Xu9Ja-Oil Pressure + Oil Temp Concerns.

[the matt 13 2 Cars]

Hi, sorry to start another thread on oil pressure and my concerns about it. I've searched and read through a few others and have a few ideas.

 

A normal day for me in the 205 involves 10-20 mile drives. On start up, the oil pressure is normally somewhere between 3rd and 4th line, rising slightly with revs, never much above the 4th line though. When the car is warm is usually drops to around the 2nd line on the gauge, sometimes just under.

 

The oil temperature is normally pretty steady, 1st line for around 3-4 miles, 2nd to 3rd line once warmed up. However, after a 5 minute semi-spirited drive (revving up to 5.5-6k on occasion) the oil temperature was approaching the 5th line. I backed off and slowed down, the temperature steadily dropped back down after 5 minutes of trotting along at 50mph in 5th gear.

 

When I return to idle quickly (like if I dip the clutch on approach to a traffic light) the oil pressure gauge drops to the 1st line. If I gradually slow the engine down as I slow down and let the revs drop slowly, it normally returns to halfway between the 1st and 2nd lines on the pressure gauge. Upon revving anything above 1500rpm, it always comes back up to the 3rd line as a minimum.

 

So, the car is a high mileage one (175k), but it's had an engine swap a few years ago. Doesn't lose oil at all (slight leak from crank pulley seal, but only a few drop), doesn't use any water at all, no smoke at all, generally seems healthy apart from this. I've had a weird issue with the pressure gauge already in that the low pressure warning light switch had a corroded terminal and this was somehow making the oil pressure gauge read all over the place. Took that off, cleaned it and it appeared to take away the random flickering all of the place with the pressure gauge.

 

The engine coolant temperature also seems good and healthy.

 

So, my question is this:

 

This has manifested itself 3 weeks before I'm due to drive to Germany. Great! What am I expecting to find when I pull the sump. I've bought a new gauge sender unit, a new cambelt and water pump for the sake of a service in preparation for the run, but I'm stumped with this. I've ordered a new relief spring and cup (the higher pressure spring), but I don't want to mask a problem by curing a symptom, rather than curing the actual problem. Is it likely to be a knackered oil pump, engine wear, relief valve issue, or is warm idle at 1st line on the gauge OK? Is the oil temperature an issue? The previous owner tells me he last filled it with 15W40, rather than 10W40, so is that also masking some of the issue? I'm planning to drop the sump off at the weekend, but am not sure whether to have a new pump ready as a backup as if I don't fix it this weekend I'll be out of time before the run.

 

Thanks in advance and sorry for the long, boring waffle above. Just trying to note as much down as possible!

[the matt 13 2 Cars]

Another note, oil pressure light never comes on after startup

[welshpug 1,661]

oil pressure sounds reasonable especially with the temps you are seeing, I would try fresh oil.

 

pumps don't tend to give issue at all even with high mileages.

[the matt 13 2 Cars]

Thanks for the reply. I'm unsure on what grade to buy...I know there are lots of debates about oil grade. I'd kinda assumed that the 10W40 semi synthetic was a good starting point unlike the 15W40 that the previous owner used.

 

At this point, a new oil and filter is a cheap and easy fix. I only want it to go to the Nürburgring and back in 3 weeks and be reliable for the trip. It's getting a new engine in August/September so don't want to throw good money after bad just yet.

[alexcrosse 124]

Love how lines are an SI unit with 205s.

 

Change the oil you big silly bear x.

[the matt 13 2 Cars]

I shall, bbgrl.

 

In fact, I may even get my backside in gear and do it tonight.

 

I promised you a pax lap on the 'ring, so I've gotta get it so I'm happy with it. If it blows up on the way home, fair enough. Just don't want to be getting a pax ride with Bonguards myself!

[Anthony 1,003]

Sounds pretty normal to me, but even if it wasn't, I wouldn't even begin to consider diagnosing any low pressure issue based on the standard gauge and sender! Generally speaking, providing the warning light isn't on at idle and the guage moves to somewhere around halfway to three quarters at 3000-4000rpm when the oil is hot then it'll be fine - it's an ever-hardy 8v after all

 

If you're really concerned, pick up a mechanical oil pressure gauge and see what that reads - I'm sure it'll be fine.

[S@m 156]

Sounds the same as mine.

[the matt 13 2 Cars]

Cheers guys. Tbh I know the pressure gauges are unreliable on them. It was more the raising oil temp that concerned me.

 

Oil pressure gauge adaptor ordered and I've got old gauges in the garage I can plonk on for checking it. I'm confident that I've got a lack of confidence in my gauge readings now. Oil temp was on third line upon arrival at work. Promptly dropped to second line upon driving over the gravel in the car park. Will swap oil and filter and flush the system as much as possible, then plonk some decent oil in. Still unsure on grade but as it's Summer and I'm heading to the ring I'm tempted to try the 10W50 Synthetic Silkolene that some people rave about.