Multiple Misfires, Codes P0300 - P0306, P358...any ideas? (4 Viewers)

[PNWFJ80]

Hey there, having trouble getting my 06 LC to run. I’ve bought a few new coil packs, swapped them around, but the only code I’ve been able to get rid of was the P358 Cylinder H Coil.

The timing belt looks new-ish, and the marks are lined up from what I’ve gathered poking around on this site.

I’m leaning towards fuel pump/filter at this rate. Any other suggestions on where to look?

 

[Spike555]

Fuel filter is cheap, $15, just replace it already.
Did you replace the spark plugs?

 

[PNWFJ80]

I have a fuel filter on order, gets here with some other parts on mon or tues. I replaced two of the spark plugs w/ the two coils I threw at it, but the spark plugs I took out were basically new.

 

[Spike555]

Why would you only replace two spark plugs? Either replace them all or don’t replace any.
It is possible that the plugs that were put in are the wrong resistance and causing all of your problems.

 

[2001LC]

Pictures of removed coils and sparks plugs along with current gap may be helpful. Also picture of engine with air pipe removed.

Assume: you did not move #8 coil to #6 cylinder. And Coil(s) moved to #6 are known good Toyota Denso or Denso. And New Spark plug(s) are factory recommend type and gap inspected/set.

I'd do a dry compression test next. Any low, then do wet, than leak down.
This will also give opportunity to check condition of all coils and spark plugs to see all if torqued in, gap and how they look.

OK, proceed to testing circuit (wires & wire block housings) to & from ECM

Ok than proceed to testing ECM

Some more history of engine would be helpful in determine issues and just as important "cause". Things like:
Mileage.
In history, did vehicle have periods of prolonged periods of not driving or starting?
Oil & oil filter change history. Was it every 5K miles or so?
Air filer history. Was it every 20K miles or sooner?
Starter ever replace?
Spark plugs: when and replaced with what from where. (many bootleg on the market)?
Fuel injector(s) ever remove.
Any vacuum leaks current or past?
Any other work or lack of on engine?

If fuel filter clogged or fuel pump weak. It can create a lean running condition. Which can have a number of issues from over heating. But the system itself will detect lean and compensate fuel trim. So overheating usual not a damaging issue to cylinder or valves. These fuel filters typically will not be an issue. The fuel pump on the VVT can be issue. In fact, I believe we've a batch of bad ones, that can not be detected with standard testing.
That said; fuel starvation (lean) will usual affect both banks. The CATS seem to get the worst of it. Your DTCs are more specific to #6 & #8. Whereas fuel starvation can't be ruled out, as it could be this just early warning of all cylinders. I'd go through spark and compression testing before throwing to many parts at it.

 

[PNWFJ80]

More detail:
- 1st codes were: P0300, 301,302, 303, 304, 305, 306, 358. I replaced the coil/plug in cylinder 8 to get rid of code 358. Cleared out the codes, still ran very rough.
- 2nd codes were: P0300, 301, 302, 303, 304, 305, 306. Cleared codes, still runs rough/misfires, did not run long enough to trigger new codes.
- Bought this knowing it ran rough/not driveable. I assumed the timing belt had snapped, but turned out it’s in good shape. 170k miles, 5 pages of car-fax dealer service history, same dealer same city. One owner till this year, new owner kept servicing at same dealer, I bought it last week at auction. Very good condition, everything works, great paint, interior’s near mint, etc.
- Existing spark plugs are new-ish(few thousand miles maybe) OEM Denzo plugs
- I replaced two coils seeing if that would eliminate the codes in those cylinders, figured I’d do a new spark plug too w/ the new coil. But again, existing spark plugs are OEM and ~new. New spark plugs are gapped correctly from Toyota, matched the ones I took out.
- I’ve went over the vacuum lines, can not find a leak/concern
- The aluminum air intake and driver’s side valve cover look to have been somewhat recently removed and replaced, and there are broken/missing wire clips in this are, kind of odd. Looks like they took the exhaust off at the header in that area too.
- Some rodent chew holes in the hood insulator and droppings in the air cleaner box. Have not found chew marks/damage to wiring or vacuum, but still a possibility. Took out glove box & inspected all wiring at the computers, no rodent activity in there.
- Passenger side O2 sensor looks newer

 

[PNWFJ80]

These are the only pics I have of the engine, I’ll add more shortly:

 

[2001LC]

Oh I miss read as only P0300 & P0306 a P358 (P0358). Interesting no P0307! But basically we taking all cylinders.

I would for sure do cylinder balance test first (compress). I was just read about a way through tech stream "active test" to cut fuel to each cylinder one at a time. This is helpful in testing balance before doing compression as you warm up. I'm head out to shop, now to do this myself.

5 pages of service history great. But drilling into it and looking for what was or was not done, is key. Like starter replaced (dropping grim into intake port), coolant leaks (overheating), fuel system issues or work performed on O2 (down stream), A/F (VVt is A/F sensor up stream), CAT can point to A/F issue and/or back pressure.

Using car fax and Toyota history and drilling into parts installed. Also call shops that come up on carfax. See what codes, when and what was done along with results. CLUES!

These can give clues to causes. Example: coolant low/leak. I look extra hard for overheating or head or head gasket issue.
Stalling or vapor-lock notes from tech or customer, may indicate a bad fuel pump.
Poor MPG may be fuel injector(s) or exhaust clogged.

 

[PNWFJ80]

Alright! Picked up a few new tools, ran a few tests, turned a few wrenches...here's what I've come up with:

Fuel Pressure Tests:
Fuel Pressure / Idle / Engine Running / 42 PSI
Fuel Pressure / 5 Min Bleed / Engine Not Running - 35 PSI
Fuel Pressure / 1 Hr Bleed / Engine Not Running - 31 PSI
Fuel Pressure / Ignition Switched to On / Engine Not Running - No Change

Engine Pressure Test:
Cyl 1 / 152 PSI / Dry
Cyl 2 / 152 PSI / Dry
Cyl 3 / 148 PSI / Dry
Cyl 4 / 0 PSI / Dry (0 PSI / Wet)
Cyl 5 / 158 PSI / Dry
Cyl 6 / 148 PSI / Dry
Cyl 7 / 148 PSI / Dry
Cyl 8 / 150 PSI / Dry

I did the pressure test on Cylinder 1, 3, 5, 7, without incident, all were 150 ish PSI. On the other bank, the engine decided it didn't want to cycle 4-5 times, it just kind of constant. I let it sit for a bit w/ the charger on it, then Cylinder 2, 6, and 8 tested the same as the other side at 150 ish PSI. The first 3-4 times testing Cylinder 4 the engine did the constant thing, finally after clearing codes, letting it sit on the charger, I got it cycle 4-5 times but could not get anything other than 0 PSI out of Cylinder 4.

I removed the fuel pump relay prior to pressure testing, and all coil packs were unplugged. All cylinders were tested with all spark plugs removed from the engine, except Cylinder 4. I had everything put back together by the time I finally threw in the towel trying to get a reading. I was using a Harbor Freight pressure tester, and it had some issues, so that can't be ruled out but I think it would be an uncanny coincidence to only **** up on Cyl 1(first time using it), but otherwise flawless on all cylinders except the six or seven seperate tries on Cylinder 4.

So, is it possible a rod's broken or something? I haven't done any electrical or vacuum tests yet, but did pick up a vacuum test kit if that will do anything above and beyond what I've already dug into. Open to any suggestions!

Pictures:

 

[PNWFJ80]

 

[2001LC]

Easy way to see if number 4 cylinder has busted rod. Pull #4 spark plug and insert a long screw driver. Turn crank 360 degrees. Screw drive will raise and low with piston, if rod connected (not broken). Pulling all spark plugs again well make this easier, but can be done with all others in.

Compression test:

First, engine must be at operating temp to get a good test. While engine at operating temp, all components have/are expanded from heat. As cylinder temp drops, so does compression reading.

Second, throttle body needs to be wide open during test. This allow ample air to be sucked in cylinder to get good compression of air. Just prop gas pedal down with a poll or helper.

Third, engine must cranking at minimum of 250 RPM. A good fully charged battery will do this just fine.

All your cylinder read low. Any below 154 PSI is out of spec. If test done with engine cold or just warm compression will read low. So was engine at operating temp or near it? If not retest.

A wet test is done by injecting about 1/2 oz of 30W oil in cylinder. Then compression tested on that cylinder quickly. Again done with hot engine.

A leak down tester takes/is a special tool. See youtube. But you can learn a lot by adding compressed air into a cylinder, which is part of what the tool does. Some compression tester have 1/4 air chuck that can be used for this, by adapting air hose from compressor. Than listen for air sound coming from oil fill tube (compression ring leak), air sound from throttle body (intake valve leak), air sound from exhaust (exhaust vale leak). Also check for bubble in radiator (head gasket leak). Again this is done with a hot engine.
Note: You will hear some air from crank case.

BTW: Fuel pump only runs when engine cranking or running.

 

[2001LC]

#6 coil shows signs that it's spark plug had walked. So much so that exhaust gasses were blowing by threads, even after warm up. What we don't know is which cylinder that coil came from. By that I mean, when PO had plugs replaced, they may have mixed up coils. Some coils are new, so they may have been even worst. Note: Your old spark plugs are USA Denso plugs so not the original factories.

Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!

TICK TICK TICK POP POP POP is a ticking time bomb, often mistaken as exhaust manifold crack or gasket leak leak. ALERT, ALERT, ALERT: Spark plugs are working themselves loose. "Walking Out" Then blowing out of head, taking their female threads of head with them! Very damaging! You think TICK...

forum.ih8mud.com

 

[2001LC]

Tip: Charge battery overnight with clamps off. Clean battery post and clamps and grease them. Take a drive using low gear to keep RPM at slow speeds will get engine hot.

 

[PNWFJ80]

You're a wealth of knowledge, appreciate the idears! It runs pretty rough at idle, not sure if I want to run it long enough to fully heat up, definitely don't want to drive it, but I think a consistent ~150 PSI when cold for all cylinders(except #4) is a good sign. I'll try the screwdriver trick in cylinder 4 in the morning.

 

[2001LC]

Oh it runs so badly, that you can not drive. So you did do compression testing while engine not at OP Temp and TB closed. Then 154PSI is not that bad.. With exception of #4 cyl.

Connecting Rods breaking in the USA made 4.7L 2UZ-fe engine, is not unheard of. But I've not heard of one case in a stock Japanese made 4.7L 2UZ of the 100 series, GX or 4runner.

I was unclear by your statements, if engine cranked over while testing #4 compression. If it did and compression gauge was threaded in and attached properly. My bet #4 has a bent valve. Very good chance this was the case.

Clues:
1 Barely running
2. #4 zero compression.
3. Timing belt looks new Toyota OEM.
4. Sold at auction. But great condition cosmetically and only mid mileage. Why go to auction!

Whereas the non VVT engine we've many accounts of engines not interfering (valve hitting piston) during a belt break. In the VVT it is generally believe they are interface engines.

Service History of vehicle at Toyota and Lexus (must call Lexus) and carfax, may tell a story. In service history drill into parts used.

If timing belt broke. Someone may have tried to see if engine was okay, by tossing on just a belt. Hard to see in picture, but water pump looks older than belt (belt looks brand new). In fact looks just like the rest of the aluminium parts around the water pump. But I need close ups to see better. By tossing on belt they could crank it over and see if any cylinder will not hold compression. It's easier to scope the engine, than put on a belt. But they may not have had a scope to look into engine. I've a $20 household drain scope I use.

It also possible belt was installed wrong. You did not show in pictures of belt, if timing marks line up? (cam sprockets to timing marks and crank to TDC mark.) Note: the "T"'s are not the timing marks.

If you've an air compressor. Hook it to cylinder #4 if it passes the screw driver test. Give it about 100 PSI. With all spark plugs out. Turn the crank 720 degrees, with a 22mm socket and long 1/2" ratchet or breaker bar.. If that cylinder can hold compression it will be very hard if not near impossible to turn the crank on compression stroke.

As you turn the crank, if cylinder holds some air pressure. As you come up on compression stroke, it becomes very hard to turn crank. So then reduce pressure from your air compressor to about 35PSI. Keep turning crank about 45 degrees more. This gets piston near top so pressure doesn't push it back down on you. Now listen for air escaping from intake valve or exhaust valve. Trick is you must be on compression stroke so all valves in #4 cylinder are or should be closed.

BTW: Someone has attached the ground wire on LH side of engine to the head cam cover bolt. This wire attaches to the engine hoisting hook. So why did they even have that off. Was it while head covers off to install new gasket and tube seals. Again clues are in service history

Good luck!

See my Master thread, with index to many helpful links in my signture line. Look under "Engines" and in "The Unicorn" for helpful links

 

[PNWFJ80]

Good news! It passed the screwdriver test, it moves!

Bad news... it won't hold any pressure and just blows air out of the intake plenum(tried it when the piston was in two different spots, high/low). Also, there's a fair amount of oil in the air intake and I'm not sure if it's supposed to be there.

So my guess is head gasket?

The drivers side/LH valve cover and the exhaust flange has been recently R&R'd, this is the area wire clips are missing, bolts were missing, etc. I tracked down brackets that work for the main wiring loom in that area, thanks for the fyi on the ground, just swapped that back to the engine hook.

The water pump looks like it was replaced at some point, not recently though.

And it needs a new drive belt, it's on my list, just not high up there at the moment.

 

[mitchjohnson000]

I agree with @2001LC. Sounds like bent valve. Could be a head gasket but I would think you would see more coolant leaks/low coolant and possibly air in the system.

 

[2001LC]

My monies on valve (provided you did test with cam in correct position). Likely bent from interference. But can also be burnt. A burnt valve can have a chunk burnt out of it and will not hold compression (seal).

I'd scope cylinder #4 as a next step.

Head gasket blown, often cause coolant to enter oil and or leak out between head and block They generally will give low compression at least two cylinders next to each other. They generally don't blow on their own. It usually takes overheating and head warps. They don't have way to blow back into intake, unless head cracked. I've heard of a few HG just leaking but it's rare, but I've not heard of one on a VVT engine. You then head air from side of engine or coming from plug hole of 2 or 6 cylinder. Or If you said bubbles in coolant, I say head gasket. Or if you see coolant crusty (Toyota pink crusty) around head gasket. Yes head gasket is blown. Or oil in coolant or milkshake as oil in crank case.

Bent, burnt or stuck intake valves cause compression to leak into intake manifold via intake port. The intake manifold has catches for oil from PCV. Air blowing back into intake could blow this oil into bottom of manifold. It will generally be just one cylinder as your compression test showed

Sometime a engine sit after water enter. The valves get stuck from rust. Guy's put rope into cylinder and then by turn crank, driving up valve with piston. I doubt this is your case, just because of mileage, condition and age.

If cam rotated where intake valve open (lobes down) it will allow air into intake, as is normal for air to move between the two. So you must have turned the crank 720 degrees to make sure,and that at no point during rotation did air stop coming out intake manifold. If you had compressor hook-in to #4 and 100 psi with all plugs out. You be able to just keep turn crank if valve not sealing with air sound coming from intake. If cylinder held air you not be able to turn crank as it entered compression stock.

A $20 endoscope that hooks to your phone, can be used to take a look into cylinder. But I've got to warn you. The cheap endoscope have a mirror to see at the 90 degree angle and don't work well. But they do work. The really nice scopes have articulating tip to change camera angle. But those are pricey, they can be rented.

You can also pull head cover and see if valves moves or not.

If bent, or burnt its a head job. Here the catch. Both head need done to keep balance if milled.

For detective work on what happened. Check to see that timing belt is on properly. That is, that timing marks line up. I've heard of tech using the "T's" as timing marks and shop then having to buy customer a VVT engine. Ignore the marks on the belt. Those are just used during install.

The LH exhaust flange, if you speaking about exhaust manifold, could be due to exhaust leak. Could be head work also. But if only the flange just pass the A/F (O2) sensor. Then may be CAT was removed. Look rear of CAT at flange bolts.. I pulled one of those just yesterday. The rear flange bolt get the worst of it and best replaced You should spot those bolts & nuts easy.

 

[PNWFJ80]

Spoke with the dealer who's serviced this rig, the drivers side recently got a new head, so that explains why the valve cover and exhaust looked to have been recently R&R's on that side. It was in their shop last month, and they had it diagnosed as a valve issue w/ cylinder 4, and at that point the owner traded it in for another car. The service adviser said a head job might fix it, but said for the money the best bet is to just do an engine swap. I personally am leaning towards a swap as well, sounds like this engine has had a few issues recently and might turn into a can of worms trying to get it working right again. Thoughts?

 

[2001LC]

Swap it. I'll again point you to my master thread below. Look at link under engine and at The Unicorn.