sirjames0_1 Posted April 9, 2012 Share Posted April 9, 2012 I've just fitted an SW mechanical oil pressure guage to my 90 200tdi, and am getting some odd (I think!) readings- wonder if anyone can help? When the oil is cold, and for about 10-15 miles, I get a pressure of around 40-50psi, but once the engine is warm, it drops to between 20-30psi. I've just driven up the motorway and the pressure sat at around 20-25psi all the way (doing 55-60mph). Is this normal, or if not, do any of you chaps know what might be causing this? Thanks in advance, James Quote Link to comment Share on other sites More sharing options...
western Posted April 9, 2012 Share Posted April 9, 2012 sounds about right, 200tdi oil pressure with engine at normal operating temperature is 1.76 to 3.86kgf/cm2 according to the genuine workshop manual 1.76 kgf/cm2 = 25.03 psi 3.86 kgf/cm2 = 54.90 psi obviously it'll change depending on how old & worn the engine is. Quote Link to comment Share on other sites More sharing options...
sirjames0_1 Posted April 10, 2012 Author Share Posted April 10, 2012 Thanks Western Quote Link to comment Share on other sites More sharing options...
western Posted April 10, 2012 Share Posted April 10, 2012 the relief valve & associated spring inside the oil pump will affect the pressure too, if the spring is old & tired it won't have the same affect on the piston oil pump kit here http://www.turnerengineering.co.uk/acatalog/info_648.html Quote Link to comment Share on other sites More sharing options...
Briarston Posted April 10, 2012 Share Posted April 10, 2012 I also have a "mechanical" gauge on my 200tdi (Disco version) engine in my 90. The engine is/was a recon. reground crank etc. and as you find, my oil pressure soon drops to around 30psi. at about 50mph when well warmed up, and always has. Tickover (a bit fast to stop the whole vehicle shaking) is usually around 12/15psi hot. I have even fitted a new OEM pump with little noticable improvement. Since then, I have read that the "O" rings in the oil punp/vac. pump drive housing can cause loss of pressure. As already stated, the book says 25 - 55psi at normal operating speeds, but others writing on this subject in the past claim much higher figures. So, to worry or not??? Quote Link to comment Share on other sites More sharing options...
RustyNissanPrairie Posted April 10, 2012 Share Posted April 10, 2012 IIRC one of the cam bearings can move on a 200tdi which also drops oil pressure, replacement isnt a DIY job as the new bearing requires line boring/honing. Quote Link to comment Share on other sites More sharing options...
Snagger Posted April 12, 2012 Share Posted April 12, 2012 I rebuilt my 200Tdi, but get similar readings to yours. The pressure really drops off as the oil warms up - I was getting 15psi at idle and only about 40 at high rpm with the oil warmed up (20 mins or so of driving). I removed the washer on the oil stat to reduce its restriction on oil from the oil cooler (the oil stat itself still closes the direct path from the pump to the filter). The result of that was that the oil temperature tends to peak slightly higher when driving at high speed on the motorway, but the oil pressure is raided to 20psi at warm idle and 50 psi at higher rpm. Cam bearings are a known problem, but they tend to be all or nothing - they wear very little but can slip out of position. If that happens, they result in virtually no oil pressure at idle and will illuminate the low pressure warning light. The book figures of 25-55psi were written for the earlier 10 and 12J normally aspirated engines which share the same oil pump and similar cam and crank shafts and bearings (the 12J and 200Tdi parts are the same, in fact). However, the 19J and Tdi have a lot more oil flow because of the relatively unrestricted demand by the turbo charger. The turbo uses a very high flow rate to keep the shaft floating in oil-jet bearings and to prevent the oil cooking, and I believe the pump simply can't keep up with the demand once the oil thins with the heat. Your figures seem typical for Tdi pressures and certainly nothing to be concerned about. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted April 12, 2012 Share Posted April 12, 2012 I get the same sort of readings on my 300Tdi using Millers EFX oil. Quote Link to comment Share on other sites More sharing options...
sirjames0_1 Posted April 13, 2012 Author Share Posted April 13, 2012 Thanks Guys- glad that it's not something to worry about :-) Quote Link to comment Share on other sites More sharing options...
Briarston Posted April 15, 2012 Share Posted April 15, 2012 I rebuilt my 200Tdi, but get similar readings to yours. The pressure really drops off as the oil warms up - I was getting 15psi at idle and only about 40 at high rpm with the oil warmed up (20 mins or so of driving). I removed the washer on the oil stat to reduce its restriction on oil from the oil cooler (the oil stat itself still closes the direct path from the pump to the filter). The result of that was that the oil temperature tends to peak slightly higher when driving at high speed on the motorway, but the oil pressure is raided to 20psi at warm idle and 50 psi at higher rpm. Cam bearings are a known problem, but they tend to be all or nothing - they wear very little but can slip out of position. If that happens, they result in virtually no oil pressure at idle and will illuminate the low pressure warning light. The book figures of 25-55psi were written for the earlier 10 and 12J normally aspirated engines which share the same oil pump and similar cam and crank shafts and bearings (the 12J and 200Tdi parts are the same, in fact). However, the 19J and Tdi have a lot more oil flow because of the relatively unrestricted demand by the turbo charger. The turbo uses a very high flow rate to keep the shaft floating in oil-jet bearings and to prevent the oil cooking, and I believe the pump simply can't keep up with the demand once the oil thins with the heat. Your figures seem typical for Tdi pressures and certainly nothing to be concerned about. Sorry to raise this thread again. Snagger, what you say interests me as I would like to see a little more oil pressure especially when hot. Looking on Microcat I can't see the washer you removed, only an "o" ring. Can you clarify for me please? Thanks Quote Link to comment Share on other sites More sharing options...
Snagger Posted April 16, 2012 Share Posted April 16, 2012 The stat housing has an o-ring, but the stat itself has a large circular washer which moves with the stat's flange across the oil filter supply port. When the oil is cold and the stat is contracted, the spring pushes the stat and washer outboard, opening the direct path between the block port and the filter while the washer blocks the flow from the oil cooler to the filter port. As the oil warms up and the stat expands against the spring, the washer is moved inboard to the other side of the filter port, so the oil cooler outlet is now open and the direct path is closed off. Oddly, the washer doesn't show up on the microfiche or in the manuals, but it's there. Even stranger is that 300Tdis have two of these washers, presumably because the filter housing's interior dimensions are slightly different and didn't match the other common parts. Quote Link to comment Share on other sites More sharing options...
western Posted April 16, 2012 Share Posted April 16, 2012 oil stat opens at 74 degrees, just in case you wanted the temp to. Quote Link to comment Share on other sites More sharing options...
Briarston Posted April 16, 2012 Share Posted April 16, 2012 The stat housing has an o-ring, but the stat itself has a large circular washer which moves with the stat's flange across the oil filter supply port. When the oil is cold and the stat is contracted, the spring pushes the stat and washer outboard, opening the direct path between the block port and the filter while the washer blocks the flow from the oil cooler to the filter port. As the oil warms up and the stat expands against the spring, the washer is moved inboard to the other side of the filter port, so the oil cooler outlet is now open and the direct path is closed off. Oddly, the washer doesn't show up on the microfiche or in the manuals, but it's there. Even stranger is that 300Tdis have two of these washers, presumably because the filter housing's interior dimensions are slightly different and didn't match the other common parts. Snagger Thanks for the explanation/clarificatio. Just found the washer you refer to in the workshop manual I downloaded sometime ago. A case of if in doubt, read the instructions! Thanks again Quote Link to comment Share on other sites More sharing options...
pathfinder Posted September 11, 2012 Share Posted September 11, 2012 Hi I have a TIM oil pressure gauge and my pressure at idle is around zero and when running down the motorway at 60-70 mph it is 20 psi? also I have notice a constant ticking that doesn't seem to go faster with the engine revs, I can hear it faintly inside the vehicle? Quote Link to comment Share on other sites More sharing options...
Ja defender Posted January 15, 2015 Share Posted January 15, 2015 Hi Pathfinder, I am experiencing the same problem as you mentioned here and would like to know if you were able to resolve this low oil pressure problem. Regards Ja Defender Quote Link to comment Share on other sites More sharing options...
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