Page 1 of 1

Diesel cat temp

Posted: Sun Jun 11, 2017 7:44 pm
by Upex
Hit the cat with the infrared temp gun today, and after a 10/min drive, the entry to cat was 125 degree ish, and the exit of cat was 95 ish.

I thought the exit of the cat should be hotter? Or had I not driven enough to get proper result?

Didn't rattle when hit with rubber hammer mind....

Re: Diesel cat temp

Posted: Sun Jun 11, 2017 8:55 pm
by Horizon
[quote="Upex"]
Hit the cat with the infrared temp gun today, and after a 10/min drive, the entry to cat was 125 degree ish, and the exit of cat was 95 ish.

I thought the exit of the cat should be hotter? Or had I not driven enough to get proper result?

Didn't rattle when hit with rubber hammer mind....
[/quote]

The cat starts to work at between 400 - 600 degs F !!!! According to this article,
http://www.aa1car.com/library/converter.htm

I know this may sound silly, but have you tried resetting the throttle body adaptations, I believe they can restrict how much the throttle opens, maybe they have gone potty.

Re: Diesel cat temp

Posted: Sun Jun 11, 2017 9:04 pm
by Upex
Nope, but will see if can figure out how yo do it and give it a whirl, anything hot yo be worth a shot lol, I'd try sacrificial rituals at this point  >:D

Re: Diesel cat temp

Posted: Sun Jun 11, 2017 9:20 pm
by X5Sport
Are you sure the temp gun is working?  I can't see the engine running properly (even badly) that low and your temp gauge would be well down too.  That being said, diesel flash ignites at just under 100°C, but it's autoignition temp is >250°C - hence the temps you are seeing looking very low and the weather is far from cold at present.

Probably worth checking the gun's calibration against something you know is right - like a boiling kettle?  Then step up to an oven with the door open once the stat turns the element off.

Re: Diesel cat temp

Posted: Mon Jun 12, 2017 6:14 am
by Upex
Good shout, will give that a whirl, as is a cheapo one, although scanning surrounds seemed on par with temps yesterday.

Car does need new stat, is running at circa 75 rather 90 ish, but as you say, does seem touch cool thinking how hot exhaust headers get etc.

She one cool cat, ha ha