Random 3SGTE idle

[Boosted_162]

Well i have a dodgy idle in the MR2 (gen 3 turbo). When hot, it mostly idles at 500rpm, and the cold idle is the normal hot idle (900ish) and with ac on, it also sits at about 900rpm. And sometimes when i come up to lights, it stalls. Now its all standard, apart from a boost gauge (it still idles low with it disconnected, it didnt stall but i didnt drive it much)

Now the car drives perfect. Pulls hard like any gen 3 turbo should! What should i be looking for? Vacuum leak? I can hear a bit of air rushing, but im not sure if its normal, just air going into the motor? Or do i just need to put the idle up a bit? If so how would i do this?

Thanks

[Boosted_162]

Anyone??

I disconnected the boost gauge, but makes no difference.

[fivebob]

Vacuum leak would make it idle higher, not lower. First step would be to check your ignition timing at idle.

[Boosted_162]

Alright, will do

Thanks fivebob

[Adamal]

I'd imagine that 500RPM is a bit low? You'd want about 700RPM, wouldn't you?

[Boosted_162]

Yeah its definately not a smooth idle! Sometimes its even lower, around 400 which is pretty much stalling. And it stalls sometimes at lights

[Akane]

When cold it should idle at 1300~1500rpm, and warm just sitting around 750~900rpm, sounds like your idle band have shifted downwards.

Why don't you try turning the idle up a notch and bring the idle band back up?

[Boosted_162]

I tried that yesterday, but it doesnt happen all the time so it will idle fine, then real low. Set it up a bit and it will idle high, and then normal. Plus theres some real suspect noises coming from the motor . So until i figure out what the hell is wrong, its off the road heres hoping its just a shield rattling...

[fivebob]

So until i figure out what the hell is wrong, its off the road heres hoping its just a shield rattling...

Do a compression test, sounds like you could have broken ring lands.

[Boosted_162]

Luckily it was only the turbo sheild, i was worried the bottom end was on its way out. Im gunna do a compression test anyway just to check the condition of the motor

Idle problem is still there tho, ill get hold of a timing light.

[Boosted_162]

Alright.. seems the noise hasnt gone. Its just much louder when the car is warm (cos oil is thinner?) and by the sounds of it, it increases with revs. The bearings havent spun as its definately not knocking, but i suspect it COULD be the bearings starting to go. This does not sound like a heat shield now does it? The manifold one is not on at the moment.

How can i find if the bearings are going? Checking oil pressures? (i remember an engine builder telling me that oil pressure gets real low when bearings are gone).

Looks like i need to find a compression tester as well

[Akane]

Here's your membership card, welcome to the club

[Boosted_162]

I got a soundclip of it today. You can hear the noise clearly. It is definately NOT that loud, its quieter than the engine note. Plus that was cold, usually hear it more while hot.

http://s186.photobucket.com/albums/x281 ... CF0087.flv