|
Post by knobi1 on Apr 10, 2016 16:33:30 GMT -5
Hey all, I have a 1993 Justy 1.2, It just so happens I made a thread about Oil Pressure issues and the things I found. Now I am back at the beginning despite all the posts I've read. It started with my dummy light flickering at idle after the motor warmed up. Scary stuff, light comes on at such a low psi. I installed a mechanical oil gauge. Readings were around 25 at cold psi and went as low as 3psi warm idle. Every 1000rpms after idle I appeared to be getting 10psi. up to 30-35. So... I changed my oil pump internals and cover with new O-ring. No luck, cold psi is now 32-36 but warm idle is the same..(20w-50) It then occurred to me that I could have a problem with my pickup tube or screen. I just finished pulling off my oil pan and I was actually praying it was clogged ha. It only had a small piece of what appeared to be RTV in the portion of screen that leads to the tube. Yes it is a small screen and tube so it could of affected it. However, I was hoping for a more noticeable blockage. So, my motor looks super clean from below, not shavings or any debris, shiny pistons and surfaces from the outside have really good color and shine , obviously not a factor in whether I have shot bearings or bad clearances, but it was nice to see. I looked in the hole where the pickup tube mounts, appears to be unobstructed. Before I regasket the pan and hope the cleaned screen does the trick. Any advice on what else to look for or do while i'm in there. Not sure If I'm up for new rod bearings and almost positive a rebuild is out of the question for me. The damn car starts up first crank every time without fail and sounds great, no knocks no ticks no misses, NOTHING. I just do not feel comfortable driving any car with low oil pressure, not fair to me or the car. I will probably have to sell my Trusty Justy if she becomes not so trusty. Thanks in advance for any help.
|
|
|
Post by knobi1 on Apr 11, 2016 19:00:27 GMT -5
|
|
|
Post by dez on Apr 11, 2016 21:57:47 GMT -5
Looks like a lower end rebuild is in order to me. You might get by if you Polish the crank and install new bearings, both rods and mains.
|
|
|
Post by knobi1 on Apr 12, 2016 0:46:41 GMT -5
Well that is bad news for me! Unfortunately, I can't afford to have the motor rebuilt and I only have so many tools and limited garage space. I was hoping to just replace the rod bearings and get by for awhile. If not I guess I'll have to put it back how it was and sell the car. Pretty depressing since I love my Justy and I want to keep it. It starts right up and doesn't make any weird sounds. Just that damn low oil pressure. I've put quite a few labor hours into this thing and countless more on the internet, as well as parts. It would suck to throw in the towel now but life sucks too so it is what it is :/
|
|
|
Post by Armageddous on Apr 12, 2016 15:59:02 GMT -5
Can you still access the chain guide? If so remove it and seal it to the block. It could be a source of lost oil pressure.
Terry
|
|
|
Post by dez on Apr 12, 2016 19:59:33 GMT -5
Can you still access the chain guide? If so remove it and seal it to the block. It could be a source of lost oil pressure. Terry If you remove counter shaft will the engine vibrate to pieces, I thought about removing mine to give more top end.
|
|
|
Post by Armageddous on Apr 12, 2016 21:50:38 GMT -5
I have no first hand experience with this. But I have read it doesn't make much difference. You need to cut the shaft and lathe the inside of the sprocket end to remove the imbalance. Then the rear bearing oil feed needs to be plugged.
Terry
|
|
|
Post by knobi1 on Apr 12, 2016 23:42:23 GMT -5
Hey guys, thanks for the replies! Terry, I have no experience with anything past what I have already been able to do here. I learn quickly but usually not by things going my way So, I took a dial caliper and tried to get an accurate reading on the crank journal. here is the info I got. Std bearing size for the crank journal as stated in the FSM is: STD 1.6525-1.6529 Mine is 1.634-1.635 As far as I could see with my caliper, these are the readings, probably not the best tool ever, but it reads to 0.001in My upper rod bearings were wore fully to the copper inside. really bad I imagine. however, the crank seems very smooth with minor lines or marks, not noticeable to the touch. From the quick math I did, it appears my crank has been turned once to 0.25 over. So the last turn this crank can get acccording to the FSM. I guess my question now is, should I try and buy some 0.25 undersize bearings(I found a place local who has some) and install those or do I pop the old ones back in and sell the car. :/ Another way to put it, will new Rod bearings be worth installing to get by for awhile or will it possibly make my situation worse and cause immediate failure of my rods or crank? Assuming the crank is still in round, but my bearings are worn badly. Will new bearings affect my oil pressure that much? It's hard to imagine such a small clearance causing such low oil pressure. I just pray that my main bearing isn't also completely worn out, that would be the nail. I'll look into the chain guide but it seems to very tricky to remove or work on without removing the motor and rebuilding out of the car. My cousin and my uncle in St. Louis are very reputable mechanics and I'm hoping to be out there later this year to see if they can help with the more in depth rebuild. Until then, I need a bandaid that will keep me driving as reliably as possible. Thanks again! -Noah
|
|
|
Post by knobi1 on Apr 13, 2016 0:07:13 GMT -5
Also after some more research, it seems like yes, bearings can lower oil pressure but I'm starting to think my oil pressure relief valve or spring is ether stuck or faulty. Anyone have experience on this? I've got the oil pump disassembled again and the oil pan off, can this be done with relative ease? I assume the front crankcase cover needs to come off to get to the spring and valve?
|
|
|
Post by knobi1 on Apr 13, 2016 23:34:16 GMT -5
Update, feel like an idiot but I just found out they stamp the bottom of the bearing with it's size. Mine say .50 so i guess I'm getting another set in that size. A machine shop near me can get them in Clevite brand for 25$ a set.. or 75 for all three sets.. shady way to sell bearings if you ask me xD A set should be for the three rods, not just one rod. Owell, this is my last hope so wish me luck.
|
|
|
Post by knobi1 on Apr 14, 2016 23:22:01 GMT -5
Update! I ordered the Rod Bearings from CBA machinery in Chandler, Az. They returned my calls promptly and were able to send me the bearings in ONE day!! What luck, they even helped me determine what the closest size would be for my situation. They had good advice and gave me alot of there time. Highly recommend there service.
Anyways, I'll be installing them tomorrow morning. With all the different people giving me input, I feel ready to get this done.
Wish me luck!
|
|
|
Post by knobi1 on Apr 15, 2016 12:33:47 GMT -5
www.youtube.com/watch?v=j7DZxqPUQto Watched this, I think I'll try for a nicer finish on my journal. I will be starting in an hour or so, I'll post some pics and update later.
|
|
|
Post by knobi1 on Apr 15, 2016 22:30:38 GMT -5
Well I didn't get the pictures uploaded or anything, i'm exhausted. I probably spent 6 hours straight, making sure I installed the bearings correctly,using plastiguage and the torque bar.. The oil pan seal is not fun at all. The bearing replacement was the easy part! The oil pan and cross member are the real PITA's. Anyways, I'll finish tomorrow morning and post some pics and my results.
|
|
|
Post by knobi1 on Apr 18, 2016 15:38:18 GMT -5
I got the rod bearings installed, the motor sounds a lot healthier and for sure has higher oil pressure. I made a stupid stupid mistake though. I did everything with the bearings and assembly so nice and I was proud of myself. I take her for a spin and realize that there is no oil feed in my mechanical oil gauge. So like any do it yourself-er, I decide to take a look at the brass compression fitting. Too bad I forgot how small it was, turns out I compressed it too tight to the hose and squished the inner tube too tight. I then lost the ferrel while attempting to remove and reuse it. Long story short, I tried to reseal it and I ended up pumping 2.8 quarts of oil out of the tiny hole the tube fits into in under 10 seconds. Seems like my oil pressure is good . Luckily I wasn't driving the car and I noticed as soon as I ran it for a few seconds. Got home, did the job right and now she runs good. I am still interested in the chain guide modification. It was definitely looking slack and I'm sure I'll need to address that before too long. The next issue I wan't to take care of is the valve lash and figuring out how to stop the chattering noise from the topend. I have a feeling I'll find some burnt exhaust valves. My spark plugs are pretty white and I haven't replaced my o2 sensor and I'm not sure where else to find what's causing my car to run so lean. Thanks for everyone's help, I'm beggining to think I can keep my Justy after all. -Noah
|
|
|
Post by knobi1 on Apr 28, 2016 0:33:41 GMT -5
Hey guys, Sorry I haven't posted for awhile. So far my Justy is running great, I've driven a few hundred mile trips and all around town. The motor is way more responsive, it starts right up. I still have an oil leak, It's a pretty bad one. I think it is from the oil pan or possibly the front engine cover, i'm not really sure. Since it wasn't leaking like this before I replaced the rod bearings and dropped the pan, I am assuming that is where the leak is coming from. Anyways, for anyone feeling hesitant about replacing there rod bearings, It really isn't that hard if you have the tools and some patience. It made a huge difference in the reliability of my car. I definitely recommend doing this if your crank is still in round and it is done before any major damage or rod knocks appear. Thanks again for everyone's help/advice, I'm sure I'll be calling upon you again soon. Such is the nature of unique cars.
|
|
|
Post by dez on Apr 28, 2016 12:20:34 GMT -5
My Offroad Justy is having similar issues now, I plan on pulling the engine soon and replacing the bearings
|
|
|
Post by jasin on Apr 28, 2016 14:44:02 GMT -5
i have just done it yesterday main and rod bearings
|
|
|
Post by fighter01 on Feb 16, 2020 11:10:28 GMT -5
Well I didn't get the pictures uploaded or anything, i'm exhausted. I probably spent 6 hours straight, making sure I installed the bearings correctly,using plastiguage and the torque bar.. The oil pan seal is not fun at all. The bearing replacement was the easy part! The oil pan and cross member are the real PITA's. Anyways, I'll finish tomorrow morning and post some pics and my results. I know this is years later and not many on this thread today but by chance do you have main and rod bearing clearance numbers ?
|
|
|
Post by justyce on Feb 22, 2020 17:34:46 GMT -5
Crankshaft Specifications:
Journal Diameter 1.6250-1.6290 in Main Bearing Oil Clearance 0.0006-0.0018 in End Play 0.0031-0.0070 in
Rod Specifications: Journal Diameter 0.6531-1.6535 in Bearing Oil Clearance 0.0008-0.0021 in Side Clearance 0.0028-0.0130 in
|
|