What would you do? - Wear on cylinder question - 1GR-FE 4.0 V6

BACKGROUND:

Truck: 2005 - 4wd dcsb - 4.0 V6 - 180k miles. Bought the truck about 5k miles ago so I don't know the past history very well and it doesn't seem very well taken care of .

In the middle of doing a head gasket job. I'm an amateur diyer so I don't know my way around the engine very well. This is by far the biggest repair I've ever done.​

DAMAGE ON CYLINDERS:

To my dismay, I found some "damage" on one of the cylinders (#5). I believe it's the cylinder that's been misfiring. It's smooth to the touch and my fingernails don't grab onto anything when I scrape it but you can see it visibly. I was a bit rushed so not 100% confident I did a good enough job picking at it. hahah I'll check again after it stops raining.

There was also a bit of rust on just the scratched parts that I wiped off (assumed due to sitting for a bit with coolant?). I'm wondering if some protective coating got chipped/rubbed off. All other cylinders and head seem ok on initial inspection.
​

IS THIS A BIG DEAL?

Can anyone chime in on whether they think this is a big deal or not? I plan to check this again after it finishes raining but what if my finger nail catches something? Is it time for new engine?​

NEXT STEPS?:

I'm trying to figure out what my next steps are. I'm obviously looking to get out of this as cheaply as possible. What would you do?​

1. Not a big deal - Replace all gaskets, surface the head and hope it lasts for many more miles
2. Remove the block and get it serviced - (I'd rather not do this unless someone experienced in this has some helpful advice. I figure at this point, getting an engine swap is a better use of money?)
3. Find a used engine and do an engine swap - (This is my last resort as it's the priciest and I'm not sure what is entailed in this process. I figure I'm not far from actually doing this as I've gotten the heads off at this point.)
4. Other - Any other affordable recommendations?

PICTURE OF SCRATCHES:


ADDITIONAL PICTURES OF CYLINDERS AND HEADS:

 

In the pics it looks like a gouge or something chipped off. But if it's smooth to the touch then it's probably just a stain of some kind. You really don't have any other options than to put it back together and send it, if it works out great, if not then look for a used motor

 

Cross hatching still looks pretty good there. If that really won’t catch a fingernail, then I would just put it back together and hope for the best. You are this far already…
If it then blows up, looks for a used motor 2007-2011 then

 

I think there's a coating that came off. I noticed a little rust that I was able to wipe off on top of those marks. The truck has been sitting for a bit so I'm sure the coolant contributed to the rust marks on top of those scratches.

 

The test is usually to feel with fingernail.
If you did your oil changes on time, it should be fine. They're also not known to be defective enough to cause that, unlike infamous Nickasil and Alusil engines.

You said it misfired. And that you're changing the headgasket. That's probably why it misfired.
Never a bad idea to do a compression test on an engine before taking it apart as well. Compression test is much easier and faster to assess baseline health of the engine, prior to teardown.

I think it is more labor to yank the entire engine out and swap it, than to do a headjob.
If you're taking the heads to a machine shop for rebuild, you can also use various things to clean up areas of the block including mating surface, such as chemical cleaners, carbide scraper by hand, but not abrasive wheels which can cause uneven surface/send abrasive debris down into it

regarding debris falling in, it can be vacuumed out, sucked out with a mityvac, ports plugged, oil change after, or simply get caught by the filter after (such as carbon being scraped)

it's probably worth referencing the FSM for guidelines, though it's not always the end-all-be-all
I think the block is aluminum and not strong iron,
but still, resurfacing (even of the heads) might not even be needed if there was no overheat condition to warp the metal, versus simply leaking and burning coolant past a bad gasket letting you know it failed (probably not enough to have made a giant puddle inside to hydrolock, rod knock, etc.)

 

Prolly fine if you cant feel it.

Remember, cross hatch means nothing if you can see reflection of your hand in the cylinder. Ive seen engines with 300k still have cross hatch but cylinders had a mirror finish. Not saying that has anything to do with your situation but just a good tip to pass along.

 

If you can't feel it, I wouldn't sweat it!

 

Most likey surface corrosion from the coolant ingress. I'd run it as is.

 

I recall reading someone replacing cylinder “sleeves”.

Beyond that, I’m of no help. I couldn’t say how difficult it is to do, or if the block needs to be out and such. Best of luck.

 

Clean up the carbon buildup in all the cylinders. Wipe the cylinder walls down with some oil so they dont rust during assembly time, clean deck surface. Check heads for being straight and clean them, DONT SURFACE/MILL THEM, and put her back together with the proper new headgaskets for another 300k of running.

That cylinder and piston look great for 180k miles. How do the others look?

 

Thanks all for everyone's feedback! I'll keep yall updated in the original post to try to keep it easier to reference.

@nd4spdbh Interesting that you say don't surface/mill them. Was planning on getting that done as it seems quite common to do and I want the best chance of success for this HG job. I'm waiting for a precision straight edge to be delivered to see if there's any warpage. Any reason why not to? I updated original post with pics of cylinder and head. I don't think it looks too bad from what I've seen in other posts but what do I know? haha

@TacoTuesday1 Thanks for your tips. Thanks for chiming in and letting me know that pulling the engine is a decent amount more work. Unfortunately I don't know the history of the truck as I've only had it for a few thousand miles. I got it for relatively cheap considering the market at the time (and now I know why ).

 

Reassemble and send it good buddy

 

Walls look good and no gouges or scratches indicating a broken ring. Assemble and enjoy. Worst case get a used motor tossed in they are relatively inexpensive.

Good job for trying to tackle it yourself. Let us know if you have more questions.

 

Everything looks awesome for 180k miles! Like stated, rotate cylinders up to the top clean off the minimal carbon build up.

As far as milling the heads, I believe FSM says it cant be done as it will change / cause issues with vvti and cam chain tension (gotta remember its one cam chain that passes head surfaces 4x, so if you deck the head by a few thou, it starts becoming measureable pretty quick in terms of cam chain.) And honestly I doubt you will find warpage so long as the motor hasnt been overheated.

 

Yes, Toyota says you can't mill the heads. However, there are plenty of folks who have done so without issues. I'm sure there is a limit of course. My engine was never overheated but the heads had a slight warpage per the machine shop who inspected them. I took off .0034" and .0035" on each of the heads when I did my head gaskets a few months ago.

 

Agree with this 100%.

 

Thanks all for everyone's feedback! Both heads seemed flat however one of the heads had a scratch on them right on the gasket sealing surface. So I sent one of the heads to a machine shop to deck it till the scratch is gone. I thought this would be the best option to try to keep the engine as close to OE spec as possible. Unless you think it's unwise to just deck one head vs both.

SCRATCH:



TIMELAPSE OF CLEANING FOR ENTERTAINMENT:
I soaked it in Mystery Marvel Oil, scraped with plastic razor, further cleaned with brake cleaner and toothbrush.
https://streamable.com/oxi33q

 

How come you didn’t ask the machine shop to just check the heads to see if they had any warpage and if so, how much? You’re already got one of the heads there. I would’ve just had them check for peace of mind.

 

@zguy1 Oh I did. He brought out a straight edge and feeler gauge and told me they're both straight but he did it pretty quickly. I told him if it's straight I'd rather keep the non-scratched head as is and brought it back home.

 

Question: Anyone have any tips on getting the oil pump gear lined up with the crankshaft? I'm starting to put the engine back together now and spent an hour spinning the gear around trying to figure out how it lines up with the crankshaft. Is there a tool or a method out there? Thanks in advance!



I ended up getting a valve job so the heads are nice and clean