Refreshing the engine (rebuild and aftermath)

[Burntboot]

Sorry to hear about all your troubles Terrance, having been down similar roads, I remember all too well how frustrating it can be.

As I read thru your story it sounds like you have replaced everything at least once and sometimes twice and nothing has effected the sound.
Given all the issues you've had with the rebuild, it does sound as though they may have taken a short cut here and there (AM h/g...)

I did note that you said the engine shop replaced the camshaft already?
Is there any possibility they used either the wrong cam (3Y vs 4Y, don't know if theres a difference or not) or possibly put in a regrind??
Back in my speed shop days, there weren't a lot of performance cams available and those that were available were incredibly spendy.
We often had cams reground and while some worked out sweet as pie others had excessive valve noise.

Given how far you've gone on this, it might be worth finding out what they put in, even if just to eliminate one more possibility.
BB

[terrence]

4y and 3y cams share the same part number so I'm not worried about that. But being that the clearance is within tolerance I assume that it's not the problem? I had this thing rebuilt over a year ago so I'm not sure they even would know. On my receipt it just shows "cam" and the price for they charged me for it (around $200). I guess it wouldn't hurt to give them a call.

[terrence]

Is it normal for the CEL to not come on when you turn the key to start?

I'm trying to check for codes since the van won't start now but I can't even get the light to come on with just the key in the ignition. Nothing changes when I jump the check engine connector.

None of the fuses are blown, battery is full and all the grounds are good.

[originalkwyjibo]

Sounds like you may have a bad bulb or possibly a computer or wiring issue. The CEL should illuminate with the rest of the warning lights when the key is in the "run" position with the engine NOT running.

[terrence]

Bulb is fine, I guess I'll have to pull the ecu and see if it's getting power and whatnot.

[timsrv]

Hello Bala. 1st thing we need to do is make sure you are jumping the correct connector. On your van the "Check Engine Connector" is among a group of 3 dead-end terminals right behind the air flow meter. It's the medium sized one and the only one with 2 wires going to it. One wire is brown and the other is gray with a black stripe. Here are some pictures of the "check engine connector":








If nothing happens when you jump those wires (no check engine light and no change in idle), and the connector is in good shape, then this indicates a problem with the ECU or the Check Engine circuit somewhere in the harness. You could try swapping ECUs (if you happen to have an extra one laying around) or you could test the harness with an ohm meter at the ECU connectors. Since you probably don't have an extra ECU, then you'll need to gain access to your ECU (mounted in the D/S pillar behind where your seat belt retracts to), and unplug the harness. Now you can test for continuity between positions "T" and "E1" in the harness. Here is a map of the ECU connections:






With the "check engine connector" empty there should be no continuity. With it jumped there should be. If the harness tests okay, then the problem is in your ECU. If you are not getting continuity between these 2 pins with the jumper in, then your problem is in the harness. If this is the case, your choice would be to find the fault and repair the harness or you could cut some insulation off these two wires at the ECU and touch them together. Touching them together at the ECU will have the same effect as jumping the engine connector, but would be somewhat of a "hack" thing to do. If you go this route, just be sure to tape them up when you're done.

If none of this works, tell me what you did, what you found, and we'll move on to a couple other things you can try. Tim

PS: When you changed the TPS did you adjust it per specs using an ohm meter?

And here's a link to a thread where a member repairs his own ECU:

http://www.toyotavantech.com/forum/s...k-engine-light

[terrence]

Amazing, thank you.

[terrence]

Pulled ecu and check for continuity at those pins and it is getting continuity when the jumper is in the check engine connector. So I guess it's an ecu issue? I cracked open the ecu and there's no visible issues, the board actually looked really clean. No blown caps, corrosion, burn marks or loose contacts. I guess one evening I'll sit down and check every component. Not much else I can do at this point..


That post is really informative Tim, but unfortunately the 3y ecu looks nothing like the 4y:

[terrence]

Anyone know anything about ceramic capacitors? I have 2 that look bad but I can't figure out what kind they are besides 1000pf capacitors. One has a B (or an 8) about the 102 and the other has a 6 above the 102. Searching around online hasn't turned up anything.

[terrence]

Well, turns out the ECU had nothing to do with the starting issue. After going through the wiring and double checking fuses and relays the damn thing just worked all of the sudden. So something got knocked loose and it fired right up. Still sounded terrible though. So it dawned on my that maybe the exhaust manifold had gotten warped over time so once again I pulled everything apart and lo and behold it was warped pretty bad. Got it ground flat and put everything back together and of course little to no change. This van still runs like roflroflroflrofl and sounds like a tractor. I made a small video of it today idling and revving. When you give it gas the engine shakes and sounds terrible. I have no idea why this thing runs so poorly, why it sounds like this and what to even check next. I made a list of what has been done to date:

Engine overhaul,
rebuild cylinder head,
new pushrods
new lifters

Water in coolant...

new cylinder head, rockers, rocker arm shaft,
new spark plugs
machined exhaust manifold

[timsrv]

Still sounds like excessive valve lash to me.......perhaps accompanied by a miss. A miss can be caused by low compression in a cylinder, no fuel in a cylinder, or no spark in a cylinder. I'd take care of the racket 1st. If indeed it is valve lash, then fixing this may even take care of the miss. No fuel to a cylinder could be an injector and no spark to a cylinder could be a defective plug wire and/or damaged plug. Did you ever measure lift and check for excessive lash? Have you checked compression? Tim

Edit: just wanted to say it's impossible to tell from a video........Everything I said is just a hunch/best guess. It's up to you to do the actual investigation and/or hire somebody. Tim

[terrence]

Still sounds like excessive valve lash to me.......perhaps accompanied by a miss. A miss can be caused by low compression in a cylinder, no fuel in a cylinder, or no spark in a cylinder. I'd take care of the racket 1st. If indeed it is valve lash, then fixing this may even take care of the miss. No fuel to a cylinder could be an injector and no spark to a cylinder could be a defective plug wire and/or damaged plug. Did you ever measure lift and check for excessive lash? Have you checked compression? Tim

Edit: just wanted to say it's impossible to tell from a video........Everything I said is just a hunch/best guess. It's up to you to do the actual investigation and/or hire somebody. Tim

I have looked everywhere in the FSM on valve train clearances and I can seem to find anything other than oil clearances. Beyond that its just how to slap it all back together. How would I go about check lash if I'm not sure what I am check for?

As for compression, I haven't checked it since I got it running again. When the rain lets up I'll check it.

[timsrv]

I'm sure I made at least one "long winded" post previously in this thread explaining how to measure/adjust valve geometry. Not sure how it could be off, but something is making a racket. No way to know for sure until you measure for lash (excess play) at each rocker/push-rod. If it is off, then the simplest solution would be to get custom push-rods (pretty sure I gave a link or 2 previously). FYI, this is not a common issue, but I've run into it before. It's usually caused by a machinist who wasn't properly trained and/or wasn't aware these valves are non-adjustable. If it's an aftermarket head, it's also possible there's dimensional errors in the height of the rocker arm mount bosses. Maybe the wrong lifters??? (who knows). Whatever the reason, if it's loose valves, then you'll need to have some custom work done. Over my career as a mechanic, I've only ran into this once. It was on a Ford 460 (also hydraulic lifers with non-adjustable rockers). In that case I was able to shim each rocker stud to obtain correct geometry.

That engine had individual rockers/fulcrums though. Since the 4y uses a common rocker shaft, the only way to adjust would be with custom length push rods. With some careful measurements, math, and some custom push-rods it could be dialed in. Of course that's assuming it's a valve lash issue causing all that racket. Tim

[Burntboot]

Terrance - Everything Tim says is spot on (no surprises there)

All I can add is my own experiences, I once had a customer with a 22R that had replaced his own VC gasket.
It kept leaking and he kept tightening. Brought it in with a sound just like yours.
Replace the A/M gasket and torqued to spec and all noises went away (valve train had been hitting the cover due to the over torqued, cork gasket)

Have you gone over it with a stethoscope? I would want to nail down just where the sound is emanating from, before doing anymore explorative surgery.

Way, way back, we had a customer that used a TV for drug store deliveries. That van led the hardest life of all.
At one point it bent a pushrod (don't remember the specifics of how or why) but as it was a weekend repair and had no parts available, we ended up swapping in a SBC pushrod, had to cut it down a wee bit and brazed the ball back on.
I never expected it to work for long but they put another 100K on it with no issue.
Pretty hack stuff and not something I would recommend, more just a food for thought type of thing.

Given how loud it is you should be able to at least track where the noise is coming from, that will be half the battle.

[terrence]

I'm sure I made at least one "long winded" post previously in this thread explaining how to measure/adjust valve geometry. Not sure how it could be off, but something is making a racket. No way to know for sure until you measure for lash (excess play) at each rocker/push-rod. If it is off, then the simplest solution would be to get custom push-rods (pretty sure I gave a link or 2 previously). FYI, this is not a common issue, but I've run into it before. It's usually caused by a machinist who wasn't properly trained and/or wasn't aware these valves are non-adjustable. If it's an aftermarket head, it's also possible there's dimensional errors in the height of the rocker arm mount bosses. Maybe the wrong lifters??? (who knows). Whatever the reason, if it's loose valves, then you'll need to have some custom work done. Over my career as a mechanic, I've only ran into this once. It was on a Ford 460 (also hydraulic lifers with non-adjustable rockers). In that case I was able to shim each rocker stud to obtain correct geometry.

That engine had individual rockers/fulcrums though. Since the 4y uses a common rocker shaft, the only way to adjust would be with custom length push rods. With some careful measurements, math, and some custom push-rods it could be dialed in. Of course that's assuming it's a valve lash issue causing all that racket. Tim

Tim, as always thank you for your advice. I am still not sure how I can check for lash on this thing other than seeing if a feeler gauge fits under the valve spring side of the rocker arm (since the pushrod sets inside of a recess in the rocker arm). You said these things are zero lash, which makes since, therefor there should be no clearance between the rocker arm and either the pushrod or valve spring? The lifters have measured and replaced the lifters (I actually have 2 different sets from different manufactures) and it made not difference.

Terrance - Everything Tim says is spot on (no surprises there)

All I can add is my own experiences, I once had a customer with a 22R that had replaced his own VC gasket.
It kept leaking and he kept tightening. Brought it in with a sound just like yours.
Replace the A/M gasket and torqued to spec and all noises went away (valve train had been hitting the cover due to the over torqued, cork gasket)

Have you gone over it with a stethoscope? I would want to nail down just where the sound is emanating from, before doing anymore explorative surgery.

Way, way back, we had a customer that used a TV for drug store deliveries. That van led the hardest life of all.
At one point it bent a pushrod (don't remember the specifics of how or why) but as it was a weekend repair and had no parts available, we ended up swapping in a SBC pushrod, had to cut it down a wee bit and brazed the ball back on.
I never expected it to work for long but they put another 100K on it with no issue.
Pretty hack stuff and not something I would recommend, more just a food for thought type of thing.

Given how loud it is you should be able to at least track where the noise is coming from, that will be half the battle.

The valve cover gasket caused an issue? I'm guessing something to do with crank case pressure? I can take my oil fill cap off and it doesn't make a bit of difference to the way my engine runs. I don't have a stethoscope but maybe I should invest in one..

[timsrv]

Tim, as always thank you for your advice. I am still not sure how I can check for lash on this thing other than seeing if a feeler gauge fits under the valve spring side of the rocker arm (since the pushrod sets inside of a recess in the rocker arm). You said these things are zero lash, which makes since, therefor there should be no clearance between the rocker arm and either the pushrod or valve spring? The lifters have measured and replaced the lifters (I actually have 2 different sets from different manufactures) and it made not difference.

If you don't have an adjustable magnetic mount and a dial indicator, you could measure lash between the rocker and the valve. However, this will only work if the rocker shaft (pivot point) is the exact center between the push-rod and valve stem. If it's off-center, it could still work, but you would need to measure how far off-center it is, then use math to determine lash on the push-rod side. If you have a suitable dial indicator and magnetic base, set it up so the business end of the indicator rests on the rocker arm (directly above the push-rod). With the lifter sitting on the base of the cam lobe, grab the rocker and rock it back and forth (hand pressure). The indicator will show how much slop (if any) is on the push-rod side.

The valve cover gasket caused an issue? I'm guessing something to do with crank case pressure? I can take my oil fill cap off and it doesn't make a bit of difference to the way my engine runs. I don't have a stethoscope but maybe I should invest in one..

I've seen what Burntboot was referring to as well. it was almost common on the 22R's with the rigid aluminum valve covers. When DIY/amateur mechanics over torque valve cover nuts it can cause an issue. Since the valve cover studs are also the rocker shaft studs, high torque on the cover can tug on the rocker shaft enough to create valve noise........but nothing like what you're experiencing. I'm not convinced the 4y stamped steel cover could transmit that much force without 1st bending/collapsing. Tim

[terrence]

Well, good new is that all cylinders have the same compression psi. Bad news it's still only 120psi. There was some oil on the #1 spark plug tho.

I pulled the valve cover and if I am understanding you right Tim, I am measuring the push rod when it's as high as it can go (on the cam lobe)? If that's the case then there is no movement in the rocker arm at all. When the cam is at its lowest point, that's a completely different story. I don't know if I should be able to push down on the lifters but the push rod can be moved down 1/4 to 1/2".

[timsrv]

120 psi isn't bad, the important thing is they're all the same. Valve lash is measured when the cam lobe is at it's base (and the valve is closed). Your push rods will be their lowest (loosest) when the cam lobes are at their bases. I personally like to rotate the engine to position the particular lobe (for the valve I'm measuring) at it's very base, then repeat X 8 (but that can be a little time consuming and not completely necessary). If you put the engine on TDC, you can measure the lash of 1/2 the valves (the loose ones). Then rotate the crank 360º and measure the other half. Tim

[Burntboot]

Terrance - Hydraulic lifters shouldn't have any play when the pushrod is at its lowest point of travel.
When you say you can push down the pushrod (1/4-1/2in), is there resistance or is it sloppy?
Neither one is right but slop is excessive play whereas squishy resistance is a bad lifter.

I've only done a couple of lifter replacements and that was a long time ago.
We used to pump them up in a can of oil till hard, prior to installing and I remember them being a b**** to do.
I wouldn't think you'd be able to get enough purchase to compress a good lifter, when its installed and pumped up.

[timsrv]

To expand on what BB said, once lifters are "pumped up" (interior filled with oil), due to the check valve inside they mimic solid lifters (oil has nowhere to go unless more oil is being pumped in). On engines with non-adjustable valves (like ours), it's not a good idea to manually "pump them up" before engine assembly. Other than external lubrication, I always installed them dry, as they will find the correct adjustment spot faster with less stress on the valve train. If you manually pump them up before installation, the valves can be over extended (at least initially) and that can make them fail to seal and/or can even result in a burnt/warped valve. In some extreme situations it's conceivable they could even contact pistons (causing extreme damage). I don't think that's what's going on here, I just felt the need to explain why they should not be pre-pumped.

If you position the engine so that any given lifter is on the base of it's cam lobe, there should be no lash (play) between the rocker arm and the valve stem. If there's enough lash to put a feeler gauge between the rocker and the valve, and the lifter is fully extended, then there's a problem. If you find excessive lash, use a flashlight to look down at the lifter while you work the rocker by hand to make sure the play is not internal to that lifter. If the push-rod is loose, and the inside of the lifter is fully extended, then you will need custom push-rods. Tim