98 c70 hpt blue smoke when started

socompsp · Post by **socompsp** » 21 Dec 2013, 06:30

ever since my dad passed in October i have been driving his car. my c70 has been parked since. i decided to start it up yesterday and it smoked like a chimney. i know it oil getting passed the valve seals, but my concern is why. it had a head job due to burnt valves less than 6k miles ago, and the seals were replaced. could they have gone bad already from sitting? is it safe to let it idle or softly drive it without worrying about burning valves again? i love this car and feel bad for letting her sit all alone for so long, and really dont want to burn more valves. what should i do?

Post by **jblackburn** » 21 Dec 2013, 07:48

Just drive it. They hate sitting. Mine will smoke up a storm sometimes.

The PCV system might need looking into - warm it up and pull out the oil dipstick and check for smoke puffing out the opening.

socompsp · Post by **socompsp** » 21 Dec 2013, 09:39

ive done the balloon test prior to it sitting and it was fine but i guess its a good idea to check again thanks.

Post by **rspi** » 21 Dec 2013, 11:16

If you checked the PCV system within 10,000 miles it still should be good. If they rebuilt the head and actually did the valve stem seals, they should NOT be leaking ANY oil, even after sitting for a year. The last equation as for oil leaks is the turbo. From what I have recently learned, leaking valve stem seals do NOT cause burnt valves.

If it's not the turbo, it could be a fuel mixture problem which will cause burnt valves. Rich or lean conditions should be fixed ASAP.

socompsp · Post by **socompsp** » 21 Dec 2013, 12:09

it was to my understanding that oil coated valves will burn. i didnt even consider the turbo, it would be my luck the seals within it have gone. i guess theres only one way to find out, drive it the 30 miles home.

Post by **rspi** » 21 Dec 2013, 12:28

Shouldn't be a problem driving it. You can pull the intake and see if the turbo has shaft play.

I thought that leaking valve stem seals caused burnt valves as well, but if you think about how many of these cars have leaking valve stem seals, all of them would burn valves. Then I have spoken to several people that did NOT have leaking seals but did burn a valve. So I visited a few very good shops in my area, including the ones that rebuild heads, and they pretty much convinced me that the problem lies in a bad fuel to air mix, which causes the valves to get hot. Likely a bad fuel injector or intake air leak.

socompsp · Post by **socompsp** » 21 Dec 2013, 14:06

in either case im worried. cause if it is a/f mix then the cause of the original burn hasnt been fixed. and if oil causes burned valves im also screwed. and if both possibley contribute then the outcome looks grim. in any case if i burn some more im gonna have some fun with it, killing the motor in the process. gonna try running it home and if i lose compression in a cyl then im disabling the wastegate and having some much deserved fun. then im either gonna get a new motor and ship to a machine shop to have it filled with forged internals, or im gonna buy that lotus ive had my eyes on. we shall see how it goes in the next few days when i get the time to go get it.

Post by **MoVolvos** » 21 Dec 2013, 20:31

_

These cars do not sit well even for a month. Next time pull the plugs and put half a teaspoon of oil into the cylinder, pull the fuel pump relay and crank the engine about half a dozen times. The fuel cleaning of and the lack of residual oil on the cylinder walls when you first fired it up created the blow by (blue smoke).

Blessings,

BKM

_

Post by **rspi** » 21 Dec 2013, 21:23

BKM, you have a trigger mouse button.

Anyway, I doubt you will burn a valve in a week. If I were you, I would figure out which valve burnt and have that injector checked (you'll have to remove it and send it to a shop).

socompsp · Post by **socompsp** » 21 Dec 2013, 23:08

well when i ran it on the day in question, it was only a minute IF that. it never had the chance to burn off the oil. ill try the oil in the cyl since it had been sitting for two months, give or take a few days, it couldnt hurt it.