Multi-causal rough idle and no power, Yaris 2004 - Toyota Yaris Forums

Dan789 · 05-11-2024, 07:41 AM

Hello all. Grateful for any advice here. First I should point out I’m not mechanically minded at all, the last time I repaired a car was in the late 90s when I changed a fuel pump on a 1979 polo!
I have Yaris Verso 1.3 petrol auto 2004.
Recently we got rough and unsteady low idle, occasional loss of power. Last weekend I cleaned the throttle body and the MAF sensor, couldn’t check plugs as did not have the correct size tool.
Thursday I noticed water sitting on top of the engine block around the top of the coil packs. I was going to drive it to get rid of it before taking off coil packs, but had zero power in gear. Could rev fine in neutral.
Today I removed plug in leftmost cylinder (1?) and there’s oil on the plug, plus the middle, top-side, looked a bit rusty. Looking into the plug well it looks like oil, plus it looks kind of grubby. All other plug wells are clean.
I tightened the bolts on the gasket cover (? The top of the engine block, I thought they might be loose causing oil leak into plug well).
I cleaned the spark plug and wiped the end of the coil pack, refitted and started. Idle fine, power restored when driving. I’ve only driven in the driveway, as I have no idea how long it will be ok for.

So, my questions are: what’s with the water sitting on top of engine block and could some of it have seeped into the plug well? If so how should I clean it all out?

For the oil on plug should I wait to see if tightening the bolts fixes it or do I need a new gasket seal?

Long post I know, trying to get as much detail as possible in.

05-11-2024, 07:41 AM	#1
Dan789 Drives: Yaris verso 2004 Join Date: May 2024 Location: Uk Posts: 4	Multi-causal rough idle and no power, Yaris 2004 Hello all. Grateful for any advice here. First I should point out I’m not mechanically minded at all, the last time I repaired a car was in the late 90s when I changed a fuel pump on a 1979 polo! I have Yaris Verso 1.3 petrol auto 2004. Recently we got rough and unsteady low idle, occasional loss of power. Last weekend I cleaned the throttle body and the MAF sensor, couldn’t check plugs as did not have the correct size tool. Thursday I noticed water sitting on top of the engine block around the top of the coil packs. I was going to drive it to get rid of it before taking off coil packs, but had zero power in gear. Could rev fine in neutral. Today I removed plug in leftmost cylinder (1?) and there’s oil on the plug, plus the middle, top-side, looked a bit rusty. Looking into the plug well it looks like oil, plus it looks kind of grubby. All other plug wells are clean. I tightened the bolts on the gasket cover (? The top of the engine block, I thought they might be loose causing oil leak into plug well). I cleaned the spark plug and wiped the end of the coil pack, refitted and started. Idle fine, power restored when driving. I’ve only driven in the driveway, as I have no idea how long it will be ok for. So, my questions are: what’s with the water sitting on top of engine block and could some of it have seeped into the plug well? If so how should I clean it all out? For the oil on plug should I wait to see if tightening the bolts fixes it or do I need a new gasket seal? Long post I know, trying to get as much detail as possible in.