Oily sheen in front of car

[kiloran]

Well, this is an odd one. We've had heavy rain here this morning, and I also used Val for a dump run. Running perfectly of course.

But just popped out to load up the second lot of recycling and there's an oily sheen on the drive running downhill from in front of the front tyres. Coolant level is fine, and so is oil level. Hasn't dropped since I checked both yesterday.

It's the whole width of the car from in front of the front tyres??? Checked the oil filter underneath and that's absolutely bone dry and I can't see any obvious leaks from the sump. No dripping.

I did stop at a garage about 4 miles from home but didn't fill up and drove back in heavy rain. Tank is just over half full.

I'm parked nose down on quite a steep section of drive.

[griston64]

Originally Posted by kiloran

Well, this is an odd one. We've had heavy rain here this morning, and I also used Val for a dump run. Running perfectly of course.

But just popped out to load up the second lot of recycling and there's an oily sheen on the drive running downhill from in front of the front tyres. Coolant level is fine, and so is oil level. Hasn't dropped since I checked both yesterday.

It's the whole width of the car from in front of the front tyres??? Checked the oil filter underneath and that's absolutely bone dry and I can't see any obvious leaks from the sump. No dripping.

I did stop at a garage about 4 miles from home but didn't fill up and drove back in heavy rain. Tank is just over half full.

I'm parked nose down on quite a steep section of drive.

PS Fluid ok ?

[NI_Volvo_Nut]

It takes a very small amount of oil to make a very large rainbow effect on a wet road

[Forrest]

Have you serviced the PCV system recently? If that isn't working well and achieving negative crankcase pressure (tendency to "suck" down the oil filler cap) then any or all of the front seals can be inclined to leak engine oil. It doesn't take very much to see it on a wet road.

[kiloran]

Originally Posted by Forrest

Have you serviced the PCV system recently? If that isn't working well and achieving negative crankcase pressure (tendency to "suck" down the oil filler cap) then any or all of the front seals can be inclined to leak engine oil. It doesn't take very much to see it on a wet road.

Ah, that might be it as it's most prominent on that side of the engine bay. It was serviced and all seals replaced but I'll check everything is connected up over there

[griston64]

Originally Posted by kiloran

Ah, that might be it as it's most prominent on that side of the engine bay. It was serviced and all seals replaced but I'll check everything is connected up over there

Knowing Luke I would imagine the PCV was fully cleaned when the engine was out of the car and before all the seals were replaced.

[kiloran]

Originally Posted by griston64

Knowing Luke I would imagine the PCV was fully cleaned when the engine was out of the car and before all the seals were replaced.

Yeah it was.

PS fluid level OK. Took it out for a run and parked in a layby, nothing obvious dripping anywhere. All lines attached where they should be. Source is central so I'll have another look at the power steering pump/rack.

Parked her nose up on the drive for the night to see if she suffers from night-time incontinence

[Laird Scooby]

If you can, use a large sheet of corrugated cardboard under the car to help pinpoint where the leak is coming from. Knowing the old engine was prone to a bit of leakage, it could also be the remains of that and a prolonged wet spell ahs loosened it on the drive causing the dead rainbow effect.

I know Luke cleaned your PCV system and renewed the front oil seals and also the rear oil seals when he checked over the replacement engine so i'd be very surprised if anything on the engine is leaking.

Also check the outside of your PAS reservoir, clean it and make sure it's dry. If the rack isn't central in the straight ahead position, even if you've had a wheel alignment done, it will cause the PAS pump to be active (rather than just turning) all the time which can overheat the PAS fluid which then foreces its way out of the breather in the filler cap and it then runs down the hoses (if it's a remote reservoir) or down the sides of the pump (integral to pump reservoir) and drip onto the floor.

[kiloran]

Remote reservoir.
Ah, thinking about it last week when it was icy she was parked on the drive with the wheels at an angle. Had her ticking over for 5 minutes like that whilst I defrosted it, when I drove off the drive there was a bit of a dead spot in the steering and a clunk. All fine after that and steering feels normal lock to lock even at low speeds - no notchiness or grabbing. Luke noticed it when he was test driving it too. Will have a good poke around the rack tomorrow if it's dry.

[Laird Scooby]

Originally Posted by kiloran

Remote reservoir.
Ah, thinking about it last week when it was icy she was parked on the drive with the wheels at an angle. Had her ticking over for 5 minutes like that whilst I defrosted it, when I drove off the drive there was a bit of a dead spot in the steering and a clunk. All fine after that and steering feels normal lock to lock even at low speeds - no notchiness or grabbing. Luke noticed it when he was test driving it too. Will have a good poke around the rack tomorrow if it's dry.

Five minutes from stone cold probably wouldn't be enough to heat the PAS fluid to the point where it might overflow the reservoir Alan although not impossible.
It sounds more as if you have a leak of air into the system, possibly on the rack on the return line. THis may cause a slight leak/misting of the union (during the MoT, the tester just pointed to the ones on mine, didn't advise it on the test or fail it for it but enough to let me know to get it sorted.

Mine sometimes does similar to what you describe, particularly if i've left it parked with the steering at an angle. Normally i straighten the wheels as i park anything (comes from a slight accident 35+ years ago where i ended up dinging the wing). In fairness i hadn't been the last one to use the car at the time and the steering wheel was in the straight ahead position.

When i come to do mine i'll be renewing the copper washers on the pipe unions on the rack and also checking the pipes where they are attached to the PAS pump/reservoir, maybe you could look in a similar area and perhaps find some clues?