HELP....Exhaust shooting white smoke when I punch it?, What is causing this white smoke?? |
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HELP....Exhaust shooting white smoke when I punch it?, What is causing this white smoke?? |
jersey914 |
Nov 4 2012, 08:34 AM
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#1
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Member Group: Members Posts: 161 Joined: 6-September 12 From: Marlton, NJ Member No.: 14,895 Region Association: North East States |
I have a 74' 2.0 running Dual Dellorto DLRA 36 carbs. I just got my car back from my Porsche mechanic and I haven't had a chance to report back to him how it is running. I figured I would check with the experts until I can speak with him next week:
The car started great and runs great except that when I really punch it in 2nd or 3rd gear - at the moment of shifting, my wife (driving behind my car) says there is a puff of white smoke that is releasing from the exhaust. When I just resume normal driving or shifting without punching the accelerator before shifting, there is no exhaust plume. I am wondering what you guys think may be causing this?? Here is what was serviced on the car in the case that you think that the problem could be related to the servicing: I had him remove the oil temp sending unit and replace sealing washer, housing o ring and housing gasket He removed oil sump screen and cleaned - replaced the gaskets and sealing washer Removed rocker assemblies and push rod tubes replaced and resealed all Adjusted valves and replaced gaskets As you can see, nothing was done to the carbs which is what I think you guys are going to say is probably the problem but because of all the oil that had leaked prior to sealing up the leaks I thought there's a long shot that there could be some correlation so i shared. The car runs great with no apparent back fires that I heard on this first 1/2 hour test drive. (IMG:style_emoticons/default/WTF.gif) |
Mike Bellis |
Nov 4 2012, 08:57 AM
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#2
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Resident Electrician Group: Members Posts: 8,345 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
Black smoke would be carbs, white smoke would be oil.
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914itis |
Nov 4 2012, 09:34 AM
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#3
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Advanced Member Group: Members Posts: 2,892 Joined: 9-October 10 From: New York City Member No.: 12,256 Region Association: North East States |
MAybe lol residue from the leaks? I would drive it for a few more miles to see if it goes away .
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DBCooper |
Nov 4 2012, 09:34 AM
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#4
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14's in the 13's with ATTITUDE Group: Members Posts: 3,079 Joined: 25-August 04 From: Dazed and Confused Member No.: 2,618 Region Association: Northern California |
In most cars white smoke would indicate antifreeze and a bad head gasket. Not most of ours, of course. If I understand your description correctly, that there's a little puff right when you shift and no other time, it sounds like worn valve guides. When you're accelerating there's pressure in the cylinders, then when you lift to shift that switches to vacuum and will pull any oil that's between the valve stems and guide into the cylinder, where it will burn with white (bluish) smoke.
If that's the case you should be able to re-create the conditions by just lifting from the gas on a long downhill slope but leaving the car in gear. The "puff" will turn into a prolonged but thinner exhale of that white smoke. |
MrLeeS |
Nov 4 2012, 09:40 AM
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#5
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Member Group: Members Posts: 62 Joined: 25-April 09 From: Albuquerque, NM Member No.: 10,300 Region Association: Southwest Region |
He had to drain the oil to do this work. What weght oil did he replace it with? It may be a thinner ol slippng past the rings under high vaccum, similar to the above valve guide suggestion. Seems the oil change is catalyst for the problem.
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Lennies914 |
Nov 4 2012, 09:52 AM
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#6
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Slacker Group: Members Posts: 828 Joined: 9-January 10 From: NorCal Member No.: 11,216 Region Association: Northern California |
My car does the same thing. Only time I can actually see it for myself is on a long downhill in 3rd gear with my foot off the accelerator. Other than that, fellow teeners have mentioned it to me on the runs. All have said valve guides.
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ConeDodger |
Nov 4 2012, 10:01 AM
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#7
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Apex killer! Group: Members Posts: 23,589 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California |
What's behind you is in the past... Move on and don't let it concern you. But check your oil often...
OOooohm... The Zen answer (IMG:style_emoticons/default/rolleyes.gif) |
gothspeed |
Nov 4 2012, 10:04 AM
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#8
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
He had to drain the oil to do this work. What weght oil did he replace it with? It may be a thinner ol slippng past the rings under high vaccum, similar to the above valve guide suggestion. Seems the oil change is catalyst for the problem. +1 ......... either too thin for the age of the guides or possibly overfilled. |
wingnut86 |
Nov 4 2012, 10:12 AM
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#9
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...boola la boo boola boo... Group: Members Posts: 1,053 Joined: 22-April 10 From: South Carolina Member No.: 11,645 Region Association: South East States |
1- Did he remove the valves themselves and mark them to put them back in proper location?
2- The same goes for the lifters and valve top-end? 3- Did he use an oil flush method that loosened up all the old varnish that may have existed in the motor prior? - important because that stuff usually develops a pattern in the way the oil flows- cleaning or flushing changes that flow geometry, so to speak 4- If more than 2 of the above, then your valves need to reseat a bit to find their new home, IF the valves weren't pulled and placed in different guides All the responses are along the same lines, waiting to see how she breaks in. Keep tabs on your oil loss and let us know. There are different thoughts around running break-in oil at this point for the next 200 miles and then change it out, probably fewer miles. Then swap over to the recommended weight. Run her below 4000 rpm for a bit and see how she responds... Good Luck, Wingnut |
jersey914 |
Nov 4 2012, 10:44 AM
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#10
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Member Group: Members Posts: 161 Joined: 6-September 12 From: Marlton, NJ Member No.: 14,895 Region Association: North East States |
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jersey914 |
Nov 4 2012, 10:50 AM
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#11
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Member Group: Members Posts: 161 Joined: 6-September 12 From: Marlton, NJ Member No.: 14,895 Region Association: North East States |
1- Did he remove the valves themselves and mark them to put them back in proper location? 2- The same goes for the lifters and valve top-end? 3- Did he use an oil flush method that loosened up all the old varnish that may have existed in the motor prior? - important because that stuff usually develops a pattern in the way the oil flows- cleaning or flushing changes that flow geometry, so to speak 4- If more than 2 of the above, then your valves need to reseat a bit to find their new home, IF the valves weren't pulled and placed in different guides All the responses are along the same lines, waiting to see how she breaks in. Keep tabs on your oil loss and let us know. There are different thoughts around running break-in oil at this point for the next 200 miles and then change it out, probably fewer miles. Then swap over to the recommended weight. Run her below 4000 rpm for a bit and see how she responds... Good Luck, Wingnut He did say prior to doing everything that I needed to run it for about 100 miles or so and then change the oil and filter again. Then do that again after another few hours of running it. Then by the third time, Most of the crap should be out. Thx! |
Gint |
Nov 4 2012, 10:51 AM
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#12
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Mike Ginter Group: Admin Posts: 16,075 Joined: 26-December 02 From: Denver CO. Member No.: 20 Region Association: Rocky Mountains |
Sounds like a coolant leak. (IMG:style_emoticons/default/laugh.gif)
QUOTE puff of white smoke A puff? Big deal. Most 914's "puff" a little smoke now and then. |
carr914 |
Nov 4 2012, 10:52 AM
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#13
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Racer from Birth Group: Members Posts: 118,694 Joined: 2-February 04 From: Tampa,FL Member No.: 1,623 Region Association: South East States |
He had to drain the oil to do this work. What weght oil did he replace it with? It may be a thinner ol slippng past the rings under high vaccum, similar to the above valve guide suggestion. Seems the oil change is catalyst for the problem. 20/50 Synthetic or Dino? |
jersey914 |
Nov 4 2012, 11:40 AM
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#14
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Member Group: Members Posts: 161 Joined: 6-September 12 From: Marlton, NJ Member No.: 14,895 Region Association: North East States |
He had to drain the oil to do this work. What weght oil did he replace it with? It may be a thinner ol slippng past the rings under high vaccum, similar to the above valve guide suggestion. Seems the oil change is catalyst for the problem. 20/50 Synthetic or Dino? Dino |
timothy_nd28 |
Nov 4 2012, 11:58 AM
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#15
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Advanced Member Group: Members Posts: 2,299 Joined: 25-September 07 From: IN Member No.: 8,154 Region Association: Upper MidWest |
water in the fuel (IMG:style_emoticons/default/confused24.gif)
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underthetire |
Nov 4 2012, 12:02 PM
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#16
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914 Guru Group: Members Posts: 5,062 Joined: 7-October 08 From: Brentwood Member No.: 9,623 Region Association: Northern California |
Sounds like a oil ring to me. Valve guides usually puff smoke when you start the car. The decel is pulling oil past the rings.
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gothspeed |
Nov 4 2012, 01:04 PM
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#17
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
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Robert21 |
Nov 4 2012, 02:15 PM
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#18
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ron21 Group: Members Posts: 288 Joined: 9-July 04 From: Seal Beach Ca 90630 Orange co Member No.: 2,330 Region Association: None |
I had some the samething happen to me , driving on fwy , doing 70 , smoke
coming from engine . it turn out to be PVC valve. put in a new pcv valve no more smoke. i do have fuel injection on my 2.0 engine . hope this helps. Attached thumbnail(s) |
jersey914 |
Nov 4 2012, 03:38 PM
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#19
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Member Group: Members Posts: 161 Joined: 6-September 12 From: Marlton, NJ Member No.: 14,895 Region Association: North East States |
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IronHillRestorations |
Nov 4 2012, 08:34 PM
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#20
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I. I. R. C. Group: Members Posts: 6,719 Joined: 18-March 03 From: West TN Member No.: 439 Region Association: None |
Worn valve guides, but until you are burning a quart of oil every 500 miles, drive it like you stole it.
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