Very low EGT's

[9DodgeFan]

Hi everyone, I'm a member of the Cummins Ram family as of December, 2021 (see personal page for more details on truck), and I'm quickly finding out there's a LOT more to diesels than what I thought I knew!
Anyway, I recently changed the air filter on my 2002 (replaced oiled Spectre with new of the same). I think it's a coincidence, but shortly after this I started noticing very low EGT readings (32*, apparently the lowest it will register) when decelerating and at idle; this did not happen previously, and EGT range seems the same otherwise. I'm thinking the probe/sensor could be going bad, but could this have anything to do with the air filter change? Any other ideas? Thanks in advance!

 

[Cummins12V98]

That is wayyy too low.

 

[NIsaacs]

If you have the mechanical gauge it could be the thermocouple or the gauge. If you have the amplifier type with a power source it is usually a bad ground. Plastic dash....

 

[9DodgeFan]

OK, so it sounds most likely to be a problem with the readings being inaccurate, rather than indicative of some other problem? I definitely will try to fix it, I guess I'm just wanting to rule out any other "big" possibilities! Thanks!

 

[Vaughn MacKenzie]

How is your truck's power? If it seems to be running normally then it's definitely something with your gauge (most likely the wiring or probe).

Regarding your air filter, I'm not familiar with Spectre but if it's anything like K&N I would throw that thing in the trash. The cheaper grade oiled air filters tend to not filter fine particles very well. Cummins even came out to specifically say not to use K&N filters. I would recommend a BHAF, can't beat paper for filtering performance.

 

[9DodgeFan]

How is your truck's power? If it seems to be running normally then it's definitely something with your gauge (most likely the wiring or probe).

Regarding your air filter, I'm not familiar with Spectre but if it's anything like K&N I would throw that thing in the trash. The cheaper grade oiled air filters tend to not filter fine particles very well. Cummins even came out to specifically say not to use K&N filters. I would recommend a BHAF, can't beat paper for filtering performance.

It seems to be running fine, good power from what I can tell. I figured it's probably an inaccurate reading in those particular situations, but being new to diesels, I wanted reassurance it wasn't likely to be caused by a different problem (especially since it seemed to happen right after changing the air filter - although I still don't see how that would have an effect on EGT).
From the threads I've read on here, it sounds like Spectre filters are basically the same as K&N (and possibly owned by the same company). It does seem like most people here don't like them, but then there are others who said they seem OK. I hadn't heard that about Cummins saying to avoid them though! The BHAF's seem to have a very good reputation on here. I've been looking around at pricing, guess I might as well go ahead and make the switch!
Thanks for your input!

 

[GAmes]

There is only one way to determine if your air filter is efficient. Oil analysis. BHAF is a generic term that covers every big paper filter out there. Some are good quality, others are not. I put out a challenge on another forum for someone to show an analysis with a silicon count under 6 using a BHAF, any brand. No one has posted one yet. My last analysis had a silicon count of 7. There were 32,719 miles on the oil. Back when I was wasting money by pouring good oil out every 5000-10,000 miles the silicon count was 2 or 3. Before you spend any money on a BHAF I suggest you see how good your current filter is.

 

[Signal73]

Bhaf=hot air intake. So many better choices out there that get cool, clean air from outside the engine bay.

 

[9DodgeFan]

There is only one way to determine if your air filter is efficient. Oil analysis. BHAF is a generic term that covers every big paper filter out there. Some are good quality, others are not. I put out a challenge on another forum for someone to show an analysis with a silicon count under 6 using a BHAF, any brand. No one has posted one yet. My last analysis had a silicon count of 7. There were 32,719 miles on the oil. Back when I was wasting money by pouring good oil out every 5000-10,000 miles the silicon count was 2 or 3. Before you spend any money on a BHAF I suggest you see how good your current filter is.

30,000+ miles on what oil?! And what driving conditions? I've considered doing an oil analysis next time I change, but I've had other things to address in the meantime so haven't researched it (other than posts on here). Also, do you use the stock air filter? I would need to find a box for mine since it just had an oiled Spectre when I bought it.

 

[BigPapa]

Just speaking to the filtration capabilities, the filters referred to as “BHAF’s” when used on our trucks are the same filters used on class 8 trucks, buses, and all kinds of heavy equipment that have logged billions of miles and hours running them. Unless you cheap out and buy one made out of paper towels or something, I don’t see how the filtration capabilities of these filters can be questioned. If there are higher silicone levels when running one, I’d have to say it would have something to do with how it’s installed, i.e. a poor or sloppy connection.

 

[GAmes]

30,000+ miles on what oil?! And what driving conditions? I've considered doing an oil analysis next time I change, but I've had other things to address in the meantime so haven't researched it (other than posts on here). Also, do you use the stock air filter? I would need to find a box for mine since it just had an oiled Spectre when I bought it.

Engine oil. Brand doesn't matter as long as it meets spec. Most miles are highway, towing. I use an AFE Proguard 7 filter, which is an oiled filter. For oil filtration I use Fleetguard LF9028 filters.

I use the Fleetguard/Monitor kits, some prefer Blackstone. Fleetguards are purchased and you pay for postage up front. Blackstone kits are free and you pay for the analysis when you send it in. Total cost for both is about the same. The reports are in different formats but the info you need is the same. https://www.cumminsfiltration.com/sites/default/files/LT15093.pdf

 

[GAmes]

If there are higher silicone levels when running one, I’d have to say it would have something to do with how it’s installed, i.e. a poor or sloppy connection.

You may be right. Perhaps someone from the TDR who uses one can enlighten us on their oil analysis.

 

[9DodgeFan]

Engine oil. Brand doesn't matter as long as it meets spec. Most miles are highway, towing. I use an AFE Proguard 7 filter, which is an oiled filter. For oil filtration I use Fleetguard LF9028 filters.

I use the Fleetguard/Monitor kits, some prefer Blackstone. Fleetguards are purchased and you pay for postage up front. Blackstone kits are free and you pay for the analysis when you send it in. Total cost for both is about the same. The reports are in different formats but the info you need is the same. https://www.cumminsfiltration.com/sites/default/files/LT15093.pdf

Very interesting, and good to know! Thanks for the info!