Mk1 Injector Seals

[Burgmeister]

So i've known for a little while that at least one of my injector seals needs replacing as when sat stationary in traffic with the heater fan turned on the cabin fills with the intoxicating scent of petrol (the fan intake is reght next to the injectors).

After a spirited 200 mile trip over the weekend the situation escalated and whilst popping in to Fleet services on the M3 the smell of burning oil and accompanying smoke was quite apparent. The engine was running fine but clearly the seals are leaking and leaking badly so i took it easy for the remainder of the journey.

When I got home I popped the bonnet and sure enough there had been an oil explosion in the general vicinity of the injectors so i mopped it up, had a prod and noticed the cam cover was very loose (i recently replaced the gasket) so the oil may have come from there?

Can the injectors leak oil??

Either way the injector seals need replacing. Is there a sensible place to buy these from as looking at MX5Parts they seem disproportionately expensive and that annoys me?

[snotrag]

Only fuel can leak from the injector seals.


Your oil leak is the cam cover. Install a new (genuine) gasket, following the correct torquing procedure and figures, and using a dab of sealant in the relevant places.

Are you sure its a fuel smell your getting>, not an oil burning smell?

[Burgmeister]

I've tightened the Cam cover back up and had a look under the bonnet after the drive to work this morning and no new oil was apparent so hopefully that's that problem solved.

Definitely a petrol smell, I've never had the injectors out in my four years of ownership and nor is there any history of work on them prior to my ownership so i've deduced that fuel must be leaking from one of them.

[skinny]

i've not heard of it happening but perhaps your pcv valve has got all gummed up and stuck closed? it's the plastic valve between cam cover and intake manifold.

easy to test (just make sure you wipe off all the oil before you blow through it!!). it should be easy to blow through in the direction from cam cover to manifold.

[snotrag]

Burgmeister said:

I've never had the injectors out in my four years of ownership and nor is there any history of work on them prior to my ownership so i've deduced that fuel must be leaking from one of them.

That makes no sense. The reason an injector seal might start leaking is generally because its been disturbed.

I'd have a good check round elsewhere.

[MX-5 Lazza]

My car has had cracked & leaky injector seals before and the smell of petrol really wasn't that strong.
Does yours still have the charcoal canister fitted?

[Burgmeister]

MX-5 Lazza said:

My car has had cracked & leaky injector seals before and the smell of petrol really wasn't that strong.
Does yours still have the charcoal canister fitted?

Hmmm…I need to have a proper look in decent light. I've put the oil down to the cam cover being loose as there is no new leakage since I tightened it back up and I had a good blast this evening to make sure.

On the fuel smell front its been there for a couple of months and you only notice it once the car is warm with the heater blowing and whilst stationary. With the fan off there is no smell so I'm assuming it must be somewhere near the fan intake but I suppose that could be anywhere under the bonnet.

[MarkK]

I had a leaking injector o-ring and had the same symptoms as you, strong smell of fuel when idling and heater on. Was easy to see the fuel dribbling down the injector with the pump running. Sealforce on eBay provided me with Viton o-rings and they gave great customer service . Hardest bit was figuring out the correct size of o-ring so ended up ordering quite a few different sizes.

[Richyvrlimited]

Burgmeister said:

(the fan intake is reght next to the injectors).

No it's not. It's on the passenger side of the engine bay in the cowl area. The injectors are on the drivers side of the engine, and actually in the engine bay.