No oil pressure after oil change............ - PeachParts Mercedes-Benz Forum

jevicjim · #1 08-03-2007, 03:50 PM

My 1987 300d 182k miles was running great so I decided to change oil and install a new Mann filter and mobil 20w-50 syn and when I started the motor I had no oil presure. I took out the filter and checked the dip tube and it was fine I even started without the filter and no oil is coming into the filter housing. If anyone has an answer it would be greatly appreciated and Thanks in advance.

Jim

TheDon · #2 08-03-2007, 03:51 PM

jeeze 20w50...

last I checked even up north 15w40 is all you need

When I do the oil in my 617 It has to build pressure.. maybe 30-45 seconds at the most...

winmutt · #3 08-03-2007, 04:21 PM

is 20w50 synthetic even diesel rated? Use 5w40 synth like the rest of the crowd. how do get that started in cold weather?

Mustang_man298 · #4 08-03-2007, 04:25 PM

It could be possible you put too thick of an oil into it, or possible your oil pump is tired and lost it's prime during the change, I've seen that happen before.
Try putting the correct oil back in it, if that won't fix it, try filling up the filter housing, get the element soaked then fill it up and close it, if it had lost it's prime that should bring it back. I always fill up my filters (on any car) anyway to presoak the elements & minimize the run time with no oil, I'm told this is very important on turbo vehicles.

You should be glad it didnt get oil when you had it open....you have no idea the mess that woulda made......

rrgrassi · #5 08-03-2007, 04:28 PM

While filling the filter housing is a good idea, it does drain back into the crank case when the engine is off. That drain back may be the ticket to priming the pump though.

klataklatacoupe · #6 08-03-2007, 05:26 PM

i hav noticed that it takes several mins for my oil preasure gauge 2 reach 3. i always figured that my guage or sending unit was just tiered. is it possible i might be suffering similar problems bcaus or improper oil weight

jevicjim · #7 08-03-2007, 05:30 PM

I have quite a few people suggesting I try the lighter oil and I will try that and let everyone know the results. Thanks all

Jim

tjohn · #8 08-03-2007, 05:33 PM

Unlikely. Synthetic 20w-50 should be thin enough for pressure to build quickly. Frankly, I think no matter what oil you're using, if it takes "several minutes" for the oil pressure to rise to 3 something is wrong with the sender or, less likely, the oil pump.

Try filling the oil filter housing with oil - it'll help bring pressure up faster. The point about being diesel rated is good too. I assume this is that Castrol product?

jevicjim · #9 08-03-2007, 05:52 PM

Correction the oil is 15w50 mobil 1 API SM,SL/CF

rrgrassi · #10 08-03-2007, 05:58 PM

When the engine is running and you remove the oil fill cap from the valve cover, can you see oil "squirting " or moving? It is possible the oil sender orthe guage decided to let go at the same time.

jevicjim · #11 08-03-2007, 06:01 PM

No oil is squirting in the valve area. Thanks for input

winmutt · #12 08-03-2007, 06:12 PM

Get Diesel rated oil and nothing else. Mobil1 5 40 is what most ppl are using around here.

stephenson · #13 08-03-2007, 06:33 PM

Not sure about the massive concern over oil type or diesel rating - none of those, even a straight 40W oil is going to prevent oil pressure and flow unless the oil pump dropped prime (pretty unusual), stopped working, or there is some weird passage blockage at just the right place ...

My take on oils we have nowadays is that most will work fine, regardless of the gasoline vs diesel rating for the first 5K miles - the diesel rating is key for more reasonable drain intervals, though.

jevicjim · #14 08-03-2007, 06:50 PM

I cant see the oil weight being the problem but since I am between a rock and a hard place I will try the 15w40 diesel oil and thanks again for the input.