1. Home
  2. Jaguar Autos
  3. Small cloud of blue smoke - potential remedy

Small cloud of blue smoke - potential remedy

Our 1994 XJ 40 4.0L (86K on the clock and bought one year ago) has had the characteristic smoke cloud (valve stem oil seals relarted) but over the last year this has reduced dramatically. The cars history includes

7 years with only 17K miles inc one year with only 600 miles. Since we bought it (one year ago) I have given it a real thrashing at least once a day and the car loves it, the engine loves it and I have to say I do too. It would appear that the 10K miles in the last year inc motorway work has done the engine the world of good. However, I have heard rumours that there may be an oil additive that will help re-soften the oil seals and therefore attenuate the (now) slight blue "puff". I am currently of the belief that the only cure is a cylinder head revamp but am open to suggestions. In my experience, once you take an engine apart in any way it is never the same again. Does anyone know about any truth in this rumour?
Reply to
snowy
Loading thread data ...

I have a 1988 XJ40, and like yours -- it puffs blue smoke in the morning. Actually, it is slightly more than a puff but not much. There is no "snake oil" additive cure for the problem. Usually, anything you add will create problems, not eliminate them. Keep in mind that anything you add to change the characteristics of one set of seals will change the characteristics of ALL the seals that it comes in contact with. That may "cure" one problem and make others.

Most owners of XJ40s fix the seals when they do the inevitable head gasket replacement. I have been fortunate, however in that I now have 208,000 miles on the clock with the same slight puff and the same head gasket. If I were you, I would just learn to live with it for now as it is really doing no harm

Webserve

Reply to
webserve

Thank you vey much. As the car has just had its MOT with perfect emissions results for the cat I am very inclined to agree. I think that the (now) one litre per 10k miles oil consumption, which can live with, I think I shall leave thngs alone. Once again thnk you!

Reply to
snowy

Hi,

Truly the puff of smoke is more of an annoyance then it is a sign of trouble. A little oil drooling down the vavles is ok by me.

Blake

Reply to
Blake Dodson

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.