Need Advice: Oil High, Knock (1 Viewer)

[mjosoba]

Afternoon all. I’ve got a 96 LX450 engine with only 84,000 original miles. It was pulled because it ‘started to knock, so we parked it and checked the oil and it was too full.’ They claim the oil cooler cracked. I realize it could be HG or something else as well. It was still driving and never overheated according to them.

I’m not out any money on this. I just wanted to get the LX.

Would it be worth tearing into it to replace my tired 260k ‘93 1FZ? I’m planning on a diesel swap someday, but it’s not an immediate plan. I’m inclined to think it would be worth it.

What is the likely list of stuff to replace?

From my reading of a bunch of threads with knocks and such over the last week or two, it seems that I’d be doing BEB’s, maybe machined/replaced crank, maybe con rods, hope the bores are good, may as well pull the head and do the gasket/make sure it’s still straight.

Obviously I’d pull the oil cooler first and pressure test it to see if it’s the actual culprit or not. That would tell me a lot about the head hopefully. Possibly another thing to do first off is bore scope it, to see if all cylinders are good still.

I’d appreciate any thoughts or additional things that could need to be replaced. Kind of want a ballpark price breakdown to see if it’s worth it to me.

Thanks, Michael

 

[gummycarbs]

Is the engine actually knocking, or is it something else, like a bad idler bearing or damaged teeth on the power steering pump? Most of the "engine knocking" threads here turn out to be something other than bad bearings.

 

[mjosoba]

Well considering the oil was drastically overfilled with oil/coolant I’m assuming it’s knocking. I’ve not seen it run. It was partially disassembled by the mechanic I bought the whole thing from when I got it and is out now.

@gummycarbs

 

[gummycarbs]

Do you know for a fact that there is or has been coolant in the crankcase?

 

[mjosoba]

Do you know for a fact that there is or has been coolant in the crankcase?

Judging by what’s coming out of the heater cores as I’ve run the new one, for sure. It’s disgusting. I’ll prob have to do quite a few flushes.

Edit: In other words, it’s a safe assumption there was a fairly free exchange of fluids. The mechanic that pulled it has had a shop for years and there didn’t seem to be a doubt in his mind. That coupled with the fluid issues, I didn’t really question it.

 

[gummycarbs]

So there's definitely oil in the coolant? I ask because there's the notorious brown sludge that you get if you mix Toyota's original red coolant with regular green coolant.

I'm continuing to ask only because the red/green sludge is a fairly common problem, whereas a failed oil cooler or oil cooler gasket is really rare. Not unheard of, but definitely rare.

 

[mjosoba]

So there's definitely oil in the coolant? I ask because there's the notorious brown sludge that you get if you mix Toyota's original red coolant with regular green coolant.

I'm continuing to ask only because the red/green sludge is a fairly common problem, whereas a failed oil cooler or oil cooler gasket is really rare. Not unheard of, but definitely rare.

I definitely understand and appreciate where you’re coming from. I put Peak Asian red back in. I could not tell you for sure if the P/O and mechanic ever switched to green coolant. It’s possible that there was leftover green in the heater cores. But I doubt it. There is no contamination in the ATF so it wasn’t the transmission warmer leaking, and according to tue mechanic, it sounded like oil and coolant evened out. Like, the coolant level dropped, and the oil level roSe. Gravity at work.

That being said, I’ll be back in town in a week or so, and will have the engine back in my possession and I can drop the pan and see what I can see.

If there is contamination, what would be a good first step? Drop the pan and check bearings, or start up top?

 

[rolliges]

Time for a LS swap; dress it up with a bunch of overlanding equipment and list it for sale on Bring a Trailer for $48K!

 

[mjosoba]

Time for a LS swap; dress it up with a bunch of overlanding equipment and list it for sale on Bring a Trailer for $48K!

. Well, that’s a different story. That’s for the LX. This is a ‘96 motor I’m thinking on refreshing and putting in my ‘93 until the day I do a diesel swap. Got all the pieces. Just need to do it. But my old ‘93 motor is TIRED.

 

[jpoole]

tired 260k ‘93 1FZ

how is it tired?
-low compression, oil consumption, power loss, odd sounds, leaks?

260k miles rarely results in a worn out 1FZ. Leaky, sucking oil past valve stem seals, running poorly due to lack of maintenance and failed rubber bits are all pretty common but truly worn out is very rare from what I've seen.

You seem to know your stuff so mostly asking out of curiosity but if it turns out that your '93 FZ has the typical good rings/cylinders/valves/bearings etc. then I'd be leaning towards just updating/resealing/refreshing the '93 engine as needed vs. overhauling an engine that likely has been sitting with water in it and run with unknown issues.

 

[gummycarbs]

If there is contamination, what would be a good first step? Drop the pan and check bearings, or start up top?

I guess if you're reasonably sure that there really has been coolant in the crankcase, you'd want to pull both lower pans and see how the big-end bearings feel. That requires that you raise the engine a bit. I've never done it, that's just what I've read.

Maybe put a scope down the spark plug holes to check for obvious damage or rust from coolant sitting in there after a possible head gasket leak.

 

[BILT4ME]

If there's coolant in the oil, how long has it been sitting like this? If over a year, you're looking at a complete rebuild because the rings will be rusty, the bearings will be pitted, even though they may be "tight". You may have to bore and do pistons, but there's a high risk of one cylinder having the bore filled with coolant and rusty to the point of pitting.

I would blow it completely apart to do a detailed inspection before I committed to even just "throwing it in the truck". Assume nothing.

 

[mjosoba]

how is it tired?
-low compression, oil consumption, power loss, odd sounds, leaks?

260k miles rarely results in a worn out 1FZ. Leaky, sucking oil past valve stem seals, running poorly due to lack of maintenance and failed rubber bits are all pretty common but truly worn out is very rare from what I've seen.

You seem to know your stuff so mostly asking out of curiosity but if it turns out that your '93 FZ has the typical good rings/cylinders/valves/bearings etc. then I'd be leaning towards just updating/resealing/refreshing the '93 engine as needed vs. overhauling an engine that likely has been sitting with water in it and run with unknown issues.

That about sums it up. I don’t think there’s any single thing actually wrong with it. Just need re-sealed and a bunch of little things. I figured since I had a motor with very low original miles, it would be a nice ‘upgrade.’ I don’t think there’s anything that would preclude me driving it anywhere I wanted (edit: on the engine currently in the ‘93). Just figured it would be easier to do on an engine that is removed.

I guess if you're reasonably sure that there really has been coolant in the crankcase, you'd want to pull both lower pans and see how the big-end bearings feel. That requires that you raise the engine a bit. I've never done it, that's just what I've read.

Maybe put a scope down the spark plug holes to check for obvious damage or rust from coolant sitting in there after a possible head gasket leak.

Yep, kind of what I figured. One thing to note, this engine is out and will be easy to pull the pans.

If there's coolant in the oil, how long has it been sitting like this? If over a year, you're looking at a complete rebuild because the rings will be rusty, the bearings will be pitted, even though they may be "tight". You may have to bore and do pistons, but there's a high risk of one cylinder having the bore filled with coolant and rusty to the point of pitting.

I would blow it completely apart to do a detailed inspection before I committed to even just "throwing it in the truck". Assume nothing.

Likely it has been around that period of time. So I guess my first step would be to scope the bores before removing the pans or head. Thank you for that thought!

 

[SaturnAscends]

Yeah, idk if low miles is always better. That 80k motor sounds like it's had a hard-knock life.

 

[mjosoba]

Yeah, idk if low miles is always better. That 80k motor sounds like it's had a hard-knock life.

. Good pun. Well, I’ll find out soonish. Hopefully.

 

[mjosoba]

Also I might note, I don’t mind tearing into this engine. It isn’t needed, and if it works out great. If not, no biggy. I’ll sell off whatever is useable and call it good.

 

[lp2k]

Is the engine actually knocking, or is it something else, like a bad idler bearing or damaged teeth on the power steering pump? Most of the "engine knocking" threads here turn out to be something other than bad bearings.

^this I would try this first and then go from there.

 

[jpoole]

@lp2k sounds like the newer engine in question is out of the donor 80/lx it came from so won't be that easy to diagnose the knock. It also sounds like it's sat for a year or so with water in the case so it will need to be inspected before it can be operated anyway.

 

[mjosoba]

^this I would try this first and then go from there.

I think we’re fairly certain it’s a knock. But, like I said, never saw this one running. The drop in coolant level, coupled with the rise in oil level leads me to ‘believe’ it’s knocking. We shall see. I will update this thread as I find stuff out. My free time seems low this days. Odd.