[SafetyDang]

5VZ-FE Load Hesitation, Stutter, Sputter *SOLVED*

I've been chasing this engine stutter for about 1 week now. When parked if I rev the engine with more than 1/2 throttle it will sputter till about ~2,000 RPM. It feels like a misfire with out the CEL. The best way to explain it is a popping sound with a slight hesitation. While accelerating from a stop if I ride the clutch a little it doesn't hesitate. If I slip the clutch and push the pedal half way down it will sputter till ~2,000 RPM then will rev up fine. If I am coasting at ~2,000 RPM or lower and floor it it will sputter in any gear. If I am coasting at ~3,000 RPM and floor it it will rev up but make popping or "misfire" sounds.

No foam or milky looking Oil
Oil was a bit low (Valve cover was seeping)
Radiator fluid in the reservoir was low. Filled with the reservoir with water and it is now green/brown not neon green. Reservoir level hasn't changed this week.
Fluid in the Radiator is neon green still
No pulsating when placing my hand over the radiator cap opening while the engine is running.
Cleaned the MAF and it didn't change.
Replaced the Fuel Filter and it didn't change.
Replaced the Air Filter and it didn't change.
SeaFoam in the gas tank and intake manifold didn't help. (About a minute or two of white smoke)
No white smoke out of Exhaust under normal conditions.
No over heating or change in water temperature.
PVC cleaned and working.
No CEL
O2 sensor changed last year
AFR sensor changed last year
Timing Belt and Water Pump Changed 2011 @ ~90,000 miles


Specs:
119,000 Miles
V6 5VZ-FE
Manual Transmission

Engine Mods:
LCE 38lb Flywheel
Deck Plate



120,000 Mile maintenance parts in the mail.
Plug Wires
Valve Cover Gasket
PCV
Grommets

From what I read I am leaning towards head gasket. Showstop (Tyler) seemed to have similar symptoms. Need to pull the plugs and check for fluid this weekend. I plan to run a chemical test and compression check maybe next week. I haven't checked the TPS but it does register on my Scan Gauge so I think I can rule that out. I was also reading about the IAC but it doesn't sound like my issue.

Anyone know the Ohm reading for the MAF, TPS, or Spark Plug Wires?

 

[Squishy!]

Sounds like a coil pack or plugs. They don't always throw a CEL. Pull the plugs and do a compression and/or leak down test if you're really worried. 119,000 on a 5VZ shouldn't have HG issues.

 

[SafetyDang]

Whats the correct way to test the coils? The only reason I'm worried was due to my low radiator fluid in reservoir as well as the color change only in the reservoir. Could just be rust since I switched to non Toyota radiator fluid.

 

[Squishy!]

I just buy one and swap one by one until the misfire goes away. Or have a buddy with known good coils and swap one at a time. I'd check plug gap and insulators first though. I've had a tiny fracture in the porcelain arc to the plug tube and cause the same symptoms. Freaked me out.

 

[superchiem]

I just buy one and swap one by one until the misfire goes away. Or have a buddy with known good coils and swap one at a time. I'd check plug gap and insulators first though. I've had a tiny fracture in the porcelain arc to the plug tube and cause the same symptoms. Freaked me out.

If only he had a 5vz sitting at home with know good coils. haha. use the one out of the rv.

 

[SafetyDang]

Solved:

Spark Plug Wires

 

[Inspectorgadgets]

Mine did that, it was a coil pack; I replaced the Spark Plugs and Wires too just as a precaution.
Hope that helps.

 

[ransomwy]

Mine was doing the EXACT same thing. No CEL. But threw a multi-cylinder and cylinder 4 misfire code.

Changed plugs - Slightly better driving but not 100%, No CEL, No more codes.

Changed air filter - No change.

Changed plug wires - SOLVED

Denso plugs - Denso (3194) K16TR11

Wires - NGK (4412) TE66 Wire Set

Thanks!

 

[coolguyw7]

Knock off Spark Plugs Hong Kong

I Had the same problems so I changed the wires and still had problems I was stumped then I tested the Ohms on the plugs There was no resistance from the plugs I purchased New plugs K16TR-11's from Hong Kong claiming that they were a Lexus Dealer there but it turns out the plugs are Knock off's So remember if the price is too good to be true it probably not! Everyone should be in the habit of test any spark plug before you buy ore in my recent discovery as soon as it comes in the mailbox. Good luck All!

 

[Starman97]

Same thing. It would start a little rough, but once it warmed up would idle fine, maybe miss once a minute or so. But if I put my foot into it, ran like crap, missing and backfiring. I have an 04, so thought it might be a Throttle Position or Accelerator Position sensor, or maybe the Cam or Crank sensor. I also noticed that when I washed the motor, it ran really bad, that should have been a big clue. I finally got an engine code, a P0304 , miss on #4. I swapped coil packs, but not the wire, it helped a little, but started to get worse again.
The plug wires seemed a little loose on the driver's side, so I tried to swap them from another motor and they did not fit? What's up with that? Took a look into the plug tube with a light and noticed the clip was still stuck to the top of the plug. Yep, that's a problem! A new set of plug wires solved it.