March 2024

Toyota Corolla Start-up rattle fix

My Toyota Corolla 2010 started to make a strange rattle sound at cold start. It's a common problem and on youtube you can find many Toyota Corolla owners describing this problem. Toyota itself claims that this might be due to a problem with the VVT (variable valve timing) cam-gear and the fix would be to replace this part. I am not really sure that this true or that there is just a single cause for this start-up rattle. My theory is that the fault on my car was due to the chain hitting the case and rattling for a second at startup. In any case I don't know the exact mechanical cause but I know the symptoms and I know that it was possible to fix this at a cost of 10$ without visiting a Toyota garage.

a view of the corolla vvt gear with chain and camshaft. I never opened my engine. This is a picture from another car and you can see that there is a chain driving the camshaft.

The symptoms of the start-up rattle:

It was more likely to happen during the winter than during the summer. During the summer I would hear this rattle sound maybe once a month while on cold winter days it would appear at least at every second start-up of the cold engine.
It's a very short rattle sound. It sounds like a loose chain hitting a metal housing.
I have recorded the rattle sound and you can listen to it here: toyota-corolla-2010-start-up-rattle-sound.mp3. You can also compare this to a normal start-up without the rattle sound: toyota-corolla-2010-normal-start-up-sound.mp3
The problem started when the car had a milage of about 90000 km. I drove around with this problem for 3 years until I was able to fix this with an oil additive. I had also contacted a toyota garage to get their opinion. They thought that it was an urgent problem but I never bought into this because it happens only for a very short time at cold start.

In other words my problem was maybe related to the viscosity of the oil and/or sludge and gum deposits on the chain or the chain tensioner. I fixed it by adding a bottle of "Rislone Engine Treatment" (part number 34102) to the oil. This might have improved the oil flow and disolved some deposits. I added it after a fresh engine oil change and at that point the oil level was already at max. So adding one bottle of this Engine Treatment liquid resulted in slightly too much oil volume. The rattle disappeared after I had driven about 30km over 3 days (the last rattle was on the 3rd day after adding Rislone and it has not come back since). I added the "Rislone Engine Treatment" during the winter months when I would normally observe this start-up rattle problem very frequently. I have now driven for more than a month without ever hearing the start-up rattle and I am faily confident that the problem is resloved.

corolla: add Rislone Engine Treatment to fix start-up rattle problem

Rislone Engine Treatment bottle front and back, part number: 34102

I will leave the Rislone Engine Treatment in the engine for few more weeks and then I will do an oil change around mid March (at that point I will have driven about 350km with Rislone Engine Treatment in the oil). After the oil change I will not add anything back because I believe that this Rislone Engine Treatment has actually disolved some deposits somewhere and it should be a permanent fix to the problem. If it does not work out as planed and the rattle comes ever back then I would update this article and let you know.

Update, 2025-03-01

After the oil change at the end March of last year (2024) I did not add any Rislone Engine Treatment and there was not a single rattle during the entire spring and summer. I was very hopeful that the issue was fixed. Unfortunately it came back in early winter as the temperatures started to go down. I added the Rislone stuff immediately. The rattle continued during the winter month but it was happening only occasionally (a few times per month, much better than last year). I would still recommend this treatment as it is an improvement. I will keep updating this article.

Update, 2025-05-17

In the past I did all oil changes at an official Toyota garage and they did always charge me for oil and oil filter. Two weeks ago I decided to do the oil change myself: The Toyota Corolla has a plastic oil filter housing. The recommenced torque to close and tighten the filter is 25 Nm. This is very little and it should feel like "just hand tightened". I had extreme difficulties to loosen the oil filter. I had to use a breaker bar extension and I broke one oil filter housing remover wrench. It was incredibly tight and I started to wonder how the mechanic in the garage would be able to loosen the filter. Finally a banged on the filter housing with a wooden stick and a hammer (I held a short wooden stick to the oil filter housing and then banged with the hammer on the stick. The wood dampens the impact a bit preventing damage at the point of impact.). This hammering causes the thread to vibrate and loosen. After the "bang treatment" I was able to unscrew the oil filter with a big socket and the breaker bar. A totally dirty oil filter came out! I can't proof this but I have the feeling that the garage charged me the last few times for the filter change but did not actually do it. They changed just the oil because they were not able to get the filter out. A clogged oil filter may be part of this start-up rattle problem. I did not add Rislone Engine Treatment after the oil change and so far so good (but it is also getting warmer. We have to wait until November/December 2025 to really know what the status is).

Parts used:
- Oil filter: FRAM extra guard CH10358
- Mobile-1 0W20 oil (oil volume: 4.2L = 4.4 Quarts = 1.1 US Gallon).
Tools used:
- Oil Filter Housing Remover Tool: 14 flutes, 64.5mm diameter (I needed two of those, one broke)
- 14mm socket for the oil drain screw
- 27mm socket (fits filter housing remover tool) and breaker bar
- Hammer and a short piece of wood (as a replacment for a rubber mallet)
- 5L pan + two small trays/pans (one for the old oil filter and one to set down the oil filter houseing and drain plug screw)
- Funnel

A supposedly higher quality oil filter for this toyota corolla is the "Mobil-1 Extended Performance Oil Filter, M1C-154A". I might try that filter at the next oil change.

corolla: unscrew a very tight oil filter

unscrewing a very tight oil filter, toyota corolla

Banging with a mallet or a piece of wood and a hammer onto the oil filter housing loosens the thread. No oil filter should be stuck such that this is needed but in practice there are a lot of "professionals" out there who have no idea that the oil filter must only be tightened to 25Nm. If you use this "bang treatment" on a stuck oil filter housing before trying to unscrew it then you will need much less torque to unscrew it and you might not need two remover tools to get the filter out.

The engine oil filter is located after the oil pump. The pump pulls oil from the oil pan and then pressurizes it before it passes through the filter. The dirty oil arrives at the filter on the outside and the filtered oil comes from the center of the oil filter. Dirt particles deposit on the outside of the filter.

References

SDS, Safety Data Sheet, Rislone Engine Treatment, It does not specify the exact composition. It's basically some kind of mineral oil. I can't really say that there is a significant difference between Rislone Engine Treatment and motor oil when I put a bit between fingers to test the viscosity. Rislone Engine Treatment might be a little thinner than normal oil but it's hard to tell. It smells different.