I replaced the oil pressure sender on my '85 190E but the gauge constantly reads 3. Prior to the R&R, the gauge read 3 constantly and when grounded read 0. What's the solution now? Is the housing the culprit for the erroneous reading?

Jeff

The new oil pressure sender can't be defective...can it?

Make sure the connector is getting in touch with the connector on the sender.
Make sure you didn't use too much teflon tape. IF so, there is no way for the sender to find ground. I use Hylamar sealant that is liquid on these.
Check for the continuity of the unit to the engine block.

__________________
Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

Benzmac,

You're right as usual, Benzmac. I'll make sure the connector wire and sender are in contact. Thanks for your reply!

Jeff

Even if teflon tape was used, the crush washer has alot of surface area to make a good ground contact.

Disconnect the wire and if you have an ohmmeter, measure the resistance between the sensor output and ground. Then do the same with engine running. I will try to find out what the readings should be in the meantime.

If your new sensor was a $50+ VDO like the one I got a couple of weeks ago, I find it hard to believe it is bad.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

mplafleur,

Sorry to all purists, but I didn't use teflon tape on the installation. The sender I put on was made by fibi-bilstein.

I took off the connector wire cap and gave it a shot of WD40. Ran the engine for a couple of minutes in the garage and now the gauge drops down slightly to 2.7. BTW, I use 10W40 oil. Gonna do an oil change this weekend and take it for a long test drive. I suppose things are okay now because when I turn the key to the second position, the gauge reads 0.

Thanks again folks,

Jeff

Good job!

I was having trouble getting the spec on the part and was afraid I was going to have to deliver on my offer.

I had forgotten the possibility of corrosion on the inside of the connector.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

mplafleur,

Thanks for the compliment, dude! Took the car out and noticed that at idle, the gauge goes down to 1.6. Everything's back to normal.

Jeff

Jeff,

Is changing this a fairly easy job? Where is it located? My OP gauge will intermittantly drop to zero while driving It's a heart stopper the first time you see it. However my engine is fine and I believe it to be what you replaced. Just wondering if I should attempt it myself or not...........TIA!

btw77,

Yep, easy as pie. The oil pressure sender is located on the oil filter housing. There's a connecting wire that is attached to it. I would also change the oil and oil filter while you're doing this job. After you've got the oil filter removed, R&R the oil pressure sender. Good luck!

Jeff

Thanks Jeff!

It looks like the part is around 60.00. I need to order some other things as well so I may add that to my list and give it a try.

You folks are the BEST!!