Engine rattle sound

[Hamza99]

I have a 2001 corolla and when starting up it sounds like a diesel. This sound carries on for about 20 minutes then goes away. The noise is coming from the engine manifold. Any ideas as to what it might be??

[FROSTYBALLS]

Moved to the Corolla club

[oldcodger]

Hi,

Which size engine do you have  ?

When you say manifold do you mean inlet or exhaust ?

Could be a few things,  valve clearances out, but improve when fully warmed  up.

Oil /pressure poor ?    oil and filter changes up to date ? have you tried some Wynns engine flush or similar just before an oil change in case the oil ways are gummed up ?

Could be a leak or broken manifold on either.

Does your model have timing chain, could be wear, rattling when cold ?

Some have experienced a rattle from a broken baffle in the inlet manifold but  think that make a noise all of the time, yours sound like a cold running problem.

[Hamza99]

Hi

It is a 1.4 vvti petrol. The sound comes from the inlet manifold. It's just been serviced recently. Not sure if it has a belt or chain. 

[oldcodger]

Hi,

Think your 1.4 is the same as mine a Chain drive.

Hard to say what the noise is,  have you removed the engines upper  plastic  top cover so you can see the inlet manifold fully  and watch it from a cold start to lookf you can see anything amiss  ?

if you have a really big , long screwdriver you could use it as a car stethoscope and see if you can locate the noise that way, but be wary of the fan/aux belt and the ht leads etc !

It might be something like a loose nut , bolt, sensor ,actuator/flap etc, so impossible to say without being there,  its not a known common problem.

Thinks like the alternator or water pump could make such noises too.

Have you had the car long ?  when did the noise start  or was it there when you got it ?

[DeTomato]

Sounds like not enough Oil is getting to the top half of the engine. Is the Oil topped up? If not, put some 5W/30 in it to see if the noise improves. Also worth changing the Oil filter if you haven't done so. And this will mean new Oil if you haven't changed it in a while also. As above though, there are many reasons for a car sounding like a diesel on warming up.