From: owner-diesel-benz-digest-at-digest.net (diesel-benz-digest) To: diesel-benz-digest-at-krusty-motorsports.com Subject: diesel-benz-digest V1 #172 Reply-To: diesel-benz-at-digest.net Sender: owner-diesel-benz-digest-at-digest.net Errors-To: owner-diesel-benz-digest-at-digest.net Precedence: bulk diesel-benz-digest Thursday, July 15 1999 Volume 01 : Number 172 Forum for Discussion of Diesel Mercedes Benz Automobiles John Meister Digest Coordinator Contents: Oil Pressure and Temperature Relationship Re: Oil Pressure and Temperature Relationship Re: Oil Pressure and Temperature Relationship Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship Re: Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship Re: Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship Re: Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship Oil Pressure? Re: Oil Pressure? Diesel Benz Digest Home Page: http://www.digest.net/diesel-benz/ Send submissions to diesel-benz-digest-at-digest.net Send administrative requests to diesel-benz-digest-request-at-digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to stag-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: Tue, 13 Jul 1999 22:11:03 +0000 From: Tony Wirtel Subject: Oil Pressure and Temperature Relationship Greetings- Last week was a hot one in the area; with a 98 degree (Farenheit, about 38 C) day I saw my oil pressure as low as 1.2 bar at idle, in gear with a/c running. I'd never seen it this low before. Car is an '85 300TD with a 617.952 motor, at 244k miles. Should this be of great concern? Normally, on a 'warm' day pressure is about 1.5 bar. Am now running Castrol 20-50. On a related note, has anyone added an auxiliary blower to force extra air over the oil cooler radiator?? With the low pressure I saw, I though this would help; could rig a system that turned on IF ignition was on, water temp above a selectable point, and vehicle speed BELOW a certain point. Finally, after running for 2+ hours I sometimes see the oil pressure pointer vibrating. It 'shakes' over a range of as high as .25 bar. Is this common or a sign of impending doom? If it's a sign of a weak spot in the gauge or tubing I'd like to find out and fix it before I get my pants drenched in oil!! Thank- Tony Wirtel '85 300TDT, 244k miles... ------------------------------ Date: Tue, 13 Jul 1999 20:27:26 -0700 From: john Subject: Re: Oil Pressure and Temperature Relationship While I like Castrol 20w50, I think your current heat wave and a TD might be asking a lot of it... Ever consider using Synthetic? The only synthethic I can recommend is AMSOIL. I use their Marine Diesel 15w40. Even the straight 30W will handle the heat and then some... specs on my website: http://www.wagoneers.com/AMSOIL wander into the Diesel section and look... I don't care if you buy from me or someone else... I wouldn't have been a dealer since 1983 if I didn't think it was a good product. :) I'm not a dealer to make money or get rich... Either way, I've seen mileage gains and temperature reductions with steady oil pressure in a wide range of rigs... FWIW, while Castrol 20w50 is good, Kendall is better. A mechanic I use when I'm too lazy to do my own has switched from Castrol to Kendall... later, john At 10:11 PM 7/13/99 +0000, Tony Wirtel wrote: >Greetings- > >Last week was a hot one in the area; with a 98 degree (Farenheit, about 38 C) >day I saw my oil pressure as low as 1.2 bar at idle, in gear with a/c running. > I'd never seen it this low before. Car is an '85 300TD with a 617.952 motor, >at 244k miles. Should this be of great concern? Normally, on a 'warm' day >pressure is about 1.5 bar. Am now running Castrol 20-50. > >On a related note, has anyone added an auxiliary blower to force extra air >over the oil cooler radiator?? With the low pressure I saw, I though this >would help; could rig a system that turned on IF ignition was on, water temp >above a selectable point, and vehicle speed BELOW a certain point. > >Finally, after running for 2+ hours I sometimes see the oil pressure pointer >vibrating. It 'shakes' over a range of as high as .25 bar. Is this common or >a sign of impending doom? If it's a sign of a weak spot in the gauge or >tubing I'd like to find out and fix it before I get my pants drenched in oil!! > >Thank- >Tony Wirtel >'85 300TDT, 244k miles... > - ----------------------------------------------------- john-at-virtual-cafe.com http://www.wagoneers.com http://www.virtual-cafe.com/~john http://www.wagoneers.com/AMSOIL/ To order 1-800-956-5695 customer# 283461 Snohomish, WA, where Jeeps don't rust, they mold... - ----------------------------------------------------- ------------------------------ Date: Wed, 14 Jul 1999 03:13:51 -0500 From: "Jon Filina" Subject: Re: Oil Pressure and Temperature Relationship Tony , aka "I watch my gauges", asked of the group: > Last week was a hot one in the area; with a 98 degree (Farenheit, about 38 C) > day I saw my oil pressure as low as 1.2 bar at idle, in gear with a/c running. > I'd never seen it this low before. Car is an '85 300TD with a 617.952 motor, > at 244k miles. Should this be of great concern? Normally, on a 'warm' day > pressure is about 1.5 bar. Am now running Castrol 20-50. Anything over 1 bar is acceptable. Here in Texas, the only time "Mathilde" got less than 1.5 bar, after about 45 minutes of freeway driving, was when I used Shell Rotella. Chevron Delo 400 has always shown 1.5 bar at idle when fully warmed up. > On a related note, has anyone added an auxiliary blower to force extra air > over the oil cooler radiator?? With the low pressure I saw, I though this > would help; could rig a system that turned on IF ignition was on, water temp > above a selectable point, and vehicle speed BELOW a certain point. I don't think you need this. It wouldn't hurt anything, but shouldn't be needed. > Finally, after running for 2+ hours I sometimes see the oil pressure pointer > vibrating. It 'shakes' over a range of as high as .25 bar. Is this common or > a sign of impending doom? If it's a sign of a weak spot in the gauge or > tubing I'd like to find out and fix it before I get my pants drenched in oil!! Are we talking at highway speeds? The oil pressure needle should be pegged at 3.0 bar at any RPM over about 1500 or so. My 240D does not have a tach, so the rpm I mentioned my not be right. As soon as I depress the pedal to pull away from a dead stop, my oil gauge hits the peg.... If your gauge is dropping a hair below 3.0 at anything over parking speeds, something is wrong. It could be a faulty sender, but something isn't right. If the fluctuation is at idle, I wouldn't worry about it as long as the pressure doesn't drop below 1.0 bar. Here in Texas, I have had very good luck with Chevron's Delo 400. Having used Mobil1 in my '76 VW Dasher many years ago, I am a believer in synthetics in relatively new engines. John would have to do a lot of whispering in my ear to convince me to change to an synthetic, such as Amsoil, on an engine with 229,000 mi. on it. For your info, I had been a Castrol user since the late '60's. The change to Delo400 came about 2 years ago. I hope the above info has helped. Jon '81 240D 229,000 mi. or so "Mathilde" ------------------------------ Date: Wed, 14 Jul 1999 08:30:35 -0500 From: Alec Cordova Subject: Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship OK, we're having this nice discussion about his oil pressure gauge hinting at FRIGHTENING things (assuming it truly is bouncing while at speed), and revisiting the old Synthetic vs. dino oil that everyone loves to contribute to, but I have a simpler question. 1985 300DT with just under 200,000 miles. Runs pretty well. I am using dino oil, and for various reasons, I am not looking to go synthetic just yet, nor am I looking for more reasons why I should. I just want current recommendations as to oil weight. My manual clearly states that 10-40 oil is suitable for year-round use, while 20-50 can be used above freezing (32F/0C). Add the following factors to this question: I am in Central Texas, where we hope for one or two good dips into the twenties each winter just to kill off the fleas, and we're often disappointed. We also hope for less than two weeks above 100 degrees in the summer, and are again often disappointed. I live about 35 miles from work, and I manage to miss most of the traffic congestion, so the car gets plenty of practice running at speed, as opposed to 20-mph crawls. Between oil changes, I still never need to add oil to this car. The manual was written over fifteen years ago, so preferences and technologies may have changed. I'm due for an oil change. Should I continue to use the recommended 10-40, or should I change to something thicker. What say you, oh great, wise, and otherwise ones? Alec Cordova Taylor, Texas 85 300DT, <200K 97 Z3 1.9, 65K ------------------------------ Date: Wed, 14 Jul 1999 08:55:17 +0000 From: richard Subject: Re: Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship i use 20/50 castrol exclusively, in all my machines , except where instructed not to... i have had good luck for years doing so...cars in my collection 220, 240, 300-sd's 80 & 81...all have good oil pressure...and idel about 1 1/2 bar...with the ac on ...deisels love heat...not over heat, but the hotter the better, ambient temp, that is...or at least mine do... have any of you you diesel purge???nice quite tune for the injector system when changing the fuel filters??? aslo a heat related topic...radiator caps...cheap and i change mine every year or two....keeps the boiling point down and prevents coolant loss richard, collector of euro cars and bikes alfa, porsche, bmw, jags, mg, vw, mg, bikes,...triumph, bsa, moto-guzzi, bmw richard, in north texas, where it's either hot as hell or cold ------------------------------ Date: Wed, 14 Jul 1999 08:15:47 -0700 (PDT) From: john Subject: Re: Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship I thought Diesels weren't supposed to use 10W40? The viscosity index improvers used in 10W40 were supposed to cause ring problems in Diesels... but if MB recommends it... guess it's ok... john On Wed, 14 Jul 1999, Alec Cordova wrote: >-->OK, we're having this nice discussion about his oil pressure gauge hinting >-->at FRIGHTENING things (assuming it truly is bouncing while at speed), and >-->revisiting the old Synthetic vs. dino oil that everyone loves to contribute >-->to, but I have a simpler question. >--> >-->1985 300DT with just under 200,000 miles. Runs pretty well. I am using dino >-->oil, and for various reasons, I am not looking to go synthetic just yet, nor >-->am I looking for more reasons why I should. I just want current >-->recommendations as to oil weight. My manual clearly states that 10-40 oil is >-->suitable for year-round use, while 20-50 can be used above freezing >-->(32F/0C). >--> >-->Add the following factors to this question: >-->I am in Central Texas, where we hope for one or two good dips into the >-->twenties each winter just to kill off the fleas, and we're often >-->disappointed. We also hope for less than two weeks above 100 degrees in the >-->summer, and are again often disappointed. >-->I live about 35 miles from work, and I manage to miss most of the traffic >-->congestion, so the car gets plenty of practice running at speed, as opposed >-->to 20-mph crawls. >-->Between oil changes, I still never need to add oil to this car. >-->The manual was written over fifteen years ago, so preferences and >-->technologies may have changed. >--> >-->I'm due for an oil change. Should I continue to use the recommended 10-40, >-->or should I change to something thicker. >--> >-->What say you, oh great, wise, and otherwise ones? >--> >-->Alec Cordova >-->Taylor, Texas >-->85 300DT, <200K >-->97 Z3 1.9, 65K >--> ---- - ------------------------------------------------------------------------- john-at-virtual-cafe.com **** Snohomish, Washington USA don't leave life without jesus, please... http://www.virtual-cafe.com/~john http://wagoneers.com - ------------------------------------------------------------------------- ------------------------------ Date: Wed, 14 Jul 1999 10:33:58 -0500 (CDT) From: matthew j mason Subject: Re: Recommended Oil Viscosity for 85 300DT WAS: Oil Pressure and Temp erature Relationship Tossing my $0.02 in... I use Castrol 20-50 in the warm weather, but I don't go any lighter than 15-40 in the wintertime... I have heard awful things about an attempt to use 5w-30 in the wintertime in one of these cars (crash-bang-boom), but I don't know about 10-40... guessing it's not much safer... I'll see what the "committee" thinks, but I'll probably stick to Castrol if the new engine deal comes through this summer... - -- Matt On Wed, 14 Jul 1999, john wrote: > > I thought Diesels weren't supposed to use 10W40? The viscosity > index improvers used in 10W40 were supposed to cause ring problems > in Diesels... but if MB recommends it... guess it's ok... > > john > > On Wed, 14 Jul 1999, Alec Cordova wrote: > > >-->OK, we're having this nice discussion about his oil pressure gauge hinting > >-->at FRIGHTENING things (assuming it truly is bouncing while at speed), and > >-->revisiting the old Synthetic vs. dino oil that everyone loves to contribute > >-->to, but I have a simpler question. > >--> > >-->1985 300DT with just under 200,000 miles. Runs pretty well. I am using dino > >-->oil, and for various reasons, I am not looking to go synthetic just yet, nor > >-->am I looking for more reasons why I should. I just want current > >-->recommendations as to oil weight. My manual clearly states that 10-40 oil is > >-->suitable for year-round use, while 20-50 can be used above freezing > >-->(32F/0C). > >--> > >-->Add the following factors to this question: > >-->I am in Central Texas, where we hope for one or two good dips into the > >-->twenties each winter just to kill off the fleas, and we're often > >-->disappointed. We also hope for less than two weeks above 100 degrees in the > >-->summer, and are again often disappointed. > >-->I live about 35 miles from work, and I manage to miss most of the traffic > >-->congestion, so the car gets plenty of practice running at speed, as opposed > >-->to 20-mph crawls. > >-->Between oil changes, I still never need to add oil to this car. > >-->The manual was written over fifteen years ago, so preferences and > >-->technologies may have changed. > >--> > >-->I'm due for an oil change. Should I continue to use the recommended 10-40, > >-->or should I change to something thicker. > >--> > >-->What say you, oh great, wise, and otherwise ones? > >--> > >-->Alec Cordova > >-->Taylor, Texas > >-->85 300DT, <200K > >-->97 Z3 1.9, 65K > >--> > > ---- > > ------------------------------------------------------------------------- > john-at-virtual-cafe.com **** Snohomish, Washington USA > don't leave life without jesus, please... > http://www.virtual-cafe.com/~john > http://wagoneers.com > ------------------------------------------------------------------------- > > > > ------------------------------ Date: Wed, 14 Jul 1999 14:08:04 -0700 From: Farnes_Quinn Subject: Oil Pressure? [When I sent this, I thought I'd cced the list. Guess I didn't, so here 'tis, for what it's worth] Y'know, guys, I'm interested in this too, but I wonder if we are picking nits here. I mean, how accurate and consistent can the oil pressure gauges be on vehicles that have been driven up to, and over, 200,000 miles? I'd expect that if you checked several cars, you'd find the gauges' accuracy is all over the place. Whether it reads 0.5 bar or 1 bar at idle is probably not as important as is the fact that the pressure gauge registers non-zero. I say that because for the last decade, at least, Ford (Fix Or Repair Daily) has placed a dummy oil pressure gauge in their pickups, Explorers, Expeditions, vans and light truck and motorhome chassis. The gauge operates like an idiot light. When the oil pressure is above a certain limit, the gauge reads approximately 50% scale regardless of engine speed. If the pressure drops below that limit, the gauge reads zero and an idiot light comes on. According to the buzz on the Ford Expedition mailing list, Ford did that because so many truck owners demanded oil pressure gauges be included in the instrument cluster, then freaked out when the oil pressure registered below 1/4 scale at idle (something MUST be wrong!). Unnecessary service visits are costly, so the idiot-gauge was created. My point is that the vast majority of automobiles have idiot lights/idiot gauges probably because analog gauges are problematic and require some education of the user to interpret properly. If you are concerned about oil pressure, and everyone should be, I'd discount what the tiny gauge in the dash reads, pull the sender, and check the pressure using a mechanical oil pressure gauge. Once you know what the oil pressure really is, you can then correlate the reading of the dash gauge with the mechanical gauge. Hope this helps. Quinn ------------------------------ Date: Thu, 15 Jul 1999 21:31:29 +0200 From: Thorsten Windhues Subject: Re: Oil Pressure? Hi out there, I think I have to comment this , as well. I sometimes drive light trucks with the "star sign". These two trucks are built in '83 and '86, I think, and are both equipped with the 240D engine that was used in the later W123 models. Of course do these trucks have an oil pressure gauge, but this gauge is somewhat different from the cars gauges. They have a scale up to 8 bar. When the engines in the winter are really cold and you start them, the pressure needle goes up to the highest point very fast like we know it from our cars. But in the summer time, when the temperatures outside are higher, the needle does not reach the 8 bar point. With the engine at idle, but not having the 80 =B0C it reaches after driving, they have a pressure of about 5 to 6 bars, when driving with the semi cold engine it goes up to 8 bars. Now after driving for a while and the engines having the proper working temperature, they show 5 to 6 bar while driving and 2 bar at idle. I think this gives an overview of the operating pressures of the 240D's (and the other 615, 616 and 617 engines) which is more informative than the infos we get from our 3bar gauges. Bye from Germany, Thorsten =20 ------------------------------ End of diesel-benz-digest V1 #172 *********************************