blue smoke now and then

bens2220 · 03-16-2012, 02:28 PM

hi, I'm new to this forum my name is Ben and lIve in the UK.
Ive just been gIven a 1973 911 t with a blue smoke problem. i have been messing around with beetle's and campers for years so have no problem with working on these.
right i will tell you a bit about the car, it ha a full engine rebuild to a 2.7 from 2.4 ( i think its a mfi) about 12 years ago. it went in for a gearbox rebuild 6 years ago the never collected by my dad?? (long story) it ran like a dream apparently before this.
it has been sat for the last 6 years being started an moved around the garage where it was left.
i got the car a few weeks ago it starts and runs like a dream but it does pop now and then, i think this is down to the injectors could be wrong. but the problem i have got is when it first starts its a bit smoky, i take it for a run then it blows loads of blue smoke then it clears up ? take it for a run then starts kick out the smoke?
not sure if this is a common problem with 911 that have been sat or just needs new valve stem seals or rings.
i spoke to a guy he said the oil can weep past the valve stem seals if the car has been sitting for a while?
any help or pointer would be great. thanks in advance Ben

Jdub · 03-16-2012, 03:00 PM

Following any run that circulates the oil thoroughly, ending with a 1 minute idle to remove oil from the sump, you should be able to start the car again when cold and get a good picture of how your car is using oil. Generally (I say GENERALLY) the pattern of cold-start smoking following this shut down routine will provide startup data on smoke.

Blue smoke when driving in town/hiway, esp. a solid puff at a time, or a seeming slowup and BANG is cause to investigate further. Valve stems? Oil control rings? Hard to say, but you'd do well to give this car a very nice long run and dump the oil, fill up to correct level (see Archives - critical this be done right) and see how it works going forward.

afterburn 549 · 03-16-2012, 03:06 PM

2.7 needs a oil up date mod. (and a bunch of other things) That might be your problem as it can not scavage fast enough in certain conditions
Like said if the stock copper guides are there that is an other problem

bens2220 · 03-16-2012, 03:13 PM

Quote:

Originally Posted by Jdub

Following any run that circulates the oil thoroughly, ending with a 1 minute idle to remove oil from the sump, you should be able to start the car again when cold and get a good picture of how your car is using oil. Generally (I say GENERALLY) the pattern of cold-start smoking following this shut down routine will provide startup data on smoke.

Blue smoke when driving in town/hiway, esp. a solid puff at a time, or a seeming slowup and BANG is cause to investigate further. Valve stems? Oil control rings? Hard to say, but you'd do well to give this car a very nice long run and dump the oil, fill up to correct level (see Archives - critical this be done right) and see how it works going forward.

thanks for the info regards shut down routine, another point i should have made is there is a lot of fumes in the cab when the heaters are on, it smell like old burning oil not fresh exhaust fumes would this be down to a problem with the heat exchanges as these were fitted when the gearbox work was done and look to be in good shape.
any advice on the popping, it sound like its coming from the rhs of the engine. i was going to pull the injectors of and get them cleaned as this is what i think the problem is.
thanks

afterburn 549 · 03-16-2012, 03:20 PM

The 2.7 is great after all the mods are done.......But most will tell you to skip it and go get AL case rather then use the mag
The 2.7 is famous for pulled studs (cylinder/head)
too small a fan
wrong heat exchngers
bad guides
How ever..once all is addresed you have a engine 30 pounds or so lighter then a Al. one i am told.
I redid my 2.7 and happy with it.....but you have do what you want
I would guess the pop to be a cylinder stud loose or broke...But ck the simple things first B4 jumping