Engine temperature

[IPAddis]

I know we've covered engine temperature to death (90 in traffic, 80 when cruising, 70 on a cold motorway) but has anyone else noticed the engine temperature becoming seperated from the otter switch in the recent cold snap?

On the way into work this morning while stuck in as much traffic as I could find (for test purposes), the temperature struggled to climb above 70. That's fine as it was very cold outside and there wasn't a lot of traffic. However the fans were switching on at 72 and switching off at 65.

Is it possible that the exhaust heats up the swirl tank (and hence the otter switch) but the engine is large enough to soak heat away from the temperature sender? Does anyone have the swirl tank heat shield (around the nearside exhaust) as shown in the bible?

Both otter switch and temperature sender have been replaced in the last 6 months and work OK when the temperature is more reasonable.

I know someone is going to say "If it ain't broke..." but it is broke as if it drops below 70 then the ECU will increase fuel and if it never gets to 90 then the ECU won't adjust the fuel map.

What's the best way to check the temperature sender and otter switch without removing them (as the temperature sender appears to be a pain in the arse to remove)? Are the infrared heat sensing meter things (as used by Mr. Heath) accurate?

Regards,

Ian A.

[david beer]

I would think it sounds like the temp sender. Mine did exactly that. If you are a serp you can use the spare one on top of the head, near the ecu temp sender. Of course i could be completely wrong!

[IPAddis]

I thought so but I've had 3 temperature senders now and they all do the same in cold weather. It was fine today when the weather was a bit warmer (green ice detector instead of red). Fans in at 85, out at 75.

It just seems that in cold weather, the otter switch heats up quicker than the engine block.

david beer said: I would think it sounds like the temp sender. Mine did exactly that. If you are a serp you can use the spare one on top of the head, near the ecu temp sender. Of course i could be completely wrong!

>> Edited by IPAddis on Friday 7th February 09:01

[shpub]

In cold weather the top of the engine does get cooled by air flow and this can create temp differences like what you are seeing....Block off the air flow through the rad and normality will return. Alternatively wait for spring.

Steve

[IPAddis]

shpub said: In cold weather the top of the engine does get cooled by air flow and this can create temp differences like what you are seeing....Block off the air flow through the rad and normality will return. Alternatively wait for spring.

Steve

Thanks Steve, I'll stop worrying about it as it only seems to happen on unusually cold days. I am going to swap my low-temperature otter switch for a normal one though as the car never gets a chance to reach 90deg for ECU adjustment.

Ian A.

[schueymcfee]

I had the same problem when I came home for Christmas, even though the car was sat in the garage ticking over, the fans kicked in at about 80c.

Sadly couldn't go for a blast without MOT, insurance etc.

Ah well, role on July!