in doubt test on the engine directly.

 

[kashurst]

if the difference is small, I wouldn't worry about it. Get it checked but its not unusual for readings to be a bit different, especially as they get older. Can be differences in engine wear, or instrumentation issues. As long as the engine pressure is within an acceptable window of oil pressure it's probably perfectly OK. My engines sometimes read slightly different at 2000rpm, sometimes they read exactly the same. At Idle hot or cold they are identical.

The thing to look for is consistency and stability of pressures, temperatures etc over the operating range. Its easy to get drawn in by small differences indicating a potentially significant (but very unlikely) problem.

 

[Sneds]

As someone pointed out on another recent thread, if you had two identical single engine boats running side by side would you expect each boat's gauges to match exactly?
Be very surprised if they did.
So long as the readings are constant and within parameters I wouldn't worry.

 

[dave p]

My fords run different pressures and Temps.

 

[omega2]

My fords run different pressures. Temps.

Ours are always under pressure. LOL

 

[dave p]

True John. Struggling to find some cod lately

 

[omega2]

True John. Struggling to find some cod lately

dON'T ASK

 

[snowbird30ds]

Two engines will very rarely have the exact same oil pressure or water temperature, everything has tolerances and as long as they read within they should be fine.
Senders and gauges are rarely exact either.

 

[gordmac]

My fords run different pressures and Temps.

So do mine!