2004 civic low oil pressure

civic
honda

#1

I have a 2004 Honda civic ex w/vtec. I had to replace the head gasket a few months ago and everything went fine, or so I thought. A couple weeks after I replaced it and started driving it again, I took off the exhaust because the guy whon had it before put the one for the wrong model on there. As soon as I tried to push it to get onto the highway, the rev limiter came in at 4k and my check engine light came on. It scared the shit out of me and I went back to the shop to put the exhaust back and srelax what was going on. I pulled the code and I can’t remember the exact number, but it was for the vtec solenoid not coming on. I checked the oil pressure and found that it was almost non existent in the head. The car runs fine, no sound of dry bearing or shaving in the oil. What should I do next?


#2

When you too it back to the shop you should have asked them to diagnose the problem rather than to put the exhaust back on again… although that was a good idea anyway.

Sounds like the variable valve timing system isn’t functioning.Take it back to them and have them look at it.


#3

Could you clarify what “wrong model exhaust” means?


#4

Okay. The shop I was using was at my college. I took the exhaust off and put it back on myself, along with the head when doing the head gasket. The exhaust that the previous owner put on it was for a coupe and not a sedan. It hangs in the wrong spot and scrapes at every speed bump. You’re correct when you say that the variable valve timing isn’t functioning. I’ve replaced the oil pressure switch on the solenoid as a desperate attempt to fix it. I believe the oil pressure isnt where it’s supposed to be. A few months after the CEL came on, I started getting my oil light coming on for a brief second at startup on occasion. I’ve checked the oil pickup for a clog, but no dice. Everything looked good. No sludge or buildup in the pan. Sorry I didn’t post this info sooner. I’ve been at work all day.


#5

By all means check your oil pressure. That’s done with a kit that has a “T” fitting to add a line to the oil pressure sender, to which a pressure gage is attached. Fluid pressure will always equalize throughout any closed system, so it cannot be not “where it’s supposed to be” unless something is blocking the passage, but I don’t think that’s the case here.

Oil pressure is created by the force of the oil pump pushing the oil through the passages in the crankshaft etc. that direct it between the sleeve bearings and their corresponding wear surfaces. The force used to push the oil through the small spaces is what causes the pressure. Low oil pressure is generally due to excess wear between the crankshaft wear surfaces and their corresponding sleeve bearings, as well as similar small spaces between the connecting rods and their bearings and to some smaller extent the camshafts bearings. When the spaces get too big, the pump can no longer maintain pressure. Sort of like trying to keep a balloon with a leak pressurized. Since oil pressure is used kind of like a hydraulic fluid to operate the variable valve timing system, insufficient pressure may affect the operation of the VVT system. All the solenoid does is open the valve to allow the oil pressure to do its job. Without the oil pressure, it’s no dice.

A compression test might give you an idea of the internal condition of the engine. I’d start with that. NOTE: if the engine was run with the oil too low, internal damage to the wear surfaces could have caused damage to the surfaces that would prevent the oil pressure from building, emulating excess wear. Take nothing for granted.

If your college programs is doing engine work this (coming) semester, this would be a really good lab project for them. A great deal can be learned from experiencing the results of excess internal wear and subsequent loss of oil pressure. The relationship between the two is not always readily understood.

Post back with the results.


#6

As much as I would love to do that… My problem is that I just finished the automotive part of my degree. I have 3 academic classes I’m going back in a few weeks to take. The issue at hand is that they can only work on it on Fridays, and they will take 2, maybe 3 class periods to do it. I have to work 5 days out of the week and go to school on 4 of those days. If I get them to work on it, I’ll be without it for maybe a month. When I checked the oil pickup tube, I really goofed up and only checked for sludge. I should have taken a second look at the main bearings. Maybe even loosened up the connecting rods and checked their bearings


#7

Well, then, the oil pressure test kit will be an investment for you. You’ll want on e at some point anyway. If the pressure is actually low, that’ll answer your question, but checking a bearing would be a good confirmation. My wild guess is that you’ll find the pressure really really low.

Sincere best on not only your problem but also your career. It’s good to hear of someone pursuing what they like rather than what they think they can get rich doing. Automotive mechanics will always be needed, and it cannot be outsourced. We can’t send our cars to China to get fixed. And good luck on the ASE exams also.


#8

If the head gasket failed to the point that it diluted the engine oil with coolant it’s possible the bearings could have washed out along with damaging the crank journals. That will cause low oil pressure.


#9

Don’t give automakers any ideas or they will bring in Chinese automotive mechanics on a work visa.


#10

“We can’t send our cars to China to get fixed”. Don’t give them ideas!


#11

Alright, so I think I’m gonna brave it out and hold off on repairs until the end of this month. I can work on the car when I start back up at college in a couple weeks. I’ll have a ride to work and school then. Hopefully the bearings are the problem and didn’t ruin the crank by then. I’ve been driving it like that for over 5 months now, whats a couple more weeks?


#12

I presume the oil is the correct spec, newly replaced, the oil filter new, and oil level on the dipstick is spot on.

Besides the good ideas mentioned above …

  • check the oil pressure in the bottom part of the engine, close to the oil pump, often can be done by removing where the sensor for the oil pressure gauge or warning light goes, and temporarily installing a shop gauge instead.

  • check the oil dipstick tube is properly seated. You probably had to remove that to change the head gasket. If it isn’t seated correctly the dipstick will produce an inaccurate reading.

  • if the oil pressure is ok down low by the pump, but low up high in the head, there may be a problem with the prior head gasket install job that is blocking an important oil passageway between the lower half of the engine and the upper half. It’s not that uncommon to discover a head gasket has been put on upside down or front/back reversed. Or just the wrong gasket for the engine.

  • could be the oil pressure in the head is actually ok, and all that’s wrong is the vtec solenoid is malfunctioning. variable valve timing solenoid malfunctions are a fairly common topic here. sometimes associated with sludge build up from not doing oil services frequently enough or using the wrong oil, but more often just b/c the part just up and fails. Best of luck.

  • edit: if the distributor shaft is involved with the oil pump drive, perhaps something went wrong w/all that during the head gasket job. Good idea to double check that linkage.


#13

Believe it or not, some of the older Benz engines actually had a dedicated oil pressure test port

I suspect that’s probably not a common feature on most engines :slight_frown:


#14

Trust me, I checked the oil pressure in the head. Pretty much non-existant. I didn’t check it anywhere else because I was low on time and didn’t have the equipment to check it. I had the spool valve checked too, just to be sure it was fine. I’m confident that the gasket was put on right because the problem appeared about 2 weeks after I changed it out. Also, there were alignment pins in the block as a se cond check.


#15

Also, there is no dipstick tube or distributor on that engine. The dipstick pops straight into the valve cover. And it has a coil-on-plug setup. So I guess theres 2 less things it could be.

The engine is a D17A2 if anyone is wondering


#16

How did you solved the issue? I’m having the same problem on my 2001 civic and it has the same issue, low pressure on the head, but the rest of the car has fine pressure. Thanks.