# >>>Pressure relief valve....or not...99.9% sure....but....



## munkittrick (Aug 27, 2006)

Hi guys, I'm 99% certain that I'll be replacing my oil cooler housing and maybe the oil filter mount as well, but when trying to locate what I THOUGHT was the oil pressure relief valve, I'm apparently wrong. I was under the impression that it's the bolt with the spring behind it on the lower passenger's side of the oil filter mounting housing, but I'm being told by Volkswagen that it's BEHIND the filter housing mount. Where is the damned pressure relief valve on this image...if you don't mind helping a confused guy out.










EDIT:

Just to clarify, I DID NOT put the red marks on the image and I'm aware that the boxed item is the oil pressure sending unit and a sealing screw cap.


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## cri-cri (Sep 27, 2009)

Let me fix that image for you:




> I was under the impression that it's the bolt with the spring behind it on the lower passenger's side of the oil filter mounting housing


You're right, that's the pressure relief valve. It's a spring and piston valve - no. 3 and 4 in the diagram. Similar to this one:










Its purpose, as the name says, is to prevent excessive pressure build-up and protect the oil cooler (_"when the oil is cold and thick, the resulting increased oil pressure forces the valve down against spring tension. This allows oil from the oil pump to go directly to the engine bearings. In by-passing the oil cooler, warm-up is speeded and the oil cooler is protected against excessive pressures that might cause it to burst"_).



> I'm being told by Volkswagen that it's BEHIND the filter housing mount


That is not the pressure relief valve. It's a check valve (a ball & spring one way valve), no. 6 in the diagram:










It's there to keep oil in the head:











On newer 1.8T (like my AUQ) the check valve is pressed in, P/N - 06A103175: 










On older 1.8T the check valve is screwed in, P/N - 077103175B:


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## munkittrick (Aug 27, 2006)

cri-cri said:


> Let me fix that image for you:
> 
> 
> 
> ...


GOOD GOD THANK YOU! I was pulling my hair out. I've literally replaced the entire lubrication system from the cam chain tensioner, to the oil pump, to the turbo lines and every other thing I could buy. Needless to say, I feel like an ass for not checking that valve first. Can it be removed, cleaned and replaced until the end of the week, do you think? I can order the part now, but I'm not sure that I can keep my job if I have to take the bus.

Thanks again!


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## groggory (Apr 21, 2003)

FAQ'd in 'oil'


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## munkittrick (Aug 27, 2006)

groggory said:


> FAQ'd in 'oil'


I searched for Pressure Release Valve, Oil Pressure Release Valve, Oil Cooler Housing Pressure Release Valve...it pulled up like 30 non-relative conversations. Is the "advanced search" capable of more accuracy now than in the past?


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## munkittrick (Aug 27, 2006)

groggory said:


> FAQ'd in 'oil'


Okay, found it. It is spelled incorrectly so it wasn't coming up in my searches.


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## groggory (Apr 21, 2003)

munkittrick said:


> Okay, found it. It is spelled incorrectly so it wasn't coming up in my searches.


What was spelled incorrectly?


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## cri-cri (Sep 27, 2009)

> Can it be removed, cleaned and replaced until the end of the week, do you think?


It took me about four hours (IIRC) to remove everything, steam clean the housing, clean the pressure relief valve, replace the check valve and put everything back together.
Note that you cannot order no. 3 & 4 (spring and plunger) separately. So if you want to replace them with new parts, you'll have to buy the entire oil filter flange assembly. It's quite expensive though. Cleaning is cheaper... Either way, you'll have to order new gasket, o-rings, bolts etc ... pretty much everything marked as "always replace" in the above pic.


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## cwyamz (Aug 1, 2012)

One of those check valves almost caused some serious damage to my new head upon start up. The new bottom end quieted right down but the head did not. It was stuck and no oil was getting to the head. Luckily the guys working on it shut it down and diagnosed the problem.

$180 would have been a drop in the bucket compaired to all the cash I had tied up in that new engine. 
http://www.ecstuning.com/Volkswagen-Golf_IV--1.8T/Engine/Mechanical/Oiling_System/ES253059/


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## munkittrick (Aug 27, 2006)

groggory said:


> What was spelled incorrectly?


http://forums.vwvortex.com/showthre...gt-Pressure-relief-valve-or-not-99-9-sure-but

The heading says "relieve" instead of relief. Threw off the search completely, but I misunderstood anyway. I thought that you were pointing me to another link, but that link clearly goes to this conversation. Thanks and sorry for the misunderstanding.


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## Three3Se7en (Jul 2, 2007)

There is good info here. Did cleaning it help any that you can tell?


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## munkittrick (Aug 27, 2006)

Three3Se7en said:


> There is good info here. Did cleaning it help any that you can tell?


 I cleaned the entire oil filter housing, the feed line and the pressure lease valve and it made a HUGE difference. I just fired her up again and heard that familiar soft ticking of a VVT 20v head and felt a lot better about the two hours I'd spent breaking that stupid housing down, but another 45 seconds of idling and even THAT "familiar" ticking is gone. It's damned near completely silent...like when it was new. I did a diesel oil system flush and ran a quart of Seafoam in a full oil change of "sacrificial" oil to clear up the pathways that I couldn't get to, but it's a HUGE difference. I'm going to let her sit overnight with the Seafoam in the crankcase and flush it again in the AM and I'll try to get some video then. Night and day!


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## groggory (Apr 21, 2003)

munkittrick said:


> I searched for Pressure Release Valve, Oil Pressure Release Valve, Oil Cooler Housing Pressure Release Valve...it pulled up like 30 non-relative conversations. Is the "advanced search" capable of more accuracy now than in the past?


Cross indexed 'pressure relief valve' in FAQ


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## E.fortney (Jul 13, 2020)

I know that I'm digging up the past, but I was wondering what code or issue got you to this point?


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## munkittrick (Aug 27, 2006)

E.fortney said:


> I know that I'm digging up the past, but I was wondering what code or issue got you to this point?


I'm sorry, but I honestly don't remember any of the details, except that my problem ended up not being a failed valve, but a stripped oil pump drive gear.


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