ooerrr... x flow oil/ engine problemo

[Jam Mad]

i'd like to run something by you guys and see if you can offer any help. this is in a '95 1700 xflow.. about 12k miles so far...

 

driving along yesterday, blatting down the a4, i lost power.. not suddenly, but with a change in the engine note, the car's momentum began to fall.. the moment that i noticed that it had happened, black smoke started puffing ( not quite pouring ) out from the bonnet. i snapped the engine off, and pulled over. oops. notice that my hazards don't seem to work. anyway.... everything looked fine, and five minutes later, we tentatively pulled away. no probs to our destination 10 miles away. from losing power, to the smoke appearing, to turning the engine off was probably about 2 seconds.

 

post mortem... there seems to be a fine spray of oil on the bulkhead. this is so localised, that whatever caused it didn't even spray oil as far as the underside of the bonnet.... it seems a very fine spray. also, the oil level is fine, and the car has just started easily. I'M PUZZLED ! i've just whipped the sparkplugs off, and although there seemed to be some oil and gunk in the thread, the business end was fine... albeit slightly dark... but i'm no expert.

 

it is as if something puffed some oil out, that burned off on the exhaust... but only did it the once, and not very powerfully...

 

any ideas please ?

 

also, i've just noticed that my radiator is leaking, dripping slowly from a corner. i'm about to fill it up with coolant to see if it stops it, but if not... can anyone please advise a 'get us home' fix ? or should i pop it into a garage for a tiny patch of solder/ weld this afternoon ?

 

thanks for your time folks....

 

j sad.gif

 

ps i must remind you all, that this only happened because four days ago, jan t and i both were chatting about how well 7s ran.... since then both he and i have suffered problems !!!!! you gotta laugh... wink.gif

[Roger King]

Wow, this is a weird one!

 

I really don't know the answer, but it may be that the oil has come from the block breather. Does it feed into a catch tank or is it left loose?

 

Come to think of it, on a car of this age, does it have a block breather at all? A lot of Caterhams of this age have it blocked off and rely solely on the filler cap, which is crazy. It may even be if this is the case, that the crankcase has pressurized and forced some oil out somewhere.

 

It would be worth a compression check in case you have suffered from piston failure (they usually break between the rings). When this happens, the engine will usually keep running, but start to breathe heavily.

[Jam Mad]

hi roger,

 

thanks for your advice.. it does have a breather that goes into a catch tank fitted down on the left hand side of the bulkhead. the tank then has a tube that lets any excess out onto the road.

 

driving home after a 10mile trip to bath this afternoon, the same thing has happened.

 

in the event of piston failure ( sounds drastic ! ) would there be other symptoms ? would the engine sound significantly different ?

 

my thoughts at the moment are either.... fine spray of oil coming from a breather tube with a tiny hole in it, or from the engine block where a gasket has ruptured. but in the case of the second, would i not expect to find oily plugs ?

 

anyway, i'm going to clean up the engine tomorrow and try and get it to do it again.. in the hope that i should be able to see where it's coming from.

 

i think we'll be speaking soon.....

 

j sad.gif

[Roger King]

When the pistons break between the rings, the broken piece is held in place by the rings, but is no longer doing it's job in locating the rings properly. Therefore the rings stop working properly. Symptoms may include heavy breathing (the car, not you), reduced performance, oiled plugs, possibly running on three and a half cylinders, etc.

 

This is why I suggest a compression test to see if all cylinders are approximately the same. A cylinder leakage test would be even better.

 

It may be nothing to do with this, but it doesn't take long to check the compressions.

[Graham Perry]

Mine used to pour smoke out the bonnet as well but it never lost power, though. The reason mine smoked like this, was that Caterhams 'ever so good' breather pot was made of plastic in which the hot oil combined with the heat of the exhaust promptly melted one day and when you braked it dumped some of the contents over the manifold !