Engine Surging/Pulsing After Timing Chain Repair - Update: Now Getting Codes

Hey all,

The chain slap became unignorable sometime this past December, and I began shopping around. After two local reputable shops quoted me about $2k less than the dealer (who confirmed the diagnosis), I decided to get the job done with one of them in early January.

At 201k miles, I decided to replace the tensioner, chains, alternator, water pump, thermostat, spark plug seals, and radiator hoses. The previous owner had already done the radiator, and I did the spark plugs within a month of buying it. Including the associated gaskets and fluids that were replaced with the job, it was costly but I figured the truck would be bulletproof for another 200k miles.

Well, within 2 miles of driving off their lot, the truck threw 2 codes: P0016 and P0017.

Immediately knew that the tech (and fellow 2nd gen owner) set the timing incorrectly. Being the end of the day on a Friday had me waiting until Monday to reach anybody. I told them what codes I got, and they asked if it'd come back if I cleared it. They did, and I told them I thought it best not to drive it anymore given my suspicions regarding the incorrect timing despite the tech's insistence that that wasn't possible.

I brought it back when they had availability to tear back into it a few weeks later, and the tech admitted that the truck threw those codes during his test drive under where he even "did some heavy pulls", but he still felt it was fine to hand it back over to me.... cool.

I let the technician know I was also feeling what I could only describe as a rhythmic pulsing from 10mph to around 40mph and around or under 2500 rpms. If you accelerate lightly, you can still feel it as the "rhythm" increases. At higher acceleration/speeds, it's not noticeable presumably because of everything else going on under the hood. The idle is solid.

I got a call a few days after I dropped it off. Unsurprisingly, they found that the timing was off by a tooth. They were getting it fixed then and then buttoning the truck back up.

That was a few days ago, and I picked up the truck last night. Other than the belt screeching something fierce for a while at start-up, and brief screams a few start-ups after (easy fix for me), there are no more codes of any kind.

But, that rhythmic pulsing under light loads is still there. I've never felt that before in my truck, my brother's Tundra, or any other car I've owned really.

I might be overly sensitive to the truck now given the cost of this repair, and the potential outcome from the tech setting the timing incorrectly the first time around.

Would appreciate any insight y'all can provide.

 

first thought is maybe the chain is off a tooth or two?

 

I'd start with doing a vacuum test and seeing how it looks. If you aren't sure what it is, you can likely find it on YouTube.

 

Expanded my forum search to include surging instead of pulsing, and came across the thread below that describes the issue I'm experiencing better than I did. It's possible I didn't notice the problem before with all the other noise and clatter coming from the front end. Or, given how long the battery was disconnected, the ECU is still recalculating alcohol density values.

Will try topping off the tank and resetting the ECU with techstream before moving to replace parts. But based on the description, I'm fairly confident on the next steps.

Helpful threads on what they attempted and how it was fixed- https://www.tundras.com/threads/surging-during-light-to-moderate-acceleration.37175/page-5

Thread about resetting ECU before parts were replaced - https://www.tundras.com/threads/rough-cold-start.36837/page-3

 

Belt squealing at start up may be from the belt being routed the wrong way. I have seen several posts about it.

 

Well, confirmed and fixed belt routing. Thanks @Slim Gym.

Drove the truck about a 50 miles away. Turned it on to head home a few hours later, and the truck threw a number of codes. The 4LO and CEL lights were flashing while the TRAC OFF light was steady on. Using the graph in the following thread didn't help - https://www.tundras.com/threads/4-lo-flashing-no-4-lo-engine-light-and-trac-light-on-too.84367/.

I found this thread that seemed to have most of the same codes I got, but am not sure what sensors he's referring to. Or, even if that is the problem I'm dealing with here since the first time I got the truck back, the timing was definitely off as I highlighted in my OP.

Codes I got:

p0300 - multiple misfires detected

p0302, 304, 306 - Cylinders 2, 4, 6 misfiring.

p0018 - Crankshaft position - Camshaft Position Correlation

p0021 - "A" Camshaft position - Timing Over- advanced or System Performance.

Cleared codes and only got p0302 and p0021 returning. This time CEL and TRAC OFF were steady on. 4LO was flashing.

Truck seems to drive normally in either lower gears/higher rpms as I discovered when downshifting to get enough power to pull off somewhere safe to wait on the tow truck.

Would greatly appreciate any insight.

 

Seems like the chain running to bank 2/4/6/8 is still not right.

 

@AZBoatHauler I've put about 100 miles on the truck since the repair was completed though. Normal for it to throw codes that far after?

 

Did you ever get this resolved. Im chasing this same issue right now and at my wits end.