I'm asking this for a friend that's not too active on the forums.

He's got a 98 XJ 4.0 with 136k miles...he said today he was driving and suddenly the engine started smoking, oil pressure dropped and it pulled to the right, even worse with the brakes on. He got home and checked the fluids and everything was ok.


One possible explanation I have is the oil pressure sender went bad (it has been erratically reading for a while I think) and it was a coincidence with a caliper seizing up.

I get this is super hard to diagnose without seeing it, which I haven't either, but I was just wondering if anyone thought they could be related. Thanks!

 

I'm betting the smoke and pulling was just a caliper getting stuck on the caliper slide (part of the knuckle). I wouldn't immediately think that would be connected to any type of oil pressure abnormality.

I have noticed that the 3 times I've responded to a post about "seeing engine smoke", all three times it was a caliper. I've had this myself, twice, and smoke from the caliper is very obvious because it rolls up out of the wheel well. Engine smoke, from oil hitting hot components, has a much higher likelyhood of going under the vehicle, and being spotted out of the rear view mirror, if at all.

Btw, if it was a passenger side caliper, perhaps it got hot enough to affect the oil pressure sending unit and mess with its readings/function (this is just a stab in the dark). If the caliper was stuck for a while it can get crazy hot. I had to spray one down in a car wash once, and even after the 4th long spray down it was too hot to touch. So I'm guessing it was originally in the 600-800f range at its worst.

 

That sounds logical. Hopefully I'll get a chance to look at it this weekend. Thanks!

 

Ended up being a stuck slide pin on the passenger side caliper. Put in new ones and seems ok.