looking at a V12 and need some advice on the engine

[holyegj]

Hello all,

Well are many years I'm now looking for a E-type and just looked at a v12 and would like your thoughts.

So its a 72 v12 from the usa, the problem is the engine is knocking / clicking on both banks at the front. Its also pushing out a bit of blues smoke, oh and the exhaust is leaking both banks. I think its had a water issue at some point as well.

So not a great one but I would like to understand more.

My questions,
1) are they prone to exhaust header issues?
2) I know that can drop valve seats, is this common and if water (or lack of water induced) are there particular valves the are vulnerable ? i.e. could this be the knocking at the front.
3) Can the cam chains make a knocking on the front?
4) I'm thinking the rings are shot so maybe the bores as well. Although it starts very well.

Many thanks for any thoughts.

Regards Geoff.

[MarekH]

1/ If you hit speed humps, then you can crack an exhaust manifold. It ought to be present as a visible black carbon track along the crack and you'll feel the gas hot escaping with a continuous phut-phut-phut sound. The manifolds are a bear to replace as the topside of the engine on that side has come off to get to them. The only saving grace is once they are thoroughly broken, it is easier to take them off in pieces than as a single unit.

2/ It isn't particularly common as the etype v12 is not known for overheating. You should be able to hear it I would have thought.

3/ There is only one chain which goes around everything. It won't knock, but if the tensioner is snapped, then you'll hear a metallic rattle from the front as you come off of the power. The whole front and bottom of the engine has to come off to replace.

4/ So the blue smoke is the valve guides then?

kind regards
Marek

[holyegj]

Thanks MarekH,

Interesting and thanks, the knock from the front of both banks sounds like a very bad tappet clearance, but you would expect taps to be all along or random where this noise is clearly from the front and seems to be both side.

;-)

Thanks Geoff

[MarekH]

You can see the chain through the B-bank oil filler cap.
There is an inspection hole for timing chain wear on the front timing cover.

It isn't always possible to remotely diagnose things without accurate descriptions, so a knock is a knock and might well be chain related.

The knowledgebase elsewhere on this site has exploded diagrams of the engine which may help you better.

kind regards
Marek

[abowie]

I would avoid it like the plague.

A rebuild on the V12 engine is likely to cost you more than the asking price of the car, and as Marek says it's hard enough to make a diagnosis of noises in engines when they're running in front of you, never mind remotely by Internet forum.

Move on and find a car with a good engine that is a registered current driver.

[lowact]

72 us spec, same as mine. Do the numbers match, Is it substantially original? If so it will need a full rebuild, even if it was in seemingly immaculate condition. Due to age, everything that is rubber or plastic (incl valve seals) will be brittle and cracked, complete dismantle and rebuild will be required. Means a car that presents with issues will save you money in the long run as you will be less likely to commit to an over-the-top purchase price. Also means all of the issues currently apparent will be found and fixed as a matter of course. Expensive if u have to pay someone else to do it. Lot of fun if you can do it yourself.