Hi, need to pull on the experience of any V12 E owners out there

I recently purchased a S3 v12 which has had a lot of money spent on it
over the last 15 years (I have full receipts for a full body restoration and associated service record). The is no specific record of the engine being rebuilt but it has had new rad, carbs, etc rebuilt over time.
Ok so down to the problems(s)

1) On hardish accelaration I get a lot of whitish smoke out the exhaust.
I'm almost sure its oil and not water but can't be 100% and guess it could be valve guide wear but I've heard these are pretty tough and it may be bore wear. Does anyone have any thoughts? Whats would be the average compression rate if I tested each bore and then added a little oil to see if that tightens up the reading for that cylinder.

2) Yesterday I took the car for a run in this 'random' UK weather. The
run was about 30mins, I then stopped for about 10 mins and upon
restart I had smoke from the louvre on the passenger side (RH drive
car). Upon opening the bonnet this appeareed to be coming from the
carb pre-heater manifold. My concern was the heat under the bonnet
which seemed huge and of course the smoke and a very hot rubber smell.
The oil was a little low but no-where near the low mark so I topped up
and drove home carefully. I also notice the dipstick was red hot and
when I removed it, smoke came from the tube (I think I found out what
this was as I since discovered having stripped the air intake off that
the tube passes over the exhaust manifold so I guess it will get hot and smoke when you remove the stick!!). Any ideas? I could see no major oil
leaks aside from some seepage from the rocker cover but this was minor.

Oil pressure wanders but is good, generally about 70psi drops to about
50 to 60 on idle but does wander, is this normal? Water temp on the
gauge is low, the fans work and have an override switch but generally
the gauge shows well below 1/2 and it never boils. It was low on water
when I got it, I have topped it up and have noticed no great loss since

Any ideas / input really appreciated

Thanks
Shaun

Submitted by NE52-32043 on Fri, 12/06/2002 - 11:37

Pat,

The dipstick on the V-12 is different than on the 6's. A tube come up on the driver's side, to the level of the valve covers. There is no felt pad. The dipstick has a plastic handle with a fluted shank that engages with the top of the tube to seal it. Even if the dipstick was out, it is unlikely that oil would rise up through the tube and spill out.

Since the "smoke" is coming from the tailpipe, this must be something internal to the engine. We all have smoke from various places -- oil dripping onto exhaust pipes, ATF leaking onto the pipes, etc. In Ginger's case, the wiring harness in the dash melting down. But if it is coming from the exhaust, it must be internal.

You might want to take a sample of the oil for testing. If there is water in it, likely a head gasket. Burning oil can be from many sources -- piston rings, head gasket, valve stem seals. It is common for these engines to blow some smoke on starting, since the valve stem seals will leak a little oil into the piston chamber while sitting (normal, not a problem). But that should disappear shortly after startup. If you're seeing smoke while running after fully warmed up, it is something else and should be checked out.

Steve Weinstein, JTC-NJ
'72 E-type 2+2
'89 XJS Coupe

p.s. Ginger, the car looks great!! I'll post a picture of Mellow Yellow when it comes back from the shop after the respray.

Submitted by mcload@ev1.net on Fri, 12/06/2002 - 10:03

Shaun: I'm not a V12 guy, buy this almost sounds reminescent of the common problem of not having a fiber/felt seal under the dipstick "stop" at the block. Check to see if you have one, or if the area around the dipstick tube on the block is wet with oil. I hope this is the case.

Patrick McLoad

Submitted by cordag@aol.com on Fri, 12/06/2002 - 09:09

I thought you guys were bringing up what happened to me at the Slalom! ;-p

Hi, Shaun, welcome to the forum. I also have a 1971 E-Type V12 (manual 4 speed) and wish I could give you technical help, but I'm just learning myself. I had an electrical short the other day and had billowing smoke coming from my dash area INSIDE the car. It was stinky. Since getting the car on the road again in July of 2000, I've had various other smokes and flames, but we won't talk about that now. Yes, that V12 engine IS hot and so are the tailpipes. The oil likes to travel down them and smoke all the way.

Hope you get your problems pinpointed quickly, and then you can drive the same.

Ginger Corda
71 SIII 2+2
Florida

Submitted by shaun@paradisi… on Fri, 12/06/2002 - 03:56

Thanks,
I guess its a little wait and see what drops!If its water then head gasket (as there are no other visible leaks from the rad), if the fluids drops any then it could be as suggested the brake fluid or TQF (I'll check revving when stationary to see if I get the same smoke effect)
Also I'll check the head compression for average.
Cheers
Shaun

Submitted by pascal@jcna.com on Thu, 12/05/2002 - 07:49

Shaun

I've always thouht white smoke was water, blue was oil. Compression may vary depending on which model / market, it was higher in the UK. Figures might be in the service manual. It's also important to make sure they are more or less even without large differences...

The V12 is a hot engine but not too that point. I rarely check my oil level when hot but the dipstick will be very how ( I got burned the first time I did... nice blister on my finger... duh) and there are some visible fumes when first opened.

Oil pressure will only wander depending on RPM with a slight reaction time. if RPM is held constant for a while, it shouldn't move.

Are you sure the smell is burned rubber ? I can't think of any rubber burning without serious consequences, could it b burned oil instead, from a leak on the exhaust ?

Pascal Gademer
72 E-type 2+2
00 XKRCoupe
99 XJR