Car burning oil when it starts

fire_kitten, Jan 16, 3:46am
Can anyone please tell if if this is a big problem, I test drove a mates car I'm looking to buy: when the car starts some smoke comes out from the exhaust. It only happens when the car hasn't been started overnight or so and it goes away pretty fast. Thanks.
jasongroves, Jan 16, 3:51am
Are you sure its smoke and not condensation!
fire_kitten, Jan 16, 3:55am
The guy who owns it said that sometimes smoke comes out, but it doesn't keep smoking.
andy61, Jan 16, 4:01am
Walk away,plenty of better cars out there.Its only going to cost you money to have the problem sorted.
morrisman1, Jan 16, 4:02am
Might be valve stem seals leaking oil down when engine isnt running. a good way to test is to drive down a steep hill (without foot on accelerator) then at the bottom floor it and see if you get blue smoke come out. Might need to get someone to follow and observe
carkitter, Jan 16, 4:04am
Valve guide seals are worn, cylinder head needs to come off.
fire_kitten, Jan 16, 4:06am
Is that an easy fix! I had someone look at it on a hoist, said it was very tidy and dry, no leaks.
bigfatmat1, Jan 16, 4:24am
Some cars you can do in place. So this may not be the case
ginga4lyfe, Jan 16, 4:32am
General rule of thumb. NEVER BUY A CAR FROM A FRIEND
tortron, Jan 16, 4:37am
what colour is the smoke!
fire_kitten, Jan 16, 4:39am
It was grey, not black.
skin1235, Jan 16, 4:46am
grey equals oil, valve guides seals are weeping
contrary to above the head does not have to come off
if you insist it must be fixed it can be done without removing the head, personally I wouldn't be too worried about it if the only sign is at the first start
like any valve work it can be messy, you certainly don't come out of the shed with clean hands
fire_kitten, Jan 16, 5:14am
Lol! Toyota Curren 96 2ltr. I will check with my mechainc tomorrow since I haven't had the chance :)
rob_man, Jan 16, 5:23am
Valve guide seals are my first call too. It can be lived with.
I would give it the downhill test though to ensure it's not the rings, this can also be tested by letting the motor idle for a few minutes and flooring it.
carkitter, Jan 16, 5:23am
The leak is within the motor not external. Oil leaks into the combustion chamber and is burnt along with the fuel and air, adversely affecting the performance, economy and eco-friendliness of the car.
carkitter, Jan 16, 5:44am
The pistons will be covered in soot and sludge. On my FWD Sigma GSR the sludge was significant and definately needed to come out to prevent pre-ignition. Replacing them in place is a short cut some mechanics have developed but I wouldn't be recommending it to a customer.

To the OP: Don't bother with this car, plenty of others around.
skin1235, Jan 16, 5:51am
good advice OP
by the time the guides seals start leaking there is going to be a lot more worn inside
replacing them alone is a stopgap measure, and yes not normally recommended to paying customers
type of thing I'd do for a mate who wanted the extra yr out of his car before replacing it ( and wrecking the old one)
skin1235, Jan 16, 8:21am
no, that big puff of smoke when you blip it at the bottom usually means stem seals
fire_kitten, Jan 17, 11:36pm
If anyone wants to know if they are right: Old worn velves leaking a bit of oil on the pistons when the cold engine starts, results in a *poof* of smoke when it starts and it won't cause any damage.
thejazzpianoma, Jan 17, 11:45pm
What so many forget is that any modern car that has been doing any sort of visible smoking for a while (even just at start up) will have more than likely well ruined the catalytic converter.

Sure you can bodge it and just cut it out in the hope that we never have a change in emission laws but you do need to be aware that if it needs to be replaced with new at any time it will be very expensive. Plus you have to fix the smoking problem or the same will happen again and ruin the new one.
thejazzpianoma, Jan 2, 1:50am
Except as explained above.