mx5cartalk.com

Hi guys, I'm still quite new to this forum so pardon my inexperience!

Recently bought a 1990 NA6 just 2 weeks ago, took it for a test drive and loved it so i bought it straight away. However just recently, when i was moving the car out from the garage, i realized that there were several drops of black oil on the floor, it has the consistency of water mixed with black stuff which i presume to be grease. After some tests, i realized that it only happens after long drives, and when the engine cools down the leak stops... anyone got any idea what it could be? A theory i have is that it's coolant, presumably linked to the overflow tank...

On a side note, there seems to be this persistent squealing every time i rev the engine, adding WD40 to the power steering/ A/C pumps seemed to stop it for a bit, however the next day the squealing came back. I tried adjusting the tightness of the belt but nothing seems to help, some advice on this matter would be appreciated!

Will the WD40 not remove grease?

Are you saying that there's a possibility of grease stuck on the pulley itself? will cleaning the pulley help?

The squealing sounds like belts slipping to me, not the pulleys or pumps themselves. Time for new accessory belts time perhaps. If they are worn no amount of tensioning will help. Coolant or other fluid dripping onto the belts can make them squeal too.

Could you have an oil leak from the engine if it is pooling on the floor? You need to see if there's any oil you can see anywhere on the engine. On the floor is the pooling towards the front of the motor position or the rear?
On the front look under the car at the front of the sump. From above look at the backsides of the front covers (there's a bit halfway up above around the upper pulley with three bolts, that you can look around behind that above the water pump... look for oil seeping there. Not necessarily dire... cam seals or perhaps crankshaft seal.
On the rear look at the top where there CAS plugs into the engine drivers side on an NA6, or further down behind for oil leaking onto the gearbox.

I have an oil leak myself this week so I guess I'm a bit sensitive to the possibility of that!

oozmakappa wrote:Are you saying that there's a possibility of grease stuck on the pulley itself? will cleaning the pulley help?

I was concerned that you might be expecting WD40 to be a worthwhile lubricant for these areas.

Don't use WD40 on belts, the point of them is to grip and turn, if you spray them with lubricant they can slip.

IF there's gunk on them use degreaser, and a rag.


As for the leak. Find where it's dripping from, then follow the wet line up.

the most common leaks are:
Rocker cover (so many put them on wrong and pinch the gasket)
CAS (same as rocker cover)
Rear main seal (usually after a fair few years, it's a prick to replace)

and the number one oil leak on cars.

Sump plug.
because people re-use the washer 100x over.

hks_kansei wrote:Don't use WD40 on belts, the point of them is to grip and turn, if you spray them with lubricant they can slip.

IF there's gunk on them use degreaser, and a rag.


As for the leak. Find where it's dripping from, then follow the wet line up.

the most common leaks are:
Rocker cover (so many put them on wrong and pinch the gasket)
CAS (same as rocker cover)
Rear main seal (usually after a fair few years, it's a prick to replace)

and the number one oil leak on cars.

Sump plug.

because people re-use the washer 100x over.

Alright guys, i jacked the car up today and took a look underneath, there's so much gunk down there that i'm surprised the wheels can turn still, did some de-greasing and did a coolant flush, will wait for it to dry out and take it for a drive again, hopefully the leaking issues will be solved by then...

Regarding the belt squeal, i added some belt dressing for the squeaking on the A/C pulley and it went away... took a look at the A/C belts and did some fiddling with the tension but no results the alternator belt was switched quite recently so it definitely isn't issues from an old belt on the alternator pulley. Not sure about the other belts, but timing belt was changed 3000kms ago. is there any specific symptoms of a worn out belt which could lead to belt squeal?

the obvious are small crack being visble in the belt, but often that's after a few years.

a worn belt will generally stretch, and the ribs inside wear down.
Belts ar pretty cheap, so I normally just replace them if I suspect they're a problem.


as for the leak, degreasing it won't stop it, BUT it will mean it's easier to spot the source (ie: it will be the new oily bit)