Seijuro

Hey guys,
New here and new to Hondas. I just picked up a 92 DX, but the oil light has been blinking. The water temperature guage in the dash also doesn't respond. The owner and I both thought it was most likely sending units that were bad. So I paid the man and got the car.

Now I'm not so sure. It starts out by blinking but shortly later it will just stay on. I was driving it last night, and I started hearing a faint rod-knock-ish sound. So I put the clutch in and shut the motor off. Let it roll for about 15 seconds, turned on the key and started the motor. Oil pressure light went off and the knock sound went away. A minute later the light started blinking again, then stays on, then knock sound returns.

So I've discovered when the light starts blinking I can shut the engine off for 10 seconds or so, turn the key back on and let the clutch out, and keep going for another 5 minutes before the light will blink again.

I'm pretty sure I do have a real oil pressure problem. But the fact that it goes away temporarily by only turning off the engine for a few seconds has me wondering if it's really the oil pump.

I'm almost wondering if perhaps the oil can't drain back to the pan properly, so all the oil is getting stuck ontop of the motor, and the light is coming on due to oil starvation at the pump? Has anybody heard of anything like this on a Honda motor? I might have an oil pressure guage somewhere, if I do I'm going to install it so I can really see what's going on.

Anyhow, I'm wondering if I could get some insight into changing the oil pump. What's involved etc, how much time should I expect to invest? And any suggestions on what pump to get? I'm familiar that sometimes there is parts interchangeability that can be better than stock. But I don't know Hondas whatsoever so that may not be the case for this one? And where is the oil pressure sending unit on the motor? And the water temperature sending unit aswell?

Thanks in advance everybody for reading this novel.

pdiggitydogg

Have you checked the oil level? Changed it since you bought it?

Inspect the pan and pickup before you decide to change the pump...its not fun and its not exactly easy to do.
You have to remove the accessory belts, the crank pulley, the oil pan, the timing belt...all before you can get the pump off.

The oil pressure sending unit is on the back of the block, its a single connector, that resembles a stereo mini-plug.
The sender is an on/off type of signal - you either have pressure, or you have zero pressure.
Temperature sender is on the head, distributor side.

dohcdelsol

stop driving the car before you throw a bearing because of no oil pressure especially if you hear a knock.

pull the oil pan and check for a clog in the oil pick up.

spin the pump and see if it makes a noise. replace it if it does.

Seijuro

I did check the oil level, it's actually a bit high if anything. I think someone else thought adding a quart might fix it or something. The oil looks good on the stick, but I'm going to drain it today and see what it looks like in bulk. A new filter couldn't hurt if the pump is tired too.

Okay so it's not an oil pressure sensor, it's an oil pressure switch. Good to know. Is it better to get to the switch from the top or from underneath?

I'm also going to be dropping the pan today to take a look at the oil pickup. I'm not familiar with the oiling systems in these cars, but being overhead cam I imagine a fair amount of oil is pumped over the head. Could it be worth my time to pull the valvecover to see if the draining passages are free, or is this so unheard of with these motors that I'd probably be wasting my time.

Removing accessory belts shouldn't be a problem, crank pulley shouldn't be a problem. What's involved in removing the timing belts? And how easily is the cam going to turn with the belt off? Anything I should keep an eye out for with pulling the pan? Is something going to get in the way? do I need to lift the motor any? This is a 5spd. car if it matters.

Thanks for the responses guys. Keep any and all ideas/hints coming!

pdiggitydogg

Switch, right
You will probably get it best, from under the car - its right by the filter.
Yeah, I was going to suggest checking the oil passages, in the head, too (but forgot)

The timing belt has a spring-loaded tensioner - undo the bolt on that and get the belt some slack and it will slide off.
You will be able to turn the cam with minimal effort, since the springs arent too stiff.

You wil probably run across several rusted-to-**** nuts and studs, when pulling the oil pan.
When you put it all back together, just be sure you dont put them back on too tight, and squish the gasket in a funny way (causing a leak).
Oh, and you probably already figured it out, but the header must come off to pull the pan.

Seijuro

Header's gotta come off.

No I hadn't figured that out. That's the kind of heads up I'm looking for. Thank you, I'll pick a header gasket up before I get to working on it. Now that I think about it though I probably should have realized the header needs to come off.
Are the header bolts (nuts/studs?) prone to breaking? Should I get a set of new bolts handy? Is there anything else to think about that comes along with dropping the header in the same manner that dropping the oil pan means dropping the header?

How many oil passeges in the head are there? And where are they located? For all I know this thing will be so cruddy I won't be able to see anything at all.

Thanks again for all the help. This n00b appreciates it

pdiggitydogg

You probably dont need a new header gasket. I have reused mine several times.
The header studs will usually only break if you tq them too much when reinstalling - theyre only ~15ft/lbs.
Hopefully, the bolts at the header/cat flange are in ok shape...

The O2 sensor is in the header. Im not too familiar on where its located on the d15, but you could always just try leaving it installed, and unplugging the connector, intsead.
You may wamt to remove a splash guard to drop the header... You dont have to...it will bend into submission for the header.

On that same note of 'd15 unfamiliarity', I cant say how many oil passages there are either...