NA rebuild advice

[Johnathon]

Well, i was on my way to fill my car up day before yesterday, and the engine developed a quiet tick, then steadily progressed to a loud clack, it sounds like it's originating from a head, however with 158k miles on the engine, even if the problem is only a head problem, it's time to refresh the engine anyways. At any time a rebuild is done it's always a pondering question as to how you would want to do the build, and as it's a automatic NA i really don't have desire to throw any power adders (nitrous) to the engine. Considering it's a high compression engine I would think it to be wise to replace the pistons as if it's knocking and it's a head issue I'm guessing that one of the pistons would also be damaged. I've not yet had the chance to pull the plenum and valve cover off the side of the engine that's making the noise to assert that it is indeed a head problem, and quite honestly i need to replace the knock sensor harness and an oxygen sensor, and both of those is way easier to do out of the car. Overall, sense it's a 1990, what upgrades can i do to improve reliability, and ease the ability to work on the car. I don't live under smog restrictions so i was thinking of deleting the EGR. Pro's, Cons? Advice as im not looking to make a lot more power out of the engine?

[t.mcginley.jr]

First off, a tick and a knock are much different sounds. If its a fairly fast ticking from the top of the engine, it's probably just a stuck lifter. Eventually the lifters get an oil buildup and get stuck. You can run a can of seafoam or marvel mystery oil in the oil for ~50-100 miles and it should take care of it. If the noise is slower and louder and comes from the bottom end, then yes you have a knock. Knock happens when one of the rod bearings go. That usually requires some machine work for at least the crankshaft.

For a solid rebuild, you might not need new pistons, it will depend on how they look when you take them out. If they are all pitted, you probably need new ones. If they are still pretty smooth and just have carbon buildup then you can reuse them. New piston rings are a good idea though. You could taken all the pistons and rods out, clean them up, hone the cylinder walls with a ball hone and then reinstall them with new bearings and piston rings (assuming the crank isn't scratched from a knock). The rest of the rebuild/refresh will consist of replacing gaskets, like head gaskets, valve covers, upper plenum, valve stem seals, etc. When you pop the heads off you can clean the valves themselves up with a drill and wire wheel. If you haven't already replaced the fuel injectors, you can do that too along with spark plugs and pcv valves. Oh an the knock sensor and O2's that you wanted to replace.

Since you will have it all apart, you can do the full timing belt job => timing belt, water pump, idlers, cam and crank seals, and auto-tensioner.

It really depends how much you want to do. You could just try running the seafoam or marvel mystery oil for a little bit and see if the tick goes away before starting any rebuilding. None of this will be cheap

[Johnathon]

for making me feel like I asked a really NOOB question. LOL

for making me want to delete the post. LOL

for actually replying, and giving very sound VERY general advice. And making me realize how worthless my post was.

The devil is always in the details. The general process and necessities of an engine rebuild i have down pat (ie this is NOT my first engine rebuild, just my first DOHC high compression rebuild).

+ (cries) Ohh how i wish it was just a matter of running sea foam or mystery oil into it. Along with that experience of rebuilding engines, unfortunately, also comes experience with how a subtle small failure can lead to catastrophic failures even with a low compression engine. which is what lead me to make the post in the first place. I know I'm going to be breaking this brute down, and throwing a mic (that i have to purchase) to about every part on it before i send it all off to a machine shop for the work that's potentially needed to be done. If i get lucky, bearings and re ringing, if not so much im looking at boring , new pistons, ect. The heads, will be rebuilt irregardless and valves replaced to the newer style that don't deteriorate (with NEW lifters - yes, expensive ). Call that action a future self preservation investment, as before i even turn a wrench on this project I'm about 98 percent certain a lifter blew. At first. 5 minutes later who knows what all else it destroyed. And who knows how long it's been that way, as i don't particularly crank my engine and pop the hood and listen to it daily.

"None of this will be cheap"
it never is.

[t.mcginley.jr]

Haha sorry man I wasn't trying to bust your balls or anything I just didn't know how much you knew about engine rebuilding or not, some people are totally clueless so I try to be general but helpful. If you're already thinking of taking it to a machine shop then by all means rebuild it from the block up the right way. That way you have an engine that will last a long time and you don't have to worry about it being done wrong. When I rebuilt mine, I only did the top end because it only had 98k miles on it so I wasn't too worried about the bottom end. These engines just take a little more patience, mainly because of the tight spaces and it having 4 separate cams. Anyway, a stuck/busted lifter on these engines isn't usually too catastrophic, it will just cause that valve not to open all the way and cause it to run a little rough, plus that annoying sound.

Assuming you're doing all the work yourself (minus machine shop stuff), it won't be too outrageous for a full rebuild. If it was a TT the pricetag would be much higher lol.

[Johnathon]

Depends, if i have to oversize Z1's kit charges 100 more for the na pistons, and wither or not the turbos on the TT were blown/worn out (most of the time they go before the engine does so I've read). Way i figure it, and in my experience,intake lifter blows, and stresses the living crap out of the bearings on that piston's connecting rod/crank journal because it's pulling a vacuum and the rest of the cylinders are being compressed, and will lead to full knock REALLY fast. Given i know very little about the internal tolerances on this bad boy as I've not looked at them yet, and given it's compression ratio,id say it happens faster than REALLY fast. Needless to say though , with ~160k miles on the engine, it's due for an overhaul. And you weren't busting my balls man, Though if you wanted to... LOL, it was a full open door.

[t.mcginley.jr]

Haha nah I save my ball-busting for my neighbor and his Integra

anyway... does it sound this bad? http://www.youtube.com/watch?v=A4VuvMUp-BI

[Johnathon]

That bad? Sure.

With that same rhythm? Nope.

I'll fire it up again when it gets light out and get a closer / more refreshed listen on it. The sound was in rhythm with the engine, that much I'm positive on, but in rhythm at 1/2 rotational speed of the crank or not is a different story. In other words as i work 3rd shift, and i was exceedingly exhausted when the event occurred, i had it towed home (and have slept sense then).

Another thing that certainly points me to the upper engine is the fact the starter had a very hard time staring the car after i cut it off when it started making the noise. Just like a valve was not opening, and consequently leads me to believe i blew a lifter.

And if i did blow a lifter, whats gonna go next LOL.

Yea, a mechanics stethoscope would be nice. But alas, i am home, and i do have some small hose that will suffice

I'll let you know more as soon as I'm able to find out.

however it does NOT sound THIS bad http://www.youtube.com/watch?v=y87nhWzewtw

[Johnathon]

0oh yea, number 6 knocking slightly, tapping the oil pan. Hopefully when i get it all apart the crank wont be too badly damaged. *sighs* new oil pan too . Money wise a swap would probably be cheaper to just get it back on the road, but for my needs i have to have something i can trust, so a full rebuild IS in order.