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  #1  
Old 12-11-2001, 11:21 PM
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Join Date: Oct 2001
Location: Minneapolis
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1987 300 TDT cold start up

I've come to expect smokey / rough idle start ups as a fact of life - usually clears up in 2 or 3 minutes. Lately though I've kept the key turned well after the engine is running (about 5 sec). Then I came across this in the owners manual regarding cold engine starting: "........release key only when the engine is firing regularly" This seems to work, smokey / rough idle time is greatly reduced. I'm assuming the glow plugs are staying on that much longer - but even after the engine is running? My concern is that this will shorten the life of the starter. Any thoughts? Thanks
By the way I just replaced all the glow plugs.

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Old 12-12-2001, 12:27 AM
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Location: Evansville, Indiana
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I'd suggest getting your compression tested, a leakdown test done if it isn't within normal range, and having your injectors checked.

Low compression from bad valves wouldn't surprise me -- I assume you have quite a bit of milage on this car by now. Niether would the need for injector repair.

You may also have tired tappets, or a bad set of o-rings on the center "bolt" on the oil filter housing cover -- this allows the oil to leak down out of the tappets overnight -- this gives low compression running until they pump back up -- makes them rattle terribly, too. They can also be bad, same effect.

Peter
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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
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  #3  
Old 12-12-2001, 08:22 AM
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Peter, Thanks for your reply. I didn't mention that I recently had a valve job - new valves / head pressure tested and resurfaced gaskets etc. etc..... This was done at the same time that the vaccum pump, timing chain and all related parts were replaced- long story- short, after a week of diagnosis the dealer found the vaccum pump bearing or parts thereof in the oil pan. I'm not sure what could have caused this or if I could have fore-seen the problem. The car has 165k on it.

The start up smoke and rough idle is really minor but I was just wondering if you had ever heard of leaving the key turned after the engine has started to speed up smooth operation. Thanks
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Old 12-12-2001, 10:09 AM
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Location: Plano, TX
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The glow plugs continue to operate after the dash light has extinguished, and also after the engine is started. They typically stay on for about a minute. Try waiting an extra 15 seconds after the dash light has gone out and see how smoothly it starts. A little extra preheating can work wonders.

Living in the South I don't have a lot of experience with diesel engines and cold weather. In my limited exposure, diesels do start differently than gasoline engines in cold weather. Rather than cranking for a bit then springing to life, diesels seem to slowly gather RPMs as the engine begins to gradually produce power. It may start out cranking at 250RPM, for example, and gradually move up to 500RPM as the engine begins firing. I think what the owners manual is conveying is that it's OK to run the starter until you see ~500RPM on the tach, rather than releasing it at 300RPM.

How cold is it when you get poor running/smoking? The car should pretty much fire up and run in anything down to 30F. Given that you have a reworked head, presumably accurate valve & injection pump timing, and good compression, the only problem area I can think of is possibly bad injectors. If the spray pattern is less than optimal cold starting and running are compromised.
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  #5  
Old 12-12-2001, 03:34 PM
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Join Date: May 2001
Location: Michigan
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The block heater makes all the difference in the world for me. Minimum smoke with it and enough without it to kill all the mosquitos in the county.

Don
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  #6  
Old 12-12-2001, 03:40 PM
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Location: Western Michigan
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Don:

I tried the block heater the first time yesterday for about an hour. The temp did not change at all. So I thought maybe the heater was bad.

Today I used an Ohm meter to measure the heater's "cold" resistance, and it was something like 30 Ohms so the heater is not bad.

Will try again to be sure everything is plugged in.
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  #7  
Old 12-13-2001, 01:15 AM
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Location: Evansville, Indiana
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Bryan:

If I don't hold the strater knob out on the 220D it stalls, and usually won't restart. Volvo the same -- think the glowplugs are shot (again!!) -- it is permissible to hold the key over until the engine is running smoothly -- but that means not missing a lot. There is an overrunning clutch on the starter so you won't damage the ring gear, but I let go of the key as soon as the engine will run without the starter.

I helps to put the car in gear, too, with an automatic -- this adds load to the engine and causes longer injection. This in turn quickly raises the prechamber temperature and cures the miss and white smoke thing.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
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