Need some wisdom!

02 Prerunner, 3.4, 286K. Last fall, replaced air boot, injectors (orig), fuel pressure regulator (orig), plugs, wires, coils. Cleaned MAF. Ran well.

Just now started barely running, very rough. Smoking (white). Fuel pressure was erratic around 42, but dropped instantly when shut off. Had all kinds of codes: 0440 type, 0300 type, 0171,172.
Replaced pump (orig), purge valve (orig) and upstream o2 sensor (orig). Tested coils w meter and examined plugs (photo attached)
Oil clean. Coolant clean. Fuel pressure steady at 42, but drops off fairly quickly after shutoff.

It's now a little smoother at startup, but becomes rough and smokes a lot. Ran codes, 302,304,306. I am mystified.

 

One glaring thing stands out. You're using single electrode plugs. Pretty sure that little white and blue label in your pic says specifically not to use single electrode plugs in favor of dual electrode.

I'd get some Denso/NGK/OEM dual electrode plugs in there. If you're getting misfires on the drivers side I'd be triple checking your wires are correctly connected to the coil packs.

After that I'd be looking to do compression test, and most probably a leak down test.

 

White smoke that won’t dissipate once it leaves the exhaust is coolant. I would have compression checked when having all the spark plugs out. You can rent a compression tester for free from almost any parts store.

I run single electrode spark plugs with no issues. 0300 multiple misfire code and 3 cylinders on the same bank won’t often spontaneously come up due to spark plugs you’ve had in it running fine for months.

All those cylinders are in the same bank. All this points towards blown head gasket. As the cooling system heats up, it pressurizes and can explain the rough running after the engine is running and coolant pressure increases to max.



But you still need to verify before proceeding.

This is an easy way to check for coolant getting into your cylinders too. You can also rent a pressure tester for free from parts stores. Check Amazon for any well reviewed cheapish borescope.

https://m.youtube.com/watch?v=CiwyPgrlbEM

 

cylinders #6 and 3 share he same ignition coil. I would swap that coil with another and see if the misfires follows the coil, if so, easy diagnosis. The one thing I do see is that cylinder #6 plug looks as if it isnt getting fuel or that is where the coolant is "cleaning" that plug. Pull the plug on #6 and start her and tell us if water/coolant squirts out, if no, then do a complete compression test.

 

He's got misfires on all cylinders in that bank. It would be hard to tell why with just switching one coil.

 

It takes 2 minutes to do. If the codes persist then a compression test. To have head gasket fail on all 3 cylinders, I am assuminging suddenly, while it is possible for a head gasket to fail on a complete bank, I have never seen it, but then since joining this forum I have read about things going wrong that I would have never imagined.

 

I'm just curious how you're going to assess a misfire code on cylinder 6 by swapping the coil / plug wire to another set of passenger / driver side cylinders if all the driver's side cylinders are already throwing misfire codes unless you have the number of misfires and there are a big difference between the number of misfires in cyl 2, 4, and 6 being shown in the code history / live data recordings.

FWIW I compression tested a family friend's chrysler V6 that was throwing codes for misfires on one or two cylinders in one bank and it turned out that there was 0 compression on the third cylinder in that bank, which was the only one not throwing codes. In some cases the misfires don't always pinpoint the problem cylinders when you have a big mechanical failure based what I found in that situation.

 

Good morning. Thanks for the responses, and catching my ignorance to the plugs! You'd think after owning this truck from day 1, I would've read that sticker by now. Swapped out w NGKs. Swapped coils around. Still white smoke, gets worse after a minute.

Ran a compression test:
#1 170 #2 160
#3 170 #4 170
#5 165 #6 160

Not horrible for a motor w 286k.

I've ordered a borescope, looking for leakdown kit.

Does anyone have experience w the KSeal Ultimate? The reviews seem good. Might buy me some time. How about 505 CRO for removing carbon deposits?

 

You’ll need the coolant pressure tester for working with the borescope - you can rent one for free from most parts stores. It’s super simple to operate.

I’ve had this leak down tester for a few years and used it multiple times with good results.

$108 OTC 5609 Cylinder Leakage Tester Kit , Black

https://www.amazon.com/gp/aw/d/B0030EVL60?ref=ppx_pop_mob_b_asin_title

A small HG leak wont always register on a compression or leak down test but won’t hurt to try seeing if you get pressure in the coolant from the leak down. You could put the coolant pressure tester on without pressurizing it while running the leak down to see if the pressure increases in the coolant system. They also sell those dye kits to see if you’re getting exhaust gasses in the coolant which can verify that too.

 

decent compression....lil low but more importantly.....all are consistant
(i compression tested my friend's car and all cylnds were low but consistent.....he bought a new C tester....tested again and all within specs.....turned out my 25yr old C tester was trash and not reading correctly)

agree with Glamisman re: #6 plug either no fuel or getting steam cleaned

peek at top of cylinder on #6 when u get borescope.....if top of piston is steam cleaned, there is your proof of HG issue


not a fan about engine in a can products.......i mean if that is the only option bc of "financial or plan on not keeping veh reasons"
hell watch a few RoadKill episodes.....sometime they work......for lil bit

 

RE: stopleak products in general.

Never used one for my engines but basically used the same thing for my wife’s AC that I had snapped a line on last year and recharged it the right way with pulling vacuum and using a manifold to check high and low side pressures while refilling it.

This year the cooling stopped altogether and after 27 years, a fair amount of places could have leaked (shraders are my suspicion as they stick open when removing the manifold quick connects). Rather than spending all the time going through and testing for the leak, I used a can of AC stopleak / refrigerant knowing that either it fixes it, or I spend time and money redoing the system with a lot of new components (compressor, condenser, dryer etc.) since after that many years it’s pretty cheap compared to the life of the parts that have been in operation for so long.

If you stopleak your engine, I’d consider the next time you have any major issue with the engine (catastrophic head gasket failure, cracked cylinder head, or severe overheating issue mainly as these engines don’t drop or burn valves typically), you plan on replacing the engine and radiator altogether instead of working on a system thats already got stopleak and possible other issues in it.