407 Es9 V6 battery recharge issues with auto / engine

[407]

I had a interesting experience with the ES9 this week, it being the daily commuter.

I had left it parked a week and went to start it and nada - battery was 9 volts. Sort of expected that as I did a lot of short trips the week before.

So pulled the battery out, recharged it overnight and refitted but did not start it until the following day.

On starting, all hell broke loose with dash warning signs, engine running rough / reving weirdly and the dreaded auto triangle of death appeared on the screen plus "Engine repair need" as a helpful after thought suggestion.

It would not rev over 1800 rpm and whilst it would drive, would only run at 20 km p/h.

I drove it into my driveway and then noticed smoke coming out of the engine, so turn off and disconnected the battery.

When I popped the hood, the smoke was coming for the back of the engine and smelt like auto transmisson fluid and not electrical.

Anyway, left it for the night and in the morning put Diag onto it see what the damage was.

Diag had the normal suspects re the engine but otherwise was clean - no auto transmisson codes at all. Tried all the actuator tests and they seemed to be okay

So I started it and it started fine - drove it and it drove fine. No MIL light, no triange of death , no weird engine reving

I suspect a few things happened

a) BSi did not shut down properly due to low battery (I've pulled the battery a few times before without any problems)
b) original low battery voltage somehow caused the auto trans torque converter to slip hence the low speed
c) not sure about the smoke but maybe related to torque converter slipping ?

Any thoughts in case it happens again ?

[MattBLancs]

Very odd!

You do see odd faults after a low battery voltage on occasion - essentially the low voltage generates odd responses when the ECU is communicating with the various sensors. Clear them and see if return (with a healthy battery) is usually the next step.

Torque converter slips in normal operation, but has a lock up clutch (effectively "bypasses" the torque converter) this shouldn't engage unless at higher, steady speeds generally. If that clutch were not to lock up would just be torque converter as usual. If that clutch were to spuriously engage then would expect car to set off on its own! Or guess rough change from neutral to drive without the "damping effect" of the torque converter. On the back of the above hypothesis then I'd say not to worry about torque converter clutch operation...

However, the source of your smoke is very much a mystery! Wondering if just a case of coincidental timing but two separate faults to be honest.

[xantia_v6]

Smoke from behind an es9 engine is almost certainly oil weeping from a cam cover, a common issue, particularly if the car has been left sitting for a while and oil has accumulated on the exhaust manifold.

I would recommend that you take the plunge and reseal the cam covers, as, if it gets worse, you could easily have an engine fire.

[407]

So a few weeks later no repeat of issues (eg same battery, still left cold a few days) and no smoke either.

I did do the cam covers but the rear one does still leak a little, but at the time the engine was pretty cold (only just started). It also did not smell like oil smoke

Anyways, did an auto transmission oil change just in case. Oil seems a bit dirty but that was after 20,000kms