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Join Date: Jan 2003
Location: Sunny Tucson, AZ
Posts: 266
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I have a 73 2.0 w/ Dellorto carbs. Engine was overhauled 3,500 miles ago with new bearings, valves & guides, honed cylinders w/ new rings.
Car puts out blue smoke when you pull away from a stop. Also notice a puff of smoke when I change gears. Using a quart of oil in 400 miles. I did a compression test last night. Reads 140lbs on all 4 cylinders. Did a leak down test cold and got #1-10%, #2-12%, #3-10%, #4-14%. Checked the #1 cylinder with the engine warmed up and got a reading of 3%. Just recently discovered that the thermostat was worn out and was not closing the flaps. Re-checked the valve adjustment 4 or 5 times. Synchronized and adjusted the carbs. Checked the timing. The car runs great. Can't figure out how it could be using oil. All of the spark plugs even look good. Any help would be appreciated. Thx, Mark SMOKIN !! |
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Join Date: Jan 2003
Location: Sunny Tucson, AZ
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Nobody willing to take a stab at my problema?? I thought for sure you guys would have some insight.
Should mention it has taken me 7 years to put the 3,500 miles on the car. Bought it a wife and 2 kids and 4 houses ago. Just now getting around to working on it. It has been sitting in the garage w/ a cover over it. Sometimes only comes out one a year for emmissions test. Put a 1,000 miles on it in the last couple of months. Bought the car from a local independent Porsche mechanic. He buys basket case cars and puts them back on the road. He helped me sell my 74 1.8 and sold me the 73 2.0. Thanks, Mark Still SSSmokin! |
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Question,
Is it improving as it is run, or getting worse? What kind of oil is in it.
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Robert 1975 Porsche 914/4-2.0 1972 Ford F100 Ranger XLT 2006 Ducati Sport 1000 323i.net RangerXLT.com |
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I did a compression test when I first noticed the smoke, at about 1500 miles. It had 120lbs in all 4 cylinders. Now it is 140lbs in all 4 cylinders.
Running 20w-50 Kendall oil. Amount of smoke doesn't seem to be changing. Since I installed new thermostat car seems to run a little better. Heater sure works better. Thx, Mark SSSmokin !!
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Location: Williamsburg, VA
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This maybe a stab but..could oil be running or dripping onto the heat exchanger? As you shift and take off the engine torques and the oil may be getting onto the HOT exchanger and then getting blown out the rear of the car as you are moving???
Just a thought? Oil coolier seals? Do you see oil under the car? Kerry
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Kerry (Back on the road, sort of) 914-6 in the Werks |
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Join Date: Aug 2000
Location: Corpus Christi, TX
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with that low of mileage I'd look real hard for a leak.
Any chance the rebuild was second rate? could be a ring installed upside down. that will let oil get past the rings. |
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Location: Sunny Tucson, AZ
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Engine is pretty dry underneath. Slight leak from oil temp sender. takes about a week to leave a drop.
Pretty sure it is coming from the tail pipe. If you shift just right it will blow a smoke ring or two. In the last post I said I was using Kendall oil? I meant Castrol, is Kendall even a brand of oil? Thx, Mark SSSmokin in Tucson AZ |
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If it was one ring installed upside down I would have a bad reading on that cylinder. Compression was 140 on all 4, checked it twice. Spark plugs all looked good. No oil on or around the plugs.
I am going to do another leakdown on all 4 cylinders only warm this time. Thx, Mark |
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Location: Corpus Christi, TX
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Kendall is indeed a brand of oil.
I don't know how much an upside down ring would affect a compression check...but it will pass oil. A worn valve guide or seal will also pass oil but should not affect compression. perhaps a valve stem seal was damaged during head assembly? I know you hate too think your rebuild is bad already, but the oil is going somewhere. Maybe an o-ring is leaking on the oil cooler? You are leaking or buring somewhere...leak is better than burn... |
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I wish it was a leak. I can deal w/ leaks.
It is leaking out the tail pipe in the form of blue smoke. Thx, Mark |
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3500 miles in 7 years...I wonder if valve stem seals, or any seals, can go bad from lack of use?
I'm using quite a bit of oil too...85000 miles...but I have not actively driven the car in 5 years. Maybe once every few months of so and it did sit for over 3 years without even starting. I just got it licenced back on the street last month. I know a have some leaks but I fear it's something more. |
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Do they have valve stem seals? I have parused the "How to Rebuild VW Eengine" manual and the Haynes manual & neither one make mention of valve stem seals.
Thanks, Mark SSSmokin !! |
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There are no valve stem seals on a type 4. When you do a compression test do it warm and get the readings. Next squirt a little oil into each cylinder and retest. If the readings go up the rings are bad/not seated. If this does nothing odds are it's the valve guides.
Geoff
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I have 140lbs of compression now. What should you expect from a fresh overhaul of a 73 2.0 w/ the US spec dished pistons?
Thx, Mark SSSmokin!!
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Ring gaps
I will bet the oil control ring gap is situated at the botom of the cylinder vs. the top. When I bought my car it smiked like a mosquito truck. After pulling the motor I discovered all kinds of lack of attention to detail. But anyway that is your problem.
I always do it myself it either gets done right or I screw it up. At least I didn't pay someone to screw it up.
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Did it smoke all the time or just when you pulled away from a stop?
Mark SSSmokin !!
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Maybe they lined all three ring gaps up on the bottom....... saw that years ago.
Geoff
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76 914 2.0L Nepal Orange (2056 w/Djet FI, Raby Cam, 9to1 compression) www.914Club.com My Gallery Page |
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Now, I'm gonna admit that I read this and I don't know it first hand. If you baby the motor too much after rebuild, the rings won't seat as they need the pressure of hard acceleration to wear in. Futhermore, if the engine continues to be run softly, the cross hatching on the cylinder walls will be worn smooth making it virtually imposible to seat the rings in any short period ot time. Even 3500 miles. I don't have a lot of patience, so I'd never have discovered this on my own. I nail 'em when they're new. You might try a couple of hard runs to see.
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Amark, for where you live I see no need for a multi-viscosity oil! speaking from experience that has always caused leaks in these motors. I would use 30 even 40wt oil in those conditions and like Zeke said "put the pedal to the metal"(just my 2 bits)
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Heck, I don't remember how high Tuscon is.
I would expect about 150 on a fresh engine. Perhaps more. The fact that the readings are coming up seems to say, to me, that the rings aren't really seated yet. Valve guide problems usually show up as smoke on overrun (coasting at high RPMs with the throttle closed), or when you get back onto the throttle after overrun. Smoke just plain on acceleration would seem to be rings. I have heard of rings that passed oil while they still held a decent amount of compression.... --DD
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