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  #1  
Old 12-12-2002, 07:07 PM
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Post valve adjustment questions

Okay adjusted the valves in my 84'300D today. Wasn't too bad even with regular "straight" wrenches. All the intakes were a little loose, about 0.005" and one was tight, 0.003" All the exhausts were around 0.010" with one at 0.007" I set them at 0.004"/0.014" COLD intake and exhaust respectively. The question is this: Were the exhausts tight enough to warrant rechecking them in a few days? I had heard about carbon building up on the seats of overly tight exhaust valves and then burning off again screwing up the adjustment? They didn't seem too bad to me but what do I know..... Thanks, RT

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Old 12-12-2002, 07:30 PM
Old Deis
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I had heard the same thing. Never have seen it come true. Valves will wear into the head and therefore become tighter over time. Whether or not there is carbon buildup in there? I wouldn't think so in our case. You said most of your valves were loose, not tight. Would seem that in order for crap to build up under the valve seat it would need to be quite loose in the first place.
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  #3  
Old 12-12-2002, 08:03 PM
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The only time I'd worry about re-setting the clearance in short order is if there is NO clearance on the exhaust valves OR it has been many thousands of miles since they were done (as in 30,000 and up....). Carbon buildup won't be significant unless the engine has been running very smoky from low compression, and the buildup isn't necessarity on the valve seat, it can also be on the valve stem, preventing it closing completely.

If the car has been serviced properly, don't worry. You had adequate clearance on all the valves to start with, I'd not expect trouble.

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
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Old 12-12-2002, 08:10 PM
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Thanks! I figured that I'd likely be okay. Yes, nothing was overly tight but I don't know when the valves were last done. The car has had regular maintenence as there are many new parts and its all in very good shape. Thanks again, RT
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  #5  
Old 12-12-2002, 08:18 PM
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No problem!

My 220D, in terrible condition (still) had and exhaust (#1) close up to less than 0.005 in a year or so (10,000 miles more or less, the odo didn't work) between adjustments. Ran much better after the second adjustment!

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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  #6  
Old 12-13-2002, 04:04 PM
Diesel Power
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Re: Post valve adjustment questions

Quote:
Originally posted by rwthomas1
Okay adjusted the valves in my 84'300D today. Wasn't too bad even with regular "straight" wrenches. All the intakes were a little loose, about 0.005" and one was tight, 0.003" All the exhausts were around 0.010" with one at 0.007" I set them at 0.004"/0.014" COLD intake and exhaust respectively. The question is this: Were the exhausts tight enough to warrant rechecking them in a few days? I had heard about carbon building up on the seats of overly tight exhaust valves and then burning off again screwing up the adjustment? They didn't seem too bad to me but what do I know..... Thanks, RT
Aren't your adjustments still tight? The specs out of my shop manual (for the 240D anyway) was .010 intake and .030 exhaust. Since the 300D is a 240D engine with another lung added, I would have thought them to be very similar if not identical?
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  #7  
Old 12-13-2002, 04:16 PM
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0.010mm=0.004" and 0.030mm=0.014" Easy to make a mistake if you don't read the fine print. RT
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  #8  
Old 12-13-2002, 04:22 PM
Diesel Power
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Looks like I'm goin' back under the hood. <>
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  #9  
Old 12-13-2002, 04:51 PM
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Whoops!! Well better loose than tight. Check the specs, I know nothing about 240's Good Luck! RT

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