Engine is shot. Knocking bad, need advice

[sci2000tech]

So after I finally got my engine started up with the new setup and worked out most of the kinks, looks like I messed something up pretty bad.

Here's the setup:

RB20det, internally stock.
RB26 ITB's
6boost manifold
KKK K3t 3070mga turbo
HKS 50mm wastegate
Z32 MAFS
Sard 500's
CarlH ROM tune
Full wire tuck


I started my build about 2 years ago and just finished up a few months ago, so the car sat for quite a while without any fluids in the engine. I swapped out the manifolds and got the valve covers powdercoated, but never tore apart the engine itself. Never took off the timing belt or touched anything internal at all.

So fast forward to a couple months ago. When I went to start her up for the first time, I filled all the fluids and cut the power to my fuel pump before I cranked it over. I cranked it for 5 - 10 seconds at a time about 10 times to build oil pressure and prime the turbo. After that I connected the fuel pump and tried to get it to start.

The car wouldn't start, so I sprayed some carb cleaned in the intake and it fired right up for a few seconds. traced the problem down to bad fuel, drained the tank/ put new gas and it started right up, but only with the MAFS unplugged and not running on all cylinders. Oil pressure and AFRs looked great

Turned out the 2 wires from the maf to the ECU were backwards, so I swapped them and it ran with the MAFS plugged in. But it still wouldn't run on all cylinders and I found out it blew the #1 coilpack at some point. This is when I first noticed a slight knock

Took it to a shop and they found the coilpack was grounding out, as well as the TPS not reading properly. They fixed both of these problems, but by now the knock was really bad and they said the engine needed to be pulled. When they cut the oil filter in half, they said it looked like it was filled with glitter.

I asked if the problem had anything to do with my ITB or turbo setup, and they said not likely at all. they also don't think it has anything to do with the tune. I was told that if I swap in a good block/head I should have no problems.

My biggest question is how could this have happened? I want to be sure that if it was something I did, I don't do it again. Should I send an oil sample off for analysis so they can tell me where the metal came from, or should I just tear the block apart to see what failed?

I also need to decide if I want to rebuild my engine(I have a spare block/head) Or if I should just buy an engine from an importer and swap it in as-is.

Any Ideas as to what kinda cost I'd be looking at for a rebuild assuming no extensive machine work is required?

How hard is it to do a rebuild in my garage with the proper tools and an FSM? The only thing I haven't messed with on my car is the engine internals.

Any advice is much appreciated. I've come too far with this setup to give up, so I'm hoping my NICO buddies can shed some light

[Yellow4g63]

Maybe some fuel got into the oil? I did the same thing with my RB20, it sat for years and I just bumped the motor till oil got to the head and fired it up. I would say just get another RB20 long block they should be dirt cheap or Step up to a RB25 long block and bolt it to your RB20 trans.

[meet07]

it always worred me that if you start the engine after a long period of time with no fluids if the cylinder walls get rusty due to moisture?? where is the knocking coming from?? The bottom end??

[sci2000tech]

It's hard to tell where the knock was coming from.

I fired up the engine again today, and didn't even hear it

The 2 cylinders closest to the firewall seem to be the issue. If I unplug the coilpacks going to those 2 cylinders, nothing changes. We know they are getting fuel and spark.

I think the next step is gonna be to do a compression and leakdown test.

[Cjmartz2k]

Compression/leak down test won't have anything to do with a spun bearing which is most likely causing that glittered oil. I'd take it a part while I was waiting for a new to you long block if it were me. RB20's are cheap even in the states now, right? Also, I like the RB25 idea a lot more, but you already have your RB20 head with the ITB's and stuff on it so I'm guessing you are going to skip that.

[TheRBguy]

An Rb20 is gunna be around $12-1300 plus shipping. Rb25 $2-2200 plus shipping.

[sci2000tech]

Ricky has an rb20 longblock for $600, so I'll probably go that rout.

If it is just a bearing, would that keep a cylinder from firing? When I unplug the coilpacks on the last 2 cylinders, there is absolutely no change in idle or engine sound.

In the long run, I think I'm going to do what Carl did and go with an rb30/r32 rb25de head. That way I can use my same manifolds, etc. But that is down the line. I don't wanna take on a bigger project until I can get my current setup working.


I'll post up a video tomorrow.

Thanks for the help guys

[StricNyne]

sucks man good luck with setup carlh has a super nasty setup and u know its kickass so if money isnt an option try that. if money is an option just get a stock rb20 long block, freshen it up with new gaskets and drop that sucker in

[Darius]

Ricky has an rb20 longblock for $600, so I'll probably go that rout.

If it is just a bearing, would that keep a cylinder from firing? When I unplug the coilpacks on the last 2 cylinders, there is absolutely no change in idle or engine sound.

In the long run, I think I'm going to do what Carl did and go with an rb30/r32 rb25de head. That way I can use my same manifolds, etc. But that is down the line. I don't wanna take on a bigger project until I can get my current setup working.


I'll post up a video tomorrow.

Thanks for the help guys

Nope, a spun bearing won't prevent the engine from firing. It sounds like you have more trouble shooting to do once you get the bottom end back in order. I agree with your plan to get your current setup working first and then make changes to it.

I'm not quite sure why you would buy another block when you could simply pull this engine and swap the bearings out of it without even taking the head off?

[Cjmartz2k]

Whoops, didn't see the not firing part. Yeah, spun bearing wouldn't do that. Ate up cam lobe or split cam could cause metal in the oil and no firing of a cylinder. Maybe pop the valve cover off and take a look?

[meet07]

You should have done a compression test a long time ago...Do that junk and then if the compression test checks out ok I would do just what Darius stated....Bearing with the head still on.

[sci2000tech]

Darius:

I think I'm going to take your advice. I'll pull everything apart and have the block inspected, throw in some new bearings/gaskets, and try it again. I have 2 other blocks just in case, so I'm sure at least one of them will be good.

How hard is it to replace the bearings for a first timer? I can read an FSM and torque bolts down in the right order and sequence, I just wanna be sure I don't miss something stupid like assembly lube.

Any tips for first startup to make sure the engine is properly lubricated?



Cjmartz:

I can't believe I didn't even think to check the cams/hydro lifters. I'll pop open the valve covers tomorrow and check everything out.


Meet07:

Yup, I'm thinkin a compression test will help determin or eliminate some possible culprits.

Should I do a leakdown test as well? I've never done either, nor do I fully understand them, so I've got a bit of research to do still.



Here's a video I took when the car was first running. If you listen, you can hear the noise at 30 seconds in. You only hear it once in this video, but as time went on, the knock became more progressive and you could hear it intermittently every few seconds. In the video, it does it when I rev the engine, but by the time I noticed the knock, it would do it at idle. weird thing is, yesterday when I started up the car, I didn't even hear the noise anymore Whatever was hitting probably broke off.

[youtube]http://www.youtube.com/watch?v=GYdS9Vd4 ... r_embedded[/youtube]


Thanks again guys!

[Yellow4g63]

I can hear it, Rod knock for sure.

[sci2000tech]

OK, that confirms what I've been thinking then.

What should I look for when I'm ordering bearings? Any specific brands, or should I go OEM? I've seen a few options on Ebay, but with moving internal parts I wanna do it right the first time.

Also, could the bearing(s) have gone out because the 2 cylinders aren't firing?

[Yellow4g63]

Your prob going to need to get the crank machined, The shop that does it will let u know what size bearings to use. But if ur going to go with a RB30 later just pick up another Rb20 long block and swap everything over to that and start driving right away.

[sci2000tech]

But if ur going to go with a RB30 later just pick up another Rb20 long block and swap everything over to that and start driving right away.

So if I use another longblock, what can I do before first startup to be sure this doesn't happen again? Should I pull everything apart, clean it, and torque it back down with assembly lube?

Last time I primed the engine before I started it, but I'm thinking that wasn't enough.

I have another block from a motorset I purchased as a perfect running engine. I pulled the head and had it rebuilt/resurfaced over a year ago, but never touched the block. I'm wondering if I should just pull everything apart and clean it, then re-assemble it as-is with the fresh head/new gaskets/ARP headstuds I have and run it as-is?

If I do that, can I get new OEM spec bearings to throw in for peace of mind since everything on that block should still be in good condition?

[Yellow4g63]

Yeah you could do that. Watch out for your turbo tho u might have some left over stuff from the last motor stock inside the oil line/turbo center section which would mean it's going to die soon too.

[Joe]

f*** man youre gonna take the word of 1 dude on the internet to rebuild a motor? and by no means do i want to disrespect him because he does know his s*** but god damn. ALWAYS diagnose first.

ive heard a terribly misfiring RB sound like that. its like half on 4 cylinders, lopey like that in terms of sound but still a smooth idle because I6's are inherently smooth.

what is your exhaust setup?

i DONT hear a knock. its too smooth for a knock. knocking has a more audible peak from my experience
this is a great representation of an extreme example rod knock http://www.youtube.com/watch?v=NTSEuO7jvl4

i dont hear any indication of knock in your video. the fact its coming and going also points to another problem. spun bearings stay spun. they dont fix themselves.

what does your oil look like? drain it into a container and let it sit for a couple days, see if there is a layer that forms on the top/bottom.

i honestly think you are dealing with a f*** UP misfire/exhaust leak combo.

first things first:
check for spark on all cylinders
check timing
check for fuel delivery on all cylinders
compression test
if all those check out pull the cam covers and look.

and by all means i could absolutely be wrong, but ALWAYS ALWAYS ALWAYS diagnose 100% before you commit something to like a god damn rebuild. what would happen if you cracked this b**** open and the bearings looked perfect?

p.s. i love gregs old wheels

p.p.s. your tires are backwards.

[TheRBguy]

I agree that sounds like something in the top end not rod knock.

[Carl H]

could possibly be a snapped cam from oil starvation...something is knocking around for sure.

[sci2000tech]

One BIG thing I wanna bring up, Timing is way off!

The shop told me that's normal and that the ECU is pulling timing because of the knock sensors. the tick marks on the crank pulley are so far off from the reference point on the timing cover that adjusting the CAS still wont line them up.

. ........... V............

i i i i i

The timing marks are all to the left of the reference point(V) like that ^

The cas will only move them so much.

I know the injectors are getting power(noid light) and I've swapped em around, so I know they're all good. I guess I could pull the spark plugs from those 2 cylinders to see if they're covered in fuel.

The coilpacks are all good and I used a noid light to make sure they're all getting power. The plugs were all checked at the shop, but I'll grab some new ones and throw em in since they're pretty old.


I'll drain the oil and let it sit for a few days. What would a layer forming on top indicate?


Exhaust leak, yes. But I can't see that causing 2 cylinders to not work. I know there are 2 broken exhaust manifold studs. Other than that it's 3" downpipe > high flow cat > 3" no name catback.

Compression test is next.


Also popped the valve covers open and everything looks clean. The cams looked perfect.


I'm still worried about the timing. I'll take a pic with the timing light.

Thanks guys.

[Yellow4g63]

It's not top end, it's a light knock. My RB lifters are noisy for a little after I start the car and it's been sitting for months but that noise goes away and sounds nothing like that. The Knock is light at this point and wont throw a rod through the block. Meh I got a good ear for that sound since it happened a lot to me over the years.

[StricNyne]

stethoscope ?

[Joe]

so your timing is way off, and you have an exhaust leak? huh...sounds like something someone in this thread said... but i cant remember who

anyway back to business:
are you unplugging your TPS when you set your ignition timing? make SURE you are trying to time the engine correctly before moving on,

next,
if you still cant get it into time check your mechanical timing. (the timing belt). you may have skipped a tooth somewhere and thats not allowing you to time the engine.

noid lights are great for verifying some things but they arent a tell all. just because you are getting power to your injectors/coilpacks doesnt mean they are actually working.

you need to physically verify spark by removing the coilpack and plug, and jumping it to the ground but this is secondary due to your ignition timing and possibly mechanical timing being royally fubar'd. if you were able to get the engine into time it wouldnt hurt to throw a set of new plugs in there too since these are probably fouled beyond belief. but timing correct first then plugs!

the exhaust leak will not cause 2 cylinders to fail but with real bad timing it can make very strange sounds come out of your engine. instead of combustion being contained in a neat and nearly sealed cylinder its now subject to escaping through your exhaust valves when they are partially open because the spark isnt firing at the correct time.

you still need to do a compression test but take the opportunity while all your plugs are out to verify spark at each coilpack.

i refuse to damn this engine with "bad bearings" when there are all these other issues going on.

[sci2000tech]

I was not unplugging the TPS, I'll try that tomorrow and check the mechanical timing as well. I'm assuming I can find out how to tell if the timing belt is lined up correctly in the FSM?

I just pulled all the plugs and made a ground, they all spark.

Just did the compression test. 140 across the board, except cylinder 3 which was closer to 130. But that's not one of the cylinders not firing so I'll worry about that later.

How can I check to be 100% sure fuel is getting into the cylinders?

[Joe]

140 across isnt bad, little low but theres 100 factors that could go into a number like that. the variation of numbers is more important than the numbers for the most part.

best way to check for fuel is to disconnect your coil pack harness, crank the engine for a few seconds, a couple times then pull your plugs, see if they are all wet.

also would be a good idea to remove the cas, leave it plugged in and rotate it to see if the injectors are clicking 1 by 1 with the ignition on.

[yotik]

140 across isnt bad, little low but theres 100 factors that could go into a number like that. the variation of numbers is more important than the numbers for the most part.

best way to check for fuel is to disconnect your coil pack harness, crank the engine for a few seconds, a couple times then pull your plugs, see if they are all wet.

also would be a good idea to remove the cas, leave it plugged in and rotate it to see if the injectors are clicking 1 by 1 with the ignition on.

Agreed!

True, troubleshooting is time consuming, but can save so much money too. It'll reveal itself. Things like knock dont sit well with me though. Id assume just rebuild for peace of mind.

[Darius]

I'm with Joe on this topic. I don't think this engine has been straightened out enough to call it a bearing failure. The noise is pretty faint for it to be rod knock. Who knows? But I'd try some free troubleshooting to confirm it before committing the time and money to replace a block.

You can easily verify the mechanical timing by removing the upper timing cover and manually rotating the crank so the orange mark on the crank pulley lines up with the bump on the lower timing cover. Then, look at the cam gears to see if the dots line up with the dashes on the upper rear timing cover. If you are still in doubt, pull the crank pulley and lower timing cover and count the teeth on the belt between the crank pulley dot and the exhaust cam gear dot to see if it matches the FSM.

For setting the ignition timing, the engine needs to be at operating temp. If you are trying to set it while it is cold, the ECU is pulling timing due to temperature and it won't be accurate. And try pulling the TPS plug while setting the timing. I cannot pull mine or the idle jumps around so irratically (surging) that I can't get a steady reading at idle. Yours might act the same way, so don't worry if it does this. Just plug it back in and retry setting it.

[Joe]

my rb25 was the exact opposite to darius when timing, the timing would be crazy and erratic when the TPS was plugged in.

[Yellow4g63]

Listen to the vid at :30 that loud tap.