NEW!!! Service Bulletin for Engine Knocking at Startup T-SB 0012-10

Ok, so did we rule out a bad right rear engine mount? I ask because I started having this knocking issue the morning after I smashed through a major pothole that wrecked both tires on the passenger side of my car. Seems like a big coincidence, but I am pushing 140k miles and I've never cleaned anything EGR or PCV-related.

 

if you're getting it all the time, can definitely be an engine mount.

 

I inspected the mount and didn't find anything wrong. Eventually I found that the coolant reservoir was severely low (i.e. about to start sucking air). I refilled, it burned a bit more, and I threw in some K-Seal to buy myself some time in case I need to evacuate to escape these SoCal fires. Fortunately the knocking on startup has been gone for the last six or so cold starts. There's a lot of debate all over the internet on whether K-Seal is or isn't a great long-term solution, so I ordered a head gasket kit, an oil catch can, and a new PCV. I'll be cleaning the manifold, tb, egr cooler, and flushing the coolant like crazy to see if I can get this car back into a condition where I'm not afraid to take it on long trips. Should be fun!

 

Jesus, things are tough down there.

 

yes, looks like their equivalent of hurricane alley.

 

Can anyone really explain technically, how replacing the intake manifold with a designed one could cause such a noise? Has this got something to do with volumetric efficiency, or something?

Just learning


Dxta

 

I'm not sure I understand. I think you're saying replacing the manifold causes the problem, whereas the old technical bulletins I was reading was saying that replacing the manifold was actually the fix. Either way the point may be moot since the consensus seems to be that the problem isn't the manifold, it's all the gunk that gets into the manifold and then into the combustion chamber.

 

Thanks for the explanations

 

Have you tried just disconnecting the EGR plug from the actual EGR? It will throw a code immediately but it should keep the EGR closed on start up and see if that's the culprit.

 

Too late for that, I'm afraid. The K-Seal made the problem go away.

In other news, I went to toss another Warranty Extension sticker from Toyota onto my warranty manual and found this gem already on there:



Just about fell over dead. Too bad the stupid thing expired at least six months before I needed it! Also makes me just a little more aggravated at my local Toyota service department who said, "never heard of it" when I called to ask about this exact problem. On the upside, this appears to be definitive proof that Toyota is aware of this and has a TSB for it somewhere. Might be good news for someone else on this forum unless they all expire at the same time.

 

I just had the rough startup this morning on my 2010 with about 81k miles. Temperature in the garage was 10 degrees F.

The only other time that this happened was several years ago when I had moved the car a few feet the prior evening in a way that the engine fired up for just a few seconds before I shut it back down. This short run cycle was not a factor this morning - just very cold temps.

I haven't inspected any of the EGR stuff on my car yet, since I didn't think i was a candidate for the plugged up condition yet at just 81k miles. And it is too damn cold to deal with right now!

Is the consensus that this rough startup is generally caused by the EGR system and intake getting obstructed? I haven't pulled any codes, but the check engine light didn't come on (so I didn't think it set a code).

EDIT: I just read a few more pages back (I haven't looked into this thread in quite some time), but I am aware of the headgasket issues and catch can suggestions. I see that the TSB was obsoleted, but still curious whether a code can be present without the MIL being on.

Thanks!

 

I think that generally, yes, that is the consensus. It could also be bad spark plugs, coil packs, or anything else that could cause a misfire, but in a lot of cases it appears to be the gummed-up EGR system that causes this. 81K miles does seem very early for this to be happening, but maybe living in a colder climate causes the issue to appear earlier.

As far as the presence of a code before the check engine light goes on, I have heard that the car will log a few misfires to establish a timeline of events before it throws an actual code, but I don't have any evidence to back this up.

 

Thanks for the feedback. I will keep an eye (ear) out for a repeat of the rough startup when I head home from work tonight. Current temperature outside is now 3 degrees F, but at least it's sunny.

 

Rough start up happened to me today as well. Loud heavy knocking with incomplete combustion fumes out the exhaust for a few minuets. No CEL.This was the first time ever. 2010 w/ 107K miles. New plugs, PCV valve, oil and filter new at 105K. Original intake, EGR valve and cooler. 9 degrees displayed on the dash. Two days prior, I started it to move it 50 feet then turned it off. It ran fine then. Ugh.

 

If I have to move 50 feet, I would do it in two or three bursts, keeping "ready" times to around 10 seconds max, to avoid engine starting.

 

It seems like that's what I need to do in the future. Thanks Mendel Leisk! I've never experienced this before. I'm guessing the short run cycle and the cold ambient tempurature can have something to do with the knock.

 

The alternative is to push the EV mode button, but I've NEVER seen that available in cold weather, cold starting.

 

I agree, it always says it is unavailable.

 

might depend on temp and battery level.

 

I should add that I think my car knows that I have been considering trading in on something newer, and this is why it is acting up. This doesn't really help with its current situation!