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no oil pressure to the head

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jonboyb

Probationary Member
6
0
Apr 2, 2007
Alpharetta, Georgia
My 1992 Laser AWD has about 20k on a performance rebuild (BS removal, 8.5:1 pistons, rods, heavily ported head, Web cams, etc) and I decided to change from the Big16G to a FP3065 ball bearing turbo. The car has run without a single issue and been to the track over 50 times easy without a single hiccup. Forced Performance requests the FP3065 be fed from the head feed location, not the filter housing like I had always used, and I decided to check my pressure at the head first. I'm so glad I did before putting the new turbo on.

At hot idle, the oil pressure gauge bounces off 0 and I only get around 10-12 at high RPM. I even went and bought a second mechanical gauge to make sure. However, I have 40 psi hot idle and 100 psi at high RPM at the filter housing (I know, I need to port the relief shroud). I should have WAY more than 0 idle, 12 at anything above 3000 at the head feed location. I inspected the cam journals for wear and they are almost mirror polished still, absolutely no grooves. It appears the head is getting plenty of oil. Lifters are very quiet also, I would expect noise with low oil pressure in the head.

Has anyone ever seen anything like this before? It seems that I would have to have a restriction in a gallery (physical blockage or head gasket blocking oil passage) or really bad clearances in the bottom-end bearings to lose so much pressure up top.
 
No, like I said, it has 40 idle/100 at RPM at the filter housing.
 
Huh?? :confused: I know that your oil pump makes the pressure with the help of the main bearings. If I was stuck with this situation I would check the o-ring on the oil pickup tube because you could be sucking some air instead of oil and if that was good I would say it was worn out main bearings. Are they still the original bearings?
 
I also read about 10psi at the feed port on the head during idle. I think this may be normal. Although I believe the head itself is recieving a higher pressure do to a designed restriction in the head. I just realized that the 3-blot plate on top of the head may have something to do with this... Someone please reasure my assumptions because I have been searching for the answer to this for a while.
 
First off Im not a newb with these cars I just never used this site much. But I am stumped. I have a 92 awd tsi motor was blown but it came with another good 6 bolt. Took the balance shafts out. Its a stock 6 bolt bottom end with a 2g head arp studs,copper head gasket, comp cams, crower springs and retainers and 1mm oversized valves. I pulled the pan off due to no oil to the head. put some oil in a jub and held it to the pickup tube while turning the pump with the drill. Oil comes out of all the rod bearings but not the oil squirters or to the head. If someone has some ideas on where too look for the problem it would be much appreciated.
 
You're probably just not spinning it fast enough. The most common way to prime the engine is to pack the oil pump when assembling. I'm assuming you're past that stage, so the easiest way is to bolt the oil pan back on, take the timing belt off, fill with oil, and use a drill/ratchet to spin the oil pump sprocket fast enough to build good oil pressure so that it will go to the head.

For reference, on my last build I totally forgot to pack the oil pump. Just spinning the oil pump, I had to hold it there for 2 minutes with an air ratchet just so the pump would 'start working'.
 
I stated in my first post that I spun it over with the drill. Putting the oil pan back on with oil in it is no different then holding a job of oil to the pick up which i did. I have ran the motor for a brief period of time it still has no oil pressure to the head.
 
i had the same problem. i didn't see any oil hitting the cam lobes. when i removed the valve cover, i started the motor and a jet of oil shot up out of the hole at the end of the oil feed line in the head. it shot 4 feet up hit the hood and splashed all over the place. this hole is the last one on the cam sprocket side of the head of the oil feed channels to the lifters. i saw that on some heads these holes are covered (there are 2 holes at the end of both intake oil feed channels to the lifters). i had asked if they are supposed to be covered or if they can be left alone cause i didn't notice any oil getting to the lobes at idle. i got no answer to my question. i have a pic in the post i mad about this. i'll look for it. i can't say if it is safe cause i drove the car for months like this, sometimes trips lasting a couple of hours and it did fine..........then it spun a rod bearing :(

by the way, when i covered those holes with my finger, oil could clearly be seen covering the cam lobes at idle.
 
I seem to be having a similar problem. I just had my bottom end rebuilt and when I started to drive it, it started knocking and my mechanic said my head was'nt getting oil. I'm not quite sure what conclusion he came to but if it helps at all; when I get it back I will let you know. Sorry....

This is the reason it's so important to prime and check for oil from the head when doing any major service.
 
I am in the same boat here. I asked on a couple sites and even called slowboy and some other shop and frankly i am amazed at how little anyone knows about the head on this car. I am having no oil pressure to the head. There is some oil making it up there but not enough to create pressure. The lifters are ticking loudly and I am not running it anymore untill it is resolved. Now, this is a fresh rebuild. New lash adjusters, excellent oil pressure, no balance shafts, oil squirters installed. I need to know where the oil is fed from the block to the head to us=nderstand where my source is. I suspect a gasket that is blocking the port slightly or something of that nature. I also am thinking the head I bought is from a n/a car....not that i see a problem with this but when the head studs were installed and the head was slid down them there was NO play. In fact I had to tap the head down with a mallet untill I could actually install the nuts. I dont know if there is a stud that has a galley attached to it or something of that nature but I am really getting pissed because evertime I ask a question I dont get a resonable response. Noone knows anything about any problems that are not mainstream on the damn forums. It is all recycled bullshit over and over. That is why I am posting here...I gave up on some other ones after waiting for some insight forever. This is my first DSM but, by no means, is this my first build. I dont know if this stuff will point to some miscalculation on my end. If i dont get any held soon I am going to run an oil feed line right from the oil filter housing directly to the oil port where the turbo used to be and say forget about it.
:talon:
 
I am in the same boat here. I asked on a couple sites and even called slowboy and some other shop and frankly i am amazed at how little anyone knows about the head on this car. I am having no oil pressure to the head. There is some oil making it up there but not enough to create pressure. The lifters are ticking loudly and I am not running it anymore untill it is resolved. Now, this is a fresh rebuild. New lash adjusters, excellent oil pressure, no balance shafts, oil squirters installed. I need to know where the oil is fed from the block to the head to us=nderstand where my source is. I suspect a gasket that is blocking the port slightly or something of that nature. I also am thinking the head I bought is from a n/a car....not that i see a problem with this but when the head studs were installed and the head was slid down them there was NO play. In fact I had to tap the head down with a mallet untill I could actually install the nuts. I dont know if there is a stud that has a galley attached to it or something of that nature but I am really getting pissed because evertime I ask a question I dont get a resonable response. Noone knows anything about any problems that are not mainstream on the damn forums. It is all recycled bullshit over and over. That is why I am posting here...I gave up on some other ones after waiting for some insight forever. This is my first DSM but, by no means, is this my first build. I dont know if this stuff will point to some miscalculation on my end. If i dont get any held soon I am going to run an oil feed line right from the oil filter housing directly to the oil port where the turbo used to be and say forget about it.
:talon:

I also can't comment on which are the actual oil passages because I've never really thought of it in that perspective. Oil pressure at the head is minimal at best, you're not talking 50+psi on boost here, common oil pressure at the head will range from 8psi-20psi hence your reasoning of not seeing 'a lot of pressure' at the head. The key thing to note is if you are getting oil at the top of the pores for lubricating the valve train.

Just to jump around in thoughts, if you bled your lifters down and have only several miles on them (or not at all), they will be tick quite a bit until they 'break themselves' in. I'd like to note that I've seen freshly bled lifters not tick even after only 10 minutes of idling.

If your head is freshly rebuilt and was hot tanked, more than likely you don't have a catastrophic blockage inside the oil passages in the head. Also, if the headgasket was put on correctly (well, you can only put it on one way), then I also don't suspect it being the issue.

Lastly, if you had resistance going down on the studs, you possibly could be running a mix of headstuds and head. The 6 bolt block requires a 12mm headstud, whereas the 7bolt block uses an 11mm headstud. If you are using the corresponding head, all should be well, if not, that could be the reason of your resistances and/or binding on the studs if you try to remove the head.

Lastly, I'm not sure what this has to do with anything, but there is in fact a stud that enters an oil galley, it is the bottom row center most stud.

fyi, in all my years of DSMing, there is not ONE question not answered yet, either specific or not. If I haven't found the answer to the problem, it's because I didn't enter the right keywords in my search. The only problem with large databases like this is that you have a lot of BS to sort through before you arrive at the correct answer. Again, in my experience, the answers are usually in front of your face, you just have to know where to look.
 
i have searched a lot. I primed the whole system with a drill and had plenty of pressure in the system. I never got pressure in the head though when i did the priming though. I looked around and posted and people said that the priming is useless...blaaa blaaa that i am not building another 350 blaa blaa. I dont know what these people smoke but there are certain things that are universal to engine building and priming either by cranking or by drill is always a must. Regardless, I menioned the problems and the responses i got were that my drill is not fast enough or that the cavities take too long to fill. I find this to once again be bs. I have the distinct feeling that the bolts are the issue. I know I am running the right head though. The motor was a 90...I f-ed the head porting it...and bought another one from dsm graveyard and both were the large port style and bolted up with almost no port matching...just cleanup of casting....to my 90 manifold. Unfortunately I do not have another head around to look at. If I did i would be blowing air in all the passages to map the flow. And yes, I cleaned the head with all plugs removed...oil and coolant...with air and brakecleaner for a couple hours making sure that everthing was out. Subsequently, I found my a-hole machinist bead blasted the head with the ports open....:notgood: I found nothing that would cause :any problems at that point. I did not however clean the block as thoroughly because the block was hot tanked and clean as a whistle.

btw i have 250 miles on her so far, but, once i got the idle air valve replaced and the engine idling at 850 i REALLY heard the lifters ticking. When it does idle all i have is a little oil drizzling out of the lifter bleed hole. I have a gauge in the old turbo oil port and it still does not read any pressure.
 
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i think that from what i see in these photos that the oil port is in fact attached to one head stud. The one in the front all the way to the left is the particular one i am thinking is right.
If that is the case then the tightness of the stud in the head bolt hole would be the culprit. now if this is in fact true, why has noone ever seen this problem before. And most importantly why is this head so tight on the studs if it is a 1g. I m very sure it is a 1g.

Does anyone know if there is a crossover year where the head studs changed to 11 mm and the ports were unchanged?
 
it seems as i am answering my own problems but i really need some people to agree with what i am finding. It looks as though head studs were 12mm untill 93. 94 they were 11. Therefore if then new head i got is a 94 then it could be that the head was from a motor with 11mm bolts but is in fact a 1g motor which has the larger ports. This in conclusion could be my dilemma. Any thoughts....please.
 
I'll chime in on this one even though I have no proof or facts - I've heard (which is a taboo word in this forum) that the 4G63 - 7 bolt motors had a slightly different head makeup due to the change of rod design for the block than the earlier 6 bolt motor/head configuration...is why the 6 bolt motors are highly in demand due to this earlier and thus heftier design.
 
I noticed you said you had balance shafts removed. Did you happen to block off the oil holes for the balance shaft bearings? If you didnt turn the bearings or have a a set of solid bearings with no holes for oil to run through chances are that would cause almost no oil pressure.
 
yes i put bearings in 90 degrees off. Also i have plenty of pressure in the bottom end. I am just talking about head. If it were the block as well then i would suspect what you were saying. Believe me, this is the first thing i checked into since the machinist installed these parts.
 
I had this problem after installing a new head on my engine with ARP studs, the old head burnt a valve and wasn't worth repairing. The lack of oil flow to the head was caused by the stud holes in the head not being drilled out correctly at the factory. They were stepped drilled from each side of the head instead of being completely drilled all the way through and smaller in diameter than my original head. The stock head bolts are smaller in diameter so it wouldn't normally be a problem. But when combined with the larger ARP studs, the oil passage to the head was completely blocked.

To fix it, I took both head to a machine shop and they drill the new head to match.
 
that is what i suspected. thanks black. I am just going to pip a 1/4 inch stainless hard line to the head on one of the inner oil galleys to the head. This combined with the oil that is making to the head should supply me with enough oil pressure to keep the valve train happy. I am going to test it out once it is hooked up. i still have a pressure gage installed in the head so I know if it is too high or low. Worst case i will either need a restricton or a larger line depending on the pressure. I am going to shoot for 20-25 psi. Thanks once again. And to verify the head bolts I checked last night are not the same size the full length. They have a relife cut in them from the factory. The ARP head studs however are large from top to bottom which would explaine the difference in oil flow over the stock bolts. SO....in conclustion this should probably be a sticky noting that If installing the arp head studs.....you should check clearance on the head bolt holes to verify you have the correct clearance before installing the head to the block. i hope that this will eventually help someone else in the future.
 
On MMCD i read 12-14psi at idle, ~100PSI WOT 4K+. BS removed. I'm pretty sure that's from the sensor on the OFH.
Question is, is it accurate?
 
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