I have a Mercruiser 5..0 MPI and was looking to purchase a new water pressure sensor / sendor (Original Part # 8M6000623 New Part # 881879010). There are some 3rd party sensors available on Ebay for around $30.00. The quicksilver sensor is around $130.00. Has anybody had any luck with these third party sensors?

Every aftermarket sensor I've tried, I've had to later replace with OEM. Oil pressure senders, water temp, and something else I can't recall.

Not saying all aftermarket parts are junk or don't work. Just saying I had issues with mine, and now ONLY buy OEM. I know it's more $, but I know when I spend the time/hassle/effort (all my own labor) it's going to work.

FWIW, I have twin Merc 350s. After replacing both engines a bit ago, one engine would read way different oil pressure than the other. (I put new senders on them since it was easy to get to and they were 20 yrs old)

Took me a while to troubleshoot, but soon as I put a OEM sender on the suspect engine, now both are very similar. (tried 2 after market). So, no more. I don't have the time do it 3x. I order OEM from whomever has it cheapest online (google the part #, check ebay and walmart and amazon too).

Thank you so much for the response and advice SabrToothSqrl. I am going to take your advice and by an OEM sensor.

The pressure sensors are all basically the same thing...its a variable resistance potentiometer. The biggest thing you have to make sure you get right is the resistance swing for the gauge. I know the VDO gauges are different then typical Merc gauges
Typical "standard" gauges are 240ohms at 0psi and 33.5 at either 80psi or 100psi depending on the gauge.
The VDO stuff i think operates backwards...i want to say its around 10ohm at 0psi and around 180ohms at 80psi or 100psi depending on the gauge...

Ive replaced my sending units with Autometer before with no issues for 1/4 of the price Merc wants for theirs

Sorry for sidetrack:
here you go Wally
https://www.autometer.com/sensor_specs

I have 5/6 7.3 fords still and these get clogged and toss a code. dont buy a mercury one , just get a high quality one...standard is good Rock auto

These ?

https://www.ebay.com/itm/284131989107?chn=ps&_trkparms=ispr%3D1&amdata=enc% 3A1_MPseKdSR_ire5AZrui0Nw57&norover=1&mkevt=1&mkri d=711-117182-37290-0&mkcid=2&itemid=284131989107&targetid=15990903358 97&device=m&mktype=&googleloc=9002327&poi=&campaig nid=15275224983&mkgroupid=131097072938&rlsatarget= pla-1599090335897&abcId=9300697&merchantid=6296724&gbr aid=0AAAAAD_QDh_5xUFeWbYq_2J_XOhaMoElc&gclid=EAIaI QobChMIvL_cjJ_h9gIVB8DICh28wQ6jEAQYDiABEgJ6uvD_BwE

and:
https://www.rockauto.com/en/catalog/...e)+sensor,5088

Pic below is of link just above ^^^

keep spares for my dads/brothers 6.2 motors in florida....sand plugs them up

Great info :thumbs
This should be a sticky.