wayfarerstranger Posted December 4, 2012 Report Share Posted December 4, 2012 MY 78 DODGE D100 TRUCK i have had for almost 2 years oil pressure has always been around 20lbs . changed the oil today oil pressure went up to 40lbs which seems more normal ..... has this happened to anyone else ? also when i drained the oil there was at least 6 1/2 qtz . i put back in 5 qtz and it barley registers on the stick , i looked up online and read where the slant 6 trucks take more oil than the cars .... 6 1/2 qtz.?? i never owned a vehicle that took that much oil even v8 trucks can anyone verify this ? Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted December 4, 2012 Report Share Posted December 4, 2012 it has been my experience that only the big block truck engines required 6 quarts...according to my manual for that year..the 225, 318, 360 used 4.250 quarts and add one for filter change..the 400 and 440 used 5.0 and add one for filter change I have the big block in my 41 Bz Cp and used the truck oil pan..it is a 6 quart unit..also the truck oil pans have their dipstick affixed to the oil pan and not the block.. Quote Link to comment Share on other sites More sharing options...
wayfarerstranger Posted December 4, 2012 Author Report Share Posted December 4, 2012 i did some research and the slant truck has a larger oil pan ?? Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted December 4, 2012 Report Share Posted December 4, 2012 larger capacity? longer due to inline 6, definitely.....I did not see the listing for this larger pan in my book..not to say it is not so..just it is not in the factory service manual for that year.....so...I went to the Mopar Engines book I have here that lists performance parts and specail application stuff...it has no mention at all to any stock 6 quart oil pan for added lube/cooling for performance built slants..they only make mention to the round track racer application having need for a special built oil pan..(think banked) key word..built..I think I would look at a stock passenger car pan and do measurements....if the pan itself looks same..I would next look to see if the dipstick tube is of the correct height...if someone repaired this at one time and got the wrong tube..the added oil could actually be a hinderance as foaming would occur as the crank whips the excess oil..foaming oil will give lower pressure reading also Quote Link to comment Share on other sites More sharing options...
wayfarerstranger Posted December 4, 2012 Author Report Share Posted December 4, 2012 i thought the same thing .. wrong dip stick or tube related ... slant 6 forum info says 6 qtz till 88 they went to 5 qtz the extra qtz may have cause whipping and lower pressure . so maybe just run with 5 and have better oil pressure .... Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted December 4, 2012 Report Share Posted December 4, 2012 i thought the same thing .. wrong dip stick or tube related ... slant 6 forum info says 6 qtz till 88 they went to 5 qtz the extra qtz may have cause whipping and lower pressure . so maybe just run with 5 and have better oil pressure .... I do not see a correlation between oil pressure and the size of the oil pan. The two are not related. Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted December 4, 2012 Report Share Posted December 4, 2012 Don...not the size of the pan but the oil level within the pan not being properly indicated..if the crankcase is overfull..the crankshaft journals are churning the oil itself and this action creates many little bubbles causing the oil to foam..foamed oil will result in low oil pressure....so if for some reason the dipstick or the dipstick tube is wrong and Chance is overfilling the crankcase with 6 instead of the proper level of 5 quarts..he could well have low pressure due to this.. Quote Link to comment Share on other sites More sharing options...
Scruffy49 Posted December 4, 2012 Report Share Posted December 4, 2012 You'll find oversized oil pans on -3 truck engines. 225-3, 318-3, 413-3 as found in D400 or larger chassis motor homes, wreckers etc. Pans physically fit standard -1 engine blocks. My 69 D100 with a 318-1 engine runs a 7 qt -3 oil pan. That's how it was when I bought it. Quote Link to comment Share on other sites More sharing options...
wayfarerstranger Posted December 4, 2012 Author Report Share Posted December 4, 2012 2 different ?`s one was wondering about the higher oil pressure , the other about oil capacity .... seems like from what i have researched it holds more than 5 qtz . some where between 6 & 7 ... i will ad one more qt if pressure drops i will take some out . this shouldn`t be this hard . Quote Link to comment Share on other sites More sharing options...
Niel Hoback Posted December 4, 2012 Report Share Posted December 4, 2012 Oil level, unless extreme, will have little or no effect on oil pressure. Too much will make foam and cause low pressure, Too little and the pump will suck air, again causing low pressure. Using just enough oil to cover the pickupone or two quarts, and the oil will bw extremely hot and cause a somewhat lower oil pressure, but probably not enough to do any damage unless severly abused by high rpms or hard turns starving the pick-up. Mark your dipstick in qts to keep track of how much you put in. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted December 4, 2012 Report Share Posted December 4, 2012 I do not see a correlation between oil pressure and the size of the oil pan. The two are not related. I stick by my statement. Too much, or too little oil may make a difference in oil pressure but the size of the oil pan has no effect on oil pressure. Quote Link to comment Share on other sites More sharing options...
Daliant. Posted December 4, 2012 Report Share Posted December 4, 2012 The oil filter may have been clogged, this will drop the oil pressure down a bit. Also some oil filter brands flow better than others, did you use a different brand of filter than the one you replaced? Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted December 5, 2012 Report Share Posted December 5, 2012 I stick by my statement. Too much, or too little oil may make a difference in oil pressure but the size of the oil pan has no effect on oil pressure. size never has anything to do with it Don...... Quote Link to comment Share on other sites More sharing options...
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