TRC, VSC and engine check + cracks in ignition coils

[Seb_90]

Hi all,

 

I'm new here.

Since yesterday mornig my Avensis t25 1.8l 2005 came up with following symptoms:

• TRC, VSC and engine check on the panel
• The car sounds like a diesel engine (misfire?) and there is a smell of petrol in the engine bay

 

Later my mate came around to read out the error messages, as follows:

• P0303 - issue 3rd cylinder 
• C0371 - yaw rate sensor
• C1201 - engine control malfunction
• C1231 - low Battery positive voltage

After reading this forum and other sources online I understand the issue is with the ignition coil pack which causes misfire and smell of petrol? But would it lead to the TRC and VSC lights coming up on the panel? Or do I need to get a new yaw rate sensor too to fix that?

Today I had quick look on the ignition coils I've got currently fitted to find out the part number. So I've removed one and it had a massive crack in it! So I've removed all of them to double check and 3 out of 4 had cracks and only the last one was OK (but fixing was actually loose). Also third coil (counting from the left side of the engine when facing it) had a bit of oil around it and around the spark plug itself.

Any idea what would have caused these cracks? Please see pictures below.

I've ordered new spark plugs and 2 used original toyota ignition coils and will fit them on the weekend.

 

 

 

[Red_Corolla]

I would go after the misfire first before worrying too much about the other codes. Often with engine faults, other systems are automatically disabled and this can cause other codes to set when there's nothing actually wrong except the engine fault. Fix the misfire and then see if your VSC faults are still coming back.

I don't know why the coil casings are cracked. Could be age related or maybe they've been stressed due to worn out plugs. But I would replace all 3 bad ones. You don't want to be running the car with a misfire for very long, because the result will be a destroyed catalytic converter - that's when things get expensive.

[Seb_90]

Quick update:

Changed all spark plugs and two out of three cracked ignition coils and the car runs better than before.

 

VSC and TRC lights went off too.

[Konrad C]

11 hours ago, Seb_90 said:

Quick update:

Changed all spark plugs and two out of three cracked ignition coils and the car runs better than before.

 

VSC and TRC lights went off too.

If you could afford it, and unless the other coils have been replaced previously, I would replace all the coils! Anyway, glad you have sorted the problem.

[Seb_90]

13 hours ago, Konrad C said:

If you could afford it, and unless the other coils have been replaced previously, I would replace all the coils! Anyway, glad you have sorted the problem.

Yes I'm planning to replace the other cracked one and buy another one as a spare, just keeping my eye on eBay to get a good deal. Thanks for an advice. 

[PabloVL]

Hi, I have had exactly the same problem with TRCOFF, VSC and engine alarm. One year ago I had the same symtoms and I replaced the plugs and one of the coils. I guess this time can be another coil, What is consistent is that both problems appeared after leaving the car outside, with warm wheather and very sunny (about 38C).

I guess it can be a design problem around thermal expansion. If any other can give details about this it can be helpful for others.

[Seb_90]

I doubt it it's a design problem tbh. 1zz-fe engines are in Avensis mk1 are still driving around in some countries in Africa in different heat than UK.

I pushed my car around Nuerburgring and it didn't have any issues. THe same engine is used in MR2 which is a bit sportier than our Avensis model but ignition coils is not a common fail as far as I am aware.

In my case I think it was just a combination of multiple things: old spark plugs, old ignition coild, old cooling fluid and an old radiator.