Oil pressure light!! What to do?

[irowiki]

Might just be the head gasket too.

My 87 ran like crap and had similar bad numbers... but I haven't compression tested after yet!

[4wdEconoBox]

I'm hoping its that simple! Mine still runs as good as it did 3 years ago when I got it, maybe its just never ran that good, but I just assumed thats how all of these cars ran and I just got used to it? haha...It just smokes more now and burns more oil though.... Its never ran hot or tried to run hot in the time that I've had it. The oil has never had coolant in it that I've seen, but the coolant has always had a brown color to it, I just assumed that someone put some type of stop leak in it before I got it... Maybe the brown color in the coolant has always been oil? Idk, I'm kind of at my whits end because I don't know what to do.... And sadly I traded my other daily driver for a project truck the week before I started noticing all of these problems...

[irowiki]

So it doesn't use coolant at all? Mine was using a cup of coolant per 30 minutes of driving!

If it is not using any coolant then I might lean less towards the head gasket, though it could be broken between cylinder passages.

[4wdEconoBox]

Nope, I just went and checked to make sure, since I replace the thermostat about 1000-1500 miles ago, it hasn't lost any. So I'm guessing that knocks out the head gasket as my problem doesn't it?

[4wdEconoBox]

I'm also thinking that the brown hue to the coolant is probably just rust, since I use water when I have to get by without antifreeze(I live in Alabama so it doesn't get very cold most of the year), it doesn't smell like oil either, it kind of has that "rust" smell ya know?

[irowiki]

Oh dear, using water could (and will) cause all sorts of problems! It isn't about the freezing so much but it helps prevent corrosion and the head gasket can fall victim to that. I would flush everything out and go with a proper 50/50 mix if you rebuild.

[4wdEconoBox]

You know, I can honestly say that I've never thought of that....Makes perfect since now that you said something though! Hmm, you learn something new everyday! Thanks

[marlinh]

4wd, don't assume your engine is stock. It may have had the crankshaft or cylinders machined. I would recommend taking it apart and measuring to make sure you don't order incorrect parts.

[4wdEconoBox]

Yeah, that's true, I mean I know it doesn't necessarily mean its stock, but when I got the car, it still had the stock spark plug wires on it....They said 1984 on them haha. But like you said, you never know if something has been done to it or not. I was just looking at the quickest way to get the parts for it and getting it rebuilt the fastest ya know? But when I go to measure everything, whats the easiest way to do that? I know with bearings I could plasti-gauge, but is there some other way of measuring to see if the crank has been refinished? With the cylinders, how would I go about measuring those? What is the stock sizes for the crank journals and cylinder walls?

[marlinh]

FSM will give you all the measurements. If the crankshaft has been ground, the bearings will have a different part number on them. Can't remember exactly, but you can measure the crank journals with digital calipers.

If your parts store doesn't mind taking back parts, you can assume it is stock and order what you think you may need. Being special order they may not like to do that.

Plastigage the bearing journals to see if they require replacement. It won't tell you if the crank has been ground though.

[Petros]

I have taken apart perhpas 40 old 3ac, 4ac, 4age and 4afe engines and have yet to find an reground crank. Most of them were in good enough shape to reuse, even if a little polishing is all it needed. the one or two that was badly scored it was cheaper to get another standard size crank from the local wrecking yard than a regrind. So it is true of many larger engines (particularly those made in Detroit), I have not found it true of the smaller Toyota engines.

Chances are pretty good that you can use standard bearings. I would order them and on the rare chance they are not standard size just return them.

[irowiki]

I bet you need a new oil pump too

[4wdEconoBox]

Alright, well thats good news! I'm going to check on a few local junkyards this week too, I was told they may have an engine, but I don't know condition or price yet, I'll let yall know when I find out!

And yeah, I planned on new oil pump, all new seals, gaskets, rings, bearings, new clutch kit(it is on its way out also), new timing belt even though mine only has 1500 miles on it, and having the head redone with new exhaust valves and intake valves ground and reseated, along with a few misc small things, I want to get this back to perfect running condition cause I love this lil old car! haha

[marlinh]

The engine I rebuilt last year (from Hermes, Petros) had ground connecting rod journals. I was surprised.

[Petros]

Hermes was in pretty rough shape when I got her in a trade from New Mexico, engine was pretty tired (but still running) and it surprises me that someone had been through the engine enough to reground the rod journals arne replace the bearings. It should have had new rings too. someone must of really abused the engine to have it get so wasted by the time I got it. Even so, I managed to drive 4,000 miles from silverton NM to Austin, rescue a CRX, and than drive back to Seattle area via southern california, hitting a deer along the way. Nice adventure that one was, I was replacing parts all along the way, but it made it back home eventually.