Why is my SR head not getting oil???

[Gmans13]

Ok you all probably know my storie by now and my head is shot because it wasn't gettin any oil. Before I go replacing anything I need to figure out why it wasn't getting oil in the first place... I don't have any nocking rods or anything like that it just appears that the top end was damaged. can anyone give me any ideas on what might be wrong or some things to check out. Thanks, Graham

[GTR-33]

Thats easy, two words. Oil Pump. Yours was probably frozen or damaged.

[Gmans13]

hmm... but wouldn;t that mean that my bottom end should be shot also if the oil pump was bad?

[Tai Mai Shu]

oil tends to go with gravitiy which also happens to be the bottom of your block.

[Gmans13]

True but I ran the engine for quite a while until noticing the problem(30-40 min +5 mile drive) and that would lead me to beleive I would have at least spun a bearing or two.

[yellow_jacket]

Low oil pressure is usually caused by bearings going bad in the bottom end. However, in your case it could easily be that the pan is slightly dented and the pump is being starved. On rare occasions you will also get a sticking check valve. I believe that the oil pump is like the KA pump that is driven off of the front of the crankshaft and it is obviously not frozen because the motor is turning over and you evidently had enough pressure to keep the bottom end lubricated. If you had zero oil pressure you would have spun a bearing. The mains need a constant flow of oil to actually perform their job.

Here is the order of what I would check(most probable is first)

1) dented pan2) pick-up clogged or loose3) clearances on the mains and connecting rods4) Gear clearances on the oil pump and the check valve.

[Gmans13]

My oil pan did have a slight dent in it but I asked a few people before and they didn't seem very worried about it. The oil was also at the very max the dip stick says. The pickup was not cloged and I pulled 2 caps off rod bearings to see how they look and they still look nice. Where is the check valve you spoke of? Thanks a lot for the tips.

[yellow_jacket]

I know you pulled the connecting rod caps, but what about the main bearing caps?

The check valve is usually located on the oil pump housing somewhere.

Who looked at your oil pan? Guys who know about SR's or guys who know a lot about cars. Most cars will be fine with a dented oil pan, the SR seems to be the exception because the pickup is so close to the pan. To be honest with you, I don't have my SR quite yet so I am not exactly sure how close it is or how small of a dent will make a difference. I do know from these forums though that a pretty small dent makes a pretty big difference on these motors.

Lastly, I would definetely check the oil pressure with a mechanical gauge.

[Samabra]

Hey I hate to ressurect an old thread, however, I am undergoing basically the same problem, mainly that I am getting no oil to my head. I changed the oil pan to one that has no dents (the one in my stock motor was pretty dented) and that didn't do anything, so now I guess I will check the pick up. My only question is: is it possible that I may have to replace the oil pump? After searching I read about the a check valve being stuck, how would I check this? And also after searching its sounding like the oil pump install would a ***** and a half, can anyone confirm this? Thanks Chris

[UsedToOwn240SX]

Do you have oil pressure gauge? Did you check if you get oil squirting by peeping into the oil filler cap while cranking? Maybe the oil squirter pipes (2 snaky pipes on the head) got clogged. It's being held by a hollow bolt near the rear of the head. Unbolt them, and clean it using EngineBrite or something. May help....

[BLue n white R1]

check the oil pan to ensure its not dented!! mines was and it burned out the cam berings...

[Samabra]

Yeah the original was pretty dented, but we took care of that. The main reason that we knew that the engine wasn't getting any oil was just that, we took off the valve cover, and checked it out, and no oil was being squirted. Man this is annoying.....

[Gmans13]

yeah my problem was the dented oil pan...I had to replace the head + cams

[NEED4BOOST]

I am experiencing the same problem right now but I DO NOT have a dented oil pan. I never ran with a dented oil pan or anything. I have a greddy oil pan (the 5.5qt pan). I noticed this problem when I was at the road course (VIR) and I noticed that I was smoking on the front straight. My dipstick had shot out of place and sprayed some oil on the manifold and thats what was smoking. Pitted immediately (luckily it was right in front of me). turned the motor off right away. I let it cool and then checked the oil level. To my surpprise it was safe! it was between the low mark and the high mark.

Now I have the motor pulled apart but I didn't have a bad head gasket and no oil leaks anywhere. I replaced the head gasket anyways. I checked my lifters, cams, rocker arms, everything is fine no scars no metal shavings nothings (yes this car is trailered). I have checked the oil squirter lines and no clogs and I even went as far as blowing out the oil passages in the head. Now would it be safe to say that my oil pump is bad?

FWIW...I change the oil twice a month, no risks wanted. And I've driving the sr20det for a total of maybe 1000 miles.

Thanks....

[BLue n white R1]

you mihgt want to try a compression check to verify the head gasket and vavle seals are good.

[NEED4BOOST]

I have the motor apart already and the head gasket was fine. I replaced it with an HKS head gasket.

[BLue n white R1]

ahh since the head is apart you may want to have the vavles and valve seat and seals loked at my last red top that I rebuild, I forgot to look at the head and just changed out the head gasket and turns out I needed a vavle job and now the head need to come off again.

[Gladius]

I need a new oil pump for my sr. Who makes one, i cant find any online except for phase2motortrend. Is it possible to just change out the internals on the pump and not mess the with outer cover?