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  #1  
Old 01-07-2010, 02:24 PM
jack_aubrey jack_aubrey is offline
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Default Oil pressure

Hi

I bought an '82 Volvo DL diesel wagon not that long ago, and recently the oil pressure warning light came on and stayed lit whenever the engine was on. I swapped the sender units to no effect, so I ran the engine for about 30 seconds with the sender unit and valve cover off the engine, and no oil emerged. So, I removed the engine from the car to check the oil pump. When I removed the pump, everything about it seemed to be in perfect working order, other than a spring-loaded tube on the right side of the pump which seemed to be stuck halfway open (first picture) (where exactly does this lead to?). After prying on it a bit, it opened all the way and then closed fully (second picture). The other possibility is that there's something stuck in one of the oilways; how would I go about testing this? Also, I hadn't driven the car enough to change the oil, so I'm not sure how long it's been since an oil filter change, but the oil pan did not have any sludge or chunks in it. Could the filter simply have been clogged enough to cause the oil pressure light to come on (or would an oil-soaked filter always block blown air, regardless of being clogged?), or is the stuck valve in the oil pump more likely the culprit and if so, how would I ensure that it was fixed?
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Old 01-07-2010, 07:50 PM
piper109 piper109 is offline
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What you are showing are pics of the pressure relief valve. This valve opens to limit oil pressure and the strength of the spring detemines how high the pressure goes.
If it was stuck in the open position, it would vent the oil to the pan without it circulating though I have a hard time believing that could happen. You could polish the spool with crocus cloth to prevent it from sticking and make sure it is free to move in its bore.
Pack the pump with grease before you reassemble as this will enable the pump to prime itself quicker.
You can temporarily remove the oil pressure switch while cranking to see if oil is circulating.

Steve
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  #3  
Old 01-10-2010, 07:00 PM
jack_aubrey jack_aubrey is offline
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Thanks for the quick reply! I took the valve apart and cleaned it as best I could, but I thought of another question: would it be more advisable to clean the valve and put it back together, or is this a problem that once it arises, will happen again, in which case should I just replace the entire pump? Could this be a problem with the spring wearing out, and if so, does anyone know the specs on the spring or where to find a replacement? On that note, I am having a devilishly hard time finding anyone advertising parts for this particular engine (NA D24, vintage 1982), including the oil pump--I wanted to replace all the rubber on the engine as long as I had it out of the car, but no one seems to have even something as simple as coolant hoses and timing belts. Does anyone know who stocks parts for this engine, and also what parts might be compatible with other models?
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Old 01-11-2010, 12:58 PM
piper109 piper109 is offline
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I have never heard of one of those valves sticking before as the spring tries to return it. I would definately polish the spool and polish the bore too. Use very fine emory !! Wrap it around a dowel to clean the bore.
If it moves freely by finger, it should move freely by oil pressure.

The spring strength controls oil pressure so you dont want to touch that spring except to replace it with a new one of the same.

The same oil pump is used on the VW D20 engine which was used in Audi 5000 of the same period and of course the D24 variants.

Check on Ebay for Volvo diesel and Audi diesel parts and you will find stuff for these engines amongst the other stuff. Bear in mind that some parts are in common with 4 cyl VW diesels but only a limited amount.

Steve
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Old 01-13-2010, 02:53 AM
MRDART MRDART is offline
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A friend of mine had a chrysler something v8 engine in his willys hotrod that had the same problem, but it was really easy for him to find new parts...
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  #6  
Old 07-20-2022, 11:14 PM
j_lepe j_lepe is offline
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Hello D24 Gurus.
I have a problem with the oil pressure of my volvo 240 from 87, since it starts it goes to the maximum 5Bar/75PSI. I have changed the sensor and it is still the same, the pressure is real. I think the motor is very noisy for this reason, any advice?
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  #7  
Old 07-21-2022, 09:31 AM
ngoma ngoma is offline
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Only thing I can think of is a stuck closed oil pressure relief valve.
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  #8  
Old 07-24-2022, 12:55 PM
v8volvo v8volvo is offline
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Have you tried testing with a temporary mechanical gauge to be sure of the actual pressure? Even if you replaced the sensor, the gauge could still be faulty and/or mismatched to the sensor if the sensor has the wrong resistance range.

Also, does the oil pressure decrease when the engine is warm? And what grade of oil are you using?

For what it's worth, VW diesel engines have long been known for running very high oil pressure after cold startup if a heavy (like 15W40) oil is being used. Stories of leaking or exploding oil filters on cold mornings are part of the legend, especially back when the cars were newer and synthetic oils were not commonplace. The pressures you are seeing might be normal for a healthy/tight engine when started cold if using a heavyweight conventional oil in the crankcase.

The engines prefer synthetic oil and most of us like to use a 5W40 weight. Some even use a 0W40 or 5W30 depending on ambient conditions and what is available. Either of those should result in less extreme pressures after cold start due to their lower cold viscosity, if what you have right now is a 15W oil.
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Old 07-24-2022, 01:47 PM
v8volvo v8volvo is offline
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For just one reference point: https://forums.tdiclub.com/index.php...897-a3.519664/

Here is a thread on a similar design early generation VW TDI engine where folks are not only reporting over 90 psi at cold start, but are actually saying it should not be much lower than that.
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