My '97 Maintenance and Transformation Thread

[TYM4FUN]

Nice pics and info,....subscribing for future reference.

 

[dranven]

I talked with a Toyota Master Tech today and he recommended replacing the piston and the ring(s). Does the wall absolutely need to be honed if I'm putting in a new ring? The wall on no. 6 has very minor scoring, but not bad.

 

[jdeitch]

I talked with a Toyota Master Tech today and he recommended replacing the piston and the ring(s). Does the wall absolutely need to be honed if I'm putting in a new ring? The wall on no. 6 has very minor scoring, but not bad.

Be careful... You may be opening Pandora's box...

Scoring? Up and down as the piston travels? Pics?

It needs a good cross hatch pattern for new rings. (bead hone) Cylinder out of round? Original size piston with file-fit rings I presume? How do the rod bearings look?
Post pics of the ring lands in the piston

 

[dranven]

Here are the photos to show what I'm talking about. I can't feel anything with my fingernail, but you can see it.

I haven't pulled the piston out yet. Not sure if I want to. Trying to get opinions on if I can leave it in there safely.


Edit: What about replacing that piston only and reusing the old rings? If I buy rings, I have to buy the whole set, which is like $220 with a discount, then file fit, etc. Since the marks can't be felt with my fingernail, maybe they aren't bad enough yet where I can get away with replacing the piston only, so it doesn't cause any damage? Or is it safe to leave it alone.

I've never been this deep, so I appreciate any and all opinions from experienced members. Thanks.

 

[jdeitch]

The scuffing on the cylinder wall does not look TOO bad. Certainly caused by the ingestion of the debris in the cylinder.

I see a few options: listed from best to worst case scenario or least time/money to most.

A
Leave it the way it is now and call it good for a motor with 200k+ that has survived swallowing a spark plug electrode or something equally fowl. You'll at least have a fresh top end.

B
Remove as much of the ridge at the top of the cylinder with scotchbrite and solvent as possible. Carefully remove the connecting rod cap. Put rubber tubing over the connecting rod bolts. Carefully tap the piston/rod out of the top of the block.

ASSUMING the piston skirt is not badly damaged and the ring lands are OK and the rings are OK and the rod bearings are OK and the ring gap is within spec.... (a lot of ifs...)

I would lightly clean up the top of the piston and carefully reassemble everything and call it good.

C
If the piston is toast replace it. It is possible the old rings will be within spec and work with the new piston, but I wouldn't bet on it. If necessary replace rings and file-fit to bore. Use bead hone to clean up cylinder. Reassemble.

D
If you have to spend the money for a full set of rings you might consider re-ringing all cylinders. Use bead hone to give each cylinder a nice cross-hatch pattern. File-fit rings for each cylinder. This will be the best you could do without a complete rebuild. This will increase compression/performance and reduce smoking/oil consumption.

E
If the rod bearing is bad I would take the plunge and pull the motor for a complete rebuild. If one bearing is bad, it's likely the rest are too.

Call me again if you would like to discuss.

 

[Kernal]

Sorry if I missed it, but how did your engine sound before you tore into it, any light knocking when at idle? Did it have good power, any smoke, high oil consumption??

 

[dranven]

Jeffrey, thanks. See how the piston is damaged near the edge? So you think the scuffing on the wall is from the debris and NOT from the mangled piston edge? I'd like to leave it if possible and button it up, but just want to be sure it's not going to cause further damage, forcing me to pull it all apart again.

Sorry if I missed it, but how did your engine sound before you tore into it, any light knocking when at idle? Did it have good power, any smoke, high oil consumption??

Sounded good during the miles I've had it (~25,000 over 2.5-3yrs). No knocking. There was a misfire type noise toward the end before I tore it down, which I attributed to the spark plug wire in the no.3 cylinder being broken and wanting to pop out of the valve cover.

Good...power? But seriously, it felt normal I suppose. It's hard to tell because when I bought it, it was completely stock. Then, I went up to 33s, then to 35s, all on stock gearing.

It smoked a bit on heavy acceleration when climbing a grade. Hard to say about oil consumption because I have a pretty bad pan arch (or rear main) leak, as well as a front timing cover leak that was also pretty bad.

 

[mod5csi]

D
If you have to spend the money for a full set of rings you might consider re-ringing all cylinders. Use bead hone to give each cylinder a nice cross-hatch pattern. File-fit rings for each cylinder. This will be the best you could do without a complete rebuild. This will increase compression/performance and reduce smoking/oil consumption.

I must have missed something. I thought you were replacing the rings on all the pistons, but keeping the original pistons. I like this option, and is probably what I would do in your situation.

 

[dranven]

I must have missed something. I thought you were replacing the rings on all the pistons, but keeping the original pistons. I like this option, and is probably what I would do in your situation.

I would like to avoid replacing any/all rings. The ring set alone is $220 with a discount. I was considering replacing the piston/rings/bearings in no. 6, but leaving the rest alone, but the rings are only sold as a set.

Basically, the approach I'm trying to take is avoiding messing with the block, but if that no. 6 HAS to be replaced, then of course I will do it. I don't want it causing further damage.

 

[jdeitch]

First things first, I hated the factory roof rack. After deliberation about removing it and having the holes welded shut, I read some threads about dropping the headliner, which I didn't want to do, but I didn't really want to use body filler to fill the holes either. I consulted LandCruiserPhil, who gave me a great idea I am happy with.

I pulled off the factory rack (no trouble / no spinning nutserts) and noticed a little bit of rust forming only at the 4 locations where the factory rack is bolted (not the vertical rods that run against the body). I used a dremel with a fine wire wheel in an attempt to knock away the rust. I did pretty well - didn't seem to get it all, but I'm pleased with the result. I sanded, primed, and painted the areas. The rods running vertical along the body left a nasty adhesive, so I got that off with a rubber eraser wheel. Then I polished it up as best I could with by orbital polisher.

Now, keep in mind, I am not a professional, so the job isn't perfect, but it's good enough for me and hey - it's the roof.

I bought some stainless steel button head hex bolts, used some marine grade clear silicone seal on the threads, and screwed them in the holes. They are 5mm x 16mm and the pitch is 0.8.

Here's the result:

Nice job. I will do the same to mine once I get my new roof rack built.

 

[Pin_Head]

The piston damage does not look like it was due to ingestion of a foreign object because it is concentrated in two small areas. It looks more like preignition or heat damage from running lean. Is your EGR working?

If it was me, I would pull the engine and either rebuild or replace the short block. You are all in now.

 

[jdeitch]

The piston damage does not look like it was due to ingestion of a foreign object because it is concentrated in two small areas. It looks more like preignition or heat damage from running lean.

Due to the valve angles the outer edges are the only/most likely place for contact damage to occur from a small foreign object. The valves come closest to the piston there.

 

[dranven]

EGR was working (no codes) and I didn't have any symptoms of pre ignition. A few others have also given their opinions that it's a foreign object contacting between the valves and the pistons at those two areas. At this point I am gonna start buttoning everything back up.

The deck and all pistons are cleaned. I cleaned up the front timing cover and put it back on.

Question: The oil pump gear spins freely. Is this ok? Shouldn't it spin with the crank? I did a search and one person mentioned it's held by "pressure" when the crank pulley and bolt are on. I'm not sure I understand that, but can anyone else confirm?

 

[crooozer]

Mate, you're a braver man that I am. I wouldn't know where half of that stuff goes back on, unreal

 

[Pin_Head]

EGR was working (no codes) and I didn't have any symptoms of pre ignition. A few others have also given their opinions that it's a foreign object contacting between the valves and the pistons at those two areas. At this point I am gonna start buttoning everything back up.

The deck and all pistons are cleaned. I cleaned up the front timing cover and put it back on.

Question: The oil pump gear spins freely. Is this ok? Shouldn't it spin with the crank? I did a search and one person mentioned it's held by "pressure" when the crank pulley and bolt are on. I'm not sure I understand that, but can anyone else confirm?

Foreign object damage doesn't look like that. The piece bangs around in the cylinder at random until either the piston is destroyed and the object exits through the piston or the object exits through a valve. The head gets damaged too. I have seen a fair amount of foreign object damage.

It is correct that the oil pump drive is held by the crank pulley clamping pressure on the drive gear.

 

[dranven]

Uhh, help!

Cleaning up the no. 1 oil pan and getting it ready to go back on. I thought this gasket is the oil level sensor gasket, but look, it's way too big. Anyone know what it is?

 

[blkprj80]

I think you got the oil level sensor gasket, but that part is the crank position sensor. I think the seal for that is NLA.
Here's a link: https://forum.ih8mud.com/80-series-tech/82601-crank-sensor.html

 

[dranven]

Awesome thanks so much! I thought that was the oil level sensor. :whoops:

I will do that "2 o ring trick" in that thread you linked. Thanks again.

 

[blkprj80]

If you can't find the two o-rings, Powderpig told me to use FIPG smeared around the old seal. That actually might be the best approach unless you know your new o-rings are compatible with engine oil. FIPG must be compatible due to all the other places it is used.

 

[scottryana]

I know I am kid of late to the game and haven't read the whole thread yet, but the top of that piston looks like it was running lean, hot or pinging. Did you get the numbers back from your injectors did you have one with a bad flow before they were fixed? I would definitely replace it while you are this far into the motor, I could see that piston cautostophically failing if leaving it the way that it is.