Mysterious leak

Technical Area Engine, Transmission, Exhaust etc
2

Can anyone shed some light on where my car may be leaking “fluid”?

 

I will start by saying the possible culprits in my opinion do not involve the following:-

 

Rocker cover. New gasket and correctly sealed at the corners. There is no sign of oil leakage from the cover.

Radiator (has been replaced and with new hoses)

New radiator cap (genuine Mazda)

CAS - 3 years ago and the car has covered no more than 3,000kms since  

The steering rack does have a slight misting (left side as viewed from the front) and I am aware of this and will be seeking to replace it shortly. However, the misting is not sufficient to cause a wet stain under the car when the car has been standing 2 to 3 days.   

 

The car is garaged. The car has been serviced thoroughly in March this year by MX5 Restorer and only covered a few 000 miles since.

The leaky patch appears to be more left side and towards the mid engine (when facing the car). Of course I am aware that a leak from elsewhere can cause the drop to form at a different point.

I’m suspicious of whether a seal has failed where the engine meets the gearbox/transmission?

Or that the patch on the floor isn’t oil but fuel?    It isn’t a vast amount maybe tennis ball sized stain on the card under the car. 

I am taking the car to Garath at MX5 Restorer on Wednesday but I am fearful of using the car for any long distance unless I can rule out that the car won’t suddenly drop its oil etc.

Please be gentle with me when answering. I am not an expert nor technically capable.

Yes I have booked the car into a garage so a solution will no doubt be forthcoming but I am merely interested in advance if any members of MK1’s have had a similar problem and the solution is relatively benign.

Any thoughts will be helpful.

Thank you.

3

Putting a white container under the car to see what colour the fluid is would be a good start.

4

heater hose ?

5

Of course that may be possible. I did have a new radiator last year but took the precaution of replacing the top and bottom hose with new Mazda parts.

 

The radiator level looks ok…maybe a tad too full but no evidence of leakage.

 

 

6

Hi Sonue

I feel your pain. We had a leak on our Eunos which after a lot of misdirection and indecisiveness on my part ended up being the new aftermarket cam cover gasket leaking very subtley from the back near the CAS, draining around the engine and eventually flicking off the water pump pulley. Virtually no oil actually dripped off the car as evenly distributed throughout.

You need to initially work out what the fluid is which can be easier said than done as petrol or coolant could mix with oil, etc on the way to the floor. I would get underneath the car after it has been stood for some while and look for a buildup of fluid. You need to know if it gearbox or engine oil, coolant, petrol or brake/clutch fluid.

Hopefully not the rear crank seal on the engine - possibly clutch slave gone?     

 

7

Thank you.

 

I will do as suggested

I’m assuming rear crank seal is an expensive engine out repair?

 

Oh well the joys of owning an old car…lol

8

Very unlikely to be the rear seal as usually leaks to the centre between engine and gearbox.

This is not a job you want to do without being absolutely sure of the leak source being the rear seal. Lots of owners will put up with a small rear seal leak until their clutch need replacing.

It is gearbox out and flywheel unbolted and then the seal can be accessed with the engine in place. Replacing the rear seal itself is a similar routine to the front seal so I would drill 2mm pilots into the seal, screw in two self tappers and use two pairs of pliers to pull on the self tappers to remove seal. Clean the seating and then insert new seal taking care to progressively and evenly press into place until seated correctly.     

9

New oil filter fitted?

Oil filter leak??