Hi

Just started having problems with my oil pressure.
When i start the car up it goes up to "normal" like around 2-3 bar, and stick to 3bar if i rev the engine.. Now when i start driving and throtteling up it can drop down to like 1-0 and then pop back up again to normal lvl's.. It seems like it drops more oftne if i drive up hill and or when I give it on the throttle..

I had it in for a compression test just befor this started and the cylindres wasnt really looking very good.. differens on the cyls ranging from 10,8 bar up to 12,8..

I've got oil in the airfilter aswell, but that was there befor this started..
The car has got 200,000km on the clock so it has seen its fair bit of action..

Eny ide on what the problem can be ?

thx

 

fixed.. blown oil pump

 

At first start in the morning I maintain 2.5-3 bar for 15-20 minutes. Once I reach normal operating temp I drop to under 1 unless I can maintain 2000 + rpm.

I see the pumps listed at $405. What wouuld be the labor cost to expect?

 

I can understand an electrical pump partially going out. I have experienced that with a fuel pump where once normal temp is reached it begins it would stop pumping.

An oil pump is mechanical, I would think it would break or work. How does it seem to work based on rpm? I can understand electrical pumps possibly having shorts/grounds etc that can develop as they warm up.

 

I am reading some threads about an oil relief valve and/or the sending unit possibly having issues that can cause my symptoms? Is this a major undertaking? I have worked all around the outside of engines before but have never went inside.

I also read a thread speaking of a shortage of oil pumps?

 

What year and model are we talking about ?

 

I'm sorry, I should know better than that! Its a 95 E420 with 128K and runs great. This problem is not producing lifter noise or power loss. When it fully warms up and the idle and low rpm driving is performed, this is when my oil pressure reads .5-0 bar. Anything above 2000 rpm is 2.5-3. Cold start is a solid 3. The oil on a cold engine is about 3/4ths the way between the Min/Max lines on the dipstick.. Engine model I think is a 119. I have no drips, leaks, very clean engine compartment and no smoke. The problem started about 2 days ago and I have driven it very little. Normally my warm engine temp is just barely below the line above the 80. I think this is 90? As long as my driving produces decent pressure, the temp guage remains stable. If I let the car idle while warm and the pressure is low, it will begin to raise in temp. I of course immediately shut it down once it reaches a mid-point between 90 and 120. I do not allow it go traverse more than half that distance. So, I am fairly sure that it is related to oil flow. I just do not know if this is truly the pump(hope not) or one of its supporting cast.

I want to start with an oil change and filter which will run me about $75. It is due for one now. I'm really hoping it is a filter issue or something in the bottom of the pan. I hate to get into dropping the pan. I have done that before on other cars to replace the seal but the thought of removing the pump and chain is a little more internal than I have been. This is why I ask what to expect on labor. When I first bought the car it had a p/s leak and the a/c hose was broken. One I performed and was very cheap to fix(p/s rebuild kit). The a/c hose as VERY expensive. I put a happy 17K in miles on it after that.

 

Updated Information

I changed the oil yesterday. I saw "some" improvement but not alot. What I did notice while spending a great deal of time under the hood is that BOTH of my auxilary fans are no longer working. I realized this when warming up after the oil change. The car sounded too quiet. So I turned on the a/c and let it run for a few minutes. No left fan. I then let it idle for about 20 minutes until it got up a little over 90C and no right fan. It usually would kick on by then.

My oil pressure problem does not fully present itself until I cross 90c. As long as it stays below that level I maintain accepable low rpm pressure and high rpm has not been a problem thus far.

What I am wondering now is when these fans stopped working(last remember hearing them about 3 days ago) they unmasked a future oil pump problem. I am also wondering if I can get these fans working again and keep the temperature in the happy range I am buying time. I realize that flirting with an oil pump is dangerous. However, as long as my temp stays below 90c, I maintain .5-1 bar at idle and sub-1500 rpm. At 1500+ I maintain 2+. These are pretty close to normal readings.

Both fans spin freely with no drag in either direction. From reading a few threads, it appears unlikely that both would go at the same time.

So, is there a common relay or fuse that they both use? I didn't see an obviously broken fuse in the fuse box on the drivers side next to the hood post.

Sorry for the long post, I am trying to give as much troubleshooting and detail as possible.

 

The Saga continues. Today I ran across a thread stating that another set of fuses was behind the fuse box! I dug into this rascal and found a large blue and large green block that each had fuses in them. Both! were blown. I replaced both and my 2 auxilary fans came back to life! I am not sure if it is a fuse per fan or if I fixed something else along the way? I do not know of any other areas of the car that is not 100%. So I suspect it is a fuse per fan.

This allows my fans to kick in just prior to the bar above 80c. When this happens, the engine never warms enough to cause the oil pressure problem that I was experiencing. At least not as dramatic. It still idles near 0, but even after 45 minutes of idle at 90 degree weather it would quickly respond with the slightest pressure on the pedal(650-700 rpm boost it to 1-1.5 bar)

I am not sure that I am out of the woods with the oil pressure but I definitely feel better at the moment.