Crankshaft Pulley?

On Thursday I noticed that my car was not accelerating properly and jerking at around 40mph. The next day it got worse and on my way to the dealership on Friday the car lost all acceleration and died while in traffic. After sitting for an hour waiting for a tow truck, I started it back up and was able to drive to the dealer but it was still having issues.

Just heard back from Toyota dealer and they are saying the crankshaft pulley needs to be replaced and he made it sound like Toyota is aware of some issue like this, however they won't have a part for me until Friday. Something just doesn't seem right with this explanation, so I wanted to check on here to see if anyone else has had similar issues. Thanks

 

Did the CEL illuminate during the break down?

 

They guy probably meant crankshaft position sensor. Several people have had this issue and a similar experience as yours.

 

The CEL did not illuminate during the issue and the pulley is what the Toyota guy said...didn't make sense to me either.

 

keep us posted....

 

If the pulley is like most, it serves as a harmonic balancer. Those can break, causing the pulley to shift and throwing the engine way out of timing.

Generally this is a problem with older high mile vehicles, not new ones.

I too suspect it will be the sensor, regardless of the words used in the conversation. The caller isn't the tech who diagnosed the issue, and may well have their own interpretation of what the tech wrote.

You likely won't know exactly until you get your completed paperwork and list of parts.

 

If the engine uses a toothed trigger pulley (not sure if they do??) they usually sit on / behind the crank pulley.

Best picture I could find is an aftermarket unit off a Mazda, but you get the basic idea:


The sensor is circled, you see those "gear teeth" looking protrusions- basically the sensor "sees" those teeth going past and uses that to figure out where the crank is for ignition timing. If that ring slips, or a tooth breaks off, your spark timing goes to shit.

So it sounds plausible, but again I have absolutely no idea if the Taco uses a crank trigger wheel.

 

It looks like it does:


Keep us posted OP, we may have to call Houston with a problem with these crank sensors
Cheers!

 

Spoke with the dealer yesterday and they confirmed that they misspoke and it is the CSPS that has failed and needs to be replaced. Evidently this is a known issue by Toyota because there is a national back order on replacement CSPS's so they will have my car for over a week. Hopefully it's just a faulty sensor and not a design flaw, which would lead to future problems after it is "fixed".

 

car, truck which is it?

 

Well, since the basic concept has been around since the mid 90's, the 'design' isn't the issue IMHO.

However, there is definitely some issue with the sensors. Maybe a faulty production run from the supplier. One who likely makes the same sensor for other marquees as well. Like the takata airbag debacle.

Here is one example, https://www.tacomaworld.com/threads...nsor-problem-in-the-2016-trd-off-road.404275/

Several other threads as well.

Good news is I'm not recalling hearing of secondary or tertiary failures. So maybe the new bits are good.

 

Crankshaft pulleys have nothing to do with timing.....

 

Take it up with Wikipedia

https://en.wikipedia.org/wiki/Crankshaft_position_sensor

 

Timing can not be changed by a broken crankshaft pulley unless the timing chain is also attached to the pulley. A broken crank sensor plate also does not "change" timing. The effect would only be to confuse the engine control module due to the signal being wrong. The timing chain never moves out of it original position.

Wikipedia doesn't build or engineer powertrains for cars last I checked.

 

There are two types of timing. Often confused. Spark (or ignition) timing and cam timing.

You just described CAM timing. This is via the timing chain, and you're absolutely right, if the timing chain doesn't slip your cam timing won't be off (unless the VVT-i solenoid is broken but that's a whole 'nother can of worms) Cam timing is where the valves open and close during the motion of the pistons.

SPARK (Ignition) timing, on the other hand, absolutely will get changed by a busted crank sensor plate. Spark timing is where the spark plug fires in the motion of the piston, which is usually before top dead center. This is the timing you set with a timing light, and this is where the terms "timing (spark) advance" and "timing (spark) retard" come from. If the ECU doesn't know where the crank is, it can't control the spark properly.