Hi friends, today I tried to build up oil pressure after an engine rebuild before actually starting the engine, but I can't get any pressure at all—it's completely zero! The oil filter is dry, too! I installed new oil lines, hydraulic lifters, guides, and a timing chain, as well as a new OE chain tensioner. I also dropped the oil pan and everything looked fine—the pickup screen was clean. I poured oil into the filter housing, but I still can't get pressure up. The engine sat without oil for two months; could that be the problem? I thought the sensor might be faulty, but since the filter is dry, it’s as if the pump isn't generating any pressure at all. What could be wrong? Maybe if I start it briefly and rev it a bit higher, the pressure would build up? Then again, could the timing chain skip a tooth without oil pressure—specifically, if there's no oil pressure reaching the tensioner?
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Oil pressure fails to build up after the engine repair.
- Thread starter Rainz500
- Start date
I recently replaced the oil level sender in one of my cars, due to a leaking O-ring. Only the O-ring needed replacement, but I figured since the sending unit was 30 years old, it was worth the $50 for a new one (which includes new O-rings). After draining the oil and removing the oil pan, I went out of town for a few days, and completed the job when I returned. Total time with the oil pan removed was about 1 week.
Filled up with new oil, started the engine, and... no oil pressure. Uh-oh. Triple checked everything, tried again, still nothing.
Well, that's not good. I've done this job...
Filled up with new oil, started the engine, and... no oil pressure. Uh-oh. Triple checked everything, tried again, still nothing.
Well, that's not good. I've done this job...
This should help ya out.
Yup... the oil pump pickup must be primed. Try the method described in the thread linked above, pressurizing the crankcase with a shop vac outlet into the oil fill hole.
I don't think the dipstick tube will work, there probably won't be enough airflow. Not sure if removing the filter housing to prime will work - this MIGHT do the trick, if you can find the right port and feed oil directly into it. Not easy though.
Overfilling the sump to 1-2 quarts above "max" miiiiiight do the trick, maybe.
If you do start the engine for any of the above methods, DO NOT rev above idle!!
I don't think the dipstick tube will work, there probably won't be enough airflow. Not sure if removing the filter housing to prime will work - this MIGHT do the trick, if you can find the right port and feed oil directly into it. Not easy though.
Overfilling the sump to 1-2 quarts above "max" miiiiiight do the trick, maybe.
If you do start the engine for any of the above methods, DO NOT rev above idle!!
Do you know,how oil filter works? There center tube,where filter element sits! Is oil coming from pump to oil filter from center tube and going to side or opposite? If oil coming from center tube to filter,then i can make vacuum to it and vacuum suck oil true pump?Yup... the oil pump pickup must be primed. Try the method described in the thread linked above, pressurizing the crankcase with a shop vac outlet into the oil fill hole.
I don't think the dipstick tube will work, there probably won't be enough airflow. Not sure if removing the filter housing to prime will work - this MIGHT do the trick, if you can find the right port and feed oil directly into it. Not easy though.
Overfilling the sump to 1-2 quarts above "max" miiiiiight do the trick, maybe.
If you do start the engine for any of the above methods, DO NOT rev above idle!!
Dirty oil enters the OUTSIDE of the filter, clean oil goes out through the center pipe.
See the FSM documentation below for the oil flow diagram.
You must remove the filter housing from the block to attempt any filling, as there is a check valve which prevents oil flow back to the pump.
See the FSM documentation below for the oil flow diagram.
You must remove the filter housing from the block to attempt any filling, as there is a check valve which prevents oil flow back to the pump.
https://www.500eboard.co/forums/misc/Manuals/Servicev3.2/W124/w124CD1/Program/Engine/119/18-1110.pdf
Thats means,that there are flow back valve,with work one way! That means it will be open when i suck oil from centre pipe! I will try it! I have A/C vacuum pump,and i can use it! It sucks veeery good!Dirty oil enters the OUTSIDE of the filter, clean oil goes out through the center pipe.
See the FSM documentation below for the oil flow diagram.
You must remove the filter housing from the block to attempt any filling, as there is a check valve which prevents oil flow back to the pump.
https://www.500eboard.co/forums/misc/Manuals/Servicev3.2/W124/w124CD1/Program/Engine/119/18-1110.pdf
And if i remove filter housing,then right port is behind that valve! I can refill from there!Nope,didnt work! There are some valve spring visible inside the housing and if i suck true centre pipe,it suck air true that hole,where the spring is visible! I think it is some cooler valve! I have filled already 11L oil to engine! And if needed,i fill another 4L oil! Untill level reaches to pump! I have no sparkplugs in the holes and if oil reaches to sylinder,it will go out from spark holes! And if the pressure builds up, I’ll drain the excess oil from the engine—I won’t start it before then!
I think it's the entire area. The oil pushes the round valve open when under pressure from the pump.But if you wach that picture,there are no port in that big hole where valve sits!Or i am blind?
Now i am officially screwed! Oil pressure gauge in cluster dont move at all,even if i put sender wire stright to ground! I thought the gauge fuse had blown, but when I pulled the fuse out, the oil pressure needle rose to 0.5 bar, the temperature gauge went to 60 degrees, and the A/C fan started running! It’s an anomaly! I put the fuse back in, and now the oil pressure needle doesn't move at all and the temp is at zero again! The A/C fan stopped too! What is going on? Now needle dont work,no pressure on the engine and to mesure pressure manually,i must buy the tester! Cool!
But why needle dont work,when i ground the wire?
Not sure. Note that if the wire at the sender is grounded, the gauge should read zero, if I'm reading the FSM chart below accurately.
FSM = Factory Service Manual. Click here to access it. You need this manual for ALL repair work!!
If you connect the wire at the sending unit directly to ground (chassis), that is effectively zero ohms resistance, and I'd expect the gauge to read zero bar pressure. If you place a resistor of ~100 ohms between the wire and ground, the gauge should read approximately 1.5 bar, etc.
If you connect the wire at the sending unit directly to ground (chassis), that is effectively zero ohms resistance, and I'd expect the gauge to read zero bar pressure. If you place a resistor of ~100 ohms between the wire and ground, the gauge should read approximately 1.5 bar, etc.
nope,i just ordered tester set! But the filter is dry and dipstic level stays same!
wow...ok...that is somewhat a sign of something not circulating at all,,You say "after an engine rebuild".....Have you had the engine in bits? or...?
Sir,you just make my day! I was already searching new lower harness! Yesterday was crying myself to sleep!
Now i have only two options-Search some right vaguum cleaner,or remove filter housing and prime pump from that oil lane port! Since I’ve already bought the non-return valve, I’m going to remove the filter housing, replace the valve, and fill the pump through there!
Attachments
Oil pan was out for cleaning! New lifters,oiltubes,chain,tensioneer and guides. Engine was without oil 2 month!
I see.
Have you tried sucking oil out of the feed "hole" in the block,that comes FROM the pump?It is the channel that leeds into the returnvalve in the oilfilterhousing,that is the oil feed.(The biggest hole/cavity so to speak )
Not yet! But tahats the way im going! Tomorrow ill try to buy a new o-rings to oil cooler lines and then i remove the housing! I tought that i prime pump from there,but sucking is much better way,thanks!
I put 11L oil to engine, but seems like not enough to reach to pump! Frustrating sht.not easy to do maybe,,but i would definetly try to make that work. Then you can suck the oil out of that hole..and maybe prime the pump that way .Especially now if you have the valve etc to replace...
Good luck
Every time i fix some thing and try to start the engine,some new sht gome up! I belive the God and i think he dont want me to start the engine not just yet!?
I wonder,what next..
Hi, I finally got the oil pressure up! I removed the oil filter housing and filled the oil pump through that opening. I bought a 2-meter transparent hose with a 10mm outer diameter and sucked oil into it from a canister. Then I inserted the end of the hose into the port where the oil exits the pump and blew the oil out of the hose. I did this three times until it wouldn't take any more; about 0.5 liters went in. After that, the pump started working immediately, and I used the starter to flush the excess oil out of the engine! I did little test too,for making sure that oil dont flow back from pump,if i let it stay for while with open pori! About an hour later, I cranked the engine again, and the pump started working immediately—the oil hadn't drained back into the sump! The test was necessary to ensure I had enough time to reinstall the oil filter housing and that the non-return valve would effectively prevent the oil from draining back on its own. Otherwise, you’d do all that work only to discover that the oil pump had drained empty again!
The worst part of the process was putting the filter housing back on—specifically, ensuring the gasket stayed in place and didn't get damaged. Doing it with two people wouldn't be bad, but doing it alone is impossible!
Finally, I inserted threaded rods into the bolt holes to hold the housing gasket in place and tightened the housing with one bolt! Then I removed the rods and screwed in the remaining bolts!
I discovered that my car only registers oil pressure once the engine actually starts! I was quite worried because, while cranking, I could see the filter housing filling with oil and oil reaching the camshafts, yet no pressure was showing! In the end, I simply started the engine, and the pressure instantly jumped to 3!
For anyone planning to remove the filter housing and work on it in the future, my strong recommendation is to do it only on a lift or over an inspection pit! You really need to be able to stand upright underneath the car; otherwise, you’ll be facing a world of trouble because there is very little working space!
The worst part of the process was putting the filter housing back on—specifically, ensuring the gasket stayed in place and didn't get damaged. Doing it with two people wouldn't be bad, but doing it alone is impossible!
Finally, I inserted threaded rods into the bolt holes to hold the housing gasket in place and tightened the housing with one bolt! Then I removed the rods and screwed in the remaining bolts!
I discovered that my car only registers oil pressure once the engine actually starts! I was quite worried because, while cranking, I could see the filter housing filling with oil and oil reaching the camshafts, yet no pressure was showing! In the end, I simply started the engine, and the pressure instantly jumped to 3!
For anyone planning to remove the filter housing and work on it in the future, my strong recommendation is to do it only on a lift or over an inspection pit! You really need to be able to stand upright underneath the car; otherwise, you’ll be facing a world of trouble because there is very little working space!
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right now engine little worries me! In gold start enine has like 1100 rpm and after 30 sec lover to like 600-650! In this time i feel engine is not smooth! Then i stop engine and start again,and engine is smooth like silk! I put coin to stay on engine,like they do on v12 and it stays up like 10 sec,cos there are no really flat surface!Congratulations. Great that you finally got it working
Do engine give his gold start info from some temperature sensor? Its like engine have too high rpm on gold and too long!Similar threads
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