Bought a 1974 on BaT and got a smoke bomb

[mark944T]

Hi all, I bought what I thought was a good 1974 911 2.7 all original CA car with 90k miles on BaT. Turns out it's a mosquito killer. I am going to attempt to rebuild myself and ordered some books and manuals from Pelicans. I have some mechanical ability and can't afford to spend $20k or whatever on a shop rebuild after what I paid.

What specialty tools will I need? I have a lift in my garage and will get an engine cart from Harbor and engine stand. I understand I need a different yoke to put into the stand. Any help is appreciated. This will be my winter project as it snows here. Getting out the heaters..

Thanks

[kenikh]

Did you do a compression/leakdown? Oil tends to weep past the valve caps and pool in the heat exchangers when a car sits a long time. This creates one hell of a smoke show.

Do a leakdown and if numbers are good, take a 100 mile drive to burn out the oil. If so inclined, then open up the valve covers and replace the valve caps with new style teflon caps.

If leakdown is bad, then at least you confirmed before tearing into a new project.

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[LIRS6]

Welcome! Ever own a 911 before? Is it steady smoke, or only when starting? Did you change oil in your new acquisition and possibly over-fill... (accurate check of oil lvl is only when engine hot and idling).

Sounds like you are up for a project, good luck.

Jason

[nomore]

Mark, my 74 came from Ebay out of Florida. I had it shipped to me in In Oakland CA. It smoked like a demon and wouldn't shift in most gears. Totally misrepresented by the seller. Going through it methodically, it now runs well. Have you driven it long enough to let it get really hot? Besides the smoking, how does it run? Don't be discouraged yet. John.

[Glenfield]

Definitely listen to the folks who are advocating for the italian tune up. Go out and thrash it and don’t jump to conclusions too soon

[cmcfaul]

Anything you dont have you can usually borrow from fellow Porsche guys. Things like engine yolk, engine stand, Cam timing tools, stud pullers and other tools you will likely not need again. Join your local PCA club. Members are eager to help one another.

Chris
73 911 E
89 Carrera

[Flat6pac]

Lots of times there is lots of oil in the exhaust from sitting.
You need to burn it out. Out in the country, run in 2 or 3rd at 3000 for a few miles, then at 4000 for a few miles. After that, you should be running clear to 4000. Over 4, you’ll start burning off oil still in the exchangers but you should be clear to 4K.
Bruce

[MIAdragon]

Link to the car on BAT?

[GH85Carrera]

A car that has been sitting may well have been "topped off" to show full of oil on the dip stick when the engine is cold. Determine the real oil level and drive it until it is at full temp, then check the oil at idle.

A leakdown test is important before you jump on a rebuild.

[Aurel]

Drive it and see how many qts of oil it consumes in 1000 miles, that would also indicate if a rebuild is needed.

[kiesan]

Originally Posted by MIAdragon

Link to the car on BAT?

Can’t speak for the op but I’m guessing one of these 2:

https://bringatrailer.com/listing/1974-porsche-911-55/

https://bringatrailer.com/listing/1974-porsche-911-59/

[mark944T]

Thanks for all the replies. I haven't driven it much, about 30 miles, and when I come to a stop smoke is coming out from under the car and it is very blue. Same as out of the exhaust. I'll drive it some more before I tear into it.

I plan on doing a compression and leak down test. I replaced lower valve cover gaskets and oil level is correct at idle. I've owned several Porsches before and do restorations on old Mustangs so have some mechanical knowledge.

Not familiar with valve caps. How would I know if they are bad? Are they in upper valve covers?

I'll check back.

[mark944T]

@kiesen, it's the first one. Since I bought the car I've learn somethings about the seller...

[kenikh]

Valve (guide seal) cap

https://www.pelicanparts.com/More_Info/96410411107.htm?pn=964-104-111-07-M30

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[Locker537]

Good on you for making the best of the situation.

[ab1752]

I think the Italian tuneup is a good idea too, lots of second gear drags and get that thing as hot as you can, provided there are not obvious leaks. Also let it idle down for a minute before you shut it down. Then do a leakdown and compression test, as others have said the flat six by nature can let some oil into the intake but is sounds like you may have something else going on.

At the very least, you can enjoy it for some nice miles then tear into it per your place. Good luck.

[mark944T]

I took it on a brisk 50 miles drive and when I pulled in to the driveway I got a big cloud of blue smoke coming up from under on the drivers side. I let it idle and the oil level was right in the middle of the two dots. It doesn't seem to matter if I go 5 miles or 50 miles the blue cloud when I stop is the same.

Here's a couple photos of that side. The exhaust pipe looked clear so I'm guessing oil is dripping on the heat exchangers from somewhere on the drivers side of the engine. The exhaust pipe will smoke blue on start up though.

[mark944T]

How difficult is it to replace valve stem seals?

[nomore]

Mark can you take a video after stopping at idle? My 74 is really sensitive to oil level, I run a bit
above the lower dot on the dipstick. I don't think new valve stem seals help like they do on a pushrod engine, it seems the guides go bad on these motors. How does the engine run, sound, pull etc? You actually can get a lot of smoke just from a real drip on the heat exchanger. John

[Fairview]

Hi Mark,

Sorry about the troubles but sounds like you have a positive attitude about it.

Does your engine make a “phut phut phut” sound when it’s running? Like it is leaking compression? Just wondering if there is compression loss between cylinder heads and the cylinders causing oil to leak out onto the heat exchangers. Been there before myself.