I'm Scared...oil Pressure Problem

[bondyshambles 23 1 Cars]

To set the scene. I couldn't take my filler cap off....then i eventually did by snapping the perrished oil filler hose. I then proceded to buy a complete silicon oil breather hose set. After replacing the hoses and the oil filler plastic tunnel i seem to have a problem with my oil pressure dropping under acceleration. The pressure is at 3/4 on tickover and drops to the first bar at about 4500rpm but never low enough for the warning light to come on. The hose that goes onto the top of the oil filler (the larger one) needed to be forced on and bored out a little to fit properly. The fit is still dead tight though. All of the hoses are on solid and have not moved. I did also remove the mesh that is in the top of the filter cap too. The car has always smoked a bit and rattled a bit on start up. I believe that there may be a slight oil leak around by the filter or it is running down by the filter somewhere but i cannot be sure that it wasn't there before. My questions are....

 

1) Have i knocked something (wiring wise) that could cause the gauge to go down under acceleration ?

 

2) Has taking the mesh out made the pressure drop?

 

3) Now that i have replaced all the hoses and the car can now breathe, has something else (a gasket maybe) blown?

 

4) Could i have put the wrong hose in the wrong place?

 

5) Is it the beggining of the end ?

 

I should also add that the car acts the same. Just the gauge is telling me something is not right.

Edited May 6, 2013 by bondyshambles

[brumster 135 1 Cars]

To set the scene. I couldn't take my filler cap off....then i eventually did by snapping the perrished oil filler hose. I then proceded to buy a complete silicon oil breather hose set. After replacing the hoses and the oil filler plastic tunnel i seem to have a problem with my oil pressure dropping under acceleration. The pressure is at 3/4 on tickover and drops to the first bar at about 4500rpm but never low enough for the warning light to come on. The hose that goes onto the top of the oil filler (the larger one) needed to be forced on and bored out a little to fit properly. The fit is still dead tight though. All of the hoses are on solid and have not moved. I did also remove the mesh that is in the top of the filter cap too. The car has always smoked a bit and rattled a bit on start up. I believe that there may be a slight oil leak around by the filter or it is running down by the filter somewhere but i cannot be sure that it wasn't there before. My questions are....

 

1) Have i knocked something (wiring wise) that could cause the gauge to go down under acceleration ?

 

Unlikely but possible I guess, is the wire becoming unconnected (bad connection or broken wire/solder joint) when something moves? So the gauge is suddenly receiving zero voltage, so heading for 0 on the gauge. But it sounds like there's too much "order" to it, if it does it always at around 4500rpm and always goes to the same point, the 1st bar. Not random enough to be a loose wire

 

2) Has taking the mesh out made the pressure drop?

No

 

3) Now that i have replaced all the hoses and the car can now breathe, has something else (a gasket maybe) blown?

No. The filler hoses are in no way connected to the oil delivery system so changing them should have in no way contributed. The engine may indeed breath a bit better, but that wouldn't have such a dramatic effect on oil pressure - you might see some more burning of oil, or oil loss out of the engine, but to suddenly drop pressure at 4500rpm is hard to connect to an oil filler pipe swap.

 

4) Could i have put the wrong hose in the wrong place?

As above, even if you have, I don't see how this could effect oil pressure. I assume there is enough oil in the engine!?

 

5) Is it the beggining of the end ?

Assuming the gauge is accurate, then it's not a good sign and I would investigate it - even though there is still enough pressure, it's clearly heading the wrong way. I would more suspect something have come off in a pipe and dropped into the sump and is blocking/restricting the pickup. I would drop the oil out, drop the sump off and investigate. If nothing obvious, drop the oil pump off and check the relief spring/general condition, or just replace it with a new one anyway. Also check the recently-discussed issue around the crank pulley bolt being loose, although since you've not touched that I would think it unlikely.

[Anthony 1,000]

Before you worry, I'd confirm the oil pressure using a mechanical gauge.

 

I've seen similar issues to what you describe from both sender and wiring issues.

 

I swear that the standard oil pressure gauge setup is the cause of more grey hairs amongst 205 owners than anything else

 

As Brumster said above, the oil breather system is not connected to oil delivery, which is what the oil pressure is measuring. I would suggest that it's coincidence that the gauge is playing games afterwards, possibly down to the wiring for the gauge sender running close to the pipe below the oil fillter tower that you were no doubt moving around trying to force the cap off.

[ALEX 98 1 Cars]

Answer = 1, yes most likely

 

Typical Peugeot, everything is rubbish, especially the wiring.

[bondyshambles 23 1 Cars]

Thanks for the replys....I am hoping that it is a wiring problem but i agree that surely it should work or not work and it never just drops to zero, it progressively goes down after about 3500-4500 range. I didn't realise that the breather side has not much to do with the pressure . There is a good chance that something could have gone into engine/sump as the hoses were in a bad state. The oil level is fine and the problem is there from cold not just warm (as oil will be hotter and thinner ?). I think an oil change is the next step but it was only changed last year (4000 miles ago) but it is black and the car was in a poor state when i got it. I have seen the thread about the crank pulley bolt, but as Brumster said i have not touched it. How much hassel is it to take the sump off ? I assume there is a gasket to replace etc?. Is the oil pump mechanically driven and how much hassle is it to change if needed ? Please remember amatuer, amatuer, amateur.

[Anthony 1,000]

As I said, I have seen these exact symptoms with sender and/or wiring faults.

 

Applying logic to French wiring gremlins is like trying to apply logic to female thought process.

 

Do not panic and start stripping the engine down, at least not until you've verified any reading using a mechanical oil pressure gauge!

 

If I were a betting man, I'd put a tenner down on the mechanical gauge showing that there's no pressure issue at all.

[bondyshambles 23 1 Cars]

Thanks Anthony. Next question where is the wiring/sensor for the oil pressure switch ?

[S@m 156]

Front of the block, just above the alternator, mushroom shaped sensor with one wire going to it. The smaller one next to it is the stop light sensor.

Edited May 7, 2013 by Sam306

[bondyshambles 23 1 Cars]

Well what a relief......I took the wire off the sender unit cleaned it up and then put it back on and its back to normal . The connector was slightly loose but definitely well on the sender unit . Just goes to show that even when it looks good....sometimes it ain't.

 

Cheers for your help once again peoples.