Blue smoke on startup?

[MadRiver]

Howdy MG people:

I'm thinking of finally diving in and buying an MGC tourer, and there's blue smoke at startup, which dissipates quickly as the engine warms up. Should I be seriously concerned?

Thanks!

 

[LarryK]

Blue smoke on startup is usually vindictive of worn valve guides. Clears up after start and may appear on heavy acceleration. If you know how to remove head, take to machine shop and replace guides, but then rings could be next with full compression up from new guides and gaskets.
It's a how bad you want the car and how you dicker price to overcome the faults. Owner must know and will dicker. I would also do compression test in front of him and show him the figures.

 

[MadRiver]

Thanks Larry. The seller says that the valve guides are new, which could point to rings. Having never done a ring job on an LBC, what does that sort of thing usually cost?

 

[Steve_S]

An MGC is much more expensive to rebuild than an MGB. Parts cost more and there are more of them. I know someone who paid nearly $10K for a performance rebuild on his C engine, but you can get it done for less of course.

 

[Bruce74B]

If the price is right I will take a look at it if you decide not to buy ;-)

Bruce

 

[tony barnhill]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]The seller says that the valve guides are new, which could point to rings.[/QUOTE]

Not necessarily. New valve guides doesn't rule out smoke from valves on startup....if they didn't properly install (or forgot to install) new valve seals, you'll get that little blue puff on startup.

& if it were rings, it probably wouldn't stop when the engine got hot as the oil thins out & would continue to sneak past bad rings - it just wouldn't be so visible.....get it hot & stand behind the car while a friend races the engine...look, feel at the tailpipe, & smell for oily smoke.....if its rings, there'll be a telltale presence.

Before I did anything, however, I'd do both a wet & a dry compression check to see if there's a problem & where its located.

Plus, what's the oil pressure both cold & hot?

Edited: I believe the car's telling you something different than the owner (https://www.theautoist.com/buying_an_MG1.htm)

 

[zahnej]

Tony is right on. I would still suspect guides and or seals. Although a compression test probably would not show guide or seal problems it's still the best test for the overall condition of rings and valve seating.

 

[tony barnhill]

Having said all that: would I let it stand between me & a solid MGC? NOOOOOOOOOOOOOOOOOOO...........

 

[LarryK]

I did not mention seals as some of the early British cars used a valve to guide tolerance. Eg:GT6 no seals in parts manuals and not available. Some used Chevrolet umbrella seals.