#2 and 4 cylinders show 600 degrees with infrared gun others 300 deg

[turbota440]

This is all at idle

Curious is it that these two cylinders are so close to the turbo and are showing a collective heat or do I possibly have two bad injectors. Anyone else see this? All other header ports right at the head show around 300 deg. Down pipe is around 400 deg

Idle also smells rich even though I've use the Gen 2 to bring down the low load scale by 10%.

 

[turbota440]

Also of note the crossover pipe under the car is just over 300 deg.

 

[NY Twin Turbo]

Not an accurate test of egt in my opinion.

 

[Rugby]

What I found in doing the same thing to my car was that the temp veriers depending on what part of the exhaust you are on. The pipe, bolt, and flange all measured different for the same cylinder.

 

[NY Twin Turbo]

Unless something is very very very bad, it will tell you nothing.
You need an egt probe in each primary and they should all be equal distance from the flange and the tips should all be centered in the exhaust stream and they should all have their tips turned in the same direction. Then you may get close.

 

[turbota440]

Car runs well after the rebuild. Just did it out of curiosity. Yeah the log just below 2 and 4 exhaust where it has the factory heat flex ribbing just before the turbo flange is also at 600 deg when I just checked it. Collector on driver side just before the crossover pipe is also at around high 500 temp. So I guess it's a no tell. Tomorrow I'll pull the plugs and look. Engine has 125 mi so far and pulls hard.
Thanks for your input guys.

 

[Chuck Leeper]

Reading plugs that are @ 125mi, and have had a break in done on them, is pretty much a crap shoot.
{Unless you find a drastic issue, like oil.}
A fresh set, a WOT blast, read them....
A good read:
http://www.wallaceracing.com/plug-reading-lm.html

 

[Nick Micale]

You should not have 300 degrees difference with a heat gun as I use mine often in troubleshooting engine issues.

Like Chuck said, check and replace the 2 plugs first.

As far as checking the injectors, you can use a finger touching them to see if they are working/clicking, and be sure the electrical connector is firmly on the injectors. Also check the pins on the injector harness for good contact.

I have also seen a worn out, old injector harness have frayed wires to some injectors causing intermittent operation of an injector?

If none of this works, swap the injectors to different cylinders.

 

[cruzn57]

if your checking at idle, don't expect the numbers to be similar on each pipe.
bring the rpm up 2000-3000 and try it, see if they get closer to the same number.
using infared heat gun , is alot better than nothing, and IS a useful tool ,
as Nick said, ck injectors, and swap them , to see if it changes,

 

[turbota440]

if your checking at idle, don't expect the numbers to be similar on each pipe.
bring the rpm up 2000-3000 and try it, see if they get closer to the same number.
using infared heat gun , is alot better than nothing, and IS a useful tool ,
as Nick said, ck injectors, and swap them , to see if it changes,

You should not have 300 degrees difference with a heat gun as I use mine often in troubleshooting engine issues.

Like Chuck said, check and replace the 2 plugs first.

As far as checking the injectors, you can use a finger touching them to see if they are working/clicking, and be sure the electrical connector is firmly on the injectors. Also check the pins on the injector harness for good contact.

I have also seen a worn out, old injector harness have frayed wires to some injectors causing intermittent operation of an injector?

If none of this works, swap the injectors to different cylinders.

Thanks Nick. Yeah I was going to do the swap of the two injectors. All the injectors are clicking. Used a stethoscope device. Complete harness and injector harness was replaced a little while ago. If anything maybe the two injectors aren't flowing correctly. They are the 60 lb Motrons. Not a lot of miles.
At idle it seems the temps are higher where the pipes converge from individual ports. The hottest spot was where the factory header has those heat expansion ribs. Like 700 deg.
This might be all moot as it's just the way the exhaust merges and the free flow. At the very collector on driver side it's 580 deg and in the middle of crossover it drop to 340 deg. Varies all over but really goes up at just before the turbo.

 

[turbota440]

if your checking at idle, don't expect the numbers to be similar on each pipe.
bring the rpm up 2000-3000 and try it, see if they get closer to the same number.
using infared heat gun , is alot better than nothing, and IS a useful tool ,
as Nick said, ck injectors, and swap them , to see if it changes,

Good idea. I will try that.

 

[Nick Micale]

[QUOTE="turbota440, post: 3587920, member: 23473".....The hottest spot was where the factory header has those heat expansion ribs. Like 700 deg.

This might be all moot as it's just the way the exhaust merges and the free flow. At the very collector on driver side it's 580 deg and in the middle of crossover it drop to 340 deg. Varies all over but really goes up at just before the turbo.[/QUOTE]

I agree, this may not be an issue?

When taking an EGT reading with a heat gun or probe it should be less than 1/2" from the header flange on each cylinder. It may take 2 or more times from a cold start to get enough valid data to determine if there is an issue or not.

If the engine is at operating temp the exhaust temp will probably be over 500 deg. at the same place on the header for each cylinder which is where I focus with the temp gun.

Still other variables come into play such as it may be 110 deg. day [Probably only here!], or a 60-70 deg. day which will vary readings greatly, or how much heat soak in the engine?

As the exhaust gas travels out of the header, the temp decreases, but since the exhaust gas from all 6 cylinders merges at the turbo exhaust inlet, this collector would be a hot spot and 700 deg. would not be unusual.

I do like your comment about the crossover being only 300 deg. which is the reason the TA race headers were designed with the shortest route [pipe] to get as much heat energy to the turbo as possible!