2003 Daihatsu Sirion • 52,000 miles

I was looking for some help with my car 2003 Daihatsu Sirion ( a Toyota) and wanted to ask you a specific question - I've described the problem below and was hoping if you could help me:
I had valve noise ( I could hear it from the top, as well as it slowly disappeared when the car was getting warm) and I decided to change the oil because I thought it was getting too tick (no idea what was the original oil, but I drove the car for at least a year and a half without any problems, going through the previous winter but this winter, the moment it started getting cold the valves started knocking).
However, after I changed the oil on my Daihatsu Sirion ( a Toyota) with a new fully synthetic 0W-40 (Mobile) the problem was still there. And it seemed as the problem was to a lesser extent (like the oil was getting up faster at the beginning). But when I left the car in the garage without driving for 2 days and afterwords I tried to start it, it was a mess: everything shaking, hard to start, valves clunking like never before and etc- which was probably due to the oil being down and it took a minute until it calmed down a bit, but the noise was still even worse than before. Again I let it warm up for 20-30 minutes, and it was ok I guess.
The engine on that Daihatsu is a small 1.0L DOHC and I thought that thinner oil would be better for the winter. Do you think a thicker oil would help (the old oil was thick, but still could hear the valves knocking and it wasn't doing that the previous winter). Can't figure out what to do exactly and how to troubleshoot.
Any help would be appreciated.



Great site!
December 12, 2011.

Do an engine flush, change to 5W-20 and check oil pressure-

Dec 12, 2011.
I believe your engine is chain driven and it could be the chain causing the noise. The valves are not hydraulics therefore they should not be the ones cauing the noise as it tapers off after warming up.

If there is too much sludge in the lubrication system, an engine flush would help but a singular flush might not be sufficient.

Dec 12, 2011.
There wasn't any sludge in the engine, the car is year 2003-2004 with only 47,000 miles on it. I also checked the oil for metal pieces, but there was nothing and it looked like good used up oil and smelled ok. (I've driven the car only 5-6,000 miles in a year and a half, thus it's not like it wasn't maintained). I don't think I need an engine flush for sure. The new oil has it's new color and didn't turn dark brown or black as it would if there was sludge. Why would I change to 5W-20: the 0W has better winter viscosity and the -20 is for the operational temperature, which in this case is ok, because the car doesn't have the noise when completely warmed up? Please explain? Oil pressure light is not on- it was on in the morning after the 2nd day when I tried to start it, but only for 4-5 seconds until it raised the oil, then it turned off. I don't have a manual oil pressure gauge to check the exact pressure, but I trust the light/sensor.

By the way, the engine is NOT chain driven, it's a belt, so there's no way the noise is from a chain. I can hear that it's from the valves for sure! Need experts, please help!

What is the engine code?

Dec 13, 2011.
Engine code is EJ-VE - 3 cylinder, 4 stroke, 69kg.

This ia a twin cam belt driven engine which uses shims for valve adjustment.

There are a few possible causes for rattling noises and without thorough checking, it is not possible to determine what is causing it.

1. Lighter oil would transmit noise easier so rattling not would be amplified.

2. When engine is started from cold, the cold start system would increase the engine speed thereby increasing the noise and decreases as the engine speed drops when it warms up.

3. Oil filter quality affects cold starts lubrications.

4. Slack in timing belt tension can increase valve train noises. Check the belt tension.

5. Wear in in the valve trains can cause the noise. Have the valve clearances checked.

6. DVVT solenoid valve sticking. I do not know if your engine is equipped with this feature, if yes, it can cause the noise if the solenoid is not working correctly.

Dec 14, 2011.
Thanks, 3, 4 or 5 seem like they should be checked; I don't think it's 6, the DVVT is working properly, and normally it would throw some codes, which is currently not the case. Will start troubleshooting.

VVT solenoid might not throw codes if it sticks.

Dec 15, 2011.