Hi everyone! I recently bought a 2016 Tacoma SR5 2.7L 4WD with 70k mi.
At idle in D or R like at a red light (idles around 550rpm) the truck vibrates. Sometimes it’s bad and shakes my head and eyes and feels like someone is kicking my seat. It tends to get worse the longer I sit at a red light. It’s worse with the brake pedal pressed, but happens a bit in drive with the parking brake on and not pushing the brake pedal. There are tons of threads about this on the tacoma forums and there doesn’t seem to be “one” solution for everyone. I have cleaned the MAF and throttle body without much or any improvement. I am planning to do spark plugs too.
No CEL, no codes or pending codes, no misfires on scanner (but it really feels like it’s missing or imbalanced). Idle long term fuel trim is about -2%.
My question is: I did a vacuum test (hooked up my mighty vac to the intake manifold port for the brake booster hose). It showed a rapidly fluttering needle between 20.0-21.5 inch hg at idle in park. My last vehicle had a steady needle when tested and most of the youtube videos I see show a steady needle during the test.
Anyone know what this means? I am thinking it’s abnormal and could be related to my shaking engine. I would appreciate knowing what you guys think and any suggestions you have.
Your intake manifold vacuum test results looks pretty good for the most part. If it was jiggling ±5 units, that could indicate a valve-train problem, but the little bit of jigging you are seeing, while that’s a little unusual, I doubt that’s the cause of your symptoms.
I think if I had that problem, no misfire codes present, and truck was otherwise in good repair, tune-up parts had been recently replaced, I’d do an engine compression test as the next step. Since you say you plan to replace spark plugs, with all plugs removed, that would be a good time to do a compression test as well.
Do you notice any symptoms when rapidly accelerating up a freeway on ramp, or going up steeper hills?
Thanks George_San_Jose1!! You guys rock on here. The car is due for spark plugs (the 60k service calls for them and it wasn’t done) but up until that point it was maintained by the dealer on schedule. I appreciate your suggestion to do the compression test and I will definitely do that while doing the plugs!
It does go quite slow in those situations you mentioned. I assumed that’s just because it’s a 4cyl tacoma, but maybe there’s more to it than that? But it doesn’t hesitate or sputter or vibrate then. Just slow. What would that indicate?
Some valve trains are very fussy about the oil. Have you been using the exact spec oil that Toyota calls for in this engine? Not just the xWy viscosity, but any additional spec #s?
Interesting. I just bought it used from a Subaru dealer and they said they changed the oil, so I guess all bets are off. Before that it was always maintained at a Toyota dealer. Do you think it’s worth changing the oil to the exact Toyota spec’d one to see if it helps?
Hey weekend-warrior! Thank you for that. I did not put in a new battery prior to this starting. It kind of did it since I had it (except for during the test drive, of course). I did try to do this idle relearn procedure after cleaning the MAF and throttle body but unfortunately it didn’t go away.
Hi Purebred! Yes I have opened the airbox a bit to peek at it and it looks bright white and new, so I didn’t take it out. I did wonder if I could get a thinner filter or something to allow it to breathe just a bit better at its lowest rpm? Is that possible?
Did these symptoms show up during your test drive or after you bought it ? Have you talked to the dealer to see if they might offer some help ? You may just need to have a shop do a diagnostic ( here will be a charge ) and give you a price to solve this .
Hey Volvo-V70! The vibes were very slight, almost nonexistent during test drive, and showed up worse after. The selling dealer told me they were going to do a bunch of stuff to diagnose and fix it under warranty and then they didn’t, instead sending the car to a neighboring Toyota dealer who did a “health check” scan and said the vibrations were “normal” because the engine was a 4cyl. However, I had brought it to another Toyota dealer myself and they thought it was abnormal. They cleaned the TB and told me to drive it for a week to see if it gets better (no change). I didn’t go back there only because I moved 2.5 hours away.
To be fair I drove 5 of these 4cyl tacomas during my search and 2 of them did vibrate at idle. It is a common complaint on Tacomaworld, but certainly not the norm. Plenty of users report completely smooth, normal idle. Some people with the problem report resolution with cleaning the MAF and TB, a few found vacuum leaks, a few added additional exhaust hangers,and several reported improvement with replacing normal-appearing but old motor mounts, and some never fix it. I was going to give up and accept that there is nothing “wrong” with my engine and just try to isolate it, but the vacuum test seemed abnormal to me.
There’ll be no codes associated with a bad harmonic balancer.
If the harmonic balancer fails, it’ll cause your Toyota Tacoma to vibrate at idle speed. As the crankshaft spins faster, the vibration will become less pronounced.
It definitely feels like an improperly balanced engine. Is there a test for the harmonic balancer? It doesn’t look asymmetric or off-center when spinning at idle.
However, the fan does look like it is spinning off-center and the serpentine belt tensioner is moving a fair bit. One youtube videos shows a guy with a 4cyl tacoma idle vibration which he concluded was caused by play in the fan clutch. I don’t have play that I can feel but my fan does look off-center and moves when it spins.
Should I try to run the engine for a minute or two with the serpentine belt off to see if it changes the vibration? I will make sure it doesn’t get hot. I don’t know that this will test the harmonic balancer necessarily, but maybe it would rule out the fan or the alternator or one of the other accessories?
