Oil Pressure

2004PassatTDI

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2004 Passat Sedan, 2016 E250 Sport
Is there an oil pressure relief spring anywhere in the oil circuit? Has anyone ever heard of these springs wearing out or breaking, assuming it exists?
 

vwztips

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2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
Yes there is. i have never had one go bad. If you are asking because you have low oil pressure and you have a chained or geared BSM then most likely the hex shaft drive has worn the edges off which allows the oil pump to slip.
 

2004PassatTDI

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2004 Passat Sedan, 2016 E250 Sport
Thank you for the reply vwztips.The car has the geared BSM with 100,000 miles on the BSM.Car has 260,000 miles total and is a 2005. After the initial STOP engine warning, the BSM and hex shaft were removed, and the hex shaft did have the edges worn off.It was replaced and seems to run very well until the engine heats up.There were no spare parts left over after we put it back together.If you baby the go-pedal, no stop engine light comes on, but if you accelerate more than babying it the stop engine comes on.The car also goes into limp mode.
We changed the oil pressure switch in case that may have been the faulty component.This made no change.Engine makes no weird sounds when we compare it side by side with my car.It starts just fine, no clouds of smoke.Temps are normal.

We would like to cover all bases since we are not mechanics.Would it be a good idea to tee off where the oil pressure switch is located and port-out a mechanical oil pressure gauge and monitor the readings?If so, what should the idle and 2000 RPM (or some other standard RPM where oil pressure is monitored) oil pressure be?

Thank you in advance,

Ernst
 

thundershorts

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2015 passat tdi sel premium 2015 golf s tdi gls tdi b5.5, 2002 eurovan,Peugeot 505 td,Citroen cx25 prestige
Hope you bought a oil pressure switch from the vw dealer and didn't use a generic or aftermarket one. The circuitry for the oil warning is unlike other cars. What you are experiencing sounds like you have used wrong switch/sensor.
 

vwztips

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2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
Just to be sure put a mechanical gauge in line. For this purpose don't worry about the t for now. Once in, cold PSI should be 55 plus when cold at idle and 20ish warm. 2500 rpm should be 37-40 psi.
 
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2004PassatTDI

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Thank you Thundershorts. I thought the price was too good to be true. We will go to the dealership and pick up the correct pressure switch. In the mean time we will pick up a mechanical oil pressure gauge and fabricate a tee-fitting.
Thank you vwtzips for the oil pressure @ RPM targets. Edit: Your suggestion makes for a faster diagnosis.
 
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thundershorts

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The pressure warning circuit I found a bit strange the way VW does it but it actually self tests. If the sender is faulty, it triggers the warning at somewhere around 2000rpm. Had one go bad in my eurovan.
 

2004PassatTDI

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2004 Passat Sedan, 2016 E250 Sport
Cold PSI at idle was 25, and then decreased slowly. It got to a point where the gauge read less than 5 after the car warmed up. Once warm and driving at about 1500 RPM the oil pressure slowly increased to 10psi.

We replaced the oil filter to give us something to do other than scratching our heads. No difference.
 

vwztips

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2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2011 Tiguan TDI/DSG 2005 Audi A4 Avant 6MQ TDI 2011 BMW X5 35d
Unfortunately it sounds like the hex shaft for the oil pump has rounded off. Only way to know for sure is to pull off the pump and inspect
 

vwztips

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Oh sorry, I forgot you had done that. Well then, back to your pressure relief valve question I suppose.
 

2004PassatTDI

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QuickTD,
The original BSM, which was chain driven, did not fail. At that time the noise from the chain was so bad that I suggested the car be flat bedded to a Guru for the geared BSM replacement. Guru stated that the chained drive fell apart as he opened it up. The cam was also replaced at the same time. Odometer reading was 160,000 ish miles.
At 260,000 ish miles the Stop Engine light went on. The car was then garaged for 2-years. We opened it and found that the Hex was upon us. We assumed it was as simple as replacing the hex shaft. So we did. Car fired right up. We then took it for a spin and were as happy as can be. A moment later the dash lite up. Talk about a buzz kill.
The only bearings we looked at were the ones in the BSM. They looked uniform in color with no gouge marks, which I took to mean they were okay. The mating surface (what rotates within the bearing) was also smooth and uniform in color. No diameter measurements were taken. Perhaps not checking the bearings in the order mentioned above is “my bad”.
We are about to try replacing the oil pressure spring/seat/housing. If that does not solve the problem, then we will have to go back in and inspect the bearings.
Thanks to everyone for their help. This is really a great forum.
Ernst
 

2004PassatTDI

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Update: We put 50 weight racing oil in the engine and then monitored the oil pressure with the newly installed oil gauge. The oil pressure at cold was marginally higher, but then decreased as the engine warmed up. Cam was replaced about 100,000 miles ago. Since then 5W-40 was used.
Owner told me he no longer has the desire to wrench on the car and will likely get rid of it ASAP. I’m going to research what it takes to inspect the cam bearings, then make a pitch to the owner to give this one last try. If not, he or I will post it for sale with full disclosure.
Thanks to all for their constructive advice.
E
 

rksiewert

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2005 Passat Wagon TDI
I had almost the exact same thing happen on my geared BSM at 100,000mi also. I went with the BSM delete kit from IDParts. $379.00. Upon close inspection not only did I find the hex key rounded off, but also the inside of the BSM shaft where the hex key goes into. If you replaced the hex key, there was probably enough slack in the keyway to grind the edges of the new key off, so it is probably catching and slipping as the shaft rotates.

Just my 2 cents from my experience.
 

deming

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(2) 2005 TDI Passat Wagons
I plan to go the balancer shaft delete route and have a new camshaft installed later this summer. Seems there are more and more of these hex keys starting to wear out and round off on the geared BSM setup.
 

DeliveryValve

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?...Upon close inspection not only did I find the hex key rounded off, but also the inside of the BSM shaft where the hex key goes into. If you replaced the hex key, there was probably enough slack in the keyway to grind the edges of the new key off, so it is probably catching and slipping as the shaft rotates.

Just my 2 cents from my experience.
To the OP and rksiewert, do you know what length hex shaft do you have? 77mm or 100mm?
 

KnoxWilson

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2001 New Beetle, 2005 Passat Sedan
I just purchased the car talked about in this forum. From reading everyone's comments, it is probably either the cam, bsm, or a combination of both, possibly mains and rods too. Which should I check first, bsm or cam? Or should I check both before I even test the engine if I think that I have found the problem with one first? Thanks for any suggestions.
 

thundershorts

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2015 passat tdi sel premium 2015 golf s tdi gls tdi b5.5, 2002 eurovan,Peugeot 505 td,Citroen cx25 prestige
You may find that purchasing a shortblock from VW is more economical and eliminates many unknowns. Besides it comes with a 12 month warranty. Although sold as a remanufactured item, its really new. Its a great way to zero time everything in lower end.
 

JETaah

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Would the possibility of the rocker shaft oil galley plugs coming out have anything to do with the low oil pressure?
 
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