V8V temp sensor

[mysteron35]

I recently changed my 4.3 manual vantage for a 4.7 sportshift. I've only had the sportshift for a few weeks and wasn't really sure I'd like it after years of manual cars, but it's great and I'm really enjoying it.

I've only covered a few hundred miles so far and was beginning to get the gear changes really smooth until a few days ago when I noticed the air con seemed to be getting a bit cold, at this point I realised the ambient air temp was far too high and a bit erratic. I guessed the under bonnet sensor had failed and as the cars under warranty not a problem, I switched off the air con and carried on. After a while the gear changes were getting harsher and on down shifts the auto blip had stopped or reduced so that the revs weren't matched resulting in some embarrassing jerky gear changes. I performed a few clutch re learns but it was still bad.

I did a bit of research and there was mention of the ambient temp sensor causing all sorts of issues including gear change quality but I couldn't think why that would be and there was no further explanation? I went out in the car tonight with my son and while on the move he switched the air con back on and instantly the gear change is back to normal leaving me a bit confused now! I've set it to manual and with a low blower setting so I don't freeze but can still change gear smoothly.

I posted this in case anyone has had the same experience in the past?

Steve.

[Divinatech]

mysteron35 said:

I recently changed my 4.3 manual vantage for a 4.7 sportshift. I've only had the sportshift for a few weeks and wasn't really sure I'd like it after years of manual cars, but it's great and I'm really enjoying it.

I've only covered a few hundred miles so far and was beginning to get the gear changes really smooth until a few days ago when I noticed the air con seemed to be getting a bit cold, at this point I realised the ambient air temp was far too high and a bit erratic. I guessed the under bonnet sensor had failed and as the cars under warranty not a problem, I switched off the air con and carried on. After a while the gear changes were getting harsher and on down shifts the auto blip had stopped or reduced so that the revs weren't matched resulting in some embarrassing jerky gear changes. I performed a few clutch re learns but it was still bad.

I did a bit of research and there was mention of the ambient temp sensor causing all sorts of issues including gear change quality but I couldn't think why that would be and there was no further explanation? I went out in the car tonight with my son and while on the move he switched the air con back on and instantly the gear change is back to normal leaving me a bit confused now! I've set it to manual and with a low blower setting so I don't freeze but can still change gear smoothly.

I posted this in case anyone has had the same experience in the past?

Steve.

Wouldn't make sense. The temp sensor for the aircon is in two parts. An air temp sensor and a light sensor. Those are both inside the car.
Ambient is outside.
If the aircon goes too cold, that would indicate the light sensor seeing strong sunshine or the inside air temp reading higher than normal temp. There shouldnt be any effect on climate control from an outside temp sensor surely?

[mysteron35]

You could be right, I'm not an expert on these cars but the first thing I noticed was the air con fan when in auto was ramping to full speed. After googling it others have had the same issue, and when I called the selling dealer (respected specialist) to report it they didn't question the air con and said they would replace the temp sensor?

More of a mystery for me is why the air con would have such an effect on the gear change, I can only guess the extra loading on the engine makes a difference to the auto blip?

Steve.

[Divinatech]

mysteron35 said:

You could be right, I'm not an expert on these cars but the first thing I noticed was the air con fan when in auto was ramping to full speed. After googling it others have had the same issue, and when I called the selling dealer (respected specialist) to report it they didn't question the air con and said they would replace the temp sensor?

More of a mystery for me is why the air con would have such an effect on the gear change, I can only guess the extra loading on the engine makes a difference to the auto blip?

Steve.

I wonder if outside temp sensor affects the ECU in conjunction with the MAF. Did it lose grunt too?

[mysteron35]

no there wasn't any loss of power, all was normal apart from the outside temp reading and the HVAC ramping up to full.

Steve.