Help: white smoke
Discussion
Hello,
I am a new member and a fairly new owner of a 2.0L S2. I was hoping someone could help me with a problem I am having with my car.
I am getting white smoke from the exhaust (which is really bad on acceleration. I have checked for water in the oil and visa versa as I initially thought of a head gasket failure. All seemed OK so I did a compression test which gave a result of 9.5 on all cylinders (should this be 11.5?). I then checked the ignition timing and this is OK. The only thing I noticed is that the timing marks on the can spigots are not exactly aligned.
Can anyone give me any ideas as I am stumped
I am a new member and a fairly new owner of a 2.0L S2. I was hoping someone could help me with a problem I am having with my car.
I am getting white smoke from the exhaust (which is really bad on acceleration. I have checked for water in the oil and visa versa as I initially thought of a head gasket failure. All seemed OK so I did a compression test which gave a result of 9.5 on all cylinders (should this be 11.5?). I then checked the ignition timing and this is OK. The only thing I noticed is that the timing marks on the can spigots are not exactly aligned.
Can anyone give me any ideas as I am stumped
You might check all of the coolant hose clamps and caps to make sure they are on tight as well. I had a problem earlier this year where one of my hoses would leak at high RPM and blow white 'smoke' behind the car. I couldn't tell for certain if it was coming out of the exhaust pipe, but the problem went away after I tightened the clamps up a bit. Mine was likely just the coolant hitting the exhaust and turning to steam, making a rather nice 007'ish smoke screen, albeit unintentionally. 
regards,
Bill
'95 S4S
regards,
Bill
'95 S4S
Paresh,
The S2 engine's normal compression ratio was 9.5:1. What Psi reading did you get for each cylinder? The Lotus-spec is 11.65-12.65 kg/ sq cm (165-180 Psi). And the readings across all four cylinders should be uniform within 10 psi. (US Federal 907s had 8.4:1 compression and were spec'd at 10.55-11.95 kg/ sq cm… or 150-170 Psi).
Is the smoke white like steam, and with a sweet smell of anti-freeze? Or does it have a bluish-gray cast and smell of burned oil? Does the engine run hotter than it used to?
Steam could indicate a blown head gasket. It could also indicate a bad intake manifold gasket (water leaking into an intake runner), a cracked head, or a cracked cylinder liner. With any of those problems, the engine will often run hotter than normal as combustion gases leak into the cooling jacket. Sometimes you can see bubbles in the header tank while the engine is running.
Bluish-gray oil smoke that gets much worse on full throttle acceleration is most likely bad rings… and/or scored cylinder walls. A brief cloud of smoke on start-up or when the throttle is first applied after coasting on over-run with the throttle closed would indicate worn valve guides.
A bad head gasket, bad intake manifold gasket or worn valve guides can be repaired with the engine in the car. Any of the other scenarios calls for a general engine rebuild.
How far off is the cam timing? The timing belt can only jump in whole tooth increments. So if the dots mis-align by less than a tooth width either side of the centerline between the cams, then the cause is just the accumulation of tolerances in manufacturing or a shaved head.
If the cam timing is off by only a tooth or two, then it's probably coincidental to the smoke problem... ie, it's not causing the smoke.
If the cam timing is off by a lot, then it's possible that a piston has struck a valve and driven it into the combustion chamber, cracking it. But that would be pretty extreme, it would be noisy, and the engine would run like crap if it ran at all. If it's running well enough to accelerate at full throttle and make smoke as you indicate, then I doubt that it's jumped timing far enough to wipe out valves.
Regards and best of luck,
Tim Engel
Lotus Owners Oftha North
Minnesota, USA
The S2 engine's normal compression ratio was 9.5:1. What Psi reading did you get for each cylinder? The Lotus-spec is 11.65-12.65 kg/ sq cm (165-180 Psi). And the readings across all four cylinders should be uniform within 10 psi. (US Federal 907s had 8.4:1 compression and were spec'd at 10.55-11.95 kg/ sq cm… or 150-170 Psi).
Is the smoke white like steam, and with a sweet smell of anti-freeze? Or does it have a bluish-gray cast and smell of burned oil? Does the engine run hotter than it used to?
Steam could indicate a blown head gasket. It could also indicate a bad intake manifold gasket (water leaking into an intake runner), a cracked head, or a cracked cylinder liner. With any of those problems, the engine will often run hotter than normal as combustion gases leak into the cooling jacket. Sometimes you can see bubbles in the header tank while the engine is running.
Bluish-gray oil smoke that gets much worse on full throttle acceleration is most likely bad rings… and/or scored cylinder walls. A brief cloud of smoke on start-up or when the throttle is first applied after coasting on over-run with the throttle closed would indicate worn valve guides.
A bad head gasket, bad intake manifold gasket or worn valve guides can be repaired with the engine in the car. Any of the other scenarios calls for a general engine rebuild.
How far off is the cam timing? The timing belt can only jump in whole tooth increments. So if the dots mis-align by less than a tooth width either side of the centerline between the cams, then the cause is just the accumulation of tolerances in manufacturing or a shaved head.
If the cam timing is off by only a tooth or two, then it's probably coincidental to the smoke problem... ie, it's not causing the smoke.
If the cam timing is off by a lot, then it's possible that a piston has struck a valve and driven it into the combustion chamber, cracking it. But that would be pretty extreme, it would be noisy, and the engine would run like crap if it ran at all. If it's running well enough to accelerate at full throttle and make smoke as you indicate, then I doubt that it's jumped timing far enough to wipe out valves.
Regards and best of luck,
Tim Engel
Lotus Owners Oftha North
Minnesota, USA
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