Avensis Engine Temp / Idle Revs Question

March 16, 2008

Hello

I'd be grateful if anyone can shed some light on a little issue I have with my Avensis 1.8 (T Reg - so I guess one of the early models), which has done about 77K miles. Regular dealer services.

Recently noticed small pools of water(?) below the engine compartment. Checked the coolant expansion when engine was cold. Tank showed coolant a little above min, so topped up to half way with more coolant. (Nothing irregular was observed inside the car, eg heating, engine temp guage, idle speed etc - all seemed normal.)

Following day, checked cold coolant level. Had gone down a little. Noticed small pool again below engine compartment. So I ran my hand over the hoses to see if there was any dampness. None found. The took off O/S front wheel and cover below engine. Noticed that there was a very slowly seepage from dipstick holder (don't know technical term for this), Wiped with tissue. More fluid seeped. Wiped again. The tissue suggested that whatever I wiped wasn't oil - not dark or oily.

Took it to a local mechanic who could took off rad cap, inserted some device into the radiator, and pumped it. He said there was no obvious leak because the pressure he put via radiator would have squirted coolant from whereever the integrity was compromised. He suggested that the only thing near where I could see the seepage is the water pump, which after 77K mile might well need replacing.

So got a few quotes and had the water pump replaced (plus timing and oil service as well). The mechanic told me to check coolant level next day and top up to half way with water. Level was just above min next day, so topped up to mid point.

Now, a week on, I don't see any pools under the engine compartment and the cold coolant level remains at mid point of expansion tank. So I think I did the right thing in getting the water pump replaced.

However, I have noticed that when I start the car from cold, the idle speed is nearly 2K. After driving for about 5 mins, the temp guage slowly start to raise. After 20 mins driving, idle revs at 1 - 1.2K, temp guage about 1/3 from cold marker.

Another 15 mins driving, idle gets to about 800 rpm and temp guage a fraction below half way. This idle speed and temp guage state is what I normally expect within 10 mins of driving.

If I put the blower on, on the max heat setting, I get plenty of hot air. But I then notice that the temp guage dips a little, and the idle speed goes up to just uder 1K rpm.

Any ideas what could cause this long time to get to 'norm' and how it could be rectified.

Also, if left, could it affect emissions for MOT? I'm thinking, if the engine management system (I think most modern cars have this) thinks 'norm' temp has not been attained (hence the lower temp indicator, higher idle revs), does it keep the fuel mixture richer than needed?

Any thoughts greatly appreciated.