DIY 5VZE rebuild

[alexh]

Hi, 1998 tacoma bought new. A bit of background info.


HG failed at about 250k miles. I repaired myself, had valve job done on heads.
When I was cleaning the block I noticed about half of the gasket was stuck to the block so large amounts of the HG were going into the oil returns.
After putting the heads on, I poured lots of oil on the heads to try and flush the oil returns, dumped old oil before initial start and did a second oil change after 1 min of running.

A while after the repair I noticed a knock for about 1 sec on cold start and knocking at about 2500 rpm with very light throttle. I thought it was rod bearing. I replaced rod bearings with engine in truck, they had some pretty good scratches on them. Plastigauge showed about 0.0025 in clearance with new bearings. This did not fix the rattle. Now I'm assuming its piston slap. My theory is that the cyl was being washed with steam for too long and piston was starved of oil. When I did HG that cyl wall looked pristine. If I start with injector unplugged on that cyl there is no startup rattle. Its been running like this for about 3000 miles. Compression on that cyl is about 20 psi less than the others. I added a oil pressure gauge and it never gets above 20 psi.

I don't want to spend a lot of money on a reman (also very long lead) and I don't want to risk a used engine. But dont want to give up on the truck as last 5 years I replaced almost all wear items - rebuilt MT, new tires, new timing set, all new hoses, ball joints, suspension bushings - the list goes on and on.

I have read the FSM engine section and it seems very thorough. I don't have micrometers/bore gauge so I have to rely on machine shop. I suppose this is typical anyhow. I was thinking engine refresh which is just hone cyls and reuse pistons with new rings (obviously replacing the damaged piston with Toyota piston with same Mark) but I'm guessing this is foolish given that piston sets are only about $150 so perhaps boring block is in order. Obviously crank has to be turned. A rebuild kit is about $1200 but I just replaced timing set so it will be a bit cheaper for me. Will have to buy hoist and stand ($500) but can recoup some of that if I don't keep it.

My concern is the main/rod bearing and piston clearance. Can I bring block/crank/bearings and pistons to the machine shop and rely on them to machine to proper clearances? Also Toyota uses piston pin bushings which also have to be clearanced. I suppose its just a matter of finding a reputable machine shop. Block deck resurface too of course. Heads should be good but will inspect and check for flatness.

I'm in the SF Bay Area (south), if anyone knows a good machine shop let me know.

Thanks

 

[aztoyman]

Finding a good machine shop is key. Don't buy any parts until they check your parts. They will tell you if you need the crank turned, block bored and or decked, if you need the rods resized and what sizes to buy if you are going to supply the parts. They should be able to recommend a brand they trust. May offer a discount if bought through them.

Some shops are all about the money and make you do it all. Some are straight up and will tell you what is necessary and may give you a recommendation on optional work.

A good shop will show you why you need what they recommend. Show their work basically. My favorite shops had check sheets where they wrote down the findings. If the deck checks out, why pay to deck it for example. If I am told drop it off and I'll get to it when I get to it, I go elsewhere.

Chances are that a well regarded machine shop is back logged. Check reviews.

One thing that seems prevalent is that big paying customers often get put to the front of the line causing even more delays. NEVER tell them that your not in a hurry or you may be the first to be be bumped.

Ask about turn around times and ask if it's a problem checking in once in a while. Ask if they will contact you if there are any parts delays or any delays actually. Don't be annoying and bug the heck out of them either. Hopefully you find a shop that your gut (and reviews) says is good to go.

Good luck with whatever you decide to do.

 

[alexh]

Finally got a used engine to start the rebuild.

For mounting the engine on a stand I noticed that the transmission mounting bolts are M10x1.0 extra fine pitch and they should be grade 8 is possible. I don't think I will find these at the big box but can order online. I saw one engine builder used studs into the block and then nuts on the engine stand. I suppose this is the best way since you guarantee full thread engagement. Just wondering how most are doing this, I don't have the bellhousing bolts but can order from Toyota if this is the easiest way to go. I have not disassembled my existing truck yet. Update - just noticed the headbolts have same thread so will see how the length works with the engine stand which I dont have yet.

Also as far as lifting the engine I assume the hoist with the highest lift (90" vs 84") is preferable to clear the front and even then it may be necessary to remove the wheels? My truck has 32" tires with 2.5" lift.

Finally, I know Toyota makes a lift bracket for the passenger side of the engine. Is it a good idea to get one of these?

Thanks

PS If you remove an engine and have to store it in less than ideal conditions at least take out the harmonic balancer bolt and grease it and then reinstall. My used engine just had very light rust on it but that bolt and the cam sprocket bolts were much tighter than the ones on my engine ever were.

 

[aztoyman]

I JUST put my engine in the other day. No body though.

I had to pull my 35's off to get the truck low enough to clear when the body was on so probably a good idea.

I used a lifting link on the passenger side and pulled the two coils off to avoid the possibility of the chain breaking it off.

I would just order grade 10.9 bolts online. Studs if you feel better with studs for the engine stand.